JPH07206484A - Production of intermediate film for laminated glass - Google Patents

Abstract

PURPOSE:To obtain the intermediate film which has been kneaded and extrusion- molded in the same stage by extrusion-molding an ethylene-vinyl acetate copolymer, the condensation product of >=5-valency alcohol and benzaldehyde and a silane coupling agent under specified conditions. CONSTITUTION:An ethylene-vinyl acetate copolymer, the condensation product of the >=5-valency alcohol and benzaldehyde and a silane coupling agent having >=1 kind of group from among the amino group, glycidyl group and mercapto group are kneaded and formed in an extruder under following conditions. Namely, the ethylene-vinyl acetate copolymer is supplied to the raw material inlet of the extruder, the condensation reaction product and silane coupling agent are supplied to the raw material inlet or a raw material inlet separately provided after the inlet, and the specific power shown by E=(capacitance of driving motor) (load current value/rated current value) (revolving speed/maximum revolving speed/(actual extrusion output) is controlled to 0.2-0.35kw.h/kg.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing an interlayer film for laminated glass.

[0002]

2. Description of the Related Art Conventionally, windshield glass used for automobiles and airplanes, and laminated glass used for window glass of buildings are made of polyvinyl butyral resin between two opposing glass plates. A sandwich structure sandwiching an intermediate film is used. However, the polyvinyl butyral resin interlayer film has a problem that blocking occurs during storage and the work of manufacturing a sandwich structure by a laminating process is complicated.

In order to solve the above problems, ethylene-
An intermediate film using a vinyl acetate copolymer has been proposed (Japanese Patent Publication No. 47-2103). However, in order to secure the transparency of the interlayer film and prevent deterioration, it is complicatedly kneaded at a low temperature in a roll mill or the like and then formed into a sheet by an extruder, which makes the manufacturing process complicated in two steps. However, there is a problem in that

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to produce an interlayer film for laminated glass in which kneading and extrusion molding can be performed in the same step. To provide a method.

[0005]

[Means for Solving the Problems]

The method for producing an interlayer film for laminated glass of the first invention comprises an ethylene-vinyl acetate copolymer, a condensation reaction product of an alcohol having a valence of 5 or more and benzaldehyde, an amino group, a glycidyl group and a mercapto group. When the silane coupling agent having at least one group selected from the group is supplied to the extruder for kneading and molding, the ethylene-vinyl acetate copolymer is supplied to the extruder from the raw material supply section of the extruder. Together with the condensation reaction product and the silane coupling agent, the raw material supply section (I) or the raw material supply section (I)
It is supplied to the extruder from a raw material supply section (II) separately provided thereafter, and the specific power (E) of the drive motor of the extruder represented by the following formula is 0.2 to 0.35 [kw · h / kg ] Extrusion molding is characterized by the range.

The method for producing an interlayer film for laminated glass according to the second aspect of the present invention is characterized in that, in claim 1, vacuum suction is performed from a vent portion provided in the extruder during extrusion molding.

The first invention will be described in detail below.

The ethylene-vinyl acetate copolymer (hereinafter referred to as EVA) used in the first invention is not particularly limited, but when the vinyl acetate content is low, the transparency of the laminated glass is low, and when it is high, the laminated glass is high. 15 to 45% by weight is preferable because the impact resistance of (1) decreases.

Examples of the condensation reaction product of a pentavalent or more alcohol and benzaldehyde used in the first invention include dibenzylidene sorbitol, dibenzylidene xylitol, dibenzylidene lucitol, dibenzylidene mannitol, bis (paramethylbenzylidene). ) Sorbitol and the like.

The silane coupling agent used in the first invention has at least one group selected from the group consisting of an amino group, a glycidyl group and a mercapto group, and is, for example, N- (2- Aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyldimethylethoxysilane, (3-glydoxypropyl) methyldiethoxysilane, 3-glydoxypropyltrimethoxysilane, 3
-Mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane and the like can be mentioned.

Next, a method for producing an interlayer film for laminated glass from the above ethylene-vinyl acetate copolymer, a condensation reaction product of a pentavalent or more alcohol and benzaldehyde, and a silane coupling agent by extrusion molding will be described. Will be described with reference to. FIG. 1 is a schematic diagram showing an extruder used in the manufacturing method of the present invention.

First, the EVA copolymer is supplied from the EVA copolymer feeder 5 to the extruder 1 from the raw material supply section (I) 3 provided in the extruder 1, and subsequently, with an alcohol having a valence of 5 or more. The condensation reaction product with benzaldehyde is fed from the condensation reaction product feeder 6 to the raw material supply section (I) 3 or a raw material supply section (II) 4 separately provided after the raw material supply section (I) 3 to the extruder 1 To the raw material supply part (I) 3 or the raw material supply part (II).
4 to the extruder 1, and extrusion molding is performed.

In the above extrusion molding, when the specific power (E) of the driving motor of the extruder becomes small, the predetermined transparency (haze value less than 1.1) cannot be obtained, and the obtained laminated glass becomes cloudy, When it becomes larger, the specific power (E) becomes less than 0.8 because the silane coupling agent becomes yellow due to thermal decomposition due to excessive kneading.
Extrusion is performed in the range of 2 to 0.35 [kW · h / kg].

The composition kneaded and molded in the extruder under the above-described conditions is degassed at the vent portion 7, shaped into a sheet by the die 8, and then cooled by the take-up roll 9 to obtain a laminated glass. The intermediate film 10 for use is obtained.

The specific power (E) of the driving motor of the extruder is an index showing the kneading amount, and is a value represented by the following equation. E [kW / h / kg] = (electric capacity of drive motor) ×
(Load current value / Rated current value) x (Rotation speed / Maximum rotation speed)
/ (Actual extrusion amount)

In the actual manufacturing process, extrusion molding is carried out by adjusting the supply amount of the extruder, the cylinder temperature, the screw rotation speed, etc. so that the specific power (E) of the drive motor of the extruder falls within the above numerical range. . As the extruder, any type of a single-screw or a multi-screw extruder having two or more screws can be used, and the shape of the screw is not particularly limited.

The second invention will be described below. The method for producing an interlayer film for laminated glass of the second invention is different from the first invention in that, in extrusion molding of EVA copolymer, vacuum suction is performed from the vent portion 7 of the extruder 1 shown in FIG. The degree of vacuum in vacuum suction is preferably 600 mmHg or more, more preferably 700 mmHg or more.

[0019]

In the method for producing an interlayer film for laminated glass according to the first aspect of the present invention, the specific power (E) of the drive motor is 0.2 to 0.3.
By kneading in the range of 5 [kW · h / kg], 5
The condensation reaction product of an alcohol having a valence higher than or equal to benzaldehyde is finely and homogeneously dispersed to serve as a nucleating agent for keeping the crystal units of the EVA copolymer at the wavelength of the transmitted light or less, and is excellent as an interlayer film for laminated glass. Adds transparency. Also,
In the method for producing an interlayer film for laminated glass according to the first aspect of the present invention, by adding a silane coupling agent to the composition, an interlayer film having excellent adhesiveness to a glass plate is provided.

In the method for producing an interlayer film for laminated glass according to the second aspect of the invention, the silane coupling agent has poor thermal stability in the presence of oxygen and is sensitive to the resin temperature, so that the specific power (E) of the drive motor is 0. By kneading in the range of 0.2 to 0.35 [kW / h / kg], heat generation due to excessive kneading can be suppressed, and further vacuum suction from the vent portion can prevent yellowing of the interlayer film.

[0021]

【Example】

(Examples 1 and 2 and Comparative Examples 1 to 3) 100 parts by weight of EVA copolymer (“Evatate 5011” manufactured by Sumitomo Chemical Co., Ltd.)
The raw material is supplied from the feeder 5 shown in FIG. 1 to the raw material supply section (I) 3, and 0.3 parts by weight of dibenzylidene sorbitol (“Gel All D” manufactured by Shin Nihon Riken Co., Ltd.) is fed from the feeder 6 to the raw material supply section (I) 3. Then, 0.05 part by weight of the silane coupling agent was supplied to the raw material supply section (II) 4, and the interlayer film for laminated glass was extrusion-molded under the predetermined extrusion conditions shown in Table 1.・ Extruder specifications Toshiba Machinery twin-screw co-rotating extruder, screw: 13
0mmφ, L = 1800mm Electric capacity of drive motor: 37kw, maximum rotation speed: 15
00 rpm

(Examples 3 and 4 and Comparative Examples 4 and 5) The same procedure as in Example 1 was carried out except that extrusion molding was performed under the predetermined extrusion conditions shown in Table 2 while vacuum sucking from the vent portion of the extruder. An intermediate film for laminated glass was obtained.

Performance Evaluation of Interlayer Film for Laminated Glass The interlayer film for laminated glass obtained in the above Examples and Comparative Examples was subjected to the following performance evaluation and the results are shown in Tables 1 and 2. (1) Transparency After sandwiching the interlayer film for laminated glass (0.8 mm thickness) between two glass plates (2.5 mm thickness) to prepare laminated glass, the laminated glass is manufactured by Tokyo Denshoku Co., Ltd. The haze value was measured using an "integration type turbidimeter".
A transparency of 0 or less was determined to be good. (2) Colorability The yellowness (YI) of the laminated glass produced in the same manner as in (1) was measured using a "color difference meter" manufactured by Tokyo Denshoku Co., Ltd. according to JIS K7103, and the yellowness was 3.0. The following was judged to have no color.

[0024]

[Table 1]

[0025]

[Table 2]

[0026]

The method for producing an interlayer film for laminated glass according to the first aspect of the present invention is as described above, in which an ethylene-vinyl acetate copolymer is added to a condensation reaction product of a pentavalent or higher alcohol and benzaldehyde and silane coupling. The specific power (E) of the driving motor of the extruder is 0.20 to 0.35 by adding the agent.
By extrusion molding under the molding conditions such that [kw · h / kg], kneading and extrusion molding can be performed in the same step, and there is no coloring due to thermal decomposition of the silane coupling agent, resulting in excellent transparency. The interlayer film for laminated glass can be directly extruded.

The method for producing an interlayer film for laminated glass of the second invention is as described above, and the ethylene-vinyl acetate copolymer is provided with a condensation reaction product of a pentavalent or higher alcohol and benzaldehyde and a silane coupling agent. Kneading by adding and extruding under a molding condition such that the specific power (E) of the drive motor of the extruder is 0.20 to 0.35 [kw · h / kg] while vacuum suction from the vent part. And extrusion molding can be carried out in the same step, the coloring due to thermal decomposition of the silane coupling agent is improved, and the interlayer film for laminated glass having excellent transparency can be directly extrusion molded.

[Brief description of drawings]

FIG. 1 is a schematic view showing an extruder used in the manufacturing methods of the first and second inventions.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Extruder 2 Drive motor 3 Raw material supply part (I) 4 Raw material supply part (II) 5,6 Feeder 7 Vent part 8 Mold 9 Take-off roll 10 Intermediate film

Claims (2)

[Claims] 1. A silane having an ethylene-vinyl acetate copolymer, a condensation reaction product of a pentavalent or more alcohol and benzaldehyde, and at least one group selected from the group consisting of an amino group, a glycidyl group and a mercapto group. When supplying a coupling agent and kneading and molding to an extruder, the ethylene-vinyl acetate copolymer is supplied to the extruder from a raw material supply unit of the extruder, and the condensation reaction product and the silane coupling agent are also supplied. Is supplied to the extruder from the raw material supply unit (I) or a raw material supply unit (II) separately provided after the raw material supply unit (I), and the specific power of the drive motor of the extruder represented by the following formula A method for producing an interlayer film for laminated glass, which comprises subjecting (E) to extrusion molding in a range of 0.2 to 0.35 [kW · h / kg]. E = (electric capacity of drive motor) × (load current value / rated current value) × (rotation speed / maximum rotation speed) / (actual extrusion amount) 2. The method for producing an interlayer film for laminated glass according to claim 1, wherein vacuum suction is performed from a vent portion provided in the extruder during extrusion molding.