Heat shrink film and its preparation methods.

Abstract

Page 1 of 1 Summary of the invention. The appearance is related to heat-shrinkable film, which has a heat shrinkage rate of... A direction perpendicular to the principal shrinkage direction, which is not high even at high temperatures, and which allows for printing on it. Heat shrink film is composed of polyester resin, which has the characteristic shrinkage property of... Heating in a direction perpendicular to the principal contraction direction will correspond to the following relationships 1 and 2: [Relationship 1] -15 < (symbol) t70-65 < 0 [Relationship 2] 0 < (symbol) t100-95 (symbol) 5 Where Atx-y is the value obtained by subtracting the heat shrinkage rate of the heat shrink film. In a direction perpendicular to the main shrinkage direction, after the heat-shrink film is immersed in the water bath for 10 seconds. At Y degrees Celsius, the heat shrinkage rate of the film is measured in a direction perpendicular to the direction of shrinkage. The main shrinkage occurs after the heat-shrink film is immersed in a water bath for 10 seconds at x degrees Celsius.

Claims

Page 1 of 3 pages of Claims 1. A heat shrink film composed of a polyester resin in which the heat shrink characteristic in the direction perpendicular to the primary shrinkage direction is consistent with the following relationships 1 and 2: [Relation 1] -15 < (symbol) t70 - 65 < 0 [Relation 2] 0 < (symbol) t100 - 95 < 5, where Atx - y is the value obtained by subtracting the heat shrink rate of the heat shrink film in the direction perpendicular to the primary shrinkage direction after the heat shrink film is immersed in a water bath for 10 seconds at Y°C from the heat shrink rate of the heat shrink film in the direction perpendicular to the primary shrinkage direction after the heat shrink film is immersed in a water bath for 10 seconds at x°C.

2. A heat shrink film of Claim 1 in which a polyester resin is composed of a dicarboxylic acid component and a diol component and The diol component consists of at least one selected from a group comprising ethylene glycol (EG), diethylene glycol (DEG), neopentyl glycol (NPG), and cyclohexane dimethanol (CHDM)3.

1. Heat shrink film of claim 2 in which the amount of ethylene glycol is 50 to 80% by mol based on the total number of moles of the diol component, and the amount of diethylene glycol is greater than 0 to 20% by mol based on the total number of moles of the diol component.

4. Heat shrink film of claim 2 in which the sum of the amounts of neopentyl glycol and cyclohexane dimethanol is 10 to 40% by mol based on the total number of moles of the diol component.

5. Heat shrink film of claim 2 in which the amount of neopentyl glycol is 20 to 30% by mol based on the total number of moles of the diol component.

6. Heat shrink film of claim 1 in which its maximum expansion rate in the direction perpendicular to the principal shrinkage direction is 3 to 15%. Page 2 of 3, page 7. The heat shrinkable film of claim 6, where the maximum expansion rate of the heat shrinkable film appears between 70°C and 90°C, when the heat shrinkage rate of the heat shrinkable film is measured in the range of 5°C between 50°C and 100°C.The heat shrinkable film of claim 1, whose heat of crystallization (Ahc), when measured by DSC (differential scanning calorimetry), is 0 to 30 J / g. The corresponding heat shrinkable film of claim 1 is at T75, which is -12 to 0%, at T80, which is -15 to 0%, and at T185, which is -10 to 0%, where Tz is referenced to the heat shrinkage rate in the direction perpendicular to the principal shrinkage direction after the heat shrinkable film is immersed in a water bath for 10 seconds at z⁻c10. The process for the preparation of heat-shrinkable film consists of: preparation of the polyester resin mixture; extrusion of the mixture to obtain a non-stretch sheet; preheating of the non-stretch sheet at a preheating temperature (T1) of 100 to 110 °C; stretching of the preheated non-stretch sheet in one direction to obtain a stretch sheet; heat treatment of the stretch sheet at a heat treatment temperature (T2) of 70 to 98 °C; and cooling of the heat-treated and stretched sheet to prepare the heat-shrinkable film.

11. The process for the preparation of the heat-shrinkable film of claim 10 where the extrusion is carried out at 260 to 300 °C.12.

13. The process for preparing heat shrink film of claim 10 where T1-T2 is 10 to 40°C.

14. The process for preparing heat shrink film of claim 10 where preheating is performed for 0.01 to 1 minute.

15. The process for preparing heat shrink film of claim 10 where stretching is performed at a stretch ratio of 3 to 5 times in one direction, front 3 of 3 faces.

16. The process for preparing heat shrink film of claim 10 which is further incorporated with printing on the heat shrink film.The process for preparing heat shrink film of claim 10, where the heat shrink characteristic of the heat shrink film in the direction perpendicular to the principal shrinkage direction is satisfied with the following relationships 1 and 2: [relation 1] -15 < (symbol) T70 - 65 < 0 [relation 2] 0 < (symbol) t100 - 95 < 5, where Atx - y is the value obtained by subtracting the heat shrink rate of the heat shrink film in the direction perpendicular to the principal shrinkage direction after the heat shrink film is immersed in a water bath for 10 seconds at Y°C from the heat shrink rate of the heat shrink film in the direction perpendicular to the principal shrinkage direction after the heat shrink film is immersed in a water bath for 10 seconds at x°C.The process for preparing the heat shrink film of Patent 10, whereby the heat shrink film shall consist of a polyester resin, the polyester resin is incorporated with a dicarboxylic acid component and a diol component. The diol component shall consist of at least one selected from a group consisting of ethylene glycol (EG), diethylene glycol (DEG), neopentyl glycol (NPG), and cyclohexane dimethanol (CHDM), and the positive amount of neopentyl glycol and cyclohexane dimethanol is 10 to 40% by mol, based on the total number of mol of the diol component;