JPS6017446B2 - Radiation resistant resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin composition with improved radiation resistance.

Wires, cables, and various equipment used in nuclear reactors, breeder reactors, ionizing radiation generators, etc. are often constantly exposed to a considerable amount of radiation; therefore, insulating materials for covering electric wires and cables for such purposes, Resin compositions used for insulating materials, packing, sealing materials, frames, hose materials, etc. in various types of equipment are required to have a high degree of radiation resistance from economic and safety standpoints.

As a result of intensive studies on improving the radiation resistance of thermoplastic resins and rubbers, the inventors have found that thermoplastic resins or rubbers have the following general formula C.

This invention was completed by discovering that a resin or rubber molded product with excellent radiation resistance can be obtained by using a polymer of acenaphthylene genide, a hydroperoxide polymerization initiator, and an appropriate amount of an organic peroxide in combination. It is. That is, the present invention provides a base polymer 1 such as a thermoplastic resin or rubber.
0 part by weight, the general formula (where X is hydrogen, chlorine or bromine atom, Y is chlorine or bromine atom, m is 2 to 6
, R is a substituent other than a halogen atom, n is an integer of 0 to 4, and when n is 2 or more, R may be the same or different, halogen whose constituent elements are units represented by m+nmi6) at least 0.5 part by weight of one or more polymers of acenaphthylene, 0.2 to 1 part by weight of a hydroperoxide polymerization initiator, and 0.5 to 1 part by weight of an organic peroxide. This radiation-resistant resin composition is characterized in that it contains parts by weight of

Although the reason why the composition according to the present invention is able to exhibit the excellent radiation resistance as described above is not necessarily clear, it is possible to The presence of the polymerization initiator significantly accelerates the condensation polymerization or graft polymerization of the halogenated acenaphthylene polymer blended into the composition, and also controls the crosslinking of the base polymer appropriately, which is preferable. It is believed that this will bring about results.

Examples of thermoplastic resins and rubbers used as the base polymer in this invention include polyethylene, polypropylene, polybutene, ethylene-pynylacetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-propylene copolymer, and ethylene-propylene. -gen copolymer, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate-
Grafted vinyl chloride copolymer, ethylene-ethyl acrylate grafted vinyl chloride copolymer, ethylene-propylene-grafted vinyl chloride copolymer, chlorinated polyethylene, chlorinated polyethylene-grafted vinyl chloride copolymer, polyurethane, polyamide, Polyester, acrylic resin, butyl rubber, chloroprene rubber, nitrile rubber, natural rubber, silicone rubber, chlorosulfonated polyethylene, styrene-butadiene rubber, styrene-butadiene-acrylonitrile copolymer, acrylonitrile-styrene copolymer, polyester-ether Examples include Last Man.

Next, the term halogenated acenaphthylene multimer as used in the present invention means that halogenated acenaphthylene is formally dehydrogenated, and is integrated by dehydrohalogenation reaction to form a multimer with a degree of condensation of 2 or more. refers to something that

Bonding points between acenaphthylene structural units include, for example,
1 (or 2), (or 2), 4' (or 4, 7', 7, 7') 4, 5' (or 4, 6', 5, 7') 5, which are easily formed. Examples include 5 (or 5, 6'), but also 1, 1'-, 1, 2-, 1 (or 2),
3'-, 1 (or 2), 4'-, 1 (or 2), 7'-, 1
(or 2), 8'-, 3, 3'-1, 3, 4'-, 3, 5'
-, 3,6'-, 3,7'-, 3,8'-, 4,8'-
combinations such as 5,5' and 6,6', 4,7'
It is also possible to condense via two bonds such as and 6,6'.

Those having a degree of condensation of 3 or more are those in which the number of constituent units is increased by any of these bonds. If the upper limit of the degree of condensation is 10 or more, the dispersibility in the composition will be significantly reduced and the effect of blending will be reduced, so it is preferable that such a condensate is It can be synthesized by introducing a halogen and then taking advantage of its high reactivity and treating it in the presence of a catalyst. The compatibility between these halogenated acenaphthylene polymers and polymeric substances is particularly good even without substituents, but it is improved by further introducing methyl groups, methoxy groups, methyl ester groups, etc.

As a result, it is recognized that it has good workability during cross-wire molding, and that it does not cause shine or bleed when molded products are used for long periods of time at high temperatures.
However, substituents with an excessively large number of carbon atoms are difficult to synthesize, and long-chain alkyl groups need to be avoided because they reduce radiation resistance. Examples of substituents introduced for this purpose include alkyl groups having 1 to 4 carbon atoms, alkoxy groups, and alkyl ester groups. In order to exhibit the effects of the present invention, it is necessary to use at least 0.5 parts by weight of the compound based on 100 parts by weight of the base polymer made of the above-mentioned resin or rubber. Next, hydroperoxide polymerization initiators used in this invention include t-butyl hydroperoxide, diisopropylbenzene hydride 0/gu oxide, cumene hydride 0/gu oxide, etc. 0.2 to 1 part by weight of the base polymer 10
The reason why the amount is limited to 0 parts by weight is that below the lower limit, the effect of the present invention will be insufficient, and even if the upper limit is exceeded, the effect of increasing the amount will hardly be observed.

Further, as the organic peroxide used in this invention, dicumyl peroxide, 1,3-bis(t-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5
-di(t-butylperoxy)hexine-3, t-butylcumyl peroxide, etc., and the reason why the blending amount was similarly limited to 0.5 to 10 parts by weight is that it is below the lower limit. This is because the crosslinking effect of the base polymer will be insufficient, and if the upper limit is exceeded, the effect of increasing the amount will hardly be observed.

The composition of this invention may be added with appropriate reinforcing properties, fillers, pigments, solvents, vulcanizing agents, crosslinking aids, heat, light stabilizers, etc., depending on its intended use. There is no problem in adding an appropriate amount as long as it does not cause any deterioration.

As is clear from the examples below, the composition of the present invention has significantly improved radiation resistance, and has great industrial value.

The present invention will be specifically explained below with reference to Examples.

Production example 1 of a multimer of halogenated acenaphthylene A solution of 4 moles of 1,2,3,5-tetrabromoacenaphthene (C, 2 days 6 BL) in benzene (500 grams), 2 moles of potassium bromide, and 0.2 moles of potassium bromate. 2 molar aqueous solution (60
0 was taken into a trill flask and mixed violently in the room.

To this, dilute 2 moles of concentrated sulfuric acid with the same volume of water, add 1
It was added dropwise at around 0qo and reacted for 3 hours. After the reaction was completed, the benzene layer was washed with water, an aqueous solution of caustic soda (2%), and water again in this order, and dried with silica gel. Next, transfer the dry benzene solution to the Sanllo flask, and add about 2
A warm ethanol solution in which molar amounts of potassium hydroxide had been dissolved was added dropwise to carry out a dehydrobromation reaction. After the reaction was completed, the benzene layer was washed with water and dried. Furthermore, benzene was distilled off under reduced pressure, and the residue was thoroughly washed and dried with hot acetone to obtain a condensate of bromoacenaphthylene. The compositional formula estimated from the elemental analysis values of the condensate was (C, 2days 3.7Br2.9).

The main components were those with a condensation degree of 2 to 5 as determined by GPC measurement. Example 2 A catalytic amount of stannic chloride was added to a chloroform solution of 1,2,3,5-tetrabromoacenaphthene and gently boiled and refluxed for about 3 hours.

After the reaction was completed, the mixture was washed with water, dried, and chloroform was distilled off.
Next, the residue was dissolved in benzene, and a dehydrobromination reaction was carried out in the same manner as in Example 1. The benzene layer was washed with water, dried, and then the benzene was removed and thoroughly washed with hot acetone. The compositional formula of the obtained condensate of bromoacenaphthylene was (C, 2nd day 4., B et al. 3), and the degree of condensation as determined by GPC measurement was 2 to 7 as the main component. Example 3 154 ml of acenaphthene was dissolved in about 340 ml of carbon tetrachloride and 1 ml of ferric chloride was added while maintaining the temperature at 0.000 ml.

Bromine 96 diluted with carbon tetrachloride while holding the light well
M was added dropwise. After the completion of the dropping, the reaction system was heated to 45 to 55°C,
The reaction was completed. Next, the catalyst was filtered off, the solution was washed with water, and carbon tetrachloride was distilled off to obtain an intermediate bromoacenaphthene condensate. Next, in the same manner as in Example 1, the bromoacenaphthene condensate was subjected to dehydrobromination reaction. The benzene layer was washed with water, dried, and then benzene was distilled off and thoroughly washed with hot acetone. Obtained bu. The composition formula of moacenaphthylene condensate is (C, 2 days, .7Br3.8)
As a result of GPC measurement, the main component was found to have a degree of condensation of 2 to 3. Examples 1 to 3 and Comparative Examples 1 to 3 Compounding agents were added to the ethylene propylene copolymer so as to have the composition shown in Table 1, and these were thoroughly kneaded with a heating roll. The resulting mixture was heated to 160 qo. A sheet of 2 sails and 3 skin thickness was produced by press molding for 306 minutes.

For each sheet obtained, initial mechanical properties, properties after irradiation with 100 MMd of Y-rays, and oxygen index according to JIS K7201 were measured and shown in the table.

As is clear from the table, when a molded composition containing a bromoacenaphthylene polymer is subjected to free radical generation treatment,
It is clear that the combination of a hydroperoxide polymerization initiator and an organic peroxide can impart excellent radiation resistance and flame retardancy. Furthermore, as shown in Example 3, if a flame auxiliary agent is further added, even better flame retardance can be achieved.

Table 1 *1: Propylene content 40% by weight *2: Manufactured by Ouchi Shinko ■, 2,2,4-trimethyl-1,
2-dihydroquinoline copolymer Examples 4 to 5 and Comparative Examples 4 to 5 Adding ingredients to polyethylene so as to have the composition shown in Table 2, and mixing these well with a heating roll, the resulting compositions was press-molded at 160qC for 30 minutes to create sheets with one side and three ribs.

The initial mechanical properties, properties after 100 Mrad y-ray irradiation, and oxygen index were measured for each of the obtained sheets, which are shown in the same table.

Table 2 *1: Density 0.920 MII. 0 *2: Manufactured by Shinko Ouchi, 4,4'-thiopis (6-t-butyl-3-methylphenol) Examples 6-7 and Comparative Examples 6-7.

Compounding agents were added to Loprene rubber to give the composition shown in Table 3, and these were thoroughly kneaded using heated rolls. The resulting mixture was press-molded at 160°C for 20 minutes to form 2- and 3-thickness sheets. Created. The initial mechanical properties, properties and oxygen index after irradiation with y-rays and 10 yen ad were measured for each of the obtained sheets, which are shown in the same table. Table 3 As is clear from the Examples above, the resin composition of the present invention has excellent radiation resistance and is particularly suitable as a coating material for articles etc. exposed to radiation.

Claims (1)

[Claims] 1. Base polymer 10 such as thermoplastic resin or rubber.
For 0 parts by weight, there are general formulas ▲ mathematical formulas, chemical formulas, tables, etc. ▼ (However, in the formula, An integer of 2 to 6, R is a substituent other than a halogen atom, n is an integer of 0 to 4, when n is 2 or more, R may be the same or different, m+n≦6) as a constituent element of at least 0.5 halogenated acenaphthylene polymers
Weight part and hydroperoxide polymerization initiator 0.2~
10 parts by weight of a radiation-resistant resin composition, and 0.5 to 10 parts by weight of an organic peroxide.