KR20030010242A - Method for fabricating a polyester sheet excelling in forming and radiating far-infrared rays - Google Patents

Abstract

PURPOSE: Provided is a process for producing an amorphous polyester sheet excellent in formability and infrared rays-emitting effect, wherein the polyester sheet can be used as a food container excellent in storage ability for a long time. CONSTITUTION: The process comprises the steps of: adding 5-50wt% of an infrared ray-emitting body having an average particle size of 0.2-7.0 micrometer to a polyester resin having an intrinsic viscosity of 0.5-0.7dl/g, and mixing and dispersing to prepare a master batch resin; heating and drying the master batch resin at 100-150deg.C for 3.0-5.0 hours; forming the multi-layered amorphous sheet containing 1.0-10.0g/m2 of the infrared ray-emitting body in a core layer or a sub layer by using a co-extruder, wherein the amorphous sheet has more than 80% of a spectral radiation rate in the infrared radiation zone(lambda is 4-25 micrometer). The infrared ray-emitting body is at least one of yellow soil, quartz porphyry, and ceramic and contains SiO2, Al2O3, MgO, (K.H3O)Al2(Si.Al)4O10(H2O.OH)2, and etc.

Description

Method for fabricating a polyester sheet excelling in forming and radiating far-infrared rays}

The present invention relates to an amorphous polyester sheet having excellent moldability and excellent far-infrared radiation effect, and comprising fine powder of at least one or more far-infrared radiators among ocher, elvan, and ceramics that emit far-infrared rays during sheet manufacturing. The present invention relates to a method for producing an amorphous polyester sheet by adding a predetermined amount of a masterbatch resin having excellent moldability and excellent far-infrared radiation effect.

More specifically, the sheet obtained in the present invention is excellent in formability during vacuum forming, pressure forming or vacuum and pressure forming, and whitening does not occur, and the various containers manufactured are semi-permanently releasing a large amount of far-infrared rays, thereby providing various foods. Molding amorphous polyester with a main component of polyethylene terephthalate, which has long-lasting freshness, has excellent aging effect, removes odors, preserves taste and nutrition, maintains humidity and activates water. It relates to the manufacture of the sheet.

Polyester, generally represented by polyethylene terephthalate, has excellent mechanical strength, thermal properties, chemical resistance, electrical properties, moisture resistance, water resistance, transparency, etc., and is then molded into a sheet, followed by various food packaging containers, molding materials, and building materials. It is used for various purposes such as agricultural, livestock and livestock materials and general packaging containers.

However, in spite of such excellent properties, the sheet made of polyethylene terephthalate itself has excellent transparency, but it is difficult to develop various uses because it is not provided with functionality. Therefore, the semi-permanent far-infrared emission effect can be expected by injecting at least one or more of the far-infrared radiators such as elvan, loess, ceramic, etc. during the sheet manufacturing process to improve the functionality. However, when the sheet is manufactured by adding the far-infrared radiator in this way, the roll wears when the sheet passes through the guide roll by the far-infrared radiator on the surface layer of the sheet, and when the sheet contains an excess of the far-infrared radiator, the sheet is broken. There are many problems, such as the occurrence of cracking of the molded article because it becomes easy to be gripped.

In order to solve the above problems, the present invention manufactures a sheet having a far-reaching effect of emitting far infrared rays by manufacturing at least one or more far-infrared radiators such as ocher, elvan, ceramic, etc. in a master batch, and then injecting them in the sheet manufacturing process. It came to the following. In more detail, in the far-infrared radiator used in the present invention, SiO ₂ , Al ₂ O ₃ , MgO, (K, H ₃ O) Al ₂ (Si, Al) ₄ O ₁₀ (H ₂ O, OH) _2, etc. It is characteristic that the component contains. In order to improve the dispersibility of the far-infrared radiator during the production of the master batch, the polyethylene terephthalate resin is pulverized in powder form, and the far-infrared radiator powder is one of fine ocher, elvan, and ceramic powders having an average particle diameter of 0.2 to 7.0 µm. After mixing the species or two or more in a mixer for 60 minutes or more, it was extruded by a twin extruder to prepare a master batch resin excellent in dispersibility. The master batch resin prepared here is contained in the core layer of the laminated sheet of three or more layers 1.0 ~ 10.0g / ㎡ to produce a polyester sheet that emits far infrared rays semi-permanently.

The present invention will be described in more detail. One or two of ethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol as an aromatic dicarboxylic acid and glycol component such as terephthalic acid, 2,6-naphthalenedicarboxylic acid, etc. Polymerized so that the ultimate viscosity is 0.5 ~ 0.7dl / g prepared by the species or more, to prepare a polyester resin having an extreme viscosity of 0.75 ~ 1.0 dl / g through a solid-phase polymerization process, and then pulverized it into a fine powder at low temperature To prepare a fine polyester powder, the average size of the powder does not exceed 50Mesh.

One or two or more kinds of far-infrared emitter particles of elvan, ocher and ceramics having an average particle diameter of 0.2-7.0 μm are mixed in a mixer for at least 60 minutes through high temperature processing and grinding, and then extruded with a twin extruder to emit far-infrared radiation. Masterbatch resin was prepared. Far-infrared radiator content of the masterbatch resin is 5.0 to 50% by weight is excellent in dispersibility. In order to further improve the dispersibility, the content of the far-infrared radiator in the resin is preferably 5.0 to 30% by weight, and if it exceeds this range, the dispersibility of the far-infrared radiator is reduced, and the chip is easily broken due to its extreme viscosity. ), A problem such as mechanical strength deterioration occurs even after sheet production. Far-infrared radiation zone formed of polyester containing far infrared emitter 1.0-10.0 g / m2 in the core layer or sublayer by heating and drying the prepared masterbatch resin at 100-150 ° C. for 3.0-5.0 hours Multiple layers of amorphous sheets having a spectral emissivity of (λ = 4 to 25 μm) exceeding 80% are obtained. The manufacturing process of the sheet will be described in more detail. One or two or more of the fine powder ocher, elvan, and ceramic having a particle size adjusted to an average particle diameter of 0.2 to 7.0 μm manufactured through high temperature processing and grinding may be described. After mixing and dispersing the polyester pulverized in a powder form for 60 minutes or more in a mixer, and extruded by a twin extruder to prepare a far-infrared radiation masterbatch resin excellent in dispersibility. At this time, in the extrusion process, water must be sufficiently removed by a vacuum apparatus in order to prevent the physical property degradation due to hydrolysis during extrusion. The master batch resin obtained here has an intrinsic viscosity of about 0.60 to 0.75 dl / g. The far-infrared radiator content in the far-infrared radiation masterbatch resin is appropriately 5.0 to 30% by weight. If this range is exceeded, the dispersibility of the far-infrared radiator is lowered, making the sheet difficult to manufacture due to the increase in the filter pressure in the melt extrusion process during sheet production, and the problem that the master batch chip is easily broken due to the decrease in the ultimate viscosity. The far-infrared radiator in the core layer or sub-layer is supplied to the core layer or sublayer by supplying the far-infrared radiation masterbatch resin having a process moisture content of 150 ppm or less to the co-extrusion apparatus through heating and drying the masterbatch resin containing the far-infrared radiator manufactured at 100-150 ° C for 3.0-5.0 hours A multilayer sheet having a plurality of layers in which the spectral reflectance of the far-infrared radiation region formed of polyester containing 1.0 to 10.0 g / m 2 exceeds 80% is obtained. At this time, it is preferable that the sheet produced by coextrusion does not exceed 90% of the total thickness of the core layer. When the filling ratio of the core layer exceeds 90%, the far-infrared radiator protrudes to the surface layer, causing problems such as damaging the guide roll during the sheet manufacturing process.

The far-infrared emissivity of the manufactured sheet is characterized in that the spectral emissivity of the far-infrared radiation region (λ = 4 to 25 μm) exceeds 80%. Therefore, an object of the present invention has an excellent far-infrared radiation effect in the production of polyethylene terephthalate sheet, has excellent process passability and excellent moldability when forming into various containers, and particularly amorphous when excellent in the long-term storage of the contents when used as food containers It will provide a polyester sheet.

In the present invention, the characteristic value and overall physical property measurement were performed by the following method.

(1) Average particle diameter of far infrared radiator

The average particle diameter of all the particles used is the particle size analyzer in the state of being dispersed in methanol.

It was measured using (Granulometer HR-850), and at this time, the particles having a volume fraction of 50% in terms of spherical shape were used as the average particle diameter.

(2) far-infrared emissivity

The value was analyzed using the evaluation method of polyester sheet of Korea Institute of Construction Materials.

(3) Haze of sheet

An amorphous polyester sheet was measured using a haze meter (300A manufactured by Nippon Denshoku), and the haze value was calculated as total scattered light / total transmitted light × 100.

(4) Wear condition of guide roll

After 48 hours of production, the surface state of the guide roll was observed through a microscope and determined as follows.

Level 1: No damage to the surface of the guide roll.

Level 2: Slight scratches on the surface of the guide roll.

Class 3: Slight scratching occurs on the surface of the guide roll.

Hereinafter, the present invention will be described in detail based on Examples and Comparative Examples.

Example 1

Liquid crystal chips with an ultimate viscosity of 0.5 ~ 0.7 dl / g are prepared through solid phase polymerization to produce base resins with an ultimate viscosity of 0.75 ~ 1.0 dl / g, and then pulverized into fine powder at low temperature. It was made into the following sizes. Here, the fine ocher powder having an average particle diameter of 1.0-3.0 μm prepared through high temperature processing and pulverization was mixed in a mixer for 60 minutes or more, and then extruded by a twin extruder to obtain a master batch resin having a far infrared emitter content of 15% by weight. It was prepared, and heated and dried at 100 to 150 ° C. for 3.0 to 5.0 hours to obtain a plurality of layers of amorphous sheets containing 4.0 g / m 2 of far-infrared radiator in the core layer in a coextrusion apparatus. The physical properties of the sheet produced by the present invention is excellent in far-infrared emissivity, far-infrared radiation energy, turbidity, process permeability and the like, as shown in Table 1, and emits far-infrared rays semi-permanently by the far-infrared radiator contained inside the sheet. Sheets were prepared.

Example 2

The sheet was obtained in the same manner as in Example 1 except that the content of the far-infrared radiator in Example 1 was 2.0 g / m 2 with respect to the polyester sheet, and the physical properties of the sheet are shown in Table 1.

Example 3

In Example 1, the sheet was obtained in the same manner as in Example 1 except that the content of the far infrared emitter was 6.0 g / m 2 with respect to the polyester sheet.

Shown in

Comparative Example 1

The sheet was obtained in the same manner as in Example 1 except that the infrared ray emitter was not contained in Example 1, and the physical properties of the sheet are shown in Table 1.

Comparative Example 2

A sheet was obtained in the same manner as in Example 1 except that the average particle diameter of the far infrared emitter in Example 1 was 6 µm, and the physical properties of the sheet are shown in Table 1.

Comparative Example 3

A sheet was obtained in the same manner as in Example 1 except that the agglomerate fine particles were used as the far infrared emitter in Example 1, and the physical properties of the sheet are shown in Table 1.

Table 1

Item unit Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Far Infrared Emitter - ocher ocher ocher - ocher Elvan Average particle diameter Μm 3.0 3.0 3.0 - 6.0 2.5 Amount g / ㎡ 4.0 2.0 6.0 - 4.0 4.0 Far Infrared Emissivity % 90.0 87.5 91.5 82.5 89.7 89.3 HAZE % 10.5 8.0 19.0 1.0 13.7 23.5 Fair passability class 1st grade 1st grade 2nd class 1st grade Level 3 1st grade

Molded article made of amorphous polyester sheet having excellent moldability and excellent far-infrared radiation effect according to the present invention can prolong the freshness retention period of stored foods by emitting far-infrared rays semi-permanently, and it is excellent in ripening effect of food and removes odors. In addition, the present invention provides a polyester sheet having excellent properties such as preservation of taste and nutrition, retention of humidity, and activation of water, and the present invention also provides a far-infrared radiator when a polyester sheet is prepared by adding a far-infrared radiator. It was difficult to manufacture because the guide roll was easily worn by the roll, and there was a closed end of the sheet due to the excessive content of the far infrared emitter. The present invention is a useful invention having the effect of improving the formability to prevent the occurrence of such a brittle phenomenon (brittle) phenomenon

Claims (3)

5 to 50% by weight of a far infrared ray radiator having an average particle diameter of 0.2 to 7.0 µm was added to a polyester resin having an intrinsic viscosity of 0.5 to 0.7 dl / g, and the mixed and dispersed far infrared ray radiation masterbatch resin was 3.0 to 5.0 at 100 to 150 ° C. After heating and drying for a time, the spectral emissivity of the far-infrared radiation region (λ = 4-25㎛) formed of polyester containing 1.0-10.0 g / m 2 of far-infrared emitter in the core layer or sub-layer was supplied to the coextrusion apparatus. A method for producing a polyester sheet having excellent far-infrared radiation effect, characterized by forming a plurality of layers of amorphous sheets exceeding this. The method of claim 1, wherein the far-infrared emitter is at least one or more far-infrared emitters of ocher, elvan, ceramics, SiO ₂ , Al ₂ O ₃ , MgO, (KH ₃ O) Al ₂ (Si.Al) ₄ O ₁₀ (H ₂ O.OH) _2, etc. The manufacturing method of the polyester sheet characterized by containing components. The method according to claim 1, wherein the far-infrared emitter finely processed is included in the core layer of the sheet, and the layer ratio of the core layer does not exceed 90% of the total thickness.