JPH03128227A - Film or sheet - Google Patents

Abstract

PURPOSE:To obtain a film or a sheet excellent in transparency and heat resistance and having high mechanical properties by shaping a polymer in which a main chain comprises a specified and repeated unit. CONSTITUTION:A polymer in which a main chain comprises substantially the repeated unit of the formula 1 is shaped to form a film or a sheet, provided that R<1>, R<2>, R<3>, R<4>, R<5> and R<6> in the formula I each represents a hydrogen atom or a lower alkyl group. This polymer can be prepared by subjecting 2,3- dihydrofuran or its derivative to cationic polymerization reaction in the presence of a suitable initiator, and it is preferred that a number average molecular weight in term of polystyrene, which is determined by gel permeation chromatography, is within the range of 5,000 to 200,000.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a film casing or sheet formed by molding a polymer having a tetrahydrofuran skeleton. It has excellent heat resistance and good mechanical properties, and can be used as various structural pipes and functional materials.

[Conventional technology]

As a polymer having a tetrahydrofuran skeleton, 2.
Polymers obtained by cationic polymerization of 3-dihydrofuran, 2,3-dihydro-5-methylfuran, etc. are known [Journal of Chemical Science, Inc.
Polymer Journal
al), Vol. 16, p. 415 (I984)], and it has also been suggested that a polymer obtained by cationic polymerization of 2,3-dihydrofuran has performance as a separator for lithium secondary batteries. [Polymer Preprints
), vol. 24, p. 317 (I983f: )].

[Problem to be solved by the invention]

The object of the present invention is to provide excellent transparency and heat resistance.

Another object of the present invention is to provide a film or sheet having good mechanical properties.

[Means to solve the problem]

The present inventors have discovered that films and sheets with excellent transparency and heat resistance as well as sufficient mechanical properties can be obtained from polymers having a tetrahydrofuran skeleton! It has been found that the hot-stretched film buttons and sheets have even improved mechanical properties.

According to the present invention, the above object is achieved by having a main chain consisting essentially of the following repeating units (I) (wherein R1, R2, R3, R4, R5 buttons and R6 are each a hydrogen atom or a lower alkyl group). This is achieved by providing a film or sheet formed by molding a polymer consisting of

R1. applied to the above repeating unit (I). R2, R3%
Examples of the lower alkyl groups represented by R4, R5, and R6 (hereinafter collectively referred to as R1 to R6) include methyl, ethyl, propyl, isopropyl, butyl, and the like. It is preferable that R1-6 represents a hydrogen atom or a methyl group, and when all of R1-6 represent a hydrogen atom, any one of R1 and R1'' represents a methyl group, and all others represent a hydrogen atom. Examples of preferable polymers include those having the following repeating units.

The polymer used in the present invention has a number average molecular weight of s, ooo
Those within the range of 200,000 to 200,000 are preferred. In the case of a polymer having a number average molecular weight larger than s or ooo, the moldability when molding a film or sheet will be insufficient, and either case is unfavorable.

Among them, the polymer applied to the present invention has the above-mentioned repeating unit (I
) may have only one type of repeating unit;
It may contain two or more types of repeating units. Also 1
The polymer used in the present invention may contain other structural units within a range that does not impair its properties.

Various additives such as plasticizers, lubricants, antistatic agents, antioxidants, and ultraviolet absorbers may be present in the polymer as necessary.

The polymer of the present invention can be produced by subjecting 2,3-dihydrofuran or its derivative represented by the following general formula (n) to a known cationic polymerization reaction in the presence of a suitable initiator.

(In the formula, 11 to 6 are as defined above.) Initiators used in producing the polymer of the present invention include protonic acids such as hydroiodic acid, chromium oxide, molybdenum oxide, Metal oxides such as: halogens such as iodine, bromine, and iodine bromide; boron halides such as boron trifluoride and boron trifluoride ether complexes: aluminum chloride, aluminum bromide, titanium tetrachloride, titanium tetrabromide,
Metal halides such as tin tetrachloride and iron trichloride; ethylaluminum dichloride, diethylaluminum chloride, diethylaluminum bromide.

Examples include organometallic compounds such as diethylzinc; carbonium ion salts such as triphenylmethyl antimony hexachloride and triphenylmethyltin pentachloride. An amount within the range of 0.01 to 10 mol, preferably 0.0 molar relative to the initiator Fi2.3-dihydrofuran or its derivative
It is used in an amount within the range of 5 to 2 moles.

As the polymerization temperature, a temperature in the range of -200'C to 100'C, preferably a temperature in the range of -100'C to 50'C is employed. The polymerization reaction is usually performed under an inert gas atmosphere such as nitrogen, argon, helium, or the like. Although polymerization can be carried out in the absence of a solvent, aromatic hydrocarbons such as benzene, toluene, xylene, and mesitylenate; aliphatic hydrocarbons such as hexane, heptane, and octane; alicyclic hydrocarbons such as cyclohexane and cyclooctane; It is preferable to carry out the reaction in the presence of a solvent such as a halogenated hydrocarbon such as methylene, chloroform, or tetrachloroethylene in terms of removal of reaction heat and ease of handling of the produced polymer. Depending on the type of initiator used, in addition to the above solvents, ethers such as diethyl ether, dibutyl ether, dioctyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and tetrahydrofuran; methyl acetate,
The polymerization reaction can be carried out more efficiently by appropriately coexisting esters such as ethyl acetate, isopropyl acetate, and methyl benzoate; and ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. The reaction time is usually selected within the range of 1 second to 100 hours. After reaching the desired degree of polymerization, the reaction is stopped by a known method, and the resulting polymer is isolated and purified.

The polymer produced in this way is processed by the T-die method.

A sheet of the film 17'c can be obtained by subjecting it to a known film forming method such as a melt extrusion method such as an inflation method, a hot press method, a melt casting method, or a calender method. The thickness of the film casing or sheet is usually 10 to 500 μm.
It is preferable that the value be within the range of . The film casing or sheet produced in this way usually has a tensile strength of 3K.
g/- or more.

By heating the above film or sheet to a predetermined temperature and stretching it uniaxially or biaxially at a predetermined magnification, it is possible to obtain a film or sheet with improved mechanical properties than the above film or sheet. can. Stretching in two axial directions may be performed simultaneously or sequentially. The stretching temperature is higher than the glass transition temperature of the polymer, and 8° below the glass transition temperature.
A temperature range of 0° C. higher is preferable, and a temperature range of 5° C. to 50° C. higher than the glass transition temperature is more preferable. When the stretching temperature is lower than the glass transition temperature, the polymer is insufficiently softened and uniform and stable stretching cannot be performed. On the other hand, if the stretching temperature is too high, thin parts of the film or sheet will be produced.

Problems such as holes in the film or sheet occur. In the case of stretching only in the -axial direction, the stretching ratio is preferably 3 times or more, more preferably 4 times or more. In the case of biaxial stretching, it is preferably 1.5 times or more in both the longitudinal and transverse directions, and more preferably 2 times or more. When the stretching ratio is smaller than these ratios, the improvement in mechanical properties is insufficient. The upper limit of the stretching ratio cannot be determined uniquely because it depends on the type of polymer and the stretching temperature;
Preferably, the elongation at break is 95% or less.

By stretching the film or sheet in this way, the tensile strength of the film casing or sheet can be increased by 1% compared to before stretching.
It can be improved by 0% or more.

The stretched film or sheet provided by the invention typically has a tensile strength of 6 Kq/- or more.

The film or sheet of the present invention may be used as a material for a film or sheet composite with other types of materials.

The film casing or sheet of the present invention can be used for various packaging, agriculture, building materials, electrical parts, optical parts, etc.

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to Examples.

The physical property values were measured according to the following methods.

(1) Number average molecule and molecular weight distribution: Determined by GPC (polystyrene equivalent).

(2) Glass transition temperature: Measured by differential thermal analysis (in nitrogen, heating rate 10°C/min).

■Tensile strength, tensile modulus 3 and elongation at break: 100■×
A test piece with a bottom shape of 20 mm was measured using a tensile testing machine at a grip distance of 30 cm and a tensile speed of 1 w x 7 minutes.

(2) Total light transmittance: Measured by a method according to ASTM D1003.

Reference Example 1 After sufficiently purging the inside of an 11-volume glass container equipped with a stirring device with dry nitrogen gas, 0.51 g of dehydrated toluene was charged into the container, and 0.01 g of boron trifluoride was charged.
After blowing into the container to reach a concentration of mol/l, the mixture was cooled to -78°C. While stirring, 100 ft of dehydrated 2,3-dihydrofuran was gradually added to the solution over 20 minutes. −
After continuing the reaction at a temperature of 78° C. for 48 hours, 1 OMt of a 1N methanol solution of ammonia water was added to the reaction mixture to stop the tetrapolymerization. Next, the mixed solution was dropped into methanol IOJ and isolated by reprecipitation according to a conventional method,
A white product of 40F was obtained. The number average molecular weight of the product is G
When calculated by PC, it is 61.0 in terms of polystyrene.
It was 00. The molecular weight distribution of the residue was 1.6.

When the product was dissolved in deuterated chloroform and its NMR spectrum was measured by 1H-NMR, it was found that 2 ions occupying equal areas on the spectrum were located at 1.9 ppm and 3.8 ppm.
absorption was observed. Regarding these absorptions, the latter can be attributed to the methine and methylene protons adjacent to oxygen, and the former to the other methine and methylene protons. ○ Make the product a tetrahydrofuran solution, and spread the solution on a Teflon sheet. When a film or sheet with a thickness of 8 μm was prepared and the infrared absorption spectrum was measured, it was found to be 2.3
-Same as in the case of dihydrofuran, wave number 91 Q cm-
Absorption due to -C-O-C- was observed at the positions "and 1060c+++-". The absorption due to the double bond observed at the 1630 cm-'' position in the case of 2,3-dihydrofuran disappeared.

These results indicate that the product is a polymer consisting of the following repeating units, and is obtained by polymerizing 2,3-dihydrofuran at its intracyclic double bond without opening its 5-membered ring. was confirmed.

The glass transition temperature of this polymer was 150°C.

Reference example 2 Reference example 11'C button 2,3-dihydrofuran 1002
By carrying out the polymerization reaction button and isolation operation in the same manner except that a mixture of 2,3-dihydrofuran 70f and 2,3-dihydro-2,2-dimethylfuran 302 was charged instead of 2,3-dihydrofuran 70f, a white product of 61F was obtained. I got something. IH of this
- As a result of NMR analysis, the product has the following repeating units ([I[) 68% by weight buttons and repeating units (fl/)
It was confirmed that the polymer consisted of 32% by weight.

The glass transition source of this polymer was [t/1162°C.

Example 1 The polymer synthesized in Reference Example 1 was heated to 100+1 at 280°C and 50Kf/- using a hot press molding machine (manufactured by Shinto Metal Industry Co., Ltd.).
IIX 1001DIX It was molded into a film with a size of 0.2 tll. This film had a smooth surface, a total light transmittance of 90%, and good transparency.

The physical properties of the obtained film are listed in Table 1.

Example 2 A polymer synthesized by a method similar to Reference Example 1 was produced using a film forming apparatus having a T-die with a slit width of 100III and a slit interval of 0.1, at a cylinder temperature of 280°C, an extrusion speed of Htsr, and a Extrusion molding was performed under the following conditions to obtain a film with a thickness of 50 μm.

The physical properties (flow direction of the resin) of the obtained film are listed in Table 1.

Example 3 The polymer synthesized in Reference Example 2 was molded using a hot press molding machine.
1001111 x 20 x 0.2 at 0℃, 50Kg/-
The physical properties of the obtained film are shown in Table 1.

Table 1 Example 1 5.2 220 8.1
90 Example 2 7.5 290
7.2 91 Example 3 3.3
230 4.8 90 Example 4 A polymer molded in the same manner as in Reference Example 1 was heated to 280°C in a hot press molding machine (manufactured by Shinto Metal Industry Co., Ltd.).

It was molded into a film with the size of 100 x 100,111 x 0.2 seagulls at 5 oKy/-. The obtained film was
2 at 160℃ using a mold biaxial stretching device (newly manufactured by Toyo Seiki Seisakusho).
Biaxial stretching was performed at a speed of 5 m/min to obtain a stretched film with a thickness of 48 μm. This film had a smooth surface, a total light transmittance of 91, and good transparency.

The tensile strength of the obtained film was 7.8 Kg/IIj, the tensile modulus was 320 Kg/-, and the elongation at break was 6.
．． It was 9%. Mechanical properties were measured in two directions perpendicular to each other, and they were almost the same. The tensile strength of the film before stretching was 5.2 Kg/txj.

Example 5 Stretching was carried out under the same conditions as in Example 4 except that the stretching ratio was changed to 1.5 times x 1.5 times.

The physical properties of the obtained film are summarized in Table 2.

Example 6 Stretching was carried out under the same conditions as in Example 4 except that the stretching ratio was changed to 4 times x 1 times. The physical properties of the obtained film are shown in Table 2.

Physical properties were measured in the stretching direction.

Example 7 Stretching was carried out under the same conditions as in Example 4 except that the stretching temperature was changed to 170°C and the stretching ratio was changed to 2.5 times x 2.5 times.

The physical properties of the obtained film are shown in Table 2.

Example 8 Stretching was carried out under the same conditions as in Example 4, except that the same polymer was used as in Reference Example 2, and the stretching temperature was changed to 172°C.

The physical properties of the obtained film are shown in Table 2.

The tensile strength of the film before stretching is 3.3 Kti.
/ It was a.

Example 9 A polymer prepared in the same manner as in Reference Column 1 was extruded using a film forming apparatus having a T-die with a width of 100 m and a slit interval of 0.1 mm, a cylinder temperature of 280°C, and an extrusion rate of 1 fl 5. Extrusion molded under f/min conditions to a thickness of 50
A μm film was obtained. Using the obtained film, stretching was carried out under the same conditions as in Example 4, except that the stretching ratio was changed to 3 times (in the flow direction of the resin) 01 times, and the thickness was 1
A stretched film of 5 μm was obtained.

The physical properties (flow direction of the resin) of the obtained film are listed in Table 2.

Table 2 Example 6 12.0 92 Example 7
8.7 92 Example 8
7.1 91 [Effects of the Invention] According to the invention, a film or sheet having excellent transparency and heat resistance and excellent mechanical properties is provided.

Claims (1)

[Claims] A repeating unit (I) whose main chain is substantially the following: ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R^1, R^2, R^3, R^ 4, R^5 and R^6 each represent a hydrogen atom or a lower alkyl group).