| 摘要 |
PROBLEM TO BE SOLVED: To provide a bearing with high safety without using lead or lead compound by a composite material laminating modified fluororesin of specified crystallization calorific value and fusing point on a reinforcing layer. SOLUTION: Modified fluororesin having crystallization calorific value of 40 J/g or below and a fusing point of 325 deg.C or below can be obtained by irradiating ionizing radial rays in a range of quantity of radiation 1 KGY to 10 MGY on fluororesin selected among tetrafluoroethylene polymer 'PTFE', tetrafluoroethylene - parfluoro copolymer 'PFA' and tetrafluoroethylene - hexafluoropropylene copolymer 'FEP' under inactive gas atmosphere having oxygen density of 100 Torr or below, preferably, 10 Torr below, in a state that fluororesin is heated at the fusing point or more. The crystallization calorific value of modified fluororesin and the fusing point are stipulated as 40 J/g or below and 325 deg.C, respectively, because wear resistance and creep resistance are remarkably lowered when the crystallization calorific value and the fusing point exceed the above values.
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