JP2000178044A - Intermediate film for laminated glass and laminated glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an intermediate film for laminated glass which has excellent antiblocking property during storage, excellent handling property when the intermediate film is to be between glass sheets, excellent deaerating property in a preliminary press-sticking process, and which enables an efficient preliminary press-sticking process at a rather low temp. in a wide tamp. range, and to produce a laminated glass. SOLUTION: This intermediate film has 2 to 50 g/cm2 creep elastic modulus at 60 deg.C. Especially, the creep elastic modulus of the intermediate film is <=30 g/cm2 at 60 deg.C, preferably 5 to 20 g/cm2, <=70 g/cm2 at 40 deg.C, preferably 30 to 60 g/cm2, and >=70 g/cm2 at 20 deg.C, preferably 80 to 120 g/cm2. Especially preferably, the intermediate film consists of a polyvinylbutyral resin containing triethylene glycol di(2-ethylhexanoate) or oligoethylene glycol di(2- ethylhexanoate) as a plasticizer.

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 and a laminated glass having an embossment formed of a large number of fine irregularities on the surface.

[0002]

2. Description of the Related Art A laminated glass in which an intermediate film made of a thermoplastic resin such as a plasticized polyvinyl butyral resin is sandwiched between glass plates is widely used for window glasses of automobiles, aircraft, buildings and the like.

[0003] In this type of laminated glass, usually, an interlayer film is sandwiched between glass plates and handled by passing through a nip roll (handling roll method) or placed in a rubber bag and suctioned under reduced pressure (vacuum bag method). It is manufactured by performing pre-compression bonding while removing air remaining between the plate and the interlayer, and then performing heating and pressing in an autoclave to perform main compression.

The interlayer of the laminated glass has adhesiveness,
In addition to good basic performance such as weather resistance, penetration resistance, transparency, etc., the interlayer films do not block (adhere) during storage, and the handling workability when sandwiching the interlayer film between glass plates is good. In addition, in order to eliminate air entrapment, good deaeration in the pre-compression bonding step is required.

[0005] In particular, the deaeration in the pre-compression bonding step affects the quality of the laminated glass. If the degassing is insufficient, the resulting laminated glass may have poor transparency or foam (bubbles) when used under severe conditions.

[0006] In order to satisfy such demands, usually, an intermediate film for laminated glass is formed with embosses having a large number of fine irregularities on its surface (both surfaces). As a form of a large number of fine irregularities, various irregularities composed of a large number of convex portions and a large number of concave portions corresponding to these convex portions have been proposed (for example, Japanese Patent Application Laid-Open No. 60-206443 and Japanese Patent Publication No. 1-332776).

[0007]

However, in the above-mentioned conventional interlayer film for laminated glass, in particular, the deaeration in the pre-compression bonding step is not yet sufficient, and the laminated glass having a large area and the laminated glass having a large curvature are particularly insufficient. When manufacturing glass, when increasing the productivity of laminated glass, or when using laminated glass under severe conditions such as using at a high temperature, foaming may occur.

In particular, recently, from the viewpoint of energy saving and improvement in productivity, an intermediate film which can be efficiently preliminarily bonded at a relatively low temperature and in a wide temperature range has been demanded.

[0009] It is an object of the present invention to provide excellent blocking resistance during storage and handling workability when an interlayer is sandwiched between glass plates, excellent deaeration in a pre-compression bonding step, a relatively low temperature and a wide temperature range. It is an object of the present invention to provide an interlayer film for laminated glass and a laminated glass which can be efficiently preliminarily pressed.

[0010]

In order to achieve the above object, according to the first aspect of the present invention, the laminated glass is characterized in that the creep elastic modulus of the interlayer film is ² to 50 g / cm ² at 60 ° C. An interlayer for use is provided.

According to the second aspect of the present invention, the creep modulus of the interlayer film is 30 g / cm ² or less at 60 ° C. and 70 g / cm ² at 40 ° C.
cm ² or less, the interlayer film for a laminated glass according to claim 1, characterized in that at 20 ° C. 70 g / cm ² or more is provided.

According to the third aspect of the present invention, the creep modulus of the interlayer film is 5 to 20 g / cm ² at 60 ° C. and 30 to 6 g at 40 ° C.
0 g / cm ^2, 20 interlayer film for laminated glass according to claim 1 or 2, characterized in that a 80 to 120 / cm ² at ℃ is provided.

According to a fourth aspect of the present invention, the intermediate film is made of a polyvinyl acetal resin containing triethylene glycol di (2-ethylhexanoate) as a plasticizer. An interlayer for laminated glass according to item 1 is provided.

According to a fifth aspect of the present invention, the intermediate film is made of a polyvinyl acetal resin containing oligoethylene glycol di (2-ethylhexanoate) as a plasticizer. An interlayer for laminated glass according to item 1 is provided.

According to a sixth aspect of the present invention, there is provided the interlayer film for laminated glass according to the fourth or fifth aspect, wherein the polyvinyl acetal resin comprises a polyvinyl butyral resin.

According to a seventh aspect of the present invention, there is provided a laminated glass wherein the interlayer film for a laminated glass according to any one of the first to sixth aspects is sandwiched between glass plates.

In the present invention, the creep modulus of the interlayer film is measured in accordance with JIS K 7115 (test method for tensile creep of plastic). However, test piece: width 1
0 mm x length 80 mm, distance between marked lines 40 mm, test load: 80 g at 60 ° C, 154 g at 40 ° C,
In the case of 20 ° C., the weight is 480 g, and the distance between the marked lines 30 minutes after the application of the load is measured and calculated.

In the present invention, as a resin constituting the interlayer, a thermoplastic resin used for a conventional interlayer for laminated glass is used. For example, plasticized polyvinyl acetal resin, polyurethane resin, ethylene-vinyl acetate resin, ethylene-ethyl acrylate resin,
Plasticized vinyl chloride resins and the like can be mentioned. These thermoplastic resins are excellent in basic performance required for laminated glass, such as adhesiveness, weather resistance, penetration resistance, and transparency.

Particularly, a plasticized polyvinyl acetal resin is preferable, and among them, a plasticized polyvinyl butyral resin is excellent because of its excellent basic performance. The plasticized polyvinyl butyral resin is obtained by adding a plasticizer to the polyvinyl butyral resin.

The polyvinyl butyral resin is mainly synthesized by a precipitation method. For example, polyvinyl alcohol is dissolved in warm water, and the obtained aqueous solution is cooled to a predetermined temperature, for example, 0 to 95 ° C.
The butyralization reaction is allowed to proceed by adding an acid catalyst and butyraldehyde thereto, and then the reaction temperature is raised to ripen the reaction to complete the reaction. Thereafter, neutralization, washing and drying are performed to obtain polyvinyl butyral. Obtain resin powder.

Here, as the polyvinyl alcohol,
Those having an average degree of polymerization of 500 to 5,000 are preferred, and more preferably 1,000 to 2,500. Average degree of polymerization is 50
If it is less than 0, the penetration resistance of the laminated glass may decrease, and if it exceeds 5,000, the production of the interlayer becomes difficult.
Further, polyvinyl alcohol having a saponification degree of 70 mol% or more is used from the viewpoint of transparency and heat resistance of the interlayer film.

The average degree of butyralization of the obtained polyvinyl butyral resin is generally preferably from 40 to 75 mol%, more preferably from 65 to 72 mol%. If the average degree of butyralization is less than 40 mol%, the compatibility with the plasticizer may be reduced, and if it exceeds 75 mol%, it may take a long time to synthesize the resin, which may hinder practical use. Further, it is generally preferable that the residual acetyl group is 30 mol% or less.

As the plasticizer contained in the polyvinyl butyral resin, for example, triethylene glycol di (2
-Ethyl butyrate), triethylene glycol di (2
-Ethylhexanoate), oligoethylene glycol di (2-ethylhexanoate), triethylene glycol dicaprylate, tetraethylene glycol di (2
-Ethylheptoate), tetraethylene glycol dicaprylate and the like are preferred. Among them, triethylene glycol di (2-ethylhexanoate) or oligoethylene glycol di (2-ethylhexanoate)
Intermediate film made of polyvinyl butyral resin containing, the boiling point of the plasticizer is high, the low temperature flexibility of the intermediate film is good,
Excellent pre-compression bonding properties are obtained, and furthermore, it is excellent in the working environment in the production of interlayer films and in the trim cutting property in the laminating process.
There are also advantages such as good hydrolysis resistance.

The above-mentioned oligoethylene glycol di (2-ethylhexanoate) can be produced by an esterification reaction between oligoethylene glycol and 2-ethylhexanoic acid. Here, oligoethylene glycol means polyethylene glycol having a relatively small average molecular weight. It is preferable that the ethylene glycol unit in the oligoethylene glycol portion contains 3 to 9 ethylene glycol units in a total amount of 90% by weight or more. When the number of ethylene glycol units is small, the compatibility with the polyvinyl butyral resin may be reduced. On the contrary, when the number of ethylene glycol units is large, the moisture resistance of the interlayer film may be reduced.

The above-mentioned oligoethylene glycol di (2-ethylhexanoate) is specifically, for example, based on 1 mol of oligoethylene glycol having a desired ethylene glycol unit (calculated from the average molecular weight),
2-2.5 mol of ethylhexanoic acid is added, and if necessary, dissolved and diluted in an organic solvent such as toluene and xylene.If necessary, a catalyst such as sulfuric acid, hydrochloric acid, or an inorganic acid such as phosphoric acid,
An organic acid such as p-toluenesulfonic acid, methanesulfonic acid or the like is added in an amount of about 0.01 to 5% by weight based on the total weight of the reactants, followed by esterification. The reaction may be performed at normal temperature and normal pressure, but preferably at 50 to 300 ° C. in consideration of accelerating the reaction and removing generated water.

The thickness of the intermediate film is determined in consideration of the penetration resistance and the like required for a laminated glass, and is approximately the same as that of a conventional intermediate film, and is preferably 0.2 to 2 mm. In addition, these intermediate films include an ultraviolet absorber, an antioxidant,
Various known additives, such as an adhesive force adjuster, may be contained. Such an intermediate film is formed by a melt extrusion method or a calender roll method as in the related art.

It should be noted that, on the surface (both surfaces) of the intermediate film, an emboss composed of a large number of fine irregularities is usually formed.
In order to form such an embossment, an embossing roll method, a profile extrusion method, an extrusion lip embossing method using a melt fracture, and the like are employed in the same manner as in the related art. In particular, the embossing roll method is suitable for obtaining a quantitatively constant amount of embosses composed of a large number of fine irregularities.

The embossed pattern is not particularly limited.
It has the same concavo-convex pattern as the conventional interlayer film for laminated glass. Generally, it consists of cones such as triangular pyramids, quadrangular pyramids and cones, truncated cones such as truncated triangular pyramids, truncated quadrangular pyramids, and truncated cones, and pseudo-pyramids with a mountain-shaped or hemispherical head. Numerous convex portions, and a concave and convex pattern composed of a large number of concave portions with respect to these convex portions, in particular, a large number of convex portions formed of mountain-shaped or hemispherical pseudo-cone,
A concavo-convex pattern composed of a large number of concave portions for these convex portions is preferable.

The dimensions of these embossed concavo-convex patterns are not particularly limited. Generally, the interval between the convex portions is in the range of about 10 to 2000 μm, particularly 200 to 1000 μm.
Those in the range of m are preferred. The height of the projection is preferably in the range of about 5 to 500 μm, particularly preferably in the range of 20 to 100 μm. Further, the length of the base of the convex portion is preferably in the range of about 30 to 900 μm. In particular, J
Ten point average roughness (Rz) specified in IS B 0601
Is preferably 20 to 50 μm.

Thus, in the present invention, the cleaning of the intermediate film is performed.
Leap modulus is 2 to 50 g / cm at 60 ° C^Two, Preferably
Is 2 to 30 g / cm^Two, More preferably 5 to 20 g /
cm ^TwoIt is said. The reason is as follows.

That is, when an intermediate film is used, in the case of degassing by the vacuum bag method, generally, the intermediate film is sandwiched between two transparent inorganic glass plates, the laminate is put in a rubber bag, and the rubber bag is evacuated. About -400 ~-
750mmHg vacuum (absolute pressure 360 ~ 10mmH
g) While increasing the temperature while reducing the pressure by suction, about 40-100 ° C
Is adopted. Also, in the deaeration by the handling roll method, generally, an interlayer is sandwiched between two transparent inorganic glass plates, and the laminate is passed through a nip roll,
For example, a pressure of about ^{2 to} 10 kg / cm ² and a temperature of about 40 to 1
A method of pre-press bonding while degassing while handling at 00 ° C. is adopted.

In this case, the ease of air release and the sealing performance during deaeration in the pre-compression bonding step depends on the temperature at the time of pre-heating (about 4 ° C.).
(0 to 100 ° C.) and a creep elastic modulus of the interlayer film. Therefore, as a result of various studies on the creep elastic modulus, in either case of deaeration by the vacuum bag method or deaeration by the handling roll method,
The creep modulus of the interlayer film is ² to 50 g / cm ² at 60 ° C.
Was found to be excellent in degassing during pre-compression bonding. In particular, in the case of deaeration by the handling roll method, the productivity is improved as compared with the case of deaeration by the vacuum bag method.

The creep modulus of the interlayer is 2 g / 60 ° C.
If it is less than ² cm2, when pre-compression bonding is performed in a relatively low temperature range, the interlayer film is too soft, and the air between the interlayer film and the glass plate cannot be sufficiently degassed. Good products are generated. Conversely, the creep modulus is 60 g / 50 g /
If it exceeds cm ² , the interlayer film is too hard, so that the peripheral seal for preventing the re-entry of air after degassing cannot be sufficiently performed, and defective products still occur.

Further, as a result of the examination, it was found that the creep modulus of the interlayer film was ² to 30 g / cm ² at 60 ° C., preferably 5 to 20 g / cm ^2.
A g / cm ^2, moreover 70 g / cm ² or less at 40 ° C., 70 g preferably 30~60g / cm ^2, 20 ℃
/ Cm ² or more, preferably 80 to 120 g / cm ² , has been found to be more excellent in deaeration during pre-compression bonding.

The creep elasticity at 40 ° C. affects the sealing property at the time of preliminary press bonding, and considering only the sealing property, the smaller the creep elasticity, the better. However, at 40 ° C., 70 g / cm
^If it exceeds ² , the seal may be defective at the time of pre-compression, and the emboss shape must be made smaller than necessary or pre-compression must be performed at a higher temperature, resulting in energy loss. In particular, 30 to 60 g / cm ² is preferable. 30g /
If it is less than cm ² , problems such as peripheral seal precedence occur.

If the creep modulus of the intermediate film is less than 70 g / cm ² at 20 ° C., the intermediate film becomes soft and the adhesion between the films is increased. Must be made larger, and sealing failure may occur at the time of preliminary press bonding. In particular, 80-1
20 g / cm ² is preferred. When it exceeds 120 g / cm ² , the adhesion between the films is suppressed, but the film and the glass plate become slippery, and when the laminate of the film and the glass plate is moved, there are problems such as the displacement of the laminate. There are problems such as difficulty in performing a cutting operation when an extra film is cut from the laminate.

Here, the creep elastic modulus of the interlayer is set in a desired range mainly depending on the type, composition, manufacturing method, molecular weight, type of plasticizer and blending amount of the resin. For example, in the case of an intermediate film made of a plasticized polyvinyl butyral resin, mainly the degree of polymerization of the polyvinyl butyral resin, the degree of butyralization,
It is set in a desired range by the amount of the residual acetyl group, the aging temperature and time during production, the type and the amount of the plasticizer.

Thus, the interlayer film for laminated glass of the present invention is obtained. In order to manufacture a laminated glass using the interlayer film for a laminated glass of the present invention, pre-compression bonding and main compression bonding are performed in the same manner as in a normal production method of a laminated glass. For example, when an intermediate film made of a plasticized polyvinyl butyral resin is used, specifically, pre-compression bonding and main compression bonding are performed as follows.

That is, in the pre-compression bonding, an interlayer is sandwiched between two transparent inorganic glass plates, and the laminate is passed through a nip roll, for example, under the conditions of a pressure of about ^{2 to} 10 kg / cm ² and a temperature of about 40 to 100 ° C. Pre-compression bonding (handling roll method) while degassing by treating with the above, or placing the above-mentioned laminate in a rubber bag, connecting the rubber bag to the exhaust system, and
~ -750mmHg vacuum (absolute pressure 360 ~ 10mm
Hg) while raising the temperature while reducing the pressure, to about 40-100
A method of pre-press bonding at a temperature of ° C. (vacuum bag method) is employed.

Next, the pre-pressed laminate is used in an ordinary manner by an autoclave or a press.
The final compression bonding is performed at a temperature of about 120 to 150 ° C. and a pressure of about ^{2 to} 15 kg / cm ² . Thus, the laminated glass of the present invention is obtained.

As the above-mentioned glass plate, not only an inorganic glass plate but also an organic glass plate such as a polycarbonate plate and a polymethyl methacrylate plate can be used. The laminated structure of the laminated glass may be not only a three-layer structure of a glass plate / interlayer / glass plate, but also a multilayer structure such as a glass plate / interlayer / glass plate / interlayer / glass plate. it can.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples and comparative examples of the present invention are shown below. (Examples 1 to 11 and Comparative Examples 1 to 5) <Preparation of interlayer film for laminated glass> By pressing an engraving mill (mother mill) for forming an emboss on the surface of a metal roll, and rotating the metal roll and the engraving mill. The engraving mill's uneven pattern is transferred to the metal roll, and then the engraving mill is shifted in the axial direction of the metal roll by the arrangement unit of the uneven pattern, and the engraving mill's uneven pattern is transferred to the metal roll by the same operation as described above. Then, an embossing roll (negative-type roll) in which a mountain-shaped uneven pattern was formed irregularly was produced.

On the other hand, as the resin, polyvinyl butyral resin (PVB resin) and vinyl chloride-ethylene-glycidyl methacrylate copolymer (PVC resin) (manufactured by Tokuyama Sekisui Co., Ltd .: average polymerization degree 700, ethylene component) shown in Tables 1 to 4 11% by weight, glycidyl methacrylate component 3% by weight), ethylene-vinyl acetate copolymer (manufactured by Tosoh Corporation: Ultracene 751, trade name 28% by weight of vinyl acetate component)
Was used.

As a plasticizer, triethylene glycol di (2-ethylbutyrate) (3G
H), triethylene glycol di (2-ethylhexanoate) (abbreviated as 3GO), tetraethylene glycol di (2-ethylheptate) (4G7
), Di (2-ethylhexyl) adipate (abbreviated as DOA), di (2-ethylhexyl) phthalate (abbreviated as DOP), and three kinds of oligoethylene glycol di (2-ethylhexanoate) (PGO)
-1, PGO-2 and PGO-3).

PGO-1 has an average degree of polymerization of the oligoethylene glycol moiety of 3.8 and contains 3 to 9 ethylene glycol units in a total amount of 96% by weight. PGO-2 has an average degree of polymerization of the oligoethylene glycol moiety of 4.8, and contains 3 to 9 ethylene glycol units in a total of 95% by weight. P
GO-3 has an average degree of polymerization of the oligoethylene glycol moiety of 5.9 and an ethylene glycol unit of 3 to 9
Is contained in a total of 96% by weight.

The above resin and plasticizer were mixed at the ratios shown in Tables 1 to 4, and the resulting mixture was melt-kneaded by an extruder and extruded into a sheet from an extrusion die to a thickness of 0.76 mm or 0.1 mm.
A 40 mm resin sheet was formed.

Using the above-described embossing roll and resin sheet, 16 types of embossed patterns having a large number of fine irregularities were formed by irregularly forming a mountain-shaped uneven pattern on both surfaces of the resin sheet by a roll embossing method (implementation). Example 11 types and Comparative Example 5 types) were produced.

(Examples 12 to 17) <Preparation of interlayer film for laminated glass> An engraving mill (mother mill) for forming an emboss is pressed against the surface of a metal roll, and the metal roll and the engraving mill are rotated, whereby the engraving mill is rotated. The concave and convex pattern of the engraving mill is transferred to the metal roll, and then the engraving mill is sequentially shifted in the axial direction of the metal roll by the arrangement unit of the concave and convex pattern, and by the same operation as above, the concave and convex pattern of the engraving mill is transferred to the metal roll, An emboss roll (negative roll) in which hemispherical irregular patterns were regularly formed was produced.

On the other hand, as the resin, a polyvinyl butyral resin (PVB resin) shown in Tables 5 and 6 was used. As a plasticizer, triethylene glycol di (2-ethylbutyrate) (abbreviated as 3GH) shown in Tables 5 and 6 was used.

The polyvinyl butyral resin (PVB resin) was synthesized in Example 12 by the following method. That is, 6000 g of polyvinyl alcohol having a polymerization degree of 1700, a saponification degree of 98.9 mol%, and a sodium acetate content of 0.5% by weight and 54000 g of water were charged into a 100-liter reaction tank equipped with a stirrer and a dropping funnel, and heated. Then, the polyvinyl alcohol was completely dissolved.

Thereafter, 300 g of hydrochloric acid having a concentration of 35% was added, and the temperature of the solution was raised to 12 ° C. (reaction temperature) while stirring.
While stirring and adding n-butyraldehyde 3
400 g was charged, and after confirming the precipitation of polyvinyl butyral, 10 minutes later, 1500 g of 35% hydrochloric acid was added.

Next, the solution was heated to 60 ° C. (ripening temperature) at a rate of 15 ° C./hour, and stirred at that temperature for 2 hours (ripening time) to carry out a ripening reaction. An aqueous sodium solution was added to neutralize the pH to 8 and neutralized. Thereafter, the slurry was cooled to room temperature, the slurry was dehydrated by a centrifugal separator, washed and dehydrated five times, and finally dried to obtain white powdery polyvinyl butyral.

In Example 13, the procedure was the same as in Example 12, except that the degree of polymerization of polyvinyl alcohol was changed to 1400, and the aging temperature was changed to 50 ° C. In Example 14, the aging temperature was changed to 50 ° C., the aging time was changed to 3 hours, and otherwise the same as Example 12. In Example 15, the aging time was changed to 3 hours, and the other conditions were the same as in Example 12. In Example 16, the polymerization was performed in the same manner as in Example 12, except that the degree of polymerization of polyvinyl alcohol was changed to 1400, and the aging temperature was changed to 40 ° C. In Example 17, the aging time was changed to 4 hours, and otherwise the same as Example 12.

The resin and the plasticizer were mixed at the ratios shown in Tables 5 and 6, and the mixture was melt-kneaded by an extruder and extruded into a sheet from an extrusion die to form a resin sheet having a thickness of 0.76 mm. did.

Using the embossing roll and the resin sheet, six types of embossed patterns having a large number of fine irregularities were formed by regularly forming a mountain-shaped uneven pattern on both surfaces of the resin sheet by a roll embossing method. Example 6 types) were produced.

The interlayer films for laminated glass obtained in Examples 1 to 17 and Comparative Examples 1 to 5 were measured for creep elastic modulus and ten-point average roughness (Rz) by the following methods. Furthermore, a laminated glass is produced using these intermediate films,
A bake test (acceleration test) was performed on these laminated glasses by the following method, and the deaeration in the preliminary pressure bonding step was evaluated. The results are collectively shown in Tables 1 to 6. In addition, some of these measurements and tests are omitted.

(1) Measurement of Ten-Point Average Roughness (Rz) of Interlayer The ten-point average roughness (Rz) specified in JIS B0601 was measured using a surface roughness meter.

(2) Measurement of creep modulus of interlayer film According to JIS K 7115, 60 ° C., 40 ° C., 20 ° C.
Was measured for creep modulus. However, the test piece: width 10 mm × length 80 mm, distance between marked lines 40 mm, test load: 80 g at 60 ° C, 154 g at 40 ° C,
In the case of 20 ° C., the weight was 480 g.

(3) Measurement of the slipperiness of the interlayer film The interlayer film was cut into 50 cm × 50 cm, placed horizontally on a glass plate (50 cm × 50 cm) having a smooth surface, and placed on the glass plate for sliding. Glass plate (length 10cm x width 10cm
× thickness 2.5 mm), and after 30 seconds, the glass plate for sliding was pulled horizontally via a spring balance, and its maximum frictional resistance (g / 10 cm ² ) was measured from the reading of the spring balance (number of repetitions: 5). . The measurement was conducted at a temperature of 20 ° C and a humidity of 40% RH.
Was performed under the following conditions. The smaller the maximum frictional resistance, the better the sliding between the glass plate and the interlayer, the easier the alignment between the glass plate and the interlayer, and the better the handling workability.

(4) Measurement of Self-Adhesiveness of Intermediate Film The intermediate film was cut into a piece of 15 cm × 15 cm, two pieces of the two pieces were superimposed, and a 13 kg weight was placed thereon, left at room temperature for 24 hours, and then subjected to a tensile test. A 180-degree peeling test was performed at a speed of 500 mm / min using a machine, and the peeling force (g / 15 cm width) was measured (5 repetitions). The measurement was performed at a temperature of 20 ° C.
The test was performed under the condition of a humidity of 40% RH. The smaller the peeling force, the better the handling workability during storage and when sandwiching the interlayer between glass plates.

(3) Bake test (acceleration test) Preliminary compression was performed by the following method (handling roll method and vacuum bag method), and then final compression was performed to produce a laminated glass.

(A) Handling roll method The interlayer film is formed of two transparent float glass plates (length 30 cm ×
The part which stuck out between 30 cm x 3 mm in thickness) was cut out, and the obtained laminate was heated in an oven at a temperature (preliminary compression temperature) of 40 to 1 for the laminate.
Preheating was performed by heating to a constant temperature in the range of 00 ° C. (every 5 ° C.) and then passing through a nip roll (air cylinder pressure 5 kg / cm ² , linear velocity 10 m / min).

(B) Vacuum bag method The interlayer film is made of two transparent float glass plates (length 30 cm ×
(Weight 30 cm × thickness 3 mm), cut off the protruding part, transfer the thus obtained laminate into a rubber bag, connect the rubber bag to a suction decompression system, and heat at the outside air heating temperature and at the same time −600 mmHg (Absolute pressure 160m
(Hg) for 10 minutes, and heated to a constant temperature (every 5 ° C.) where the temperature of the laminate (preliminary pressure temperature) is in the range of 40 to 100 ° C., and then returned to the atmospheric pressure to perform the preliminary pressure bonding. finished.

The laminate thus obtained was held in an autoclave at a temperature of 135 ° C. and a pressure of 12 kg / cm ² for 20 minutes, and then the temperature was lowered to 50 ° C. and returned to the atmospheric pressure to complete the final pressure bonding. Thus, a laminated glass was produced.

The laminated glass was heated in an oven at 145 ° C. for 2 hours under the severe conditions, taken out of the oven and cooled for 3 hours, and the number of foams (bubbles) generated in the laminated glass was examined. The temper was evaluated. The number of test is 1
In Examples 1 to 11 and Comparative Examples 1 to 5, good deaeration was achieved by the handling roll method (the number of foams was 3 in 100 sheets).
The following shows the pre-compression bonding temperature range in which the number of sheets can be obtained.
Further, in Examples 12 to 17, the numbers of foams generated at the pre-compression bonding temperatures of 50 ° C, 60 ° C, and 70 ° C by the handling roll method and the vacuum bag method are shown.

[0066]

[Table 1]

[0067]

[Table 2]

[0068]

[Table 3]

[0069]

[Table 4]

[0070]

[Table 5]

[0071]

[Table 6]

[0072]

As described above, according to the present invention, the anti-blocking property during storage and the workability when sandwiching an interlayer film between glass plates are excellent, and the deaeration in the pre-compression bonding step is excellent. An interlayer film for laminated glass that can be efficiently preliminarily pressed at a low temperature and in a wide temperature range can be obtained.

Therefore, when a laminated glass is manufactured using the interlayer film of the present invention, even when a laminated glass having a large area, a laminated glass having a large curvature, or a case where the productivity of the laminated glass is increased, the laminated glass can be removed. Is performed sufficiently, the layer of the interlayer is satisfactorily smoothed along the surface of the glass plate, particularly excellent in transparency, and does not cause foaming even when used under severe conditions. It is possible to efficiently produce a laminated glass having good adhesion to the interlayer film, excellent transparency, and good quality.

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Claims (7)

[Claims] 1. The creep elastic modulus of an interlayer film is 2 to 60 ° C.
An interlayer for laminated glass, which has a weight of 50 g / cm ² . 2. The interlayer film has a creep modulus of 30 at 60 ° C.
g / cm ² or less, 70 g / cm ² or less at 40 ° C., 20 ° C.
The weight is 70 g / cm ² or more.
The interlayer film for laminated glass according to 1. 3. The creep elastic modulus of the interlayer film is 5 to 60 ° C.
30 to 60 g / cm ² at ^{20g / cm 2, 40 ℃,} 20
The interlayer film for laminated glass according to claim 1, wherein the interlayer film has a temperature of 80 to 120 g / cm ² at a temperature of ° C. 4. The method according to claim 1, wherein the intermediate film is made of a polyvinyl acetal resin containing triethylene glycol di (2-ethylhexanoate) as a plasticizer. Interlayer for laminated glass. 5. The method according to claim 1, wherein the intermediate film is made of a polyvinyl acetal resin containing oligoethylene glycol di (2-ethylhexanoate) as a plasticizer. Interlayer for laminated glass. 6. The interlayer film for laminated glass according to claim 4, wherein the polyvinyl acetal resin comprises a polyvinyl butyral resin. 7. A laminated glass comprising the interlayer film for laminated glass according to claim 1 sandwiched between glass plates.