JP2012121768A - Interlayer for laminated glass and laminated glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interlayer for laminated glass excellent in adhesiveness with glass regardless of using polyvinyl alcohol resin as a raw material, hardly causing bubbling or variation of physical properties derived from water absorption as causative; and laminated glass made by using the interlayer for laminated glass.SOLUTION: This interlayer for laminated glass has a multilayer structure including three or more layers, in which at least one layer except outermost layers is a polyvinyl alcohol resin layer containing the polyvinyl alcohol resin and a polyhydric alcohol, and the outermost layers are polyvinyl acetal resin layers containing a polyvinyl acetal resin and a plasticizer.

Description

The present invention provides an interlayer film for laminated glass that has excellent adhesion to glass and hardly causes foaming and changes in physical properties caused by water absorption despite the use of polyvinyl alcohol resin as a material, and the interlayer for laminated glass The present invention relates to a laminated glass using a film.

Laminated glass is safe because it does not scatter glass fragments even if it is damaged by an external impact. Therefore, laminated glass is widely used as a window glass for vehicles such as automobiles and railways, aircraft, and buildings.
As a laminated glass, a laminated glass in which an interlayer film for laminated glass containing a polyvinyl acetal resin and a plasticizer is interposed between a pair of glasses and is integrated is generally used (for example, Patent Document 1).

However, a polyvinyl acetal resin needs to be manufactured through a complicated manufacturing process in which an aldehyde is reacted using a polyvinyl alcohol resin as a raw material, and is generally expensive. Also, from the viewpoint of reducing the impact on the environment in recent years, the amount of polyvinyl acetal resin whose manufacturing process is complicated should be reduced if possible.

On the other hand, using polyvinyl alcohol resin instead of polyvinyl acetal resin as a material for an interlayer film for laminated glass has been studied.
However, the interlayer film for laminated glass produced from the polyvinyl alcohol resin has a problem that the adhesive strength with glass is weak and peeling easily occurs. Moreover, since the interlayer film for laminated glass produced from polyvinyl alcohol resin has high water absorption, there is a problem that foaming is likely to occur when heated, and physical properties greatly change depending on the amount of water absorption.

JP 05-186250 A

The present invention provides an interlayer film for laminated glass that has excellent adhesion to glass and hardly causes foaming and changes in physical properties caused by water absorption despite the use of polyvinyl alcohol resin as a material, and the interlayer for laminated glass It aims at providing the laminated glass which uses a film | membrane.

The present invention is an interlayer film for laminated glass having a multilayer structure of three or more layers, wherein at least one layer excluding the outermost layer is a polyvinyl alcohol resin layer containing a polyvinyl alcohol resin and a polyhydric alcohol, and the outermost layer is It is an interlayer film for laminated glass which is a polyvinyl acetal resin layer containing a polyvinyl acetal resin and a plasticizer.
The present invention is described in detail below.

The interlayer film for laminated glass of the present invention has a multilayer structure of three or more layers, at least one layer excluding the outermost layer is a polyvinyl alcohol resin layer, and the outermost layer is a polyvinyl acetal resin layer.
By adopting such a multilayer structure, a part of the polyvinyl acetal resin can be replaced with a polyvinyl alcohol resin to reduce the use amount of the polyvinyl acetal resin as a whole, in addition to the problem of adhesion to glass and water absorption. It is possible to prevent the occurrence of foaming and physical property changes caused by the cause.

The polyvinyl alcohol resin layer contains a polyvinyl alcohol resin and a polyhydric alcohol.
The polyvinyl alcohol resin can be usually produced by saponifying a polyvinyl acetate resin. The minimum with the preferable degree of saponification of the said polyvinyl alcohol resin is 30 mol%, and a preferable upper limit is 99.9 mol%. When the degree of saponification of the polyvinyl alcohol resin is less than 30 mol%, the penetration resistance of the obtained laminated glass may be reduced, and when it exceeds 99.9 mol%, the compatibility with the polyhydric alcohol may be reduced. is there. The minimum with a more preferable saponification degree of the said polyvinyl alcohol resin is 45 mol%, and a more preferable upper limit is 99.3 mol%.

The minimum with a preferable polymerization degree of the said polyvinyl alcohol resin is 500, and a preferable upper limit is 5000. When the polymerization degree of the polyvinyl alcohol resin is less than 500, the penetration resistance of the obtained laminated glass may be lowered, and when the polymerization degree exceeds 5000, it is difficult to produce industrially. The minimum with a more preferable polymerization degree of the said polyvinyl alcohol resin is 700, and a more preferable upper limit is 4000.

The polyhydric alcohol plays a role as a plasticizer in the polyvinyl alcohol resin layer. By using a polyhydric alcohol as a plasticizer, an interlayer film for laminated glass having excellent transparency can be obtained.
The polyhydric alcohol is not particularly limited, but at least one polyhydric alcohol selected from the group consisting of glycerol, diglycerol, triglycerol, polyglycerol, ethylene glycol, diethylene glycol, and triethylene glycol is preferable.

Although content of the said polyhydric alcohol in the said polyvinyl alcohol resin layer is not specifically limited, The preferable minimum with respect to 100 weight part of the said polyvinyl alcohol resin is 20 weight part, and a preferable upper limit is 150 weight part. If the content of the polyhydric alcohol is less than 20 parts by weight, the interlayer film for laminated glass may become too hard, which may cause problems in handleability. If the content exceeds 150 parts by weight, the interlayer film for laminated glass Penetration resistance may be reduced. The minimum with more preferable content of the said polyhydric alcohol is 30 weight part, and a more preferable upper limit is 100 weight part.

The polyvinyl acetal resin layer contains a polyvinyl acetal resin and a plasticizer. By making such a polyvinyl acetal resin layer as the outermost layer, even if the polyvinyl alcohol resin layer is included as an inner layer, the problem of adhesiveness with glass and the occurrence of foaming and property change caused by water absorption are prevented. Can be prevented.

Although the said polyvinyl acetal resin is not specifically limited, Since the adhesive force with respect to glass is excellent, it is preferable that it is a polyvinyl butyral resin.
The degree of acetalization of the polyvinyl acetal resin is not particularly limited, but a preferable lower limit is 63 mol% and a preferable upper limit is 73 mol%. When the degree of acetalization of the polyvinyl acetal resin is less than 63 mol%, the water resistance of the interlayer film for laminated glass obtained may be lowered. When the degree of acetalization of the polyvinyl acetal resin exceeds 73 mol%, the penetration resistance of the laminated glass may be lowered. The minimum with a more preferable acetalization degree of the said polyvinyl acetal resin is 67 mol%, and a more preferable upper limit is 70 mol%.
The degree of acetalization is a value indicating the mole fraction obtained by dividing the amount of ethylene groups to which acetal groups are bonded by the total amount of ethylene groups in the main chain as a percentage. The amount of ethylene group to which an acetal group is bonded can be measured using, for example, JIS K 6728 “Testing method for polyvinyl butyral”.

Although the content rate of the hydroxyl group of the said polyvinyl acetal resin is not specifically limited, A preferable minimum is 15 mol% and a preferable upper limit is 38 mol%. When the content of the hydroxyl group is less than 15 mol%, the penetration resistance of the laminated glass may be lowered. If the hydroxyl group content exceeds 38 mol%, the interlayer film for laminated glass becomes too hard, which may cause problems in handling. The more preferable lower limit of the hydroxyl group content of the polyvinyl acetal resin is 20 mol%, and the more preferable upper limit is 35 mol%.
In addition, the content rate of the hydroxyl group of polyvinyl acetal resin is the value which showed the mole fraction calculated | required by remove | dividing the amount of ethylene groups which the hydroxyl group has couple | bonded with the total amount of ethylene groups of a principal chain in percentage. The amount of ethylene groups to which hydroxyl groups are bonded can be determined, for example, by measuring the amount of ethylene groups to which hydroxyl groups of polyvinyl alcohol as a raw material are bonded using JIS K 6726 “Testing methods for polyvinyl alcohol”.

Although the acetylation degree of the said polyvinyl acetal resin is not specifically limited, A preferable minimum is 0.1 mol% and a preferable upper limit is 20 mol%. When the acetylation degree of the polyvinyl acetal resin is less than 0.1 mol%, the water resistance of the interlayer film for laminated glass obtained may be lowered. When the acetylation degree of the polyvinyl acetal resin exceeds 20 mol%, the penetration resistance of the laminated glass may be lowered. The minimum with more preferable acetylation degree of the said polyvinyl acetal resin is 0.3 mol%.
The degree of acetylation is the value obtained by subtracting the amount of ethylene groups to which acetal groups are bonded and the amount of ethylene groups to which hydroxyl groups are bonded from the total amount of ethylene groups in the main chain. This is a value obtained by dividing the mole fraction obtained by dividing by the base amount as a percentage.

The polyvinyl acetal resin can be usually produced by acetalizing polyvinyl alcohol.
Although the average degree of polymerization of polyvinyl alcohol used as the raw material of the said polyvinyl acetal resin is not specifically limited, A preferable minimum is 1000 and a preferable upper limit is 5000. When the average degree of polymerization of the polyvinyl alcohol is less than 1000, the penetration resistance of the obtained laminated glass may be lowered. When the average degree of polymerization of the polyvinyl alcohol exceeds 5000, the rigidity of the obtained polyvinyl acetal resin becomes too large, and it may be difficult to mold the interlayer film for laminated glass. The more preferable lower limit of the average degree of polymerization of the polyvinyl alcohol is 1300, and the more preferable upper limit is 4000.

The plasticizer is not particularly limited. For example, triethylene glycol-di-2-ethylhexanoate (3GO), tetraethylene glycol-di-2-ethylhexanoate (4GO), triethylene glycol-di-2 -Ethyl butyrate (3GH), tetraethylene glycol-di-2-ethyl butyrate, tetraethylene glycol-di-n-heptanoate, triethylene glycol-di-n-heptanoate, pentaethylene glycol-di-2-ethylhexa Noate, octaethylene glycol-di-2-ethylhexanoate, nonaethylene glycol-di-2-ethylhexanoate, decaethylene glycol-di-2-ethylhexanoate, tetraethylene glycol-di-n- Examples include octanoate. Of these, triethylene glycol-di-2-ethylhexanoate (3GO) is preferred.

Although content of the said plasticizer in the said polyvinyl acetal resin layer is not specifically limited, The preferable minimum with respect to 100 weight part of said polyvinyl acetal resins is 30 weight part, and a preferable upper limit is 70 weight part. When the content of the plasticizer is less than 30 parts by weight, the interlayer film for laminated glass becomes too hard, and the handleability may deteriorate. When content of the said plasticizer exceeds 70 weight part, a plasticizer may isolate | separate from the intermediate film for laminated glasses. The minimum with more preferable content of the said plasticizer is 35 weight part, and a more preferable upper limit is 63 weight part.

The polyvinyl acetal resin layer is a metal salt containing Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, etc. for the purpose of adjusting the adhesion between the glass and the interlayer film for laminated glass, Li, An organic acid ester of a metal such as Na, K, Rb, Cs, Mg, Ca, Sr, or Ba may be contained. When the above metal salt or metal organic acid ester is not contained in the interlayer film for laminated glass, the adhesion between the interlayer film for laminated glass and the glass becomes too strong, so that the penetration resistance of the laminated glass is sufficient. It may not be obtained.

The polyvinyl alcohol resin layer and the polyvinyl acetal resin layer may contain additives such as an ultraviolet absorber, an antioxidant, a light stabilizer, a pigment, a dye, a colorant, and an infrared absorber as necessary.
Further, when the interlayer film for laminated glass of the present invention has an inner layer in addition to the polyvinyl alcohol resin layer, the inner layer has an ultraviolet absorber, an antioxidant, a light stabilizer, a pigment, a dye, a colorant, an infrared ray. You may add additives, such as an absorber.

The thickness of the interlayer film for laminated glass of the present invention is not particularly limited, but a preferred lower limit is 0.2 mm and a preferred upper limit is 1.5 mm. When the thickness of the interlayer film for laminated glass of the present invention is less than 0.2 mm, the penetration resistance of the interlayer film for laminated glass may be reduced. When the thickness exceeds 1.5 mm, the thickness suitable for laminated glass is reduced. It may exceed. The more preferable lower limit of the thickness of the interlayer film for laminated glass of the present invention is 0.3 mm, and the more preferable upper limit is 1.3 mm.

The preferable lower limit of the ratio of the thickness of the polyvinyl alcohol resin layer to the thickness of the interlayer film for laminated glass of the present invention is 5%, and the preferable upper limit is 95%. When the thickness of the polyvinyl alcohol resin layer is less than 5%, the environmental effect may not be substantially recognized due to the cost of replacing the polyvinyl acetal resin. When the thickness exceeds 95%, the polyvinyl acetal resin Even if it has a layer as the outermost layer, sufficient penetration resistance may not be ensured. The more preferable lower limit of the ratio of the thickness of the polyvinyl alcohol resin layer is 10%, and the more preferable upper limit is 90%.
In addition, when it has two or more said polyvinyl alcohol resin layers, the thickness of the said polyvinyl alcohol resin layer means the sum total of the thickness of all the polyvinyl alcohol resin layers.

The minimum with the preferable ratio of the total thickness of the said polyvinyl acetal resin layer which occupies for the thickness of the intermediate film for laminated glasses of this invention is 5%, and a preferable upper limit is 95%. When the total thickness of the polyvinyl acetal resin layer is less than 5%, the penetration resistance of the obtained laminated glass may be reduced. The effect of may not be substantially recognized. A more preferable lower limit of the ratio of the total thickness of the polyvinyl acetal resin layer is 10%, and a more preferable upper limit is 90%.

The method for producing the interlayer film for laminated glass of the present invention is not particularly limited. For example, the resin composition constituting each layer may be formed by extrusion molding using a co-extruder, or each layer may be formed. May be prepared separately and then laminated.

A laminated glass in which the interlayer film for laminated glass of the present invention is sandwiched between two transparent plates is also one aspect of the present invention.
The said transparent plate is not specifically limited, The transparent plate glass generally used can be used. Specific examples thereof include inorganic glass such as float plate glass, polished plate glass, mold plate glass, meshed plate glass, wire-containing plate glass, colored plate glass, heat ray absorbing plate glass, heat ray reflecting plate glass, and green glass. Moreover, organic plastics boards, such as a polycarbonate and a polyacrylate, can also be used.
The two transparent plates may be the same type of transparent plate or different types of transparent plates. Examples of the combination of different kinds of transparent plates include a combination of inorganic glass and organic plastics plate.

The use of the laminated glass of the present invention is not particularly limited, and can be suitably used for window glass of vehicles such as automobiles and railways, window glass of buildings, and the like. In particular, when used as automotive glass, it can be used as windshield, side glass, rear glass, and roof glass.

ADVANTAGE OF THE INVENTION According to this invention, despite using polyvinyl alcohol resin as a material, it is excellent in adhesiveness with glass, and the intermediate film for laminated glasses which does not produce the foaming and physical property change caused by water absorption, and this laminated glass A laminated glass formed using the intermediate film can be provided.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Example 1
(1) Preparation of polyvinyl butyral resin composition 40 parts by weight of triethylene glycol di-2-ethylhexanoate (3GO) as a plasticizer and 2,6-di-t-butyl-p-cresol 0 as an antioxidant .2 parts by weight and 0.8 part by weight of an ultraviolet absorber having a benzotriazole structure (“TINUVIN 326” manufactured by Ciba Specialty Chemicals) are added and stirred for 30 minutes using a stirrer, and the plasticizer solution is added. Obtained.
The obtained plasticizer solution was sufficiently mixed with 100 parts by weight of polyvinyl butyral resin (PVB: average polymerization degree 1700, butyralization degree 68.5 mol%, hydroxyl group amount 30.6 mol%, acetyl group amount 0.9 mol%), A polyvinyl butyral resin composition was obtained. At this time, the magnesium acetate aqueous solution was added so that the Mg concentration in the polyvinyl butyral resin composition was 65 ppm.

(2) Preparation of a polyvinyl alcohol resin composition 70 parts by weight of glycerol was added to 100 parts by weight of a polyvinyl alcohol resin (average polymerization degree 1700, saponification degree 88 mol%) and mixed thoroughly to prepare a polyvinyl alcohol resin composition. .

(3) Production of interlayer film for laminated glass The polyvinyl butyral resin composition and the polyvinyl alcohol resin composition are co-extruded using a co-extruder to form a polyvinyl butyral resin layer (thickness 100 μm) / polyvinyl alcohol resin layer. An interlayer film for laminated glass having a three-layer structure in which (thickness 700 μm) / polyvinyl butyral resin layer (thickness 100 μm) was laminated in this order was obtained.

(4) Production of laminated glass The obtained interlayer film for laminated glass was held for one week under constant temperature and humidity conditions of 23 ° C. and relative humidity of 28%, and then two transparent float glasses (length 300 mm × width 300 mm × Sandwiched between 2.5 mm thick (clear glass) to form a laminate. The obtained laminated body was crimped | bonded for 10 minutes on 100 degreeC conditions using the vacuum bag, and the laminated glass was obtained.

(Examples 2 to 4)
In the preparation of the polyvinyl alcohol resin composition, an interlayer film for laminated glass and a laminated glass were obtained in the same manner as in Example 1 except that ethylene glycol, diethylene glycol or triethylene glycol was used instead of glycerol.

(Comparative Example 1)
The polyvinyl alcohol resin composition prepared in Example 1 was extruded using an extruder to obtain an interlayer film for laminated glass having a thickness of 900 μm.
A laminated glass was obtained in the same manner as in Example 1 except that the obtained interlayer film for laminated glass was used.

(Comparative Examples 2 to 4)
In the preparation of the polyvinyl alcohol resin composition, an interlayer film for laminated glass and a laminated glass were obtained in the same manner as in Comparative Example 1 except that ethylene glycol, diethylene glycol or triethylene glycol was used instead of glycerol.

(Evaluation)
The following evaluation was performed about the laminated glass manufactured in the Example and the comparative example.
The results are shown in Tables 1 and 2.

(1) Penetration resistance evaluation The obtained laminated glass (length 300 mm x width 300 mm) was adjusted so that its surface temperature was 23 ° C. Next, in accordance with JIS R 3212, a hard sphere having a mass of 2260 g and a diameter of 82 mm was dropped from the height of 5 m onto the central portion of the laminated glass. The same evaluation was performed for six laminated glasses, and the case where the hard sphere did not penetrate within 5 seconds after the hard sphere collided was regarded as acceptable for all the six laminated glasses. If the number of laminated glasses in which the hard sphere did not penetrate within 5 seconds after the collision of the hard sphere was 3 or less, it was rejected. When the number of the laminated glasses that did not penetrate the hard sphere within 5 seconds after the collision of the hard spheres, the penetration resistance evaluation was again performed on the 6 laminated glasses. If there are 5 laminated glasses that did not penetrate the hard sphere within 5 seconds after the collision of the hard sphere, add another new laminated glass, and the hard sphere will not penetrate within 5 seconds after the collision. The case was accepted.

(2) Foaming evaluation The obtained laminated glass (length 300 mm × width 300 mm) was held in a constant temperature bath at 80 ° C. for 1 month in a vertical state. The number of foaming produced in each part of the part less than 1 cm and the part of 1 cm or more from the edge of the laminated glass after holding was visually observed.

(3) Peel test The obtained laminated glass was kept in a constant temperature and humidity chamber with a relative humidity of 95% at 50 ° C for 1 day in a vertical state. Immediately after that, after the laminated glass was stored in a refrigerator at −10 ° C. for 1 day, the case where no peeling was observed between the glass and the interlayer film for laminated glass was accepted, and the case where peeling was observed was regarded as unacceptable. .

ADVANTAGE OF THE INVENTION According to this invention, despite using polyvinyl alcohol resin as a material, it is excellent in adhesiveness with glass, and the intermediate film for laminated glasses which does not produce the foaming and physical property change caused by water absorption, and this laminated glass A laminated glass formed using the intermediate film can be provided.

Claims (5)

An interlayer film for laminated glass having a multilayer structure of three or more layers,
At least one layer excluding the outermost layer is a polyvinyl alcohol resin layer containing a polyvinyl alcohol resin and a polyhydric alcohol,
An interlayer film for laminated glass, wherein the outermost layer is a polyvinyl acetal resin layer containing a polyvinyl acetal resin and a plasticizer. 2. The polyhydric alcohol is at least one polyhydric alcohol selected from the group consisting of glycerol, diglycerol, triglycerol, polyglycerol, ethylene glycol, diethylene glycol, and triethylene glycol. The interlayer film for laminated glass described. The interlayer film for laminated glass according to claim 1 or 2, wherein the polyvinyl acetal resin layer contains a metal organic acid ester or metal salt. 4. The interlayer film for laminated glass according to claim 1, wherein the plasticizer contained in the polyvinyl acetal resin layer is triethylene glycol di-2-ethylhexanoate. A laminated glass, wherein the interlayer film for laminated glass according to claim 1, 2, 3 or 4 is sandwiched between two transparent plates.