KR19980017430A - Propylene Resin Sheet and Manufacturing Method Thereof - Google Patents

Abstract

The present invention relates to a propylene resin sheet and a method for producing the same. The propylene resin sheet coated with a solid material having a specific surface area of 1 to 20 m 2 / g and a density of 0.5 to 5 g / cm 3 on at least one surface of the propylene resin layer and the propylene resin layer has excellent transparency for various high-quality stationery and packaging. Not only suitable for use as, but also excellent in slip resistance, blocking resistance, and excellent post-processing, there is an advantage that the processability in the manufacturing is good.

Description

Propylene Resin Sheet and Manufacturing Method Thereof

The present invention relates to a propylene resin sheet and a method for manufacturing the same. Specifically, the present invention relates to a propylene resin sheet suitable for use in various high-quality stationery and packaging because of its excellent transparency and processability, and good post-processability and printability. It is about.

Currently, the most widely used plastic materials for packaging materials, stationery, office supplies, electrical appliances, tools, toys, and the like are polystyrene, polyvinyl chloride, polyolefin, and polyterephthalate.

Among them, polyvinyl chloride has the advantage of being transparent and inexpensive to manufacture, but its use is limited because chlorine gas is generated to contaminate the environment during combustion.

Polystyrene has good transparency and mechanical properties, but there is a problem in that the odor is severe during the manufacturing process, black smoke and dust during incineration, as well as a large manufacturing cost.

Polyterephthalate, which is another plastic material, has excellent transparency, but is expensive and stiff, and has a problem of difficulty in processing due to severe turbidity.

In accordance with these problems, research on colorless, harmless, low-cost general-purpose resins is being actively conducted, and polyolefin-based resins are in the spotlight as general-purpose resins. Among them, polypropylene has a density of 0.90 to 0.92 g / cm3, which is the lightest and most transparent plastic among general purpose plastics, and has excellent heat resistance, electrical insulation, chemical resistance, flex resistance, and no harm. Range and volume are increasing rapidly.

On the other hand, like other plastic materials, the polypropylene sheet is required to improve the slip resistance and the blocking resistance. To this end, a commonly used method is to add a solid inside a polypropylene sheet. However, the method of adding solids therein requires a large amount of solids to be added, thereby degrading the transparency of the sheet.

The technical problem to be achieved by the present invention is to provide a thermoplastic resin sheet suitable for use in various high-level stationery, packaging because of excellent transparency and fairness and good post-processing.

Another object of the present invention is to provide a method for producing the above-mentioned thermoplastic resin sheet.

1 is a block diagram of an apparatus for manufacturing a propylene resin sheet according to an embodiment of the present invention.

In order to achieve the above object, in the present invention, at least one surface of the propylene-based resin layer and the propylene-based resin layer is coated with a solid material having a specific surface area of 1 to 20 m 2 / g and a density of 0.5 to 5 g / cm 3. A resin sheet is provided.

In addition, in order to achieve the above another object, in the present invention, the propylene-based resin is melted and kneaded in an extruder, and then extruded in the form of a melt sheet through a die, and rapidly cooling and solidifying the extruded melt sheet to prepare a sheet. And applying to the at least one surface of the sheet a coating composition in which a solid having a specific surface area of 1 to 20 m 2 / g and a density of 0.5 to 5 g / cm 3 is dispersed in an organic solvent. A method for producing is provided.

In particular, it is preferable that the inside of the extruder has an initial temperature of 150 to 200 ° C, a final temperature of 200 to 250 ° C, and the die extrusion temperature of 200 to 250 ° C.

The propylene resin usable in the present invention includes polypropylene or a copolymer of propylene and other olefins, and has a melt index of 1 to 20 (g / min) and a melt temperature of 130 to 180 ° C. Preferred copolymers include propylene-ethylene copolymers, propylene-butene copolymers, propylene-ethylene-butene copolymers, and the like.

In addition, the solid material applied to at least one surface of the propylene resin sheet has a specific surface area of 1 to 20 m 2 / g, a density of 0.5 to 5 g / cm 3, and a coating amount of 0.01 to 0.5 g / m 2 is preferable. If the coating amount is less than 0.01g / m2, the effect of the present invention is insignificant, and if the coating amount is more than 0.5g / m2, a large amount of uneven pattern is generated on the surface of the sheet is poor appearance.

In addition, in the propylene resin, known additives such as antistatic agents, antioxidants, ultraviolet stabilizers, nucleating agents and the like may be added within a range that does not impair the effects of the present invention.

Hereinafter, the present invention will be described in detail through a specific method for producing a propylene resin sheet.

1 is a block diagram of an apparatus for manufacturing a propylene resin sheet according to an embodiment of the present invention.

Referring to FIG. 1, propylene-based resin is introduced into the extruder 3 through a hopper. The extruder 3 has a screw (not shown) that is rotated by the drive motor 4, and the temperature rises while moving toward the tee-die 5 at the resin inlet. Preferably the initial temperature in the extruder is 150 to 200 ° C, the final temperature in the extruder, that is, the extrusion temperature is preferably 200 to 250 ° C. This is because when the extrusion temperature is less than 200 ° C., unmelted resin is contained and bubbles are formed on the surface of the sheet. When the extrusion temperature is higher than 250 ° C., thermal decomposition of the resin may be promoted to decrease physical properties of the sheet.

The melt sheet 6 extruded through the tee-die 5 is sent to a molding machine, which is preferably a triangular belt type. Referring to FIG. 1, the molding machine 10 includes a first cooling roll 11, a second cooling roll 12, a heating roll 13, and three rolls 11 and 12 driven by a motor 16. 13 is composed of a steel belt 14 and a nip roll 15 rotating above.

Here, the nip roll 15 serves to uniformly cool the same as forming the extruded melt sheet to a certain thickness, and it is preferable to circulate the cooling water therein. It is preferable that the surface temperature of the nip roll 15 is maintained at 15-40 degreeC. If the surface temperature is less than 15 ℃, not only the temperature control is difficult, but also the bending of the melt sheet is solidified, if it exceeds 40 ℃ it is difficult to quench the melt sheet is broken in the stretching process, especially transverse stretching process This is because there is a problem that the phenomenon occurs frequently.

The surface of the first cooling roll 11 is coated with a circular rubber band in order to prevent the steel belt 14 from turning off, and serves to suppress the formation of spherical metal by rapidly cooling the melt sheet.

The second cooling roll 12 cools the steel belt 14 and is attached to the steel belt 14 so as to allow the transfer sheet to be easily separated.

In addition, the heating roll 13 is to reheat the steel belt 14, the melt sheet (6) extruded from the tee-die enters between the first cooling roll 11 and the nip roll (15) to the steel belt (14) It acts to keep it completely in contact.

The melt sheet 6 sent to the molding machine 10 as described above is attached to the steel belt 14 while entering between the steel belt 14 and the nip roll 15 on the first cooling roll 11, in the attached state The sheet is manufactured by passing along the lower portion of the triangle (△), and then passing through the second cooling roll 12. Herein, the temperature of the steel belt 14 is preferably 100 to 150 ° C., which is less than 100 ° C., so that the belt and the sheet do not adhere well, so that the surface layer is not formed. Because it is difficult. The rotation speed of the steel belt is preferably 10 to 30 m / min.

On the other hand, high glossiness of the sheet surface is one of the most important factors in order to improve the transparency of the sheet, which can be solved by sufficiently close the sheet to the mirror surface to mirror the roll or belt surface in contact with the sheet. To this end, the resin must be molded into sheets while inducing a pooling phenomenon (banking phenomenon).

Subsequently, the propylene-based resin sheet of the present invention is prepared by applying and drying the coating composition in which the solid material is dispersed in an organic solvent to a molded sheet. The coating method can be made by conventional methods. For example, roll coating, knife coating, extrusion coating, spray coating and the like can be used, preferably roll coating.

In the present invention, the solid material is preferably calcium carbonate, alumina, talc, silica, polymethyl methacrylate resin, or the like. In addition, it is preferable that the specific surface area of a solid is 1-20 m <2> / g, and a density is 0.5-5 g / cm <3>.

The organic solvent is not particularly limited as long as the selected solid material is dispersible and applicable to the coating process. However, it is preferable that the organic solvent has excellent binding property with the propylene resin. For example, methanol, ethanol, isopropyl alcohol, water and the like.

In particular, it is preferable that the carboxylate is further added to the coating composition used by this invention. Carboxylic acid salts improve dispersibility to the solvent of solids and bondability with propylene-based resins, such as hydroxy-p- (t-butyl) benzene aluminum carboxylate, sodium olylbenzene carboxylic acid, and olylbenzene carboxyl. Potassium acid, potassium fluoro carboxylate, and the like are preferred. In addition, the amount of the carboxylate added is preferably 0.05 to 0.30% by weight based on the coating composition. If the addition amount is 0.05% by weight of minor, the effect of the present invention is insignificant, and when it exceeds 0.30% by weight, there is a problem that the coating pattern occurs due to the aggregation phenomenon or the transparency is deteriorated.

On the other hand, according to the present invention, it is preferable to corona-treat the sheet surface before applying the coating composition. The propylene-based resin has a small surface tension and therefore is not good in bonding strength with the coating layer. The degree of corona treatment is preferably such that the surface tension of the surface is 38 dyne / cm or more.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not necessarily limited thereto.

Various performance evaluation of the sheet | seat manufactured by the Example and comparative example of this invention was performed by the following method.

1) density

Using a density gradient tube consisting of carbon tetrachloride and normal heptane, it was measured by the immersion method under a temperature condition of 25 ° C.

2) K value (β crystal content)

The diffraction intensity was measured using an X-ray diffractometer (model name: D-MAX3C) manufactured by PIGAKU (Japan), and then calculated according to Equation 1 below.

[Equation 1]

However, the larger the K value, the more transparent the sheet becomes.

3) haze

Using a haze meter (model name: SEP-H) of Nihon Seimitsu Kogakw Co., Ltd., scattered light and transmitted light values were measured using a C-light source and calculated according to Equation 2 below.

[Equation 2]

4) glossiness

It was measured using a glossiness meter (model name: GC-4010) of Gardner Neotek (USA) (reference diameter: black diameter, measuring strength: 60 degrees).

5) coefficient of friction

It measured on the conditions of 1.0 kg of load and the speed of 150 mm / min using the surface tester (model name: 2227001) by Saisaku-sho (Japan).

6) Blocking phenomenon

The phenomenon of lumping when the sheet and the sheet are brought into close contact with a certain temperature and pressure is referred to as a blocking phenomenon.

Example 1

Polypropylene having a melt index of 2.1 (g / 10 min) and a melting point of 145 ° C. was discharged at a speed of 270 kg per hour under an extrusion temperature of 220 ° C. and a screw rpm of 120, followed by a nip roll of 15 m / min, maintained at 30 ° C. It was formed into a sheet by passing between belts rotating at speed and maintained at 120 ° C. The surface of the sheet was corona discharged.

0.5 g of polymethyl methacrylate particles having an average particle diameter of 0.5 m and a specific surface area of 3.2 m 2 / g were dispersed in a mixed solvent (weight ratio 0.1: 10: 89.9) consisting of fluoroalkyl potassium carbonate, isopropylene alcohol and water The coating composition was prepared. The prepared coating composition was applied on the surface of the corona discharge treated sheet, and then dried at 120 ° C. to prepare a 300 μm-thick propylene resin sheet coated with 0.10 g / m 2 of polymethylmethacrylate.

Various physical properties of the prepared sheet were measured and shown in the table. The density was 0.911 g / cm 3, K value 15%, glossiness 135%, light transmittance 87%, haze 2.5%, and the surface roughness was 0.027 μm. Due to the low coefficient of friction, no blocking phenomenon occurred, resulting in very good processability.

Example 2-5

In the same manner as in Example 1, the sheet was prepared by changing the production conditions within the scope of the present invention as shown in the table, but the physical properties of the prepared sheet were generally good. Moreover, it was also favorable in terms of processability.

Comparative Example 1-5

In the same manner as in Example 1, the sheet was prepared by changing the manufacturing conditions outside the scope of the present invention as shown in the table. As shown in the table, the prepared sheet did not have any one or more of the measured physical properties.

division Polypropylene PMMA ¹ Temperature condition ² Sheet water castle Melt index Melting temperature Average particle diameter Specific surface area Application amount T _ci T _cf T _ex T _bs density K value Light transmittance Haze Glossiness Coefficient of friction Blocking phenomenon unit g / 10 minutes ℃ Μm cm ² / g g / m ² ℃ g / cm 3 % % % Μm - - Example One 2.1 145 0.5 3.2 0.10 170 220 220 120 0.911 14 87 2.5 135 0.27 Nil 2 9.5 162 0.6 3.9 0.15 155 205 205 105 0.907 21 87 2.6 137 0.25 Nil 3 15.6 155 0.5 4.1 0.09 185 235 235 135 0.912 10 88 2.2 133 0.21 Nil 4 5.2 159 0.4 9.5 0.21 160 210 210 110 0.910 17 88 2.1 135 0.25 Nil 5 12.1 161 0.3 6.2 0.17 180 230 230 130 0.911 12 87 2.3 137 0.29 Nil Comparative example One 5.5 149 - - - 155 205 205 105 0.906 15 86 2.5 136 0.68 With 2 6.9 162 0.4 3.2 0.005 165 215 215 115 0.907 17 87 2.4 132 0.76 With 3 9.4 169 0.8 1.1 0.005 170 220 220 110 0.910 13 87 2.6 129 0.61 With 4 3.2 165 0.5 3.3 0.10 185 235 235 135 0.911 3 85 12 115 0.46 Nil 5 14.5 164 0.5 3.2 0.13 180 260 260 180 0.912 0 85 10 110 0.31 Nil

In Table 1, 1 PMMA: Polymethylmethacrylate

2. Process temperature condition

Tci: Initial temperature in the extruder

Tcf: final temperature in the extruder

Tex: Die Extrusion Temperature

Tbs: Belt surface temperature.

As can be seen from the above, the propylene resin sheet of the present invention is excellent in transparency and suitable for use in various high-quality stationery and packaging, and is excellent in post-processing due to its excellent sliding property and blocking resistance. There is an advantage that the fairness is good.

Claims (10)

A propylene resin sheet, wherein a solid having a specific surface area of 1 to 20 m 2 / g and a density of 0.5 to 5 g / cm 3 is applied to at least one surface of the propylene resin layer and the propylene resin layer. The propylene-based resin sheet according to claim 1, wherein the propylene-based resin is a copolymer of propylene and at least one olefin selected from the group consisting of ethylene and butene. The propylene-based resin sheet according to claim 1, wherein the solid material is at least one selected from the group consisting of calcium carbonate, alumina, talc, silica, and polymethyl methacrylate resin. The propylene-based resin sheet according to claim 1, wherein the application amount of the solid is 0.01 to 0.5 g / m 2. The propylene resin is melted and kneaded in an extruder, and then extruded through a die in the form of a melt sheet, Preparing a sheet by rapidly cooling and solidifying the extruded melt sheet; And At least one surface of the sheet, comprising applying a coating composition in which a solid having a specific surface area of 1 to 20 m 2 / g and a density of 0.5 to 5 g / cm 3 is dispersed in an organic solvent. Manufacturing method. 6. The method of claim 5, wherein the inside of the extruder has an initial temperature of 150 to 200 ° C., a final temperature of 200 to 250 ° C., and the die extrusion temperature of 200 to 250 ° C. 7. . The method for producing a propylene resin sheet according to claim 5, wherein the melting sheet is cooled and solidified by being in close contact with cooling means having a surface temperature of 15 to 40 ° C. The method for producing a propylene resin sheet according to claim 5, wherein the coating composition contains 0.05 to 0.30% by weight of carboxylate based on the total weight of the coating composition. 9. The group of claim 8, wherein the carboxylate is comprised of hydroxy-p- (t-butyl) benzene aluminum carboxylate, sodium butylbenzene carboxylate, potassium butyl carboxylate and potassium fluoro carboxylate. Process for producing a propylene-based resin sheet, characterized in that at least one selected from. The method for producing a propylene resin sheet according to claim 5, wherein the surface of the sheet to which the coating composition is applied is subjected to corona discharge immediately before the coating composition is applied.