US 12,313,191 B2
Heat shrink tube and method for forming same
Mineyuki Noda, Shizuoka (JP); Hiromasa Yabe, Shizuoka (JP); Hideki Kikuchi, Hamamatsu (JP); Kei Miyamoto, Hamamatsu (JP); and Kota Suzuki, Hamamatsu (JP)
Assigned to NISSEI ELECTRIC CO., LTD., Hamamatsu (JP); and CHEMOURS-MITSUI FLUOROPRODUCTS CO., LTD., Tokyo (JP)
Appl. No. 17/638,299
Filed by NISSEI ELECTRIC CO., LTD., Hamamatsu (JP); and CHEMOURS-MITSUI FLUOROPRODUCTS CO., LTD., Tokyo (JP)
PCT Filed Aug. 26, 2020, PCT No. PCT/JP2020/032161
§ 371(c)(1), (2) Date Feb. 25, 2022,
PCT Pub. No. WO2021/039837, PCT Pub. Date Mar. 4, 2021.
Claims priority of application No. 2019-158783 (JP), filed on Aug. 30, 2019.
Prior Publication US 2022/0349500 A1, Nov. 3, 2022
Int. Cl. B29C 48/09 (2019.01); B29C 48/88 (2019.01); B29C 61/02 (2006.01); B29K 27/00 (2006.01); B29K 27/18 (2006.01); B29L 23/00 (2006.01); B32B 7/028 (2019.01); F16L 11/12 (2006.01); F16L 47/22 (2006.01); H01R 4/72 (2006.01); H02G 15/18 (2006.01)
CPC F16L 11/12 (2013.01) [B29C 48/09 (2019.02); B29C 48/9115 (2019.02); B29C 61/025 (2013.01); F16L 47/22 (2013.01); B29K 2027/16 (2013.01); B29K 2027/18 (2013.01); B29K 2995/0035 (2013.01); B29K 2995/0098 (2013.01); B29L 2023/001 (2013.01); B29L 2023/005 (2013.01); B32B 7/028 (2019.01); B32B 2307/736 (2013.01); H01R 4/72 (2013.01); H02G 15/1806 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A peelable heat shrink tube composed of a fluororesin,
wherein the fluororesin is a copolymer melting at a temperature equal to or higher than a melting point to show fluidity, and is a copolymer of an unsaturated fluorinated hydrocarbon, an unsaturated fluorinated chlorinated hydrocarbon, or an ether group-containing unsaturated fluorinated hydrocarbon, or is at least one copolymer selected from copolymers of these unsaturated fluorinated hydrocarbons and ethylene,
wherein the peelable heat shrink tube has a peel strength of 10 N or less, wherein the peel strength is measured by providing a 50 mm notch near the center of the diameter at one end of a measurement sample measuring 150 mm, holding the measurement sample by chucks of a tensile tester, peeling the measurement sample by 70 mm at a tension speed of 200 mm/min, and measuring a maximum strength,
wherein a determination coefficient calculated from [Equation 1] below using an elastic modulus ratio (%) is more than 0.00, but 0.90 or less, the elastic modulus ratio (%) being obtained by measuring, on a straight line passing through regions (A), (B) and (C) below, elastic moduli of at least three points freely selected from each region, provided that a wall thickness of the tube at a cross-section perpendicular to an extrusion direction of the tube is 100%, the elastic modulus ratio (%) being a ratio of an average value of the elastic moduli in each region and an average value of the elastic moduli in all the regions,
(A) Region of less than 30% from an interior of the tube
(B) Region of 30% or more, but less than 70%, from the interior of the tube
(C) Region of 70% or more from the interior of the tube

OG Complex Work Unit Math
where X, Y and covariance represent the following:
X: Proportion of a position of each point, where the elastic modulus was measured, from the interior of the tube
Y: Elastic modulus ratio in each region
Covariance: Average of a product of deviations of X and Y,
wherein the elastic modulus is measured by performing static nanoindentation measurements with points of measurements separated by a distance equal to or more than 3 times a diameter of a dent, and by using a measuring device with an indenter of the Berkovich type under the following measurement conditions:
room temperature as a measuring temperature,
a maximum indentation force of 1,000 μN,
an indentation speed of 200 μN/sec, a full load application time of 1.0 second, and an unloading speed of 200 μN/sec.