HU180992B - Process for the modification of polyamide and polyester fibrous materials - Google Patents

Abstract

A process for modifying high polymers, in particular fibrous high polymers, by radiation-chemical graft polymerization of one or more polymerizable compounds, characterized in that a high polymer contacted with a polymerizable compound at temperatures from above the glass transition point of the high polymer to the boiling point of the polymerizable compound intensively squeezed and irradiated at tree temperatures. 2. The method according to claim 1, characterized in that the polymerizable compound is briefly heated to the contacting temperature. 3. The method according to claim 1 and 2, characterized in that the high polymer is sprayed with the heated contacting agent.

Description

The present invention relates to a process for the modification of polyamide and polyester fiber materials by means of a radiochemical graft polymerization with a polymerizable compound.

A process for modifying synthetic condensation polymers such as polyesters is known in which synthetic condensation polymers are contacted with low molecular weight unsaturated polymerizable compounds such as acrylic acid or maleic acid and subjected to ionizing radiation. The disadvantage of the process is that a long impregnation time is required to achieve the required weight gain and that a large amount of homopolymer is formed in the presence of small molecule unsaturated polymerizable compounds upon irradiation of the material to be modified.

In addition, there is known a process for improving graft polymerization or graft copolymerization activated by energy-rich ionizing radiation, wherein the grafting rate is increased by heating the polymer to be treated with a polymerizable compound, such as itaconic acid, to a reaction temperature of glass. The disadvantage of the process is that the accelerating effect of temperature rise in graft polymerization can only be exploited within the glass transition temperature range, since at higher temperatures, the free radicals formed by ionizing radiation in the polymer due to micro-Brownian motion have a very short lifetime. they cannot initiate polymerization. As a result, the grafting rate is reduced and a relatively large number of homopolymers are formed, making the process uneconomical and difficult to control (British Patent No. 820 120 5, German Patent Publication No. 1,145,135).

It has also been proposed to prevent homopolymer formation by keeping the polymer 10, such as polyamide or polyester, and unsaturated compounds, such as acrylic acid, at elevated temperatures for a short period of time and removing the homopolymers between reaction steps. The disadvantage of the process is that it is complicated and requires special equipment (Swiss Patent No. 533,200).

It was also suggested that the impregnation process and the radiation be performed separately. However, this method is only feasible if the swelling materials are used in the impregnation process (German Patent No. 101,710).

The object of the present invention is to eliminate the formation of large amounts of interfering homopolymers and to set up economical operating parameters.

It is an object of the present invention to reduce the reaction time during the modification of polyamide and polyester fiber materials. According to the invention, the polymeric fibrous material is contacted with a 5 to 25% aqueous solution of acrylic acid, methacrylic acid or ma 30 leic anhydride.

1180992 at a temperature greater than the glass transition point of the polymer to the boiling point of the polymerizable compound, the resulting product is evaporated off and irradiated with 1 to 5 Mrad doses of accelerated electrons at room temperature.

The invention is illustrated by the following examples:

Example 1

The polyamide chain loop fabric weighing 70 g / m ² surface area was impregnated with 8% aqueous acrylic acid solution at 90 ° C for 30 seconds, then spun out with 70% juicing and irradiated with electron accelerator head (Scanner) up to 1 Mrad dose, weight gain of 9% based on weight of starting material. Alternatively, methacrylic acid may be used instead of acrylic acid. Irradiation can be performed up to 5 Mrad doses.

Example 2.

V

A circular polyester web weighing 150 g / m ^{2 was} sprayed with a 20% aqueous solution of maleic anhydride at 90 ° C and finally evaporated.

Spraying and juicing are repeated six times in succession. The contact time is less than 1 minute. The material is irradiated with accelerated electrons up to 2 Mrad ⁵ doses. Weight gain after radiation is 14%.

Claims (1)

A process for modifying polyamide and polyester fiber materials by radiochemical graft polymerization with a polymerizable compound comprising contacting the polymer to be modified with a 5-25% aqueous solution of acrylic acid, methacrylic acid or maleic anhydride at a temperature greater than the point of glass transition of the polymer at room temperature, the product thus obtained is spun off and irradiated with electrons at a temperature of 1 to 5 Mrad at room temperature.