JPH10278064A - Glazing material made of thermoplastic resin, and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To greatly improve the transparency, and impart a high rigidity, and also, improve the appearance by a method wherein a hollow structure is formed by injecting a pressurizing gas of a pressure in a specified range to the outer peripheral part, and a lamination-integration technique by injection molding is applied. SOLUTION: Two sheets of surface members 30, 30' are cut out from a polycarbonate resin sheet for which a silicon based thermosetting hard coat layer is provided. The two sheets of the surface members are fitted in a die for injection molding in such a manner that either one of the hard coat layers 3, 3' may become the external surfaces of a molded article. After fitting the surface members, the die is closed, and a molten polycarbonate resin is injection- filled from a side gate into the formed cavity, and a lamination-integration- molding is performed with both surface members. Also, after approx. 18.5 sec since the start of the injection of the molten resin, a pressurized gas of 20-500 kg/cm<2> is injected, and a hollow structure 4 is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glazing material made of a thermoplastic resin, which replaces a transparent window glass or a glass structure having a function or a design provided thereon, and a method for producing the same. Specifically, the present invention is particularly high in rigidity, transparency, lightweight, excellent in safety, durability, economy, and excellent surface appearance, automotive parts, medical care, security,
The present invention relates to a glazing material suitable for many uses such as building materials and household articles, and a method for producing the same.

[0002]

2. Description of the Related Art Glazing materials such as window glass in automobile parts and building materials have conventionally been composed of a transparent glass body,
Usually, it is constituted by an outer peripheral frame made of metal, resin, wood or the like into which this is fitted. These materials have problems such as heavy weight, cracking, many parts and assembling steps, low productivity, a separate process of imparting designability, and poor durability.

[0003] In order to reduce the weight, a plastic molded product formed by extruding or extruding a synthetic resin extruded plate or casting plate by hot bending or injection molding is applied to the main body instead of glass, and rigidity is required. For the outer peripheral portion, a method of supplementing rigidity with a reinforcing member such as a sheet metal, and a method of improving the shape rigidity by installing a rib on the outer peripheral portion have been adopted.

[0004]

However, when a reinforcing member such as a sheet metal is applied to the outer peripheral portion, the number of parts and the number of assembling steps are not reduced, and the weight is heavy. In addition, when the ribs are provided on the outer peripheral portion, if the thickness of the ribs is increased in order to increase the rigidity, there is a disadvantage that the weight becomes heavy and the appearance of the outer peripheral portion becomes poor due to sink marks. Further, when the main body is made of plastic, a hard coating step for imparting surface hardness and a printing step for imparting design properties are separately required.

That is, in the prior art, the outer peripheral portion of the plastic molded product requiring high rigidity requires the same number of parts and assembling man-hours as before, or causes poor appearance due to sink marks, and furthermore, hard coat and the like. There is a problem that a printing process is required.

[0006]

Means for Solving the Problems The present inventors have intensively studied to solve such a problem and to obtain a method for industrially advantageously producing a thermoplastic resin glazing material.
A hollow structure is formed by injecting a pressurized gas at a pressure of 20 to 500 kg / cm ² into the outer peripheral part, and by applying the lamination and integration technology by injection molding, the transparency is remarkably excellent, the rigidity is high, and the appearance is also high. The present inventors have found that a glazing material which is excellent and imparts desired functionality and design properties can be economically manufactured with relatively few steps, and has reached the present invention.

That is, the present invention is a glazing material made of a thermoplastic resin obtained by integrally molding a transparent main body portion and a high-rigidity outer peripheral portion, and the main body portion has a surface laminated and integrated on its surface. The outer peripheral portion has a hollow structure and ribs, and the hollow structure has a pressure of 20 to 500 kg / cm ² before the molten resin loses fluidity during integral molding.
Glazing material made of a thermoplastic resin formed by injecting a pressurized gaseous material.

The method for producing a thermoplastic resin glazing material of the present invention typically includes the following steps. (1) From a transparent thermoplastic resin film or sheet having a functional layer having at least one function selected from the group consisting of hard coat, anti-fog, anti-static, anti-reflection and heat ray blocking on one side, (2) mounting the surface material in an injection mold so that the functional layer becomes the outer surface of the molded product;
(3) closing the mold and injecting and filling a molten thermoplastic resin to laminate and integrate with the surface material;
(4) a step of injecting a pressurized gas at a pressure of 20 to 500 kg / cm ² into the mold to form a hollow structure; and (5) a step of opening the mold and removing a molded product.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the accompanying drawings. 1 and 2 are a cross-sectional view and a bottom view, respectively, illustrating an example of the thermoplastic resin glazing material of the present invention. FIG. 1 is an enlarged cross-sectional view taken along line AA ′ of FIG. It is shown. In both figures, 1 is a transparent body portion, 2
Denotes a high rigidity outer peripheral portion, 3, 3 ′ denotes a functional layer, 4 denotes a hollow structure, 5 denotes a rib, 10 denotes a glazing material, and 30, 30 ′ denote surface materials.

In the present invention, the thermoplastic resin used for integrally molding the transparent main body portion and the highly rigid outer peripheral portion is not particularly limited as long as it has transparency. In particular,
Examples of the resin include a polycarbonate resin, a composition of a polycarbonate resin and a polybutylene terephthalate resin, a polymethyl methacrylate resin, a copolymer of acrylonitrile and styrene, a polystyrene resin, and a resin such as a copolymer of methacrylate and styrene, or a composition thereof. In particular, polycarbonate resins have excellent impact resistance and are therefore suitable for use in various glazing materials.

As the polycarbonate resin, it is preferable to use an aromatic polycarbonate. In particular,
2,2 bis (4-hydroxyphenyl) -propane, 2,
A polymer obtained by a known method from one or more divalent phenolic compounds exemplified by 2-bis (3,5-dibromo-4-hydroxyphenyl) propane and a carbonate precursor exemplified by phosgene Can be exemplified. In particular, in the present invention, in addition to high rigidity, transparency,
From the requirements of heat resistance and impact resistance, a viscosity average molecular weight of 15 calculated from a methylene chloride melt viscosity at 25 ° C.
000-30000 aromatic polycarbonate resins are preferred.

A dye may be added to the thermoplastic resin used in the present invention in order to give an arbitrary color tone. For example, azo dyes, cyanine dyes, quinoline dyes,
It can be selected from those usually used for coloring thermoplastic resins such as perylene dyes. The compounding amount may be appropriately selected within a range that does not impair the transparency. Further, within the range not impairing the object of the present invention, for example, an effective expression amount of a stabilizer, a release agent, and an ultraviolet absorber may be added.

In the present invention, the transparent thermoplastic resin film or sheet laminated and integrated as a surface material is:
Its thickness is usually 100 to 1000 μm, preferably 2
The thickness is from 00 to 700 µm, and is not particularly limited as long as it is a thermoplastic resin film or sheet having transparency. However, taking into account that the thermoplastic resin film or sheet is laminated and integrated with the thermoplastic resin to be melt-injected and filled, usually, the same type as the thermoplastic resin for injection is selected. It is preferable from the viewpoint of the fusing property and the optical uniformity. If possible, it is better to use a resin having a higher molecular weight than the resin for injection in order to prevent the film or sheet or the functional layer or the design imparting layer which may be formed thereon from becoming out of shape.

The thermoplastic resin film or sheet may have, if desired, at least one function selected from the group consisting of hard coat on one side, anti-fogging, anti-static, anti-reflection and heat ray blocking. Layers can be provided.

For forming a functional layer on a thermoplastic resin film or sheet, various conventionally known methods are used. To form the hard coat layer, a primer layer is provided as required, and a hard coat agent such as an epoxy-based, acrylic-based, amino-resin-based, polysiloxane-based, or colloidal silica-based is applied. Can be used. For forming the antifogging layer, a method in which an antifogging paint containing a water-soluble or hydrophilic resin and a surfactant as essential components is usually applied and cured can be used. In addition, for the antistatic layer, antireflection layer, heat ray blocking layer, etc., apply a paint that provides these functions and cure, or form a thin film layer having these functions by a method such as vacuum evaporation. Can be. In addition, these functional layers may be used as a composite layer to simultaneously provide two or more functions. Further, in addition to these functional layers or to the functional layer, it is also possible to form a design imparting layer by a method such as applying a cosmetic coating treatment in advance or embossing to give a design. It is. The formation of these designability imparting layers is not limited to the front side and the back side of the thermoplastic resin film or sheet, and can be formed in any place, in any size, in any order. is there.

In the present invention, for the purpose of accelerating the thermal fusion with the thermoplastic resin filled with the melt-injection and ensuring the lamination integration, the thermoplastic resin film or sheet is provided with
A surface coated with a primer can also be used. As the resin used for the primer coat, a resin having a higher melt viscosity than the thermoplastic resin for injection and adhering well to the film or sheet is selected. For example, there is a resin of the same kind as the injection resin and having a higher molecular weight or a substance mainly containing the same, and a resin which is cured by heat or ultraviolet rays.

The thickness of the transparent main body in the present invention is preferably 1 to 20 mm. If it is less than 1 mm, the rigidity of the transparent main body tends to be insufficient, and
If it exceeds 0 mm, the weight reduction is likely to be impaired. The thickness of the transparent main body portion is more preferably 2 to 15 mm. When the glazing material of the present invention is used for window glass for automobiles or the like, the thickness of the transparent main body portion is preferably 2 to 2 from the viewpoints of rigidity, weight, and transparency.
It is 10 mm, more preferably 2.5 to 8 mm.

In the present invention, the pressurized gas used to form the hollow structure in the high-rigid outer peripheral portion is a gaseous substance at normal temperature and normal pressure. Any substance may be used as long as it is inert, but nitrogen gas is preferred in view of safety and economy. The time to start injection of the pressurized gas into the molten resin in the cavity is before the molten resin loses fluidity, and should be 1 second or more and 40 seconds or less from the start of injection of the molten thermoplastic resin into the cavity. Is preferred. If the injection start time of the pressurized gas body is less than 1 second, the adhesion between the injection-filled molten thermoplastic resin and the surface material to be laminated and integrated is impaired. On the other hand, if the injection start time of the pressurized gas body exceeds 40 seconds, a desired hollow structure cannot be formed due to solidification of the molten thermoplastic resin, and sinks may occur on the surface. The start time of the injection of the pressurized gas is more preferably 2 to 30 seconds.
The pressure of the pressurized gas needs to be ²⁰ to 500 kg / cm ² . The pressure of the pressurized gas is 20 kg / cm ²
If it is less than 1, a desired hollow structure cannot be formed, and sinks may occur on the surface. On the other hand, the pressure of the pressurized gas body is 500 kg
If it exceeds / cm ² , there is a problem in that the molded product is released from the mold, or that the pressurized gas leaks from the highly rigid outer peripheral portion to the transparent main body. The pressure of the pressurized gas body is more preferably 40 to 400 kg / cm ² . It is preferable that the injection of the pressurized gas into the thermoplastic resin in the cavity is continued until the thermoplastic resin in the cavity is cooled and solidified to some extent.

In the present invention, the high-rigid outer peripheral portion is provided with a rib outside the above-mentioned hollow structure, and the rib or the high-rigid outer peripheral portion including the rib is originally for attaching the glazing material to a predetermined position. Then, the required shape is designed. The thickness of the rib (the thickness in a direction parallel to the surface of the transparent main body) is preferably 1 to 1 of the thickness of the transparent main body.
5 times. If the thickness of the rib is less than 1 time, the rigidity of the outer peripheral portion is likely to be insufficient, and if it is more than 5 times, the weight reduction is easily impaired. The thickness of the rib is more preferably 1.2 to 4 times the thickness of the transparent main body. of course,
As a result of forming the hollow structure to reduce the weight, it is necessary to design the shape in consideration of not losing the required rigidity. In addition, if necessary, a functional layer or a design-imparting layer can be formed on the high-rigidity outer peripheral portion, similarly to the transparent main body portion. In this case, if the same functional layer or design-imparting layer as the transparent main body part is applied, the size of the surface material to be mounted on the inner surface of the mold, the transparent main body part and the highly rigid outer peripheral part should be combined. Only the size of the outer surface.

[0020]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples.
The present invention is not limited in any way without departing from the gist thereof.

Example 1 Referring to FIGS. 1 and 2, first, a polycarbonate resin sheet having a total thickness of 0.5 mm (trade name, manufactured by Mitsubishi Engineering-Plastics Corporation) provided with a silicon-based thermosetting hard coat layer Iupilon sheet CFI-1. The viscosity average molecular weight of the polycarbonate resin in the sheet is 28,000.
Two surface materials (30) and (30 ') were cut out. At this time, one (30 ′) has a shape conforming to the surface shape of the transparent main body portion (1) on the bottom surface of the molded product shown in FIG. 2, and the other (30) has a shape conforming to the surface shape of the upper surface of the molded product. And

Each of the two surface materials was mounted in an injection molding die such that the hard coat layers (3) and (3 ') became the outer surfaces of the molded product. Specifically, one side (3 ')
A transparent body portion (1) defined by a groove-like portion for forming a rib (5) on an inner surface of a mold (usually, a movable mold) defining a bottom side of a molded article. The other (3) is brought into contact with the flat surface of the trapezoidal part for forming the mold, and the other (3) is placed on the flat bottom surface of the inner surface of the mold (usually the fixed mold) defining the upper surface of the molded product They were brought into contact and fitted respectively.

After mounting the surface material, the mold is closed, and the formed cavity is filled with a molten polycarbonate resin (trade name Iupilon ML-300, manufactured by Mitsubishi Engineering-Plastics Corporation; viscosity average molecular weight 21,000).
Was injected and filled from a side gate (position indicated by 6 in FIG. 1), and the both surfaces were integrally laminated. Also, 18.5 seconds after the start of the injection of the molten resin, nitrogen gas of 130 kg / cm ² was injected from the position indicated by 7 in FIG. 1 to form a hollow structure (4). Next, the mold was opened and the quarter window molded product (10) shown in FIGS. 1 and 2 was taken out. The thickness of the transparent main body portion (1) of the molded product was 4 mm, the thickness of the rib (5) was 8 mm, and the height was 10 mm.

Comparative Example 1 A molded product was obtained in exactly the same manner as in Example 1 except that no pressurized gas was injected.

Comparative Example 2 A molded product was obtained in exactly the same manner as in Example 1, except that the injection pressure of the above-mentioned pressurized gas body was 15 kg / cm ² .

In each of the above Examples and Comparative Examples,
Each of the five molded products was evaluated for sheet adhesion and sink marks at the outer peripheral portion. The evaluation items, that is, the sheet adhesion between the surface material and the injection resin, and the sink on the gate side on the outer peripheral portion and on the opposite side were visually observed. Table 1 shows the results.

[0027]

[Table 1]

[0028]

According to the present invention, a transparent high-rigidity thermoplastic glazing material having a hollow structure can be manufactured efficiently and economically with stable quality. On the surface of the thermoplastic resin glazing material, a hard coat layer, an anti-fog layer, an antistatic layer, an anti-reflection layer, a functional layer such as a heat ray blocking layer, and various design property imparting layers, It can be easily formed without increasing the number. The thermoplastic resin glazing material obtained in this way has high rigidity, excellent transparency, light weight, safety, durability, and economy, and has improved defects such as sink marks in the outer peripheral portion, It is also excellent in appearance, and is used in many applications such as automotive window glass, medical care, security, building materials, and household goods.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one example of a thermoplastic resin glazing material of the present invention.

FIG. 2 is a bottom view of the thermoplastic resin glazing material of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transparent main body part 2 High rigid outer peripheral part 3, 3 'functional layer 4 Hollow structure 5 Rib 10 Glazing material 30, 30' Surface material 6 Injection port of molten resin 7 Injection port of gas

Continuing from the front page (72) Inventor Hidehiko Kamano 5-6-1 Higashi-Hachiman, Hiratsuka-shi, Kanagawa Pref. Mitsubishi Engineering Plastics Co., Ltd. Technology Center

Claims (7)

[Claims] A glazing material made of a thermoplastic resin obtained by integrally molding a transparent main body portion and a high-rigidity outer peripheral portion, wherein the main body portion has a surface material laminated and integrated on its surface. The outer peripheral portion has a hollow structure and ribs, and the hollow structure is formed by injecting a pressurized gas at a pressure of 20 to 500 kg / cm ² before the molten resin loses fluidity during integral molding. Glazing material made of thermoplastic resin formed. 2. The thermoplastic resin is a polycarbonate resin, a polymethyl methacrylate resin, a copolymer of acrylonitrile and styrene, a polystyrene resin, a copolymer of methyl methacrylate and styrene, or a composition of these resins. The glazing material made of thermoplastic resin according to claim 1, characterized in that: 3. A functional layer is provided on the outer surface of the surface material, and the functional layer is at least one function selected from the group consisting of hard coat, anti-fogging, anti-static, anti-reflection, and heat blocking. The thermoplastic resin glazing material according to claim 1, wherein the glazing material has thermoplastic resin. 4. The thermoplastic resin glazing material according to claim 1, wherein the thickness of the rib is 1 to 5 times the thickness of the transparent main body. 5. A transparent thermoplastic resin film provided with a functional layer having at least one function selected from the group consisting of hard coat, anti-fogging, anti-static, anti-reflection and heat ray blocking on one surface. Or a step of producing a surface material having a predetermined shape from a sheet; (2) a step of mounting the surface material in an injection molding die so that the functional layer is an outer surface of the molded product; A step of closing the mold and injecting and filling a molten thermoplastic resin to laminate and integrate with the surface material; (4) a pressure of 20 to 500 k in the mold.
g / cm ² of a pressurized gaseous body to form a hollow structure, and (5) a step of opening the mold and removing a molded product, the glazing material being made of a thermoplastic resin. Manufacturing method. 6. The thermoplastic resin for injection is a polycarbonate resin, a polymethyl methacrylate resin, a copolymer of acrylonitrile and styrene, a polystyrene resin, a copolymer of methyl methacrylate and styrene, or a composition of these resins. 6. The method for producing a thermoplastic resin glazing material according to claim 5, wherein: 7. The thermoplastic resin according to claim 5, wherein the thermoplastic resin constituting the film or sheet is of the same kind, high molecular weight or a composition thereof as the thermoplastic resin for injection. A method for producing a resin glazing material.