JPS61284419A - Manufacture of crosslinked resin thin film - Google Patents

Abstract

PURPOSE:To obtain a crosslinked resin thin film, by a method wherein a base material thermoplastic resin layer is brought into a sheetlike state by laminating a crosslinkable uncrosslinked thermoplastic resin layer on one side or both the sides of the base material thermoplastic resin layer and the crosslinkable thermoplastic resin layer is peeled off by making the same crosslink after the laminated sheet has been oriented by more than a specific value at least in one direction. CONSTITUTION:As for a base material thermoplastic resin, though it is not limited especially if the same is orientatable, the resin which is orientatable at the temperature lower than the crosslinkable temperature of crosslinkable thermoplastic resin is desirable. As for the crosslinkable thermoplastic resin also, though it is not limited especially if the same is a crosslinkable resin, silicone series resin or urethane series resin or butadiene series resin or flourine series resin is desirable. As for a film manufacturing method, though calendering roll method or extruding method or solution method, though calendering roll method or extruding method or solution coating method is available, any method will do. As for orientation magnification, at least more than 1.2 times are necessary in one direction to become effective in thinning a film, and more than 1.2 times respectively in longitudinal and lateral direction are desirable. With this construction, a crosslinked resin thin film of less than 200mu is obtained easily.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for producing a resin thin film having a crosslinked structure.

(Prior Art) Conventionally, the method for producing thin films of crosslinked resins, especially rubber-like materials, has been to form sheets using calender roll sheet molding machines or extrusion sheet molding machines. It has been difficult to make thin films, especially film-like films with a thickness of 200 μm or less.

(Problems to be Solved by the Invention) In the case of the above-mentioned conventional method, when the film thickness is reduced, it becomes difficult to peel it off from the forming roll, etc. To prevent this, it is necessary to apply a striking agent or to laminate it with a support material. However, increasing the take-up speed makes it easier to cut, and as a result, it is difficult to make a thin film of 200 μm or less. Furthermore, as the film thickness becomes thinner, it becomes difficult to control the thickness, making it impossible to create a uniform thin film.

(Means for Solving the Problems) As a result of intensive research into the above problems, the present inventors came to invent the following method.

That is, a crosslinkable uncrosslinked thermoplastic resin layer is laminated on one or both sides of a base thermoplastic resin layer to form a sheet, and the laminated sheet is stretched 1.2 times or more in at least one direction. This is a method for producing a crosslinked resin thin film characterized by crosslinking and peeling off a thermoplastic resin layer.

The base thermoplastic resin described in the present invention is not particularly limited as long as it can be stretched, but a resin that can be stretched at a temperature lower than the crosslinkable temperature of the crosslinkable thermoplastic resin is preferred. For example, polyester resins such as polyethylene terephthalate, polyolefin resins such as polyethylene, fluororesins such as polyethylenetetrafluoroethylene and polyvinylidene fluoride, or polyvinyl alcohol resins are suitable.

In addition, the crosslinkable thermoplastic resin is not particularly limited as long as it is a crosslinkable resin, but silicone resin,
Preferred are urethane resins, butadiene resins, isoprene resins, chloroprene resins, and fluorine resins. Sili: +-7 series +M fat is dimethylsiloxane unit (
CHI)2-SiO as a main component, and is often produced by heating ring-opening polymerization of cyclic dimethylsiloxane produced by hydrolyzing dimethyldichlorosilane with acid or alkali, but is not particularly limited to this method. Also,
Silica, calcium carbonate, or titanium oxide may be added as a reinforcing agent or filler. Crosslinking agent to peroxide 7”/
El, bis2.4 dichlorobenzoyl peroxide.

Use dicumyl peroxide, etc.

The urethane resin used in the present invention is made by reacting diisocyanate with polyester or polyether. Diisocyanate includes 1,5 naphthylene diisocyanate 1”+ N,N'(4,4' dimethyl)3
．． 3" diphenyl diisocyanate, 4.4' diphenylmethane diisocyanate, etc. are applicable, but are not limited to these. In addition, polyesters containing adipic acid and ethylene glycol, or adipic acid, diethylene glycol, and triol as main components are suitable. However, the butadiene resin used in the present invention includes styrene butadiene resin,
Examples include acrylonitrile butadiene resin and cis-butadiene resin. Styrene butadiene resin uses water as a dispersion medium,
It is produced by copolymerizing styrene and butadiene by emulsifying them with soap, or by solution polymerizing styrene and butadiene.

The method is not particularly limited to these methods. Acrylonitrile butadiene resin is copolymerized by emulsifying acrylonitrile and butadiene in a ratio of about 3=7 using water as a dispersion medium. These crosslinking agents are preferably sulfur, but are not particularly limited thereto.

The fluororesin used in the present invention is a copolymer of vinylidene fluoride and propylene hexafluoride or a copolymer of vinylidene fluoride and ethylene chloride trifluoride, but is not limited thereto. The crosslinking agent is preferably an aliphatic polyamine derivative, but is not particularly limited thereto.

Methods for forming the resin film include a calender roll method, an extrusion method, and a solution coating method, and any method may be used. Further, the stretching method is not particularly limited, but uniaxial stretching using two rolls and uniaxial or biaxial stretching using a tenter method are suitable.

In particular, the simultaneous two-wheel stretching method using the tenter method can grip only the edges of the laminated sheet and stretch the sheet while holding the center part in the air without damaging it.

Moreover, it is the best method because it allows you to increase the magnification both vertically and horizontally. The stretching ratio needs to be 1.2 times or more in at least one direction to increase the effect of thinning the film, and 1.2 times or more in each direction.
It is preferably twice or more. Furthermore, if the crosslinkable thermoplastic resin has adhesive properties, a method is adopted in which it is laminated only in the center of the base thermoplastic resin sheet. Further, the crosslinking method may be a method of heating the laminated sheet, or a method of irradiating the laminated sheet with radiation such as an electron beam, but is not particularly limited to these methods.

The crosslinked resin thin film produced by the method of the present invention can be used for battery separates, gas or liquid separation membranes, clothing coatings, and the like.

(Example) The details will be explained below using examples.

Example 1 Dimethyl silicone, gas-phase silica, and calcined diatomaceous earth silica were mixed, benzoyl peroxide was added as a crosslinking agent, a sheet with a thickness of 200μ was made by a calender roll method, and immediately a sheet with a thickness of 120μ without polyethylene terephthalate was made. Laminated on stretched film. The laminated sheet was simultaneously stretched by two wheels at 90°C by a tenter method to 3 times the length and width, and after crosslinking by heating at 125°C, only the silicone thin film was peeled off. The thickness of the silicone thin film is 24μ, and Table 1
It possessed such good performance.

Table 1 Example 2 Zinc oxide and ethylene olerea were added as a crosslinking agent to a chloroprene resin, and aldol-α-naphthylamine was further added as an anti-aging agent, and the mixture was kneaded using a kneading roll machine. Furthermore, using a calendar roll machine, the thickness is 200mm.
A sheet of μ was prepared and immediately laminated with an unstretched polyethylene terephthalate film. The laminated sheet was simultaneously biaxially stretched to twice the length and width at 90°C using a tenter method, and then stretched at 150°C.
After crosslinking by heating, only the chloroprene thin film was peeled off.

The chloroprene thin film had a thickness of 50 μm and had good rubber elasticity.

(Effects of the Invention) As described above, according to the method of the present invention, it is possible to easily produce a crosslinked resin thin film of 200 μm or less, which has been difficult to produce in the past.

Claims (3)

[Claims] (1) A crosslinkable uncrosslinked thermoplastic resin layer is laminated on one or both sides of the base thermoplastic resin layer to form a sheet, and the laminated sheet is stretched 1.2 times or more in at least one direction, and then crosslinked. 1. A method for producing a crosslinked resin thin film, which comprises crosslinking and peeling off a thermoplastic resin layer. (2) The crosslinkable thermoplastic resin is a silicone resin. 1 selected from urethane resin, butadiene resin, isoprene resin, chloroprene resin, and fluorine resin
The method for producing a crosslinked resin thin film according to claim 1, characterized in that one or more types are used. (3) The method for producing a crosslinked resin thin film according to claim 1, characterized in that the laminated sheet is stretched by at least 1.2 times in both length and width by a simultaneous biaxial stretching method.