JPS623049A - Interlayer for laminated glass - Google Patents

Abstract

PURPOSE:The titled interlayer, obtained by subjecting a film prepared by molding a composition containing PVC and a plasticizer to specific bonding treatment and having improved bonding processability, penetration resistance and transparency. CONSTITUTION:An interlayer for laminated glass obtained by incorporating 100pts.wt. PVC having 300-600 average polymerization degree with 5-40pts.wt. plasticizer, e.g. trioctyl phosphate, and, as necessary, an additive, e.g. heat- resistant stabilizer, antioxidant, ultraviolet light absorber, etc., molding the resultant composition, coating the resultant film with a film of a vinyl chloride based copolymer having carboxyl groups and/or hydroxyl groups or subjecting the above-mentioned film to plasma treatment or plasma polymerization to carry out bonding treatment. Thereby, the aimed interlayer for laminated glass having no mutual autohesion properties of films at ordinary temperature without requiring the application of an antiblocking agent is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an interlayer film for glass, and more specifically to a composition containing polyvinyl chloride having a specific average degree of polymerization and a plasticizer in a specific ratio. By a) coating this film with a film made of a vinyl chloride copolymer having carboxyl 33 d-3 and/or hydroxyl groups, and b) subjecting it to an adhesive treatment such as plasma treatment or plasma polymerization. The present invention relates to an interlayer film for laminated glass that not only has excellent adhesion processability but also has excellent penetration resistance, transparency, etc.

[Description of conventional technology] Laminated glass, which is obtained by sandwiching an interlayer film for laminated glass between two glass plates, heating and pressurizing it, is widely used today for window glass of automobiles, aircraft, high-rise buildings, etc. has been done.

Conventionally, a polyvinyl butyral film has generally been used as an interlayer film for laminated glass.

In actual use, this resin film is made into an intermediate film by adding about 30 parts by weight of a high boiling point plasticizer such as dibutyl sebacate (DBS) to 100 parts of polyvinyl butyral. However, this plasticized polyvinyl butyral film has a strong adhesive surface at room temperature, so when winding up the produced intermediate film,
This stickiness is prevented by spraying an anti-blocking agent made of powder such as bicarbonate of soda on the surface of the membrane. For this reason, laminated glass production involves the complicated steps of removing this powder by washing with water and then drying, which poses a major difficulty in the work process. In addition, if the glass was sticky, it would be difficult to position the glasses together, and air would remain between the glasses, which could easily cause quality problems.

Therefore, in order to solve these difficulties, when forming a film,
It does not show any self-adhesion at room temperature, so there is no need to spray the anti-blocking agent conventionally used for plasticized polyvinyl butyral films, and washing and drying of the film is also not necessary when making laminated glass. It has been desired to develop a laminated glass interlayer film that has excellent adhesion processability and other properties such as penetration resistance.

[Object of the Invention] The purpose of the present invention is to improve the workability of complicated adhesive processing during the production of laminated glass, and to provide an interlayer film for laminated glass that has excellent properties such as penetration resistance and transparency. , especially used in automobile windshields.

[Structure and operation of the invention] The object of the present invention is to provide an interlayer film for laminated glass shown below.
is achieved.

That is, in the present invention, a composition containing 100 parts by weight of polyvinyl chloride having an average degree of polymerization of 300 to 600 and 5 to 40 parts by weight of a plasticizer is used as a film, and the film is subjected to any of the following adhesive treatments a) carboxyl An interlayer film for laminated glass characterized by being coated with a film made of a vinyl chloride copolymer having M% of groups and/or water, and subjected to b) plasma treatment or plasma polymerization.

Polyvinyl chloride has been widely used since it is inexpensive. However, commonly used polyvinyl chloride has an average degree of polymerization of about t,ooo, and even if it is plasticized by adding a plasticizer, the temperature when heat-pressing it with glass after film production is, for example, 170°C. This is not preferable because the thermal decomposition of polyvinyl chloride causes discoloration to brown.

Therefore, in the present invention, polyvinyl chloride with a low degree of polymerization is used as a material that can press-bond the film and glass at a low processing temperature that does not cause discoloration.

That is, the polyvinyl chloride with a low degree of polymerization plasticized with a plasticizer used in the present invention has a lower polymerization degree when heated compared to general-purpose polyvinyl chloride (average degree of polymerization of about i, ooo) that is also plasticized with a plasticizer. has high fluidity and therefore can be processed at lower temperatures.

The average degree of polymerization of polyvinyl chloride used in the present invention is 30
0 to 600 is desirable. If the average degree of polymerization is higher than 600, it is undesirable because high temperatures are required when press-bonding the film and glass, that is, when manufacturing laminated glass.If the average degree of polymerization is lower than 300, the film strength decreases, making it difficult to use as laminated glass. Favorable performance cannot be obtained.

Therefore, in the present invention, the average degree of polymerization is 300-600.
using polyvinyl chloride.

The plasticizer used in the present invention is not particularly limited, and any general plasticizer can be used as long as there are no problems in terms of transparency, compatibility, etc.

The appropriate amount of plasticizer to be blended is 5 to 40ffi 1M parts per 100 parts by weight of polyvinyl chloride.

In addition to the polyvinyl chloride and plasticizer described above, various additives can be added to the present invention. For example, heat stabilizers, antioxidants, ultraviolet absorbers, solvents, etc.

A composition comprising polyvinyl chloride, a plasticizer, etc. can be kneaded using a heated roll, a pressure kneader, an extruder, or the like, and then formed into a film using a heated press, a T-die, or the like.

Even if the film obtained in this way is heat-pressed to glass as it is, its adhesion to the glass is inherently poor, and it will not peel off when subjected to impact, so it does not have the performance as laminated glass. Not yet.

Therefore, as a result of various studies to improve adhesion with glass, we found that by performing one of the two adhesion treatments shown below, we could show good adhesion to glass and have no self-adhesion between the films. Furthermore, it has been found that it exhibits good performance as a laminated glass.

(Adhesion Treatment 1) A method of coating a film made of the above composition with a film made of a vinyl chloride copolymer having carboxyl groups and/or hydroxyl groups.

That is, a vinyl chloride copolymer having a carboxyl group is dissolved in an organic solvent, and the solution is applied or immersed onto the surface of a film for laminated glass and dried to form a carboxyl group and/or a water M group on the film surface. Alternatively, the solution can be coated on paper or film with release properties such as release paper or polyester film, and then dried and the resulting film is pressed onto the surface of the laminated glass film. It is also possible to coat with Here, examples of vinyl chloride copolymers containing carboxyl groups include U-ON 400 x 110A, Zeon KP-2 and the like of vinyl chloride copolymers containing hydroxyl groups, and tetrahydrofuran and the like are used as solvents.

(Adhesion Treatment 2) A method of plasma treatment or plasma polymerization of the surface of a film made of the above-described composition.

Plasma treatment or plasma treatment activates the surface of films such as polyethylene that are difficult to adhere to, or polymerizes adhesive monomers on the surface.
It is already known to transform surfaces into adhesive-friendly surfaces. However, in the present invention, by plasma treating and plasma polymerizing the surface of a film made of a composition whose main component is polyvinyl chloride, it is possible to increase the adhesion to glass and find good performance as a laminated glass. did it. In this method, as a result of examining various conditions, air and argon gas were found to be the best gas to be introduced during plasma generation. Nitrogen gas caused a slightly higher amount of glass scattering than air or argon gas during the penetration resistance test of laminated glass, but it did not penetrate.

[Description of Examples] The present invention will be specifically described below based on Examples, Comparative Examples, and Conventional Examples. In addition, all the blending values in each table are at the highest weight.

Examples 1 to 4 and Examples 1 to 3 The compositions shown in Table 1 were blended and each was extruded into a sheet with a thickness of 0.78 M using an extruder to obtain a film. These films were subjected to adhesive treatment by methods A to D as shown below.

Next, in order to examine the self-adhesion of these films, the adhesion between the films was measured by the following measuring method, and the results are shown in Table M1. Furthermore, JIS-R-3212 1' was used to examine the performance of laminated glass.
A penetration resistance test and a measurement of visible light transmittance were conducted using the following method in accordance with the ``Test Methods for Automotive Safety Glass''. The results are shown in Table 1.

(Adhesion treatment method) A: A film was immersed in a solution obtained by dissolving Zeon 400X 110A (carboxyl vinyl chloride copolymer) in tetrahydrofuran (THF), and then air-dried.

B: The film was immersed in a solution obtained by dissolving Zeon KP-2 (hydroxyl group-containing vinyl chloride copolymer) in THF, and then air-dried.

C: Shimadzu plasma polymerization equipment (product name: LCVD
-20- Using 4001 L I G>, the pressure is 0,
065T Orr, discharge power 230V x 0.4
A, argon as inflow gas 40cc,/n+in
Plasma treatment was performed for 1 minute while injecting at a flow rate of .

D: Shimadzu plasma polymerization equipment (product name: L C
V D -20- 4001 L I G) For use, pressure 0, O65 Torr, release My<') - 2
30Vx O, 4A, inflow gas and dry air 40c
c/ Illin. Plasma treatment was performed for 1 minute while injecting at a flow rate of .

(Method for measuring adhesion between films) Two films were placed horizontally together, a load of 0.5 ka/Cti was applied for 1 hour in an atmosphere of 40°C, and then 20
A T-peel test is performed at 25 am at °C.

Furthermore, this film was sandwiched between two pieces of glass measuring 30.5rz x 30.5a and 2.8# thick, left in a hot press at 130°C for 10 minutes, and then heated at a pressure of 15ka/7 for 10 minutes. The thickness of the film was 6.36 mtn (the thickness of the interlayer film was 0.76 mtn).
A transparent laminated glass of m) was obtained.

(Penetration resistance test) A laminated glass kept at 20°C was placed horizontally, and 2.2
An 8 kg steel ball with a smooth surface was dropped from a height of 4 m to the center of the glass surface, and those that did not penetrate were designated as A, and those that passed through JEJ were designated as B.

(Visible light transmittance) Spectrophotometer (manufactured by Hitachi, Ltd.) from 4001μ to 750
Transmittance (%) up to mμ was measured.

As is clear from the results in Table 1, the average degree of polymerization is 400
The films of Examples 1 to 4, which were prepared using polyvinyl chloride with a polyvinyl chloride of 550 to 550 and a plasticizer in a range of 5 to 40 parts, and which were subjected to the adhesive treatment described above, showed no self-adhesion between the films. When the glass was not shown and they were sandwiched between two pieces of glass to form a glass, good characteristics were shown.

On the other hand, in Comparative Examples 1 and 3, the films of Examples 1 to 4 were simply sandwiched between two pieces of glass to form a laminated glass.
At the same temperature of 130°C, the film did not exhibit adequate fluidity, and when it was made into a laminated glass as it was, air bubbles were created between the film and the glass, which was undesirable. Comparative Example 1 and Comparative Example 3 were able to produce bubble-free laminated glass by applying temperatures of 160°C and 155°C, respectively, but the film turned slightly brown.
I didn't like it. Furthermore, Comparative Example 2 had poor penetration resistance.

Conventional Example 1 In order to evaluate plasticized polyvinyl butyral, which is generally used in automobile windshields, commercially available polyvinyl butyral, dibutyl sebacate, and an ultraviolet absorber were blended according to the proportions shown in Table 2.
19 to make the interlayer film using an extruder. In the same manner as in Example 1, the adhesion between the laminated glasses, the penetration resistance test after the laminated glass was prepared, and the visible light transmittance were measured, and the results are shown in Table 2.

Table 2 In this conventional example 1, the adhesion between the films is 5.2 kg/25
In order to exhibit the peeling force of M and to prevent the adhesives from adhering to each other, treatment such as spraying an anti-tack agent was necessary.

[Effect of the invention 1] As explained above, after forming a film from a composition containing polyvinyl chloride having an average degree of polymerization within a specific range and a plasticizer within a specific range, chloride containing carboxyl groups and/or hydroxyl groups is used as an adhesive treatment. The interlayer film for laminated glass of the present invention, which is obtained by coating with a film made of a vinyl copolymer or by plasma treatment or plasma polymerization, does not exhibit self-repairing properties at room temperature when formed. , there is no need to spray the anti-blocking agent conventionally used in plasticized polyvinyl butyral membranes, and there is no need for washing and drying the membrane, resulting in excellent adhesion processability between the interlayer membrane and laminated glass.

In addition, when the interlayer film of the present invention is used to make laminated glass, it not only has excellent penetration resistance but also excellent transparency, so it is suitable as an interlayer film for automobile windshields and window glass of high-rise buildings. used for.

Claims (1)

[Claims] 1. Polyvinyl chloride 10 having an average degree of polymerization of 300 to 600
A composition containing 0 parts by weight and 5 to 40 parts by weight of a plasticizer is made into a film, and the film is subjected to one of the following adhesive treatments a) A film made of a vinyl chloride copolymer having carboxyl groups and/or hydroxyl groups. 1. An interlayer film for laminated glass, characterized in that it has been subjected to coating, b) plasma treatment or plasma polymerization.