JP3124348B2 - Tetrafluoroethylene copolymer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to related to a melt-moldable tetrafluoroethylene copolymer.

[0002]

2. Description of the Related Art Polytetrafluoroethylene has excellent chemical resistance, heat resistance and electrical properties, but cannot be melt-molded.
Hexafluoropropylene copolymer (FEP) and tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA) have been developed and are commercially available. However, FEP and PFA have excellent mechanical properties at high temperatures, and particularly, resins having low elastic modulus and high elastic modulus at high temperature are desired.

Further, JP-A-1-131215 discloses a fluorinated thermoplastic polymer represented by the formula ( 1) or ( 2),
U.S. Pat. No. 3,978,030 discloses a polymer obtained by polymerizing a monomer represented by the formula ( 3).

[0004]

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[0005]

[0006]

These polymers are non-crystalline and have a high glass transition temperature, and have a high elastic modulus below the glass transition temperature. However , these polymers are polymers of special monomers and are economically disadvantageous.

Further, in JP-B 63-18964, tetrafluoroethylene and perfluoro (2,2-dimethyl
-1,3-dioxole), that is, both R ¹ and R ²
There is disclosed an amorphous copolymer with a monomer represented by the formula 3 which is a trifluoromethyl group (hereinafter abbreviated as PDD), but this copolymer has a lower glass transition temperature than a homopolymer of PDD. However, mechanical properties at high temperatures are reduced.

[0009]

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention shall be the object of providing excellent resin mechanical properties at high temperature has not been known to the new.

[0011]

Means for Solving the Problems The present invention includes a unit 95 to 99 mol% based on Te tetrafluoroethylene consists unit 1-5 mol% based on the monomer represented by the following formula (1), melt molding And the volume flow rate is 0.2-5
Provided is a tetrafluoroethylene copolymer having excellent mechanical properties at a high temperature of 0 mm ³ / sec . _{CF 2 = CFO (CF 2)} n CF = CF 2 (1) ( wherein, n represents an integer from 1 to 6.)

Radical polymerization is used as the polymerization method. That As the polymerization method, means as long as it proceeds radically is not limited by any means, for example, an organic radical initiator, inorganic radical initiator, light, ionizing radiation or the like thermal polymerization. As the method of radical polymerization, bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization can be used. The molecular weight can be controlled by the monomer concentration, temperature, initiator concentration, chain transfer agent concentration, and the like.

The polymerization composition of the copolymer can be controlled by the proportion of each monomer charged. CF ₂ in the copolymer of the present invention
= Amount of _{CFO (CF 2) n CF =} CF 2 in based units is 1 to 5 mol%. If it is less than 1 mol%, the melt formability is poor, and if it exceeds 5 mol%, the crystallinity is reduced and the mechanical properties at high temperatures are reduced.

The volume flow rate is an index of melt moldability, and is 0.2 to 50 mm ³ / sec . 0.2 mm ³ / sec Not <br/> Mitsurude has poor moldability, mechanical characteristics is lowered by 50 mm ³ / sec greater. The volume flow rate in the present specification was measured by using a high flow type flow tester manufactured by Shimadzu Corporation, placing the copolymer in a cylinder having an inner diameter of 9.5 mm, maintaining the temperature at 380 ° C. for 5 minutes, and then applying a 7 kg piston load. Inner diameter 2.1mm,
It is extruded through an orifice having a length of 8 mm and the extrusion speed (mm ³ / sec) at this time.

[0015] One or more copolymerizable monomers
May be copolymerized within a range not exceeding 5 mol%.Can
You.

[0016]

Example 1 An autoclave equipped with a stirrer having an internal volume of 1200 ml was degassed, and 1,440 g of 1,1,2-trichloro-1,2,2-trifluoroethane (hereinafter abbreviated as R113 ) was used.
0.9 g of methanol, CF ₂ ＣＦCFO (CF ₂ ) ₂ CF
= CF ₂ (hereinafter, abbreviated as BVE.) 44.4 g, tetrafluoroethylene (hereinafter referred to as TFE.) 7
8 g was charged, the temperature was raised to 50 ° C., and 1 ml of a 1% R113 solution of bis (perfluorobutanoyl) peroxide was added to initiate polymerization. An additional charge of TFE was made to keep the pressure constant. Further, 5.5% by weight of BVE was additionally charged with respect to the added amount of TFE. 0.5 ml each of 1% R113 solution of bis (perfluorobutanoyl) peroxide was added 10 minutes and 20 minutes after the start of polymerization, 1 ml each, 40 minutes, 60 minutes, 70 minutes, and 100 minutes.
After a total of 4 ml, the mixture was charged. 82 additional TFE charge
When the amount reached g, the polymerization was stopped. The polymerization time was 3 hours.

The slurry-like copolymer obtained was R113
And dried at 100 ° C. for 10 hours to obtain 87.6 g of a copolymer. The composition of this copolymer was obtained by X-ray fluorescence analysis of oxygen, and the ratio of units based on TFE / units based on BVE was 98.5 / 1.5 (molar ratio). The volume flow rate was 2.6 mm ³ / sec. The tensile rupture strength at 200 ° C. is 131 kg / cm ² , and the dynamic elastic modulus at 200 ° C. measured by a dynamic viscoelasticity measuring device (Leo Vibron DDV, manufactured by Toyo Baldwin) is 7.0 × 10 ⁷ dy.
n / cm ² .

Examples 2 to 4 and Comparative Examples 1 to 4 Polymerization was carried out by the polymerization method of Example 1 except that only the charged amounts were changed as shown in Table 1. Table 2 shows the physical properties of the obtained copolymer. It was found that the copolymer of the present invention had a high tensile strength at break at 200 ° C. and a high dynamic modulus at 200 ° C.

[0019]

[Table 1]

[0020]

[Table 2]

[0021]

Industrial Applicability The tetrafluoroethylene copolymer of the present invention has excellent mechanical properties at high temperatures and can be used as a molded article, a film, a sheet, a lining and a wire covering material used at high temperatures.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08F 214/26 C08F 216/12-216/20

Claims (1)

(57) [Claims] 1. Unit 95 based on tetrafluoroethylene
And 99 mol% consists of units 1-5 mol% based on the monomer represented by the following formula (1), is capable of melt molding, volume flow rate is 0.2 to 50 mm ³ / sec, the hot so
A tetrafluoroethylene copolymer having excellent mechanical properties . _{CF 2 = CFO (CF 2)} n CF = CF 2 (1) ( wherein, n represents an integer from 1 to 6.)