JPS6032625A - Manufacture of linear low-density polyethylene extruded laminate base sheet - Google Patents

Abstract

PURPOSE:To produce the titled sheet at high speed that is thin and excellent in adhesive strength between the film and the base, by melt-extruding a linear low- density polyethylene to which a low-density polyethylene is incorporated in a specified amount to be laminated onto a base sheet surface. CONSTITUTION:A mixture in which a low-density polyethylene is added in an amount of 10-40wt% to a linear low-density polyethylene is melted and extruded to be laminated onto a base sheet (e.g. paper, cellophane, etc.) to produce the intended sheet. EFFECT:The sheet is excellent in stiffness, mechanical strength, heat resistance, cold resistance, heat sealability, chemical resistance, barrier property, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for manufacturing linear low density polyethylene extruded laminate substrate sheets.

BACKGROUND ART Conventionally, methods of extrusion laminating polyethylene onto base sheets such as paper have been widely used, and laminated products such as polyethylene laminated paper are widely used in various packaging fields.

Such polyethylene is specifically low density polyethylene (
a=9.915-0.925) is used.

Waterproof and moisture proof, #11J property, #1 oily mechanical strength.

Thermal adhesiveness 0 Various properties such as dimensional stability, gloss, and transparency are imparted to products such as polyethylene laminated paper. It is unsuitable for extrusion lamination because it has poor drawability, it is difficult to laminate at high speed, and it also has disadvantages of poor adhesiveness.

In the recent packaging industry, there has been a demand for thinner polyethylene laminates from the viewpoints of resource saving and low cost◇ The present invention solves this problem and reduces the thickness of polyethylene ν extruded laminate onto the base sheet surface. It can be made as thin as possible,
The purpose of the present invention is to provide a technology that can perform laminating processing at high speed and with excellent adhesive properties.0 Below, 1. The structure of the present invention will be explained.0 That is, 1.
Low density polyethylene (hereinafter referred to as single K)
It is characterized by melt-extrusion lamination of a mixture containing 10 to 40 wt% of LDPI (abbreviated as LDPI) onto the base sheet surface. Here, LLDPE is a resin that has a relatively low density like medium-low density polyethylene, and has fewer monobranches like high-density polyethylene. It has excellent properties and other physical and chemical properties.

Also, LDPIi! is less than l Q wt% (LLDP
If I is 90 wt% or more, surging will occur during extrusion.

This is not preferable because the neck-in phenomenon becomes stronger.

If this occurs, the drawability (#meat processability) will deteriorate, which is undesirable. Therefore, LDPK is blended at 10 to 4 Q wt% with respect to I and LDPFi K to prevent Kt-ging and neck-in phenomena from occurring during extrusion. K.L.

In addition, the drawability is improved to facilitate melt extrusion.

This melt extrusion temperature is empirically preferred to be about 800 to 820°C.As the base sheet, kraft paper, cellophane, aluminum foil, etc. may be used as appropriate, and preferably these materials are laminated. Preheat the surface, corona discharge, gas flame, or zero. The present invention is constructed as described above, in which the adhesive is pretreated to improve adhesion by an appropriate surface oxidation treatment.

It has the following effects.

(1) First, LL used as a main component in the present invention
DPI has particularly excellent draw and drag properties compared to medium-low density polyethylene and high-density polyethylene, and the melt extrusion temperature of the resin is 800-820℃, which is 20℃ compared to 880-840DK for conventional polyethylene. In addition, the processing speed can be increased, and the laminate thickness of extruded molten polyethylene can be coated on the base sheet surface with a laminate thickness several times thinner than conventional ones (0, former 2 or less), and there are no pinholes. The occurrence of this is extremely rare.

(2) Therefore, a product made of extrusion laminated polyethylene mainly composed of the base sheet KLLDPFi has a small winding diameter, is lightweight, and has excellent handling properties. ! Left behind I, LD
PI extrusion laminated products (processed paper, etc.) K is LLDPI
A #1 properties are imparted, such as rigidity.

Mechanical strength, heat and cold resistance, heat sealability.

Claims (1)

[Claims] (1) A linear low-density polyethylene characterized by blending a-density polyethylene t-10 to 4Q wt% with respect to linear low-density polyethylene and melt-extruding and laminating a R:54 compound onto the base sheet surface. Manufacturing method for extruded laminate base sheet ◎゛ (2. In the method for manufacturing a linear low-density polyethylene extruded laminate base sheet according to claim 1, the treated surface of the base sheet is previously subjected to surface oxidation treatment. It is characterized by having been given the following.