JPS6033908B2 - Manufacturing method of matte roll - Google Patents

Description

[Detailed description of the invention]

The present invention is directed to the production of a matte roll that is used to produce a sheet that has an extremely good matte state and exhibits little appearance of so-called matte appearance during secondary forming such as vacuum forming (hereinafter abbreviated as matte sheet). It is about the method. Conventional matte rolls use a method of imparting unevenness to the roll surface.

[1] Etching with a chemical solution mainly composed of ferric chloride or ferric nitrate, '2) Sandblasting, or a combination of {1} and ■. Matte rolls are produced by chromium plating the rolls, usually below loAm. However, since these methods provide unevenness only by etching or sandblasting, (1
'The irregularities are too fine or too large to diffuse the light rays sufficiently effectively. ■Since the proportion of concave parts is large, when transferred to a sheet, the proportion of convex parts becomes large, and the heat of secondary forming easily melts the convex parts, making it easy to flatten the sheet. There were disadvantages such as not being able to obtain In addition, the chrome plating applied to matte rolls will not deteriorate due to oxidation due to the unevenness imparted by etching or sandblasting, etc.
Conventionally, the main objective was to protect against dissolution deterioration caused by resin additives, abrasion deterioration caused by resin, etc., so most plating was thin, with a round thickness of less than 10 mm. In order to obtain a matte sheet that has an extremely good matte state and does not become matte due to vacuum forming or the like, the present invention provides a matte roll that has irregularities of an appropriate size and a surface that has a large proportion of convex portions. The purpose is to obtain. Appropriate unevenness on the roll surface not only scatters light rays effectively and maintains a good matte surface, but also prevents problems caused by resin wrapping around the roll when rolling a molten resin sheet, such as This can prevent the occurrence of wrinkles or the resin from wrapping around the entire circumference. The convex portions on the roll surface preferably have a diameter of 5 mm to 100 Am, and when the diameter is 5 mm or less, the height of the convex portions tends to be lower than the troughs. Also, 100r
If it is more than m, the number of convex portions per unit area decreases, and it is thought that the scattering of light rays is not performed effectively. In addition, if the proportion of concave portions on the roll surface is large, the sheet made by roll rolling will have a large proportion of convex portions;
These convex portions are easily melted by the heat of secondary forming such as vacuum forming, and the sheet surface tends to become flat. On the other hand, when the proportion of the convex parts on the roll surface is large, the proportion of the concave parts on the sheet surface is also large, and the heat received by these concave parts is easily absorbed into the interior of the sheet, and the shape is not easily deformed and the gloss is hard to return to matte. It becomes an eraser sheet. Further, since the proportion of the convex portions on the roll surface is large, the molten resin is removed by the convex portions during rolling and is easily filled into the concave portions. It is thought that if the ratio of the recesses on the roll surface is large, the recesses will be blocked by the surrounding protrusions, making it difficult to fill the recesses with molten resin.Actually, in areas where there is insufficient filling, no protrusions are formed and the shape is completely flat. There are many places where this happens. As a result of intensive studies based on the above findings, the present inventors found that a roll having a surface with a large proportion of convex portions appeared due to the thick plating, which was unimaginable using conventional methods. I put it out. That is, the present invention is a method for manufacturing a matte roll, which is characterized in that fine convex plating grains are provided on the roll surface by thickly exposing and depositing chrome plating on the surface of the metal roll. The thickness of the chrome plating is preferably in the range of loAm to 100 m, and if it is less than 10 m, the number of granular convex plating, so-called plating flowers, will be reduced. Moreover, if the diameter exceeds 100 mm, the diameter of the plated grains becomes large, and the matte sheet produced thereby will have a poor matte state and will easily become matte during vacuum forming, which is not preferable. As for chromium plating, the extremely common sergeant grade, fluoride bath, fluoride, sodium chromate, chromium sulfate, or black chrome plating can be used without any problem. Of these, in Sargent's opinion, in order to thickly deposit chrome plating, the current density must be set to 1.
If the ratio is higher than H/d, the current efficiency will increase and the surface that is the object of the present invention will be more likely to be obtained. Also, the common temperature is 45~5y0
This is preferable because it has less internal stress during plating and has good peckability. The matte roll according to the present invention can be used to produce a matte sheet made of thermoplastic resin such as polyolefin, polystyrene, A-spotted resin, etc., but the matte sheet produced thereby can be used particularly for secondary processing such as vacuum forming. Because it does not lose its luster during molding, it can be applied to automobile interior materials, interior decoration materials, etc., and its industrial value is high because it can significantly reduce process, equipment, and material costs compared to matte sheets made by painting. It's large. EXAMPLES In order to further clarify the present invention, Examples will be described. Example 1 Chromic acid concentration 300g/day 2S042.
The surface of a sword with a diameter of 2,500 mm and a length of 350 mm (Material: SS steel) is made of Yumejiiron chloride as the main component. After pre-treatment with an quenching solution, washing with water and drying, it was introduced into the plating process and chrome plated for 150 minutes at a temperature of 45°C and a current density of 20 A/d, resulting in a whitish surface with a plating thickness of 30 mm. A matte roll was obtained. When a matte sheet made of Amo resin was prepared using this o-ru, the behavior of the dog was completely good. The properties of this sheet are shown in Table 1. Also shown is a microscopic photograph of the roll surface of FIG. 1. Small plating grains (crystals) are observed over the entire roll surface. Reference Example 1 A roll similar to that used in Example 1, which had been prepared and etched, was introduced into a plating process, and plating was performed for 30 minutes under the same conditions as in Example 1, resulting in a plating thickness of 5 m. A matte roll was obtained. When an ABS resin matte sheet was produced using this roll, the matte state was poorer than that of Example 1. The properties of this sheet are shown in Table 1. Furthermore, FIG. 2 shows a microscopic photograph of the roll surface. Although the grain size of the plating is small, it is observed that the number of grains is small and non-uniform. Comparative Example 1 The surface of a willow tree (made of SS steel) with a diameter of 2,500 mm and a length of 350 mm was treated with an etching solution containing ferric chloride as a main component, washed with water, and dried to produce a matte roll. When a matte sheet made of Amo resin was produced using this roll, the matte state was worse than that of Reference Example 1.
The properties of this sheet are shown in Table 1. Further, a microscopic photograph of the surface of this roll is shown in FIG. It is observed that the unevenness is fine and the boundaries between peaks and valleys are angular. Example 2 A plating bath with a chromic acid concentration of 450 g/day, 43 g/day, 5 g/day of trivalent chromium, and a small amount of anti-spatter agent was constructed, with a diameter of 250 mm and a length of 350 mm (Material: SS steel). The surface of the plate was pre-treated with an etching solution containing ferric chloride as the main component, washed with water, dried, and then introduced into the plating process, followed by 9-powder chromium plating at a temperature of 45 OO and a current density of 70 A/d. When applied, the surface of the plated plate, which was 70m thick, turned gray and matte. The rules were obtained. When an Amo resin matte sheet was produced using this roll, the matte state was almost good.
The properties of this sheet are shown in Table 1. Further, a microscopic photograph of the surface of this roll is shown in FIG. Relatively large plating grains are observed over the entire surface of the roll. Table 1 (Note') Cloth measurements were made using Nippon Denshoku 600 cloth. As mentioned above, the matte roll according to the present invention can provide a {1} good matte sheet (gloss 3 or less) due to the difference in surface shape compared to the conventional thin chrome-plated roll. {2} This matte sheet has very little deglossing due to heat during vacuum forming, and a non-glossy vacuum-formed product can be obtained (gloss 5 or less after forming). Glue There is little resin adhesion to the matte roll during extrusion molding of the matte sheet, and there are fewer problems such as wrinkles. These effects can be obtained by simply increasing the plating thickness. Furthermore, this thick hazy plating method can be applied to molds for injection molding, etc., to make molded products matte and give them release plasticity, so it is of great value.

[Brief explanation of the drawing]

FIG. 1 is a micrograph of the matte roll surface in Example 1 of the present invention, FIG. 2 is a micrograph of the matte roll surface in Reference Example 1, and FIG. 3 is a micrograph of the matte roll surface in Comparative Example 1. , FIG. 4 is a micrograph of a matte roll in an example of the present invention. Figure 4: Bonito, Gutanada, Nada, Sea bream, Bonito, Bonito warehouse

Claims (1)

[Claims] 1. A method for producing a matte roll, characterized in that fine convex plating grains are provided by thickly electrodepositing chrome plating on the surface of a metal roll. 2. The method for manufacturing a matte roll according to claim 1, characterized in that the thickness of the chrome plating is 10 μm to 100 μm.