KR100779254B1 - Method for preparing a decoration sheet - Google Patents

Abstract

The present invention relates to a method for manufacturing a decoration sheet, and to a method for manufacturing a decoration sheet replacing PVC which is environmentally harmful and having high glossiness, excellent scratch resistance, weather resistance and molding workability. The decoration sheet according to the present invention is obtained by reverse gravure coating, drying and curing a polyurethane coating composition on top of a glycol-modified polyethylene terephthalate fabric.

Decoration sheet, glycol modified polyethylene terephthalate, polyurethane coating composition, reverse gravure coating

Description

Manufacturing method of decoration sheet {Method for preparing a decoration sheet}

The present invention relates to a method of manufacturing a decoration sheet (Decoration sheet), to replace the environmentally harmful PVC and to a method of manufacturing a decoration sheet having a high gloss, excellent scratch resistance, weather resistance and molding workability.

Conventional decoration sheets have been used by laminating PVC fabric, or PVC fabric and PET, but the gloss is low and scratches are easily generated, resulting in the appearance of scratches and aesthetics.

If you look at the PVC decoration sheet, it is not only difficult to express the desired pattern, but also the hardness is so weak that the surface is scratched or contaminated with contaminants of everyday life, so it is not easy to remove it, and it is difficult to increase the color, and it is also difficult to incinerate or fire. The city has been classified as an environmentally harmful substance that is subject to international regulations because it emits a large amount of toxic gas and has a fatal problem. In addition, indoor air pollution prevention laws have been enacted in Korea, and symptoms such as headaches and respiratory diseases caused by chemicals such as formaldehyde and organic solvents emitted from building materials and finishing materials are caused by sick house syndrome and chemicals. It is causing social diseases such as substance hypersensitivity.

A method for replacing PVC, which is an environmentally harmful substance, is attracting attention. For example, Korean Patent No. 563208 is harmless to humans and the environment, and can be manufactured at room temperature to increase the production speed. An upper layer material composed of paper and an olefinic resin having a desired shape printed thereon; And it is made of a polyurethane is described for the decorative sheet produced by aging for a predetermined time or more after bonding, including an adhesive for bonding the paper and the upper layer material at room temperature. In addition, Korean Laid-Open Patent Publication No. 10-2006-0015330 has a high rigidity, excellent dimensional stability under high temperature, transparency after heating and molding processability in a wide temperature range. Laminated film containing 50 or more layers less than 30 nm, or density is 1-1.4 g / cm <3>, the thermal contraction rate in the longitudinal direction at 180 degreeC is -2 to 2%, and elongation at break in at least one direction is 100- A biaxially oriented polyester film of 1000% is described.

However, while replacing PVC, which is an environmentally harmful material, excellent development of gloss and scratch resistance and less discoloration to ultraviolet rays is required.

Accordingly, the present inventors have developed a decoration sheet having excellent physical properties by reverse gravure coating, drying, and curing a polyurethane coating composition on top of a glycol-modified polyethylene terephthalate fabric, and the present invention was completed based on this.

It is an object of the present invention to provide a method for producing an excellent decoration sheet which is excellent in moldability, gloss and scratch resistance, and is less discolored to ultraviolet rays while replacing PVC which is an environmentally harmful substance.

The method for preparing the decoration sheet is a polyurethane coating composition having a composition ratio of polyol to isocyanate groups of 100: 20 to 100: 50 on top of a glycol-modified polyethylene terephthalate (hereinafter referred to as PET-G) fabric. Reverse gravure coating to a thickness of μm; Drying for 2 to 5 minutes with hot air at 95 to 105 ° C. such that the actual coating surface temperature is 50 to 60 ° C .; It includes a step of curing at room temperature for 3 to 4 days after cooling by spinning for 10 to 20 seconds at a rate of 10 ~ 15m / sec dry air of 20 ~ 25 ℃ ℃.

Looking at the present invention in more detail as follows.

Method for producing a decoration sheet according to the present invention, the reverse gravure coating of a polyurethane coating composition having a composition ratio of polyol to isocyanate groups of 100: 20 ~ 100: 50 on the top of the PET-G fabric to a thickness of 2 ~ 10㎛ step; Drying for 2 to 5 minutes with hot air at 95 to 105 ° C. such that the actual coating surface temperature is 50 to 60 ° C .; And spinning for 10 to 20 seconds at a rate of 10 to 15 m / sec at 10 to 25 ° C. for drying air, followed by cooling for 3 to 4 days at room temperature.

First, the PET-G fabric is a PET-G fabric, which is provided as a white sheet by extruding a glycol-modified polyethylene terephthalate fabric chip including TiO ₂ (titanium oxide-white pigment). The titanium oxide is known to use about 8 to 15% by weight, more preferably 10 to 13% by weight as a colorant used to make the transparent resin white in the production of the fabric.

In addition, the step of reverse gravure coating a polyurethane coating composition having a composition ratio of polyol to isocyanate groups of 100: 20 ~ 100: 50 in the thickness of 2 ~ 10㎛, most preferably 3 ~ 5㎛ on the PET-G fabric It includes.

If the coating thickness of the coating composition is less than 2㎛ coating too thin to evenly coat the PET-G fabric uncoated site occurs, if more than 10㎛ more than the curing reaction is slow to roll the sheet with a roll When the disadvantage of blocking occurs.

In addition, the polyurethane resin coating composition has a composition ratio of polyol to isocyanate groups of 100: 20 to 100: 50, and the polyurethane resin is chemically referred to as a component having an -NCO group (isocyanate group) and an -OH group. A component having a (hydroxyl group) reacts to form a -NHCOO- structure (called a urethane bond), wherein the isocyanates include TDI (toluene diisocyanate), MDI (diphenylmethane diisocyanate, Diphenylmethane Diisocyanate), HMDI (hexamethylene diisocyanate, Hexamethylene Diisocyanate), etc. are mentioned. In addition, the polyol refers to a copolymer obtained by introducing a polyether polyol, a polyester polyol, or a modified group such as acryl into the resin.

In addition, the -NCO group in the coating composition causes a curing reaction with the polyol (-OH component) component, but in the conventional method of curing the ultraviolet (UV) curing reaction for a quick reaction, but in the present invention using the reaction Use thermosetting method. Conventional ultraviolet (UV) curing reaction has the disadvantage that the unreacted monomer in the reaction can remain, and also discolored by ultraviolet light. In addition, the decorative sheet to which the UV-curable coating is applied has a hardness of about 3H, which is advantageous for scratches and the like, but it is difficult to use for molding because cracks are easily generated during molding. Therefore, if you want to use the most representative of the cube-shaped plate used, there is a disadvantage to use by bonding each part by cutting individually to the size suitable for each side of the object.

Although the hardness of the coating composition in the present invention is 2H softer than the UV curable coating agent, it can be easily formed under the conventional working conditions. As it can be applied in the same way as PVC decoration sheet by molding method, it is excellent in workability. In particular, the surface hardness is very good and the gloss is superior to conventional PVC.

On the other hand, reverse gravure coating method is a method in which the coating roll carved with CELL, etc. is rotated in the opposite direction of the direction of the fabric to transfer the coating liquid to the fabric and there is no press roll.

After the reverse gravure coating method of coating the drying in the drying furnace 2 to 5 minutes, more preferably 2 to 2.5 minutes with a hot air of about 95 ~ 105 ℃ so that the actual coating surface temperature is 50 ~ 60 ℃ Go through the steps. If the heating temperature is too high, energy consumption is large and may cause cracking during molding due to excessive hardening. Further, after drying, the air is cooled by blowing 20 to 25 ° C dry air at a speed of 10 to 15 m / sec for 10 to 20 seconds, preferably 10 to 13 seconds. Due to this cooling treatment, the effect of blowing unreacted monomers remaining on the surface and preventing blocking can be obtained.

After cooling, the sheet may be cured at room temperature for 3 to 4 days to obtain a decoration sheet.

The decoration sheet obtained by the manufacturing method according to the present invention not only has high glossiness, but also has excellent scratch resistance, weather resistance, moldability, and water resistance after molding.

Although the present invention will be described in more detail with reference to the following examples, the present invention is not limited thereto.

Example  One

Reverse-gravure coating of polyurethane coating composition with a composition ratio of 100: 33 polyol to TDI on the top of PET-G fabric (manufactured by Dong-A Co., Ltd.) with a thickness of 3 µm, and the actual coating surface temperature in the drying furnace was 50 After drying for 2 minutes with hot air at 100 ° C. to ˜60 ° C., 20 ° C. dry air was spun at 10 m / sec for 10 seconds to cool, followed by curing at room temperature for 3 days to obtain a decoration sheet.

Gloss, scratch resistance and surface by the decorative sheet obtained in Example 1 and the PVC sheet (Comparative Example 1) and UV coating sheet (Comparative Example 2) of the prior art as a comparative example The hardness, weather resistance, moldability, and water resistance after molding were tested and the results are shown in Table 1 below. See note for experimental methods.

Table 1

standard Example 1 Comparative Example 1 Comparative Example 2   Remarks  Glossiness  93-97  80-85  93-97   Measurement at 60 ° C using BYK micro-tri-gloss  Scratch resistance  Great  usually  Great   Mar resistance  Surface Hardness (Pencil Hardness)  2H  2B-B  3H   Use Mitsubishi Uni Pencil 5H, 4H, 3H, 2H, H, F, HB, B, 2B, 3B, etc.   Weather resistance   More than 240 hours   20 hours   120 hours   Measurement of gloss change rate after a certain time using Q-Panel's QUV instrument. (Delta E = 0.3 or less)  Formability  Moldable  Moldable  Molding impossible (crack)  There should be no crack in the bent part after molding   Water resistance after molding   Good   Good   Bad   After attaching the sheet coated with glue to the wooden board by heat, the specimen cut in half was deposited for 3 days at 40 ℃, and the peeling of the wood and the sheet was confirmed.

As can be seen through Table 1, the decoration sheet according to the present invention was able to increase the glossiness of the decoration sheet more than 90 degrees, and also excellent scratch resistance, UV coating, without using environmentally harmful PVC It can be seen that it has a hardness of 2H lower than that of Comparative Example 2, but is advantageous for molding, and also has good weather resistance, moldability, and water resistance after molding.

Claims (1)

Reverse gravure coating of a polyurethane coating composition having a composition ratio of 100: 20 to 100: 50 polyol to isocyanate groups on the top of a glycol-modified polyethylene terephthalate (hereinafter PET-G) fabric Doing; Drying for 2 to 5 minutes with hot air at 95 to 105 ° C. such that the actual coating surface temperature is 50 to 60 ° C .; And 10-25 ° C. dry air at a rate of 10-15 m / sec for 10-20 seconds to cool, followed by curing at room temperature for 3-4 days; Method of manufacturing a decoration sheet comprising a.