Unlock instant, AI-driven research and patent intelligence for your innovation.

Polypropylene film for in-mold labels

A polypropylene film and in-mold label technology, which is applied in applications, household appliances, and other household appliances, can solve the problems of label curling and high cost, and achieve the effect of preventing difficult stretching

Active Publication Date: 2015-04-15
TOYO TOYOBO CO LTD
View PDF15 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0013] However, it is also known that most conventional polypropylene films for in-mold labels have the following problems: stretching or shrinking of the film due to the tension applied to the film during the above-mentioned processing, specifically printing and lamination, Therefore, after the label is formed, the label is curled (for example, refer to Patent Document 9)
[0014] In order to suppress curling, in printing and lamination processing, it is necessary to adjust the processing conditions at high frequency, or increase the thickness of the polypropylene film, or select the central part of the width direction of the polypropylene film as an in-mold label substrate, etc. , so the label is forced to be a costly structure

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Polypropylene film for in-mold labels
  • Polypropylene film for in-mold labels
  • Polypropylene film for in-mold labels

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0195] As polypropylene resin, use M w / M n =7.7, M z+1 / M n =140, MFR=5.0 / 10 min, mmmm=97.3% propylene homopolymer (manufactured by Japan Polypropylene Corporation: NOVATEC (registered trademark) PP "SA4L") (hereinafter referred to as "PP-1"). Use a 60mm extruder to extrude from a T-die at 250°C into a sheet, cool and solidify with a cooling roll at 30°C, stretch to 4.5 times in the longitudinal direction (MD direction) at 135°C, and then wrap both ends Clamp it with a jig, introduce it into a hot air oven, and preheat it at 170°C, then stretch it to 8.2 times in the transverse direction (TD direction) at 160°C, and then cool it at 168°C while relaxing it at a relaxation rate of 6.7%. Carry out heat treatment. Then, corona treatment was performed on one side of the film, and it was taken up by a winder. The thickness of the film thus obtained was 20 μm. The properties of the polypropylene resin are shown in Tables 1 and 2; the film forming conditions are shown in Table 3...

Embodiment 2

[0199] With respect to 90 parts by mass of the above-mentioned "PP-1", 10 parts by mass of low molecular weight polypropylene (Hi-WAX "NP105" manufactured by Mitsui Chemicals, Inc.) with a molecular weight of 10000 was added, and the total was taken as 100 parts by mass. The extruder was melt-kneaded to obtain pellets of the mixture "PP-2". A thin film was obtained from the pellets by the same method as in Example 1. The properties of the polypropylene resin are shown in Tables 1 and 2; the film forming conditions are shown in Table 3; and the physical properties of the obtained film and the amount of curl of the label are shown in Table 5.

Embodiment 3

[0201] With respect to 70 parts by mass of the above "PP-1", adding w / M n =4.6, M z+1 / M n =22, MFR=120g / 10min, mmmm=98.1% 30 mass parts of propylene homopolymers were dry-blended, and the mixture "PP-3" was obtained. Using "PP-3", a film was obtained by the same method as in Example 1. The properties of the polypropylene resin are shown in Tables 1 and 2; the film forming conditions are shown in Table 3; and the physical properties of the obtained film and the amount of curl of the label are shown in Table 5.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

A polypropylene film suitable for in-mold label applications is provided. The polypropylene film for in-mold labels is mainly composed of polypropylene resin, and is characterized in that the heat shrinkage rate in both the machine direction (MD) and the transverse direction (TD) at 150°C is not more than 9%, Young's modulus in the MD is not less than 2 GPa, Young's modulus in the TD is not less than 4 GPa, and haze is not more than 6%.

Description

technical field [0001] The present invention relates to a polypropylene film for in-mold labels excellent in heat resistance and mechanical properties. Background technique [0002] Conventional polypropylene film has a shrinkage rate of tens of percent at 150°C. Compared with PET, etc., it has low heat resistance and low rigidity, so curling is likely to occur due to shrinkage during lamination processing, which becomes a defect. s reason. [0003] In order to solve these problems, it is known to form a stretched film using polypropylene having high stereoregularity and narrow molecular weight distribution to form a film having high temperature rigidity and heat resistance (for example, refer to Patent Document 1, etc.). [0004] In addition, it is known that a stretched film made of polypropylene having high stereoregularity and a wide molecular weight distribution can be suitably used as a capacitor film excellent in electrical insulation and mechanical properties (for e...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): C08J5/18B29C55/14G09F3/04B29K23/00B29L7/00
CPCB29K2023/10C08J5/18B29C55/143B29C55/14C08J2323/12C08L23/12
Inventor 木下理山田浩司多贺敦
Owner TOYO TOYOBO CO LTD