Thin film polyurethane foam laminate and method for manufacturing same

Abstract

The present invention relates to a thin film polyurethane foam laminate and a method for manufacturing the same, the method comprising the steps of: (a) generating a foam composition of a gas-liquid mixture by feeding, as raw materials for a foam composition without using water, which is a chemical foaming agent, polyol, isocyanate, a moisture absorbent, micro hollow spheres, and an additive into a mixer, followed by mechanical foaming through a foaming gas; (b) supplying the mechanically foamed gas-liquid mixture from the mixer to a discharger connected to a connection tube; (c) coating the gas-liquid mixture, which is discharged from the discharger, on a first base film to a predetermined thickness; (d) attaching a second base film on a surface of the gas-liquid mixture coated on the first base film, and hardening the resultant structure with the attached second base film in a thermal hardener, thereby generating a polyurethane foam layer; (e) releasing the second base film after the completing of the thermal hardening step, coating a coating agent on a surface of the hardened polyurethane foam layer, and then laminating a coating film using a UV hardener; and (f) collecting the polyurethane foam laminate with the laminated coating film, using a collection roll. A low-density polyurethane foam laminate having a very thin thickness, which is required by a sealing member and a buffer applied to an electronic device, can be molded by: adding, in the foaming composition, zeolite as a moisture absorbent for absorbing residual moisture and micro hollow spheres causing less aggregation between cells; performing mechanical foaming using nitrogen as a foaming gas; and then performing thermal hardening. Therefore, the low density molding is suitable for a sealing material and cushioning material of an electronic device, where a polyurethane foam laminate with super thin thickness is required.

Description

technical field [0001] The present invention relates to a thin-film polyurethane foam laminate that can be used as a cushioning material and sealing material for the interior of electronic devices such as smartphones, and a manufacturing method thereof, and more specifically, relates to a thin-film polyurethane foam layer that can be molded with a very thin thickness at a low density A pressed body and a method for producing the same, wherein when molding the polyurethane foam laminate, a moisture absorbent is added to the foaming composition, thereby suppressing a chemical foaming reaction caused by residual moisture contained in the foaming composition, and The hollow microspheres with less inter-pore aggregation phenomenon replace the pore structure laminate formed inside the foam laminate by the chemical foaming reaction in the prior art. Background technique [0002] Generally, for electronic devices using displays such as smartphones and tablet PCs, cushioning material...

AI Technical Summary

Problems solved by technology

[0005] However, the technology of the following [Document 1], compared with the previously developed cushioning material and sealing material made of curable polyurethane, has 0.10 to 0.25 g / cm 3 The advantages of horizontal low density, but because the molding thickness is thicker at the level of 0.3 ~ 3mm, it cannot meet the recent requirements as the thickness of the buffer material and sealing material as mentioned above, so it cannot effectively fill between the parts of electronic equipment the gap problem

[0006] In addition, in order to solve these problems, the density of the foam laminate becomes excessively high at 0.7 to 0.8 g / cm when the conventional curable polyurethane production method is applied and the thickness is molded to a desired level of 150 to 200 μm 3 Level (25% C.F.D. value 1kgf / cm 2 above), so that the pore structure formed inside the foam laminate is thin, and therefore, there is a problem that it is almost impossible to perform the functions of a cushioning material and a sealing material

[0007] In addition, in the above [Document 1], when the artificial film is laminated and cured, due to the chemical foaming in the foam layer, it will expand by 2 to 4 times and foam. Therefore, to manufacture a thickness of 200 μm, it is necessary to use The coating thickness of the foaming composition of 50~80 μm level is coated on the base film, yet, with existing coating technology (roll coater, comma coater (Commacoater), blade coater) is difficult to Coating the foaming composition on the base film at a thickness of 80 μm or less, especially, polyurethane having a molded thickness of 100 to 150 μm that is not suitable for coating the foaming composition at a coating thickness of 30 to 50 μm Problems with methods of manufacturing foam laminates

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