KR0173023B1 - Base sheet for case container and preparing method of the same - Google Patents

Abstract

The present invention relates to a base sheet for a case and a method of manufacturing the same. Uniaxially containing a non-stretched propylene resin sheet containing 0.01 to 1.0% by weight of a carboxylate compound and a sulfonate compound and 0.1 to 10% by weight of an inorganic lubricant based on the propylene resin sheet, respectively, based on the propylene resin. Or the base sheet for the case in which the biaxially stretched propylene-based resin film is laminated is excellent in transparency and high quality, and foreign materials such as dust are not attached well, and when the case is manufactured as a case, it is damaged in the process of separating and combining the case and contents. It is easy to speed up the packaging process without any scratches or scratches.

Description

Base material sheet for case and manufacturing method thereof

The present invention relates to a base sheet for a case and a method for manufacturing the same, and in detail, excellent transparency and high quality, foreign matters such as dust do not adhere well, in the process of repeatedly separating and combining the case and the contents when manufacturing the case The present invention relates to a case base sheet and a method of manufacturing the same, which are easy to speed up the packaging process without being damaged or scratched.

Currently, many packaging materials are used for packaging materials, stationery, office supplies, electrical appliances, tools, toys, etc. Recently, case base materials for storing floppy disks, audio tapes, and video tapes are used. The packaging cases used for this purpose, unlike the packaging cases used for other purposes, can be a variety of printing, high-quality, foreign matter such as dust should not stick well. In addition, in the process of repeatedly separating and joining the case and the contents, various characteristics such as no damage or scratching and soft touch are required.

A material that satisfies these characteristics to some extent is paper, which is easy to manufacture and print, but has a disadvantage in that the yellow phenomenon due to moisture and long-term storage is severe and it is difficult to maintain the sharpness of printing for a long time.

In accordance with the problem of such a paper, a white polypropylene sheet having a high level of inorganic particles such as titanium dioxide is replacing paper.

However, in order to use such a material as a product, a sheet having a thickness of 400 to 500 μm is first printed at 3 degrees or more, and then a cutting and sealing process is performed. In the process, foreign matter such as dust adheres or curls. There is a problem that the process failure rate is large. In addition, when packaging in two or more piles, there are many problems that need to be improved, such as the occurrence of static electricity, making the high-speed process difficult.

Therefore, the object of the present invention is to solve the above problems, excellent transparency, high-quality, foreign matter such as dust does not adhere well, when the case is manufactured when the case is not damaged or scratched in the process of repeating the separation and combination of the case and the contents The present invention provides a case base sheet for which the packaging process can be speeded up easily.

In order to achieve the above object, in the present invention, 0.1 to 10% by weight of the non-stretched propylene resin film and propylene resin, each containing 0.01 to 1.0% by weight of carboxylate compound and sulfonate compound, based on propylene resin. A base sheet for a case is provided, in which a uniaxial or biaxially stretched propylene resin film containing% inorganic lubricant is laminated.

Another object of the present invention is to provide a method for producing a base material sheet for a case which is excellent in transparency, easy to speed up the packaging process, and has excellent post-processing properties such as printing, lamination, cutting and sealing.

In order to achieve the above object, in the present invention, a sodium benzoate compound and a sodium sulfonate compound are added to a propylene resin having a melt index of 1-10 (g / 10 minutes), and then a propylene resin sheet is prepared. Making; Adding an inorganic lubricant to a propylene resin having a melt index of 10-20 (g / 10 minutes), melt extruding and uniaxially or biaxially stretching; And it provides a method for producing a case sheet sheet comprising a step of laminating the sheet and the film prepared in the above step.

The present invention is characterized by providing a base sheet for a case by manufacturing a non-stretched sheet having a transparent luster and a pattern on the surface and at least a uniaxially stretched film having an excellent activity and easy printing, and then laminating it. .

Examples of the propylene resin usable in the present invention include polypropylene or copolymers with other olefins. In addition, the propylene resin has a melt index of 1 to 20 (g / 10 minutes), the melting temperature of 130 to 180 ℃, but the composition ratio is 80 to 97 mol% of propylene, 3 to 20 mol of olefins other than propylene It is preferable that it is%. Preferred examples include propylene-ethylene copolymers, propylene-butene copolymers, propylene-ethylene-butene copolymers, and the like.

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

According to the present invention, the sheet constituting the outer layer is excellent in transparency and the surface may have a variety of gloss and patterns, the film constituting the inner layer is excellent in the activity and has a surface property that is easy to print work It is important. Therefore, the film which comprises an inner layer and an outer layer differs in the composition and ratio.

The carboxylate-based compound is added to the sheet for the outer layer of the case according to the present invention, which is intended to improve transparency of the propylene resin and to improve adhesion to the belt during the manufacturing process. In this case, the usable carboxylate-based compound is not particularly limited as long as it is a compound having excellent thermal stability and good dispersibility, and preferably, hydroxy p- (t-butyl) benzene carboxylic acid aluminum, octyl benzene carboxylic acid Sodium, octylbenzenecarboxylic acid potassium and the like. In addition, the addition amount is preferably 0.01 to 1.0% by weight relative to the propylene resin, which is less than the effect of the present invention when less than 0.01% by weight, when exceeding 1.0% by weight not only contaminates the roll but also sheet This is because gray spots occur on the surface.

In the present invention, anionic antistatic agents such as sulfonate-based compounds and phosphate-based compounds are added to remove static electricity, which is a major cause of foreign matter adhesion to the sheet surface. Of these, preferred anionic antistatic agents are sulfonate compounds, and examples thereof include, but are not limited to, sodium octylbenzenesulfonate, potassium nonylbenzenesulfonate, sodium ondecylbenzenesulfonate, and the like.

In addition, the addition amount is preferably 0.01 to 1.0% by weight based on the propylene resin. This is because when the amount is less than 0.01% by weight, the effect of the present invention is insignificant, and when the amount is more than 1.0% by weight, foreign matter adhesion can be promoted.

According to the present invention, the outer layer sheet is manufactured through the following process.

First, a propylene resin having a melt index of 1-10 (g / 10 minutes), a carboxylate compound described above, an anionic antistatic agent and other additives are mixed. As the mixing method, either dry mixing or melt mixing can be applied, but melt mixing that can be uniformly mixed is preferable.

Subsequently, the mixed resin is melted in an extruder, extruded through a die provided in front of the die, quenched, and then molded to produce an unstretched sheet. In this case, the extrusion temperature is preferably maintained in the range of 200 to 240 ℃, which is when the extrusion temperature is less than 200 ℃ containing the cosmetic melt is formed bubbles on the surface of the sheet, if it exceeds 240 ℃ thermal decomposition This is because development is promoted and the physical properties of the film are lowered.

The screw in the extruder is preferably a biaxial screw, and as the molten resin is kneaded by rotation and generates frictional heat, the rotation speed is preferably as high as possible, and 100 to 150 rpm is appropriate.

Under such conditions of screw speed and extrusion temperature, the amount of extrusion is preferably maintained in the range of 250 to 300 kg per hour.

The inner surface and the periphery of the extrusion die should be in good polishing condition to uniform the sheet thickness and prevent the occurrence of fringes. The die is also preferably installed so as to face downwards vertically at the bottom of the extruder, but may be positioned horizontally or at an inclined angle between vertical and horizontal as needed.

The extruded resin is quenched while being in close contact with a cooling roll (casting roll) to form a sheet, wherein the surface temperature of the roll is preferably 15 to 40 ° C. This is because not only temperature control is difficult at temperatures below 15 ° C., but also sheet warping occurs, and when it exceeds 40 ° C., quenching is difficult and crystallinity becomes large and opaque. In addition, the roll surface temperature is uniform throughout, so that the deviation should be adjusted so as not to exceed a maximum of 3 ° C.

Generally, it is difficult to apply static electricity to propylene resin.

Therefore, the method of closely contacting the extruded resin to the cooling roll is preferably blown air to the sheet by the air knife method or by using a roll polishing method rather than the electrostatic application method.

In addition, the molding machine is not particularly limited as long as it is conventionally used, in particular, a triangular (Δ) belt type sheet molding machine is preferable.

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

According to the present invention, the glare caused by the reflection of the surface is so large that the gong of the sheet looks low, and to improve the sticking phenomenon between the mirrored suits (blocking phenomenon) and to lower the frictional force, the surface of the suit is formed using a roll formed with unevenness. Can be embossed. In this case, the shape, depth, and the like of the unevenness can be varied depending on the use of the sheet to be manufactured.

In detail, it is preferable that the unevenness formed according to the present invention has a unit plane area of 1-500 μm ² , and a shape having a depth of 0.1-5.0 μm so as to be 0.01 to 0.1 mm apart. In addition, the irregularities may be formed in various shapes such as pyramid, diamond, cone, sphere, ellipse, etc. in the form of embossed or engraved, double embossing is preferable.

When the sheet is reheated using a roll having such a shape, the surface of the sheet is embossed in the process. In this case, it is preferable that the sheet is brought into close contact with the reheating conditions at a roll surface temperature of 50 to 70 ° C. at a pressure of 1 to 10 kg / cm 2, which is less than 50 ° C., which makes it difficult to transfer the shape to the sheet surface. If it exceeds, since the resin adheres to the roll, the surface gloss may be worse. In addition, the reheat treatment process according to the present invention can be performed at any position in the sheet manufacturing process.

The film for the inner layer, which is another component of the case base sheet of the present invention, is produced through the following process.

First, an inorganic lubricant is added and mixed with the propylene resin having a melt index of 10-20 (g / 10 minutes) to improve the activity and prevent the blocking phenomenon. In this case, preferred kinds of inorganic lubricants include silica, calcium carbonate and kaolin, and the amount of the inorganic lubricant is preferably 0.1 to 10% by weight based on the propylene resin. This is because when less than 0.1% by weight, the effect of improving the activity and preventing blocking phenomenon is insignificant, and when it exceeds 10% by weight, the transparency of the film is inferior.

Subsequently, according to the method for producing the outer layer film, the mixed resin is melted in an extruder, extruded through a die provided on the front surface, quenched, and at least uniaxially stretched to produce an inner layer film.

When the unstretched sheet for the outer layer and the film for the inner layer are manufactured through the above process, the surface of any one of the sheet and the film can be appropriately designed as ink according to the use of the case. In this case, since high speed printing is possible in a roll state, it is preferable to design on the film for inner layers uniaxially stretched at least rather than a non-stretched film.

In preparing the case sheet of the present invention, the main component of the ink to be used is not particularly limited as long as it is conventionally used. Preferably, there are amide, vinyl acetate, acryl, ethyl cellulose and the like.

In addition, the discharge treatment may be performed to increase the ink aptitude of the film surface, and the surface treatment may be performed using a copolymer or an organic substance to improve printability.

After the above process, the unstretched sheet and the stretched film are combined so that the print layer is located in the middle. In this case, in terms of productivity, it is preferable to make it into a roll state. At this time, aqueous solutions such as starch, casein, polyvinylacetate, vinyl acetate, acrylic emulsion, wax, and the like may be used as intermediate materials, and transparency and printing of the film may be used. Anything can be used as long as it doesn't hurt the state.

According to this method, the propylene sheet composed of the composite layer can be processed at high speed, and the process step is shorter than that of the existing substrate, and thus many economic benefits can be maintained as well as a clear printing state for a long time.

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 produced by the Examples and Comparative Examples of the present invention was carried out by the following method.

1) haze

Using a haze meter of Gardner Neotek Co., Ltd., the scattered light and transmitted light values were measured using a c-light source and calculated according to the following equation.

2) glossiness

It was measured using Gardner Neotek's (US) gloss meter (model name: GC-4010) (standard diameter: black diameter, measurement strength: 60 degrees).

3) 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: 4002) of Ike-Engineering Co., Ltd. (Japan).

4) Antistatic Characteristics (Antistatic)

The surface resistance of the film was measured using an insulation resistance measuring instrument of the US Hewlett (20 ℃, relative humidity 65%, applied voltage 500V)

5) Surface Roughness

Using a heat gradient tester (model name: HG-100) manufactured by Kosaka Co., Ltd. (HG-100), the sealant was sealed at a pressure of 3 kg / cm 2 for 2 seconds, and then a temperature having a seal strength of 10 g / cm or more was initially sealed. Set to.

7) Printability Evaluation

After imparting a surface tension of 39 dyne / cm or more to the surface of the film, the oxidation neutralization ink (trade name: POP-K) and the ultraviolet curing ink (brand name: RT-7) are then bar coded, and the oxidation neutralization ink is at room temperature. After natural curing for 12 hours at, UV light inks were cured for 4-5 seconds using an ultraviolet curing tester (Model name: UV 151, Samneung Sheet Metal Industry), and then observed the peeling state of the ink layer using a tape. It was evaluated by the following criteria.

The ink layer does not fall at all: ◎

Slightly dropped (within 20%): ○

Normal fall (within 20 ~ 50%): △

Much drop (over 50%): ×

8) Evaluation of foreign material adhesion (time-lapse)

After 24 hours under conditions of 30 ° C. and 50% relative humidity, after exposure to the outside, the adhesion state of the foreign material was evaluated according to the following criteria.

No foreign material at all: ◎

Some foreign matter: ○

Foreign body usually occurs: △

Lots of foreign objects occur: ×

9) Fairness

The phenomenon of bleeding due to sheet cutting and the process condition in the sealing operation were evaluated comprehensively.

Example 1

100 g of homopolypropylene resin having a melt index of 4.5 (g / 10 min), a melting temperature of 165 占 폚, 0.03 g of hydroxy p- (t-butyl) benzenecarboxylic acid aluminum, and 0.03 g of sodium octylbenzenesulfonate were mixed. . The resulting resin mixture was discharged at a speed of 275 kg per hour under ship rpm 135 and an extrusion temperature of 210 ° C., cooled on a 30 ° C. cooling roll, and then closely molded to a rotating metal belt at a speed of 18 (m / min). Through the process to prepare a non-stretched sheet of 300 ㎛ thickness. Further, before the final winding of the sheet, reheating was performed under conditions of a surface temperature of 60 ° C. and a force of 4 kg / cm 2 using a roll having an uneven unit area of 250 μm ² and a pyramid embossed shape having a height of 4 μm at intervals of 0.07 mm. Various physical properties of the prepared sheets were measured. The internal contents were clearly seen at 3.5% of haze, and the surface resistance was maintained at 10 ¹⁵ kPa.

0.5 g of silica having an average particle diameter of 0.3 μm was added to 100 g of a random polypropylene resin having a melt index of 12.1 (g / 10 min) and a melting temperature of 140 ° C., and then a rate of 250 kg per hour under an extrusion temperature of 230 ° C. and a screw rpm of 120. Was discharged and adhered with air to a cooling roll at 25 ° C. Then, the film was stretched 6 times in the longitudinal direction at 120 ° C. and 9.5 times in the transverse direction at 150 ° C., heat-set at 200 ° C., and then discharged to the film surface to prepare a 20 μm thick film having excellent printability.

Various physical properties of the prepared film were measured, and the surface roughness was 0.021 μm and the initial sealing temperature was 200 ° C.

Finally, the non-stretched film excellent in transparency prepared in the above step and the printed stretched film were laminated at high speed in a roll state, and the printed layer was positioned at an intermediate portion, thereby manufacturing a case base sheet. Various physical properties of the produced film were measured, and all the work processes such as surface glossiness of 45%, coefficient of friction of 0.35, dust adhesion prevention, cutting and sealing were all good.

Example 2-5

In the same manner as in Example 1, but the manufacturing conditions were changed within the scope of the present invention as shown in the table to prepare a case base sheet, the physical properties of the prepared sheet was generally good.

Comparative Example 1-5

In the same manner as in Example 1, but the manufacturing conditions were shown in the table to the outside of the scope of the present invention to prepare a case base sheet, the physical properties of the prepared sheet was generally not good.

As can be seen from the above, the sheet produced according to the present invention is excellent in transparency, high-quality, foreign matter such as dust is not attached well, when the case is manufactured in the case of damage in the process of repeatedly separating and combining the case and the contents It is easy to speed up the packaging process without any scratches or scratches.

Claims (15)

Uniaxially containing a non-stretched propylene resin sheet containing 0.01 to 1.0% by weight of a carboxylate compound and a sulfonate compound and a 0.1 to 10% by weight inorganic lubricant based on the propylene resin, respectively, based on the propylene resin, or A biaxially stretched propylene-based resin film is laminated, wherein the base sheet for a case is used. The case sheet according to claim 1, wherein the propylene resin is a copolymer of propylene and at least one olefin selected from the group consisting of ethylene and butene. The case sheet according to claim 2, wherein the content of propylene is 80 to 97 mol% with respect to the propylene resin. The method of claim 1, wherein the carboxylate compound is one selected from the group consisting of hydroxy p- (t-butyl) benzene carboxylic acid aluminum, octyl benzene carboxylic acid sodium and octyl benzene carboxylic acid potassium Base material sheet for case to assume. The case sheet according to claim 1, wherein the sulfonate compound is one selected from the group consisting of sodium octylbenzenesulfonate, potassium nonylbenzenesulfonate, and sodium undecylbenzenesulfonate. The case sheet according to claim 1, wherein the inorganic lubricant is one selected from the group consisting of silica, calcium carbonate and kaolin. Adding a sodium benzoate compound and a sodium sulfonate compound to a propylene resin having a melt index of 1-10 (g / 10 min), thereby preparing a propylene resin sheet; Adding an inorganic lubricant to a propylene resin having a melt index of 10-20 (g / 10 minutes), melt compression, and then uniaxially or biaxially stretching; And laminating the sheet and the film prepared in the above step. The method of claim 7, wherein the carboxylate compound is one selected from the group consisting of hydroxy p- (t-butyl) benzene carboxylic acid aluminum, octyl benzene carboxylic acid sodium and octyl benzene carboxylic acid potassium The manufacturing method of the base material sheet for case made into. The method of claim 7, wherein the sulfonate compound is one selected from the group consisting of sodium octylbenzenesulfonate, potassium nonylbenzenesulfonate, and sodium undecylbenzenesulfonate. The method of claim 7, wherein the inorganic lubricant is one selected from the group consisting of silica, calcium carbonate and kaolin. The method of manufacturing a base sheet for a case according to claim 7, further comprising the step of designing the surface of the stretched film attached to the sheet as ink. 12. The method of manufacturing a substrate sheet for a case according to claim 11, further comprising corona discharge treatment of the surface to be patterned. The method of claim 11, wherein the main component of the ink is at least one selected from the group consisting of amide, vinyl acetate, acryl, and ethyl cellulose. The extruded sheet is heat-treated by using a roll surface having embossed irregularities having a unit area of 1-500 µm ² and a depth of 0.1-5.0 µm at intervals of 0.01 to 0.1 mm. Method for producing a base sheet for a case characterized in that it further comprises a step. The method for manufacturing a case base sheet according to claim 14, wherein the heat treatment is performed under a condition of a roll surface temperature of 50 to 70 ° C and a pressure of 1 to 10 kg / cm 2.