JP2504671B2 - Transparent synthetic resin laminate - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent synthetic resin laminated board, and more particularly to a transparent vinyl chloride resin laminated board having excellent welding suitability.

[0002]

2. Description of the Related Art Vinyl chloride resin plates have corrosion resistance, chemical resistance,
Due to its excellent mechanical strength, it is used in various industrial corrosion-resistant materials, building materials, and a wide range of other applications.

In general, a vinyl chloride resin plate of this type is manufactured by using a sheet having a predetermined thickness formed by calender molding as a constituent material, stacking a plurality of the sheets, and press-molding by heating and pressing to obtain a laminate having a desired thickness. It is done by Further, in the above-mentioned press molding process, by making mirror surface press plates contact the upper and lower surfaces of the laminated plate, so-called gloss is applied to the surface of the plate material to improve the surface smoothness and the transparency of the transparent plate in particular. It is supposed to do.

[0004]

By the way, the synthetic resin laminate produced by the above-mentioned method is often welded to produce a desired molded article for practical use. However, when manufacturing a water tank or a showcase with a transparent synthetic resin laminated plate, if the required welding is applied to the plate, the surface of the plate in the heated area near the weld becomes cloudy and frosted glass-like cloudy. There is a problem in that the transparency phenomenon is impaired due to the phenomenon of deterioration and the appearance of the product is impaired.

The inventors of the present invention have made various studies on the cause of such a clouding phenomenon, and have found that it is due to the following reason. That is, the synthetic resin laminate produced by the method as described above has good smoothness imparted to the surface by press molding during production and maintains a high degree of transparency. Since the temperature exceeds the heating temperature at the time of press molding, the surface of the resin laminate causes a so-called luster restoration phenomenon that restores the surface state of the sheet at the time of calender molding,
It was found that the surface condition of the calender sheet, which is not yet sufficiently smooth before glazing, was reproduced, causing white turbidity due to diffuse reflection and a decrease in transparency.

Based on such knowledge, the first method considered as a countermeasure for preventing the occurrence of the above-mentioned white turbidity phenomenon is to set the press temperature at the time of forming the laminated plate to a sufficiently high temperature to prevent the above-mentioned lusterless phenomenon from occurring during welding. It is a method of suppressing. However, in this case, not only the heat source of the existing press molding machine needs to be replaced, but new equipment investment is required, but there is a risk that the vinyl chloride resin itself will be thermally decomposed by press molding at high temperature, and it will be stable. Another problem arises in that it is difficult to obtain quality synthetic resin laminates.

It is an object of the present invention to solve the problem of welding resistance of a transparent synthetic resin laminate mainly composed of vinyl chloride resin as described above by a method as simple as possible.

[0008]

As a result of further experiments and studies to achieve the above object, the present inventors have found that the surface of a transparent vinyl chloride resin substrate has a specific surface roughness, glossiness and thickness. It has been found that it is possible to prevent clouding of the periphery of the welded portion during welding by coating and laminating a transparent transparent synthetic resin film or sheet having a certain thickness into one body, and completed the present invention.

That is, according to the present invention, the surface roughness (JIS B 06) is provided on at least one surface of the transparent vinyl chloride resin substrate.
01 average roughness of 01) 1 μm or less, surface gloss (gloss at an incident angle of 60 ° according to JIS Z8741) 6
A gist of a transparent synthetic resin laminated plate is characterized in that a surface covering material composed of a transparent synthetic resin film or sheet having a thickness of 0% or more and a thickness of 0.05 mm or more is laminated and integrated.

The vinyl chloride resin used for the transparent vinyl chloride resin substrate is a vinyl chloride homopolymer, a chlorinated vinyl chloride homopolymer, or a copolymer of vinyl chloride and vinyl acetate, ethylene, propylene or the like, Alternatively, a mixture of two or more kinds of these polymers is used. Particularly, a homopolymerized polyvinyl chloride resin having an average degree of polymerization of 600 to 1300 or a mixture of two or more kinds of the polyvinyl chloride resins is preferably used. The vinyl chloride resin substrate may be added with stabilizers, lubricants, reinforcing materials, ultraviolet absorbers, colorants and the like, which are usually added to polyvinyl chloride resin, if necessary.

The transparent synthetic resin film or sheet to be laminated on the transparent vinyl chloride resin substrate as a surface coating material may be any as long as it is compatible with the vinyl chloride resin of the substrate,
The type is not particularly limited. Most preferably, for example, one made of vinyl chloride resin is used, but use of another material such as acrylic resin is also acceptable. As a method for forming the resin film or sheet,
As long as the required surface properties it is molded in conditions resulting calender method, a press method, an arbitrary like extrusion method or inflation method, the required surface properties in combination of those two or more methods It may be finished.

The transparent synthetic resin film or sheet used as the surface coating material in the present invention has a surface roughness (JIS
10 point average roughness according to B 0601, the same below) 1μ
m or less, preferably it is necessary that those 0.2μm or less. When a surface roughness of more than 1 μm is used, it is not possible to prevent clouding of the surface around the welded portion during the welding process, and the effect of the present invention cannot be achieved sufficiently.

When a transparent synthetic resin film or sheet having a surface roughness of 1 μm or less and a glossiness (glossiness at an incident angle of 60 ° according to JIS Z 8741, the same applies hereinafter) of less than 60% is used, After all, it is not possible to sufficiently prevent clouding of the surface during welding. 80 is particularly desirable
% Or more, particularly preferably 100% or more.

The transparent synthetic resin film or sheet should have a thickness of 0.05 mm or more, preferably 0.1 mm or more. That is, if the thickness is less than 0.05 mm, wrinkles may occur on the surface due to heat shrinkage of the transparent synthetic resin film or sheet during welding.
Alternatively, tearing may occur, resulting in poor skin of the laminate. The upper limit of the thickness is not particularly limited, but it is common to use the one having a thickness of 1.0 mm or less in terms of cost, moldability and the like.

The surface coating material is generally laminated and integrated on both surfaces of the transparent vinyl chloride resin substrate. However, when the welding surface is limited to one surface, it is assumed that the surface coating material is laminated on only one surface. Is also good.

[0016]

The present invention provides a transparent synthetic resin laminated plate,
As described above, since a surface coating material made of a resin film or sheet having a surface roughness of 1 μm or less and a glossiness of 60% or more and having excellent surface smoothness and glossiness per se is integrally laminated on the surface thereof. Compared with conventional general transparent synthetic resin laminates, that is, vinyl chloride resin laminates, it is possible to obtain high quality with much more excellent transparency and surface glossiness. It can improve the weldability which has been a problem.

That is, the synthetic resin laminate according to the present invention is
Even when this is locally heated to perform welding, it is possible to avoid the phenomenon of white turbidity in which the surface of the peripheral region of the welded portion becomes cloudy. The reason why such an effect can be enjoyed has not been completely clarified yet, but in consideration of the elucidation result of the occurrence of the white turbidity phenomenon of the conventional product as described above, at the time of manufacturing the synthetic resin laminate. In the stage prior to press molding in, the surface coating material that already has excellent surface smoothness and glossiness is used, and since this is coated and integrated on the surface part, it can be heated at high temperature during welding. It is considered that this is because the degree of deterioration of the surface properties due to glossiness is suppressed to a low level, and as a result, turbidity that does not become visible to the naked eye does not occur. In addition, as seen in the results of the examples below.
As a matter of fact, the surface coating material is defined in the present invention.
As long as it has a specific surface texture, it will not melt regardless of the type of resin.
It is thought that a suitability is obtained.

The transparent synthetic resin laminate having improved weldability as described above according to the present invention is obtained by separately preparing a surface coating material and laminating and integrating it on the surface of the resin substrate by a conventional method. Therefore, there is also an advantage that the existing equipment can be used as it is for relatively inexpensive production without requiring any special new production equipment.

[0019]

【Example】

Examples 1 to 5 and Comparative Examples 6 to 10 In manufacturing a synthetic resin molded plate (1) having a laminated structure as shown in FIG. 1, first, as a constituent material of the substrate (2),
Vinyl chloride resin calendar sheets (2a), (2b) and (2c) made of a vinyl chloride resin homopolymer and having a thickness of 0.5 mm and prepared by a calendar molding method were prepared.

On the other hand, as the surface coating materials (3) and (3), there are three kinds of synthetic resin films or sheets of the following A, B and C which are different in material, manufacturing method and thickness, and which will be described later. As shown in Table 1, a total of 10 kinds of materials having different surface roughness and glossiness were prepared.

(Surface Coating Material) A ... A 0.5 mm thick calender sheet made of a copolymer of vinyl chloride resin and ethylene was pressed by a press plate having an inherent surface roughness at 175 ° C. for 15 minutes to synthesize it. Resin sheet.

B ... A calender sheet having a thickness of 0.5 mm and made of a copolymer of vinyl chloride resin and ethylene.

C ... Thickness 50 produced by a conventional method
μm acrylic film.

The vinyl chloride resin sheet (2a)
(2b) (2c) are laminated on each other to form a substrate (2), and the surface coating material (3) is formed on the upper and lower surfaces thereof in various combinations.
(3) was overlaid and press-molded by heating and pressing to obtain various synthetic resin laminates. The pressing conditions used here were a chromium-plated plate as the pressing plate, a heating temperature of 165 ° C., and a pressing time of 15 minutes.

A total of 10 kinds of synthetic resin laminated plates obtained as described above were used as samples, and welding tests were conducted on the samples. This welding test was carried out by welding a welding rod at a temperature of 200 to 210 ° C. to the plate surface of the synthetic resin laminate using a hot air gun.

Then, for each sample after welding, the occurrence of clouding around the welded portion was visually inspected and evaluated by the following items. Table 1 shows the results.

(Evaluation of Welding Properties) ⊚: No white turbidity is observed.

A slight white turbidity is observed.

Δ: Significant white turbidity is observed.

X: There is remarkable cloudiness and the transparency is impaired.

[0031]

[Table 1] As can be seen from the results in Table 1, the transparent synthetic resin laminates of Sample Nos. 1 to 5 according to the specified conditions of the present invention produced almost no white turbidity around the welded portion, but surface roughness. All of the transparent synthetic resin laminates of Sample Nos. 6 to 10, which deviate from the specified conditions of the present invention in any one or more of the glossiness, were cloudy around the welded part.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration example of a transparent synthetic resin laminated plate which is an object of the present invention.

[Explanation of symbols]

 (1) ... Transparent synthetic resin laminated plate (2) ... Transparent vinyl chloride resin substrate (2a) (2b) (2c) ... Calender sheet (3) ... Surface coating material

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Claims (1)

(57) [Claims] 1. A transparent vinyl chloride resin substrate having a surface roughness (10-point average roughness according to JIS B 0601) of 1 μm or less and a surface glossiness (JIS Z 874) on at least one surface.
1. A transparent synthetic resin having a surface coating material having a glossiness of 60 ° (incidence angle of 60 °) of 60% or more and a thickness of 0.05 mm or more, which is a transparent synthetic resin film or sheet, is integrally laminated. Laminated board.