JPH024711B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION When performing graft polymerization by chemically bonding a vinyl compound to a functional group of a fiber by the action of radiation, the presence of oxygen in the air poses a major obstacle. In such cases, it is common to exclude air and perform the process in a nitrogen stream.

The present invention uses an oxygen absorbent to extremely reduce the oxygen concentration in a sealed container without replacing inert gas such as nitrogen with air, and uses various fibers and vinyl materials in a deoxygenated state. This is a method of promoting graft polymerization with a compound.

In other words, various types of fibers are impregnated with a vinyl compound in an amount that matches the processing purpose, deliquified and dried, and then either a container with extremely low air permeability or a container with poor air permeability (sheet-like various synthetic The amount of oxygen in the container is extremely reduced (at least
(300 ppm or less) Next, the oxygen absorber is removed from the container or is still sealed and irradiated with radiation to cause polymerization.

Conventionally, when processing with beta rays such as electron beams, it is continuous radiation processing in which the radiation source is fixed and the irradiated object is moved, so nitrogen gas is continuously flowed into the irradiated area and air is This method requires a large amount of inert gas, which makes it difficult to adjust the operation and is a major factor in increasing processing costs.

Furthermore, in the case of machining with gamma rays such as cobalt 60, a rotary machining method is required, which requires a complicated operation to flow inert gas into the irradiated object in a closed container and replace it with oxygen. Moreover, it is inefficient, and there are many restrictions on the shape and size of the fibers to be processed, resulting in high processing costs.

A major feature of the present invention is that deoxygenation can be carried out quickly, easily, and inexpensively by omitting the above-mentioned operation of replacing the gas with an inert gas and by using an oxygen absorbent.

In this method, the polymerization reaction can be started by simply preparing an air-blocking container and an appropriate amount of oxygen absorbent, making the operation extremely simple. In addition, since the amount of oxygen can be reduced as much as possible using an oxygen absorber, the graft polymerization between the fiber and the vinyl compound can be carried out more efficiently compared to the conventional method of replacing inert gas with air. Grafting efficiency has also been significantly increased, making it possible to save on processing agents and irradiation doses.

In this method, similar effects can be obtained by performing graft polymerization reactions of various polymer compounds on natural polymers such as paper, wood, and leather in addition to fibers.

The contents will be explained below using several examples of rot processing using gamma rays.

Example 1 Flame-retardant processing of cotton and polyester fibers Cotton and polyester fibers were impregnated with a 30% aqueous solution of vinyl phosphonate oligomer, dehydrated, dried, and then laminated with vinyl chloride and polyamide to produce a film with extremely low air permeability. Place it in a bag, seal it with an appropriate amount of oxygen absorber, and after 24 hours have elapsed, the internal oxygen content will be reduced to 100 ppm or less, and gamma rays will be irradiated at 1 Mrad for cotton and 2 Mrad for polyester fiber. , it was possible to perform graft polymerization of 17% or more based on the weight of the fiber. As a result, we were able to confirm the flame retardant effect with a limit oxygen index of 27%, which is a flame retardant evaluation index. This shows excellent flame retardancy, with the treated fabric showing no self-combustibility at all when it is separated from the flame, although it actually carbonizes when exposed to the flame.

Example 2 Flame retardant treatment of wool Wool was impregnated with a 10% aqueous solution of vinylphosphonate oligomer, dehydrated and dried, and then irradiated with 1 Mrad of gamma rays in the same manner as in Example 1. As a result, a flame retardant effect with an oxygen index of 28% or more was observed.

Example 3 Hydrophilic processing of polyester fibers Polyester fibers were impregnated with acrylamide, dehydrated, dried, and then irradiated with 2 Mrad gamma rays in the same manner as in Example 1. As a result, the moisture absorption rate was 7
% results were obtained. This had a moisture absorption rate comparable to that of unprocessed cotton.

Example 4 Antistatic processing of polyester fibers Polyester fibers were impregnated with a 5% aqueous solution of polyethylene glycol diacrylate, drained, dried, and then exposed to gamma rays in the same manner as in Example 1.
It was irradiated with 2 Mrad. As a result, a triboelectrostatic voltage of 600 volts was obtained with a processing amount of about 2% grafting rate based on the fiber weight. Note that this is the triboelectric voltage
The equivalent of raw cotton was 650 volts, while polyester fiber was 6000 volts.

Example 5 Meltproof processing of polyester fibers and nylon fibers Polyester fibers and nylon fibers were impregnated with acrylic acid, dehydrated and dried, and then irradiated with 2 Mrad gamma rays in the same manner as in Example 1. After irradiation, the fibers were soaped to remove unfixed materials, and then treated with an aqueous solution of sodium bicarbonate to convert the vinyl acid polymer on the fibers into Na salt. As a result, an excellent anti-melting effect was found on unprocessed fibers.

Example 6 Silk bulking process Silk was impregnated with a 40% aqueous solution of methacrylamide, dehydrated and dried, and then irradiated with gamma rays at 1 Mrad in the same manner as in Example 1. After irradiation, a soaping treatment was performed to remove unreacted substances. As a result, a graft ratio of 30% was obtained relative to the fiber weight.

As shown in the examples above, various fibers are impregnated with an aqueous solution of a vinyl compound, dehydrated and dried, and then placed in a container with extremely low air permeability or a container with low air permeability along with an oxygen absorber. By enclosing the container, the amount of oxygen in the container is extremely reduced without replacing the air with an inert gas such as nitrogen, and the amount of oxygen in the container is irradiated, making it durable for various fibers. We have invented a method for carrying out various modification processes.

Claims (1)

[Claims] 1. After impregnating various types of fibers with vinyl compounds, they are sealed together with oxygen absorbers in containers with extremely low or poor air permeability, and graft polymerization is carried out using radiation in deoxidized conditions to ensure durability. A method of performing various modification processes that are rich in properties.