JPS59123623A - Colored polyvinyl chloride sheet that can be readily shaped - Google Patents

Abstract

PURPOSE:To obtain the titled colored polyvinyl chloride sheet that can be formed under the same heating and molding conditions and can provide a formed article whose physical properties are not scattered, by applying a color having a specified stress-strain curve on the undersurface of a colored polyvinyl chloride sheet. CONSTITUTION:To the undersurface of a colored polyvinyl chloride sheet having one or more colors is applied a color {for example, the color corresponding to gray [the curve (b)], in case the sheet is black [the curve (a)] and/or red [the curve (c)]} having a stress-strain curve that is intermediate of the stress-strain curve of the color of said colored polyvinyl chloride sheet that will be resulted in when it is formed, so that the intended colored polyvinyl chloride sheet is obtained which can be formed readily under heating and forming conditions in conformity with the color of the undersurface. EFFECT:A formed item that is uniform in color and gloss and has beautiful tone can be obtained.

Description

[Detailed Description of the Invention] The objective is to mold the molded product under a single heating molding condition regardless of color, with little variation in the physical properties of the resulting molded product, and with uniform color, gloss, etc. Uniform and
To provide a colored polyvinyl chloride sheet from which molded products with beautiful colors can be obtained.

Furthermore, another object of the present invention is that when a polyvinyl chloride sheet with two or more different colors is molded under a single heat molding condition, there is little variation in physical properties, and there is no unevenness in color, gloss, etc. An object of the present invention is to provide a colored polyvinyl chloride sheet from which a molded product having uniquely uniform and beautiful colors can be obtained.

In the present invention, polyvinyl chloride sheet (hereinafter simply PVC)
"sheet" refers to non-foamed or foamed PVC sheets alone, laminated sheets of various non-foamed or foamed PVc sheets, and PVC composites in which the laminated body is lined with foam. shall mean.

The various colored PVC sheets described above are softened by heating and molded into desired shapes using molds to produce products.

BACKGROUND ART Conventionally, it has been known to manufacture three-dimensional products by molding synthetic resin sheets into various shapes. For example, three-dimensionally molded synthetic resin sheets made of composite polyolefin foams such as polyethylene and polypropylene are known.

However, polyolefin-based composite synthetic resin sheets are not suitable for producing deep-drawn products due to their three-dimensional shape, especially when they are deep-drawn, and therefore are not suitable for producing deep-drawn products.On the other hand, PVC composite sheets are not suitable for deep-drawing. Since it has the advantage of not causing foam breakage, it is widely used for deep drawing products.

However, according to the research of the present inventors, colored PVC
When heating a sheet, the heat absorption rate varies depending on the color of the sheet, so it was found that 1) VC sheets have stress-strain curves during molding that depend on the color.

The drawing shows the relationship between stress and strain during molding when the color of the PVC sheet is black (curve aL, gray (curve b), and red (curve C). However, the physical properties of PVC sheets, that is, the stress-strain curves, vary greatly depending on the color.

Therefore, even if PVC is made of the same material, when molding colored PVc sheets, the heating temperature and heating time during molding must be changed depending on the color, as well as the degree of vacuum during vacuum forming in the molding means, the press pressure during press molding, etc. Need to change. If PVC sheets of different colors are simply molded under molding conditions that correspond to the PVC material, for example, the same heating temperature, same heating time, and same degree of vacuum, the physical properties such as the shrinkage rate of the PVC sheets may change. This variation, of course, causes unevenness in the color, gloss, etc. of the molded product, resulting in defective products. Therefore, conventionally colored PVC sheets are molded at different heating temperatures and temperatures depending on the color.
The heating time, degree of vacuum during vacuum forming, etc. are selected each time for manufacturing.

However, in on-site molding work, the Pv of the same material
Even though it is a C sheet, the color is simply different, so it is complicated to change and set the heating temperature and heating time in the molding method, the degree of vacuum during vacuum forming, or the press pressure during press molding each time. However, there is a large risk of making a mistake in selecting the appropriate heating temperature, heating time, degree of vacuum during vacuum forming, or press pressure during press forming, and as a result of the incorrect selection, the shrinkage of the PVC sheet as described above may occur. This may cause variations in physical properties such as ratio, and may cause unevenness in the color, gloss, etc. of molded products, resulting in a large number of defective products.

Furthermore, the conventional molding conditions mentioned above have the disadvantage that they cannot be applied at all to molding PVC sheets whose same surface is colored in two or more different colors.

As a result of intensive research to improve the above-mentioned conventional drawbacks, the present inventors have found that by adopting the structure described in the claims, colored PVC sheets of different colors can be easily molded under the same heat molding conditions. In addition, it was possible to obtain a colored PVC sheet that is easy to form and can be formed into a beautiful molded product with no variation in the physical properties of the molded product and no unevenness in groove color, gloss, etc.

That is, the present invention provides a color in which the back side of a colored PVC sheet having one or more different colors has a stress-strain curve that is an intermediate condition of the stress-strain curve during molding based on the color of the colored PVC sheet. This is a colored PVC sheet that is easily shaped and characterized in that it is colored and can be easily molded under heat molding conditions corresponding to the color of the back side.

To further explain the present invention in detail, as shown in the drawing, it is recognized that the colored PVC sheet has a stress-strain curve corresponding to the color of the colored PVC sheet during molding, but the gray (curve b) in the drawing is Black (curve ma) and red (curve C) are located in the middle of the curve.

Therefore, when the colored PVC sheet is black, the back side is colored gray, which is an intermediate condition of the stress-strain curve during molding between black and red, as is clear from the above drawing, and the stress-strain curve of the gray color is If the heating temperature, heating time, and vacuum degree of vacuum forming correspond to the wire, there will be little variation in the physical properties of the molded product, and there will be no significant unevenness in color, gloss, etc.

The color, which is an intermediate condition in the stress-strain curve, is a relative relationship; for example, if a colored PVC sheet is red, moldability can be improved by coloring the back side gray as described above. .

The color of the intermediate condition in the stress-strain curve can be selected as appropriate, but during molding, especially during deep drawing, the color on the back side passes through the surface of the colored PVC sheet, which is the skin, and the color changes from the original color of the colored PVC. It is not desirable to obstruct the color, and for this reason it is preferable that the color of the back side be gray.

PVC used in the present invention includes polyvinyl chloride, polyurethane, polyethylene, polystyrene, polyester,
It may be a non-foamed or foamed material of thermoplastic synthetic resin such as polyamide, ABS, EVA, etc., or it may be mixed with a thermosetting synthetic resin as appropriate.

The pigments or dyes to be applied to the colored PVC sheets of the present invention include various inorganic pigments commonly used in these synthetic resin sheets such as carbon blank, titanium white, titanium yellow, and Bengara, as well as various organic pigments. Pigments or dyes can be used.

The colored PVC sheet is made of polyamide (l) pressed PVC
Additives such as plasticizers, solvents, stabilizers, blowing agents, fillers, crosslinking agents, or flame retardants can be mixed into the mixture.

A colored PVC sheet can be formed by a known method such as a calendering method, a laminating method, or a casting method.

The color of the intermediate condition in the stress-strain curve formed on the back side of the colored PVC sheet can be formed by applying a color coat or dye coat having the color, or a separate PVC sheet having the color formed on the back side. A lamination method may be applied to the back side of the colored PVC sheet. When laminating the separate J" VC sheet, it is best to laminate a sheet with a thickness of about 3 mm, but depending on the color, it may be difficult to
, 3m+++ or less.

Furthermore, what is noteworthy about the present invention is that when a colored PVC sheet is colored in two or more different colors, the back side thereof is molded under molding conditions of a color corresponding to the intermediate condition of the stress-strain curve of the colors. It is possible.

For example, if the colored PVC sheet is a so-called two-tone color of two colors, black and red, it is practically difficult to know in conventional heat forming because the heat forming conditions are different, but in the present invention, the colored PVC sheet Stress in black and red -
A gray color (1 in the figure), which is an intermediate condition between the strain curves (a and C in the figure), is formed on the back surface of the colored PVC sheet, and molding conditions corresponding to the gray stress-strain curve, which is the intermediate condition. ,
For example, heating temperature 100-200°C, heating time 5-20 minutes, degree of vacuum during vacuum forming 500-760 +tan Hg
/Cn+2 and vacuum forming 1 is sufficient. Furthermore, when forming, press forming may be used instead of vacuum forming.

Note that the present invention is not limited to the two-tone color scheme of black and red, but any desired color may be used, or three or more different colors may be used. However, it is possible to obtain stress-strain curves for each different color, form a color located in the intermediate condition on the back side of the colored PVC sheet, and then mold using a single heat forming condition corresponding to the color in the intermediate condition. Deep drawing may also be possible. If necessary, the back side may be achromatic.

Next, the case of molding using the present invention will be described with reference to examples.

Example (]) Colored PVC sheet (a) 976 m2 was added to black PVC seed carbon blank 0.8. Sheet thickness: 0.61 yuan.

(+)) Gray PVC sheet, carbon blank, titanium yellow, titanium white, and square pattern total 0.6. , 7.2 Addition. Sheet thickness 0
．． 6 anal (c) red pvc sea donkashare sodo (dup
(manufactured by ont, product name), carbon blank, titanium white, total addition of 0.4 Ky/cm. Sheet J thickness 0.5m
m0 (2) Back side laminated PVC sheet carbon blank, titanium yellow, titanium white and Bengara total 0-
A gray PVC sheet with a thickness Q of 3 mm and 6 Ky/cm2 added thereto is laminated on the back side of the colored PVC sheet.

(3) Molding conditions (a) Heating temperature 150'Q (b) Heating time 5 minutes (c) Degree of vacuum in vacuum forming mold 600-760
When the PVC composite sheets of the present invention, each laminated with a gray PVC sheet on the back side, were processed under the above conditions, they could be molded regardless of the color of the surface, and even with deep drawing molding, there was no home breakage. There are none.

The resulting molded products have almost no imperfections in physical properties, and are beautiful with no unevenness in color or gloss.

[Brief explanation of the drawing]

The drawing shows stress-strain curves for each color during molding. Patent applicant: Kyowa Resi Co., Ltd. Same Tokyo Seat Co., Ltd. Agent Rikichi Ichikawa Same as Tatsuya Endo

Claims (1)

[Claims] The back side of the colored polyvinyl chloride sheet having one or more different colors has a color having a stress-strain curve that is an intermediate condition of the stress-strain curve during molding based on the color of the colored polyvinyl chloride sheet. A colored polyvinyl chloride sheet that is easily shaped and characterized in that it can be easily molded under heat molding conditions corresponding to the color of the back side.