JPH05125251A - Heat-and radiation-resistant composition - Google Patents

Abstract

PURPOSE:To obtain the title compsn. which is flexible, excellent in radiation resistance, and useful as an insulating material for a wire or cable used in a fast breeder reactor. CONSTITUTION:The title compsn. is prepd. by mixing at least one resin selected from the group consisting of polyetheretherketone, polyetherimide, thermoplastic polyimide, and polyethersulfone with a water-cross-linkable silylated olefin polymer in a wt. ratio of 3:7-7:3.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a heat-resistant and radiation-resistant composition having improved flexibility.

[0002]

2. Description of the Related Art Recently, in nuclear power plants, conversion to new power reactors such as fast breeder reactors has been rapidly promoted for the purpose of improving energy utilization efficiency. The demand for electric wires and cables used below is increasing.

Further, construction of nuclear fuel cycle related facilities such as spent nuclear fuel reprocessing facility is also active, and high temperature,
There is an increasing demand for electric wires and cables that can withstand high radiation.

By the way, many electric wires and cables used in the above facilities are required to have flexibility such as cables for manipulators.

However, conventionally known heat- and radiation-resistant wires and cables use an aromatic polymer represented by a polyimide resin as an insulating coating material, and the aromatic polymer is extremely hard. However, it was difficult to apply it to applications requiring flexibility.

On the other hand, polyethylene and polyurethane are known as relatively flexible materials, but these materials are difficult to use in a severe radiation environment and 1M
There is a problem that crosslinking progresses and becomes hard even when irradiated with radiation of Gy level, and further, heat resistance is insufficient, so that it is difficult to use for the above-mentioned applications.

Therefore, it has been considered to add flexibility by blending an aromatic polymer having excellent heat resistance and radiation resistance with a relatively soft polymer such as polyethylene, but it is not flexible. Although improved, there was a problem that the softening point was lowered and the heat distortion resistance and creep resistance were impaired.

[0008]

As described above, with the rapid increase in the construction of fast breeder reactors, spent nuclear fuel reprocessing facilities and the like, electric wires with excellent heat resistance and radiation resistance and good flexibility are also provided. -The demand for the development of insulation coating materials for cables is increasing, but the reality is that materials with such characteristics have not yet been obtained.

The present invention has been made in response to the problems of the prior art as described above.
It is an object of the present invention to provide a heat-resistant and radiation-resistant composition which is useful as a material for insulating coatings of cables, has excellent heat resistance and radiation resistance, and has good flexibility.

[0010]

Means for Solving the Problems As a result of intensive studies to obtain such a heat-resistant and radiation-resistant composition, the present inventors have found that polyetheretherketone, polyetherimide, thermoplastic polyimide and polyether monkey. It has been found that the above object can be achieved by compounding at least one selected from the group of phonons with a hydrolyzable silyl-modified olefin polymer at an appropriate ratio, and completed the present invention.

That is, the heat-resistant and radiation-resistant composition of the present invention comprises (A) polyetheretherketone (hereinafter PE).
EK), polyetherimide (hereinafter referred to as PEI), thermoplastic polyimide (hereinafter referred to as TPI), and polyether sulfone (hereinafter referred to as PES), and one or more kinds ( B) Hydrolyzable silyl-modified olefin polymer is mixed in a weight ratio of 3: 7 to 7: 3.

Component (A) PEE used in the present invention
K, PEI, TPI and PES are in the order of (I) to
A crystalline or amorphous thermoplastic resin having a molecular structure as shown in formula (IV), both of which have excellent heat resistance and radiation resistance, and also excellent flame retardancy. .. Examples of commercially available products include VICTREX manufactured by ICI Japan as PEEK and GE Plastics Japa as PEI.
Ultem manufactured by n company and TPI manufactured by Mitsui Toatsu Chemicals, Inc.
Examples of ew-TPI and PES include VICTREXPES manufactured by ICI (all above are trade names).

[0013]

[Chemical 1]

The silyl-modified olefin polymer as the component (B) used in the present invention is polyethylene, polypropylene, ethylene / propylene copolymer, ethylene / propylene / silicone copolymer, ethylene / ethyl acrylate copolymer, An ethylene-vinyl acetate copolymer or the like grafted with a trialkoxysilane such as vinyltrimethoxysilane. The polymer component and the graft component are combined with a radical generator such as dicumyl peroxide in an extruder. It can be obtained by supplying and heating and kneading at an appropriate temperature. Such a silyl-modified olefin-based polymer is rapidly cross-linked by a silanol condensation catalyst such as dibutyltin dilaurate in the presence of water.

In the present invention, one or more of the above silyl-modified olefin-based polymers can be arbitrarily selected and used.

In the present invention, the silyl-modified olefin polymer as the component (B) and the PEE as the component (A) are used.
The mixing ratio with one or more of K, PEI, TPI and PES is in the range of 3: 7 to 7: 3 by weight. If the mixing ratio is out of this range, the characteristics of both components are out of balance, and the effect of mixing cannot be obtained.

The composition of the present invention may contain, if necessary, antioxidants, ultraviolet absorbers, plasticizers, lubricants, pigments and other additives as long as the effects of the present invention are not impaired. ..

The composition of the present invention is obtained by uniformly mixing the above-mentioned components using a conventional kneading machine such as a twin-screw kneading extruder.
A silanol condensation catalyst such as dibutyltin dilaurate that promotes the hydrocrosslinking of the silyl-modified olefin-based polymer is added and mixed in a usual range, and molded by a general plastic molding method such as injection molding or extrusion molding, and finally. By hydrolyzing the silyl-modified olefin-based polymer, a desired molded article having excellent heat resistance and radiation resistance, good flexibility, and excellent flame retardancy can be obtained. ..

Therefore, the composition of the present invention can be widely used for various applications in which the above-mentioned characteristics are required, including applications as an insulating coating material for various electric wires and cables used in fast breeder reactors and the like.

[0020]

As described above, in the heat and radiation resistant composition of the present invention, PEEK, PEI and T excellent in heat resistance and radiation resistance are provided.
At least one selected from the group consisting of PI and PES was mixed with a hydrolyzable silyl-modified olefin polymer, which is flexible and finally crosslinked to improve heat distortion resistance and creep resistance, in a specific ratio. As a result, the flexibility of the saturated styrene / isoprene thermoplastic elastomer is imparted without impairing the heat resistance, radiation resistance, and other characteristics of PEEK, resulting in good heat resistance and radiation resistance. It also has excellent flexibility and flame retardancy.

In addition, since it can be handled in the same manner as a general resin composition at the time of mixing and molding, it has the above-mentioned characteristics including the use as an insulating coating material for electric wires and cables used in a fast breeder furnace. It can be widely used for required applications.

[0022]

EXAMPLES Examples of the present invention will be described below. In addition, all "parts" in the following sentences shall show "weight part." The silyl-modified olefin polymer used in the examples is as follows.

Silyl-modified low-density polyethylene (hereinafter abbreviated as silyl-modified LDPE): NUC 9025 (trade name of low-density polyethylene manufactured by Nippon Unicar Co., Ltd.) 100 parts, vinyltrimethoxysilane 2 parts, dicumyl peroxide 0.3 parts are reserved. After mixing, the mixture is fed to an extruder and kneaded by heating at 200 ° C. Silyl-modified ethylene / propylene copolymer (hereinafter abbreviated as silyl-modified EP): EP51 (trade name of ethylene / propylene copolymer manufactured by Nippon Synthetic Rubber Co., Ltd.) 100 Parts, 2.5 parts of vinyltrimethoxysilane and 0.5 parts of dicumyl peroxide are premixed, then fed to an extruder and kneaded by heating at 200 ° C. Silyl-modified ethylene / propylene / silicone copolymer (hereinafter abbreviated as silyl-modified EPS) : SEP (Ethylene
100 parts of propylene / silicone copolymer (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), 2.5 parts of vinyltrimethoxysilane, and 0.5 parts of dicumyl peroxide are premixed, and then supplied to an extruder and heated and kneaded at 200 ° C. Examples 1 to 1 8 Each of the above silyl-modified olefin-based polymers and PEEK
PEEK Natural (trade name of Mitsui Toatsu Chemicals, Inc.), PEI
Ultem 4000, TPI New-TPI, PES VICTREX PE
S and S were supplied to the hopper of a twin-screw kneading extruder (screw diameter 35 mm) with the composition shown in Table 1, and the cylinder temperature was 300 to 35.
The mixture was heated and kneaded at 0 ° C., extruded, and then cut to obtain a compound chip.

Then, the obtained compound chip 100
Then, 0.1 part of dibutyltin dilaurate (DBTDL) was added to the parts and premixed, and then the mixture was supplied to an extruder and extrusion-molded into a predetermined shape, and allowed to stand as it was to crosslink the silyl-modified olefin-based polymer to prepare a sample. Subsequently, the bending elasticity, heat distortion resistance, and radiation resistance of these samples were evaluated, and the results shown in Table 1 were obtained. In each property evaluation, the bending elasticity is the bending elastic modulus measured by the test based on ASTM D790, and the heat distortion resistance is ASTM D.
The heat distortion temperature measured by the test based on 648, and the radiation resistance was evaluated by the elongation residual ratio after γ-ray 6 MGy irradiation.

For comparison, the PEEK, PEI, TPI and PES used in the above examples were evaluated for the same characteristics as in the examples. These results are shown in Table 2 as Comparative Examples 1 to 4, respectively. Further, instead of the silyl-modified olefin-based polymer in the case of the examples, each olefin-based polymer that is not silyl-modified, that is, NUC 9025 of low density polyethylene (LDPE), EP51 of ethylene-propylene copolymer (EP), or ethylene. The compound chips produced by using SEP of propylene / silicone copolymer (EPS) in the same manner as in the example were evaluated for the same characteristics as in the example. These results are shown in Comparative Examples 5-1.
1 is also shown in Table 2. For Comparative Example 9,
This is an evaluation of a compound chip obtained by adding and mixing butyltin dilaurate to a compound chip in the same manner as in the example.

[0026]

[Table 1]

[0027]

[Table 2]

As is clear from the above tables, the composition according to the present invention contains PEEK, PEI, TPI and PE.
Compared with the case where each S was used alone (Comparative Examples 1 to 4), the heat distortion resistance was slightly reduced, but the flexibility was much improved, and when an olefin polymer that did not undergo silyl modification was blended (Comparative Examples). Compared to 5-11), the heat distortion resistance is significantly improved.

[0029]

As described above, the heat and radiation resistant composition of the present invention is a PEE excellent in heat resistance and radiation resistance.
A hydro-crosslinkable silyl-modified olefin-based polymer that is flexible and finally cross-linked to improve heat distortion resistance and creep resistance is added to one or more selected from the group consisting of K, PEI, TPI and PES. Since they are mixed in a ratio, they have good heat resistance and radiation resistance, and also have excellent flexibility. Therefore, the composition of the present invention is useful in a wide variety of applications where the above-mentioned properties are required, including an insulating coating material for cables for manipulators used in fast breeder reactors, reprocessing facilities for spent nuclear fuel, and the like. ..

Claims (1)

[Claims] 1. At least one selected from the group consisting of (A) polyetheretherketone, polyetherimide, thermoplastic polyimide, and polyethersulfone, and (B) a hydrolyzable silyl-modified olefin polymer. A heat-resistant and radiation-resistant composition, characterized by being mixed in a weight ratio of 3: 7 to 7: 3.