JPS6354014B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color-fast polyolefin composition, and more particularly to a polyolefin composition that prevents discoloration or coloring of polyolefin molded articles such as polyolefin fibers and improves heat resistance. Polyolefins are generally molded at high temperatures above their melting point, but by adding alkyl-substituted phenol stabilizers, etc., thermal decomposition of polyolefins can be prevented during molding, and the stability of molded products during use can be improved. can be done. On the other hand, it is known that when these phenolic stabilizers are blended with polyolefin, the molded product gradually becomes colored yellow or brown at room temperature. In particular, products such as polyethylene fibers and polypropylene fibers have the disadvantage that they turn yellow or pink when exposed to combustion gas from oil stoves or propane combustion gas from gas dryers, which significantly reduces the value of the textile products. Therefore, in order to prevent combustion gas discoloration and discoloration of these polyolefin fibers, phenolic additives that cause discoloration and discoloration are not used, or phenol-triazine stabilizers developed for fiber molded products are used. The addition of only a small amount of this material significantly deteriorates the heat resistance of the fiber. To solve these discoloration problems, we added 3,4,5,6-dibenzo-1,2-oxaphosphane-2-oxide, trilauryltrithiophosphite, and benzoin to polypropylene containing phenolic antioxidants. Composition for preventing discoloration of textile products by adding acid etc.
17443) has been proposed. However, since this composition uses a phenol stabilizer which causes discoloration and discoloration, the discoloration resistance effect is still insufficient. Therefore, in order to solve this problem, the present inventors conducted various studies on stabilizers that do not use phenolic antioxidants, which cause coloration. The present invention has been completed by discovering that by using a compound and a thiodialkanoic acid ester compound in combination, molded products such as polyolefin fibers can be prevented from discoloration and discoloration due to combustion gas, and molded products with excellent heat resistance can be obtained. . That is, the present invention provides a color-fast polyolefin composition (a), characterized in that each of the following compounds (a), (b), and (c) is blended as a stabilizer in 100 parts by weight of a polyolefin. As a heterocyclic hindered amine compound, di-(2,2,6,6
-tetramethyl-4-piperidyl) sebacate or succinic acid and N-(2-hydroxyethyl)-2,
0.01 to 1 part by weight of a condensate of 2,6,6-tetramethyl-4-hydroxypiperidine, (b) distearylpentaerythritol diphosphite or tris(2,4-di-
0.01 to 1 part by weight of t-butylphenyl) phosphite, (iii) as a thiodialkanoic acid ester compound,
0.01 to 1 part by weight of distearylthiodipropionate or dilaurylthiodipropionate. The polyolefins used in the present invention are homopolymers or copolymers of α-olefins such as ethylene, propylene, butene-1, and 4-methylpentene-1, or copolymers containing these as main components with other monomers. or a mixture of these. The amount of the stabilizer added to the polyolefin is 0.01 to 1 part by weight, preferably 0.01 to 0.5 part by weight of the hindered amine compound per 100 parts by weight of the polyolefin.
parts by weight, the organic phosphite compound is 0.01 to 1 part by weight, preferably 0.01 to 0.5 part by weight, and the thiodialkanoic acid ester is 0.01 to 1 part by weight, preferably
It ranges from 0.01 to 0.6 parts by weight. Addition amounts other than this cannot sufficiently achieve the purpose of the present invention. In the present invention, among the antioxidants conventionally used, for example, 6-4-hydroxy-3,5-tert-butylanilino)-2,4-bisoctylthio, which has a slight gas yellowing resistance effect, is used. −
Even small amounts of 1,3,5-triazine can be added. Hindered amine compound used in the present invention,
The organic phosphine compound and the thiodialkanoic acid ester stabilizer are added to the polyolefin by a commonly used addition method. For example, a suitable method is to blend a stabilizer into polyolefin powder or polyolefin pellets, premix them, and then knead them in an extruder. In addition to the above-mentioned stabilizers, the polyolefin composition of the present invention also contains a neutralizing agent, a lubricant, an anti-blocking agent,
Antistatic agents, pigments, fillers, etc. can be used in combination. As described above, from the polyolefin composition of the present invention, it is possible to obtain molded articles such as fibers that not only have excellent gas discoloration resistance due to combustion gas, etc., but also have good heat resistance. The present invention will be specifically explained below using Examples. Examples 1-3, Comparative Examples 1-6 Polypropylene powder with melt flow rate 15
A hindered amine compound, an organic phosphite compound, and a thiodialkanoic acid ester are blended into 100 parts by weight in the proportions shown in Table 1, premixed using a Henschel mixer, and then this mixture is melt-kneaded using an extruder at 220°C to form pellets. It became. The pellets are spun into undrawn yarn of 12 denier using a fiber spinning machine at a spinning temperature of 290° C. using a treated oil. This undrawn yarn is drawn using a dry roll drawing machine.
The yarn was drawn twice at 100°C to produce a drawn yarn of 6 denier. Further, a sample drawn yarn was obtained by post-treatment using a treated oil agent. The gas colorability and heat resistance life of this sample yarn were measured and the results are shown in Table 1. For gas coloring, wrap a 60g sample yarn bundle in gauze and hang it from a support frame so that the sample package is 1 meter directly above the tip of a convection oil stove. Operate the oil stove in this position for 5 hours and visually check for discoloration of the yarn. I judged it. The evaluation was ◎, which did not cause coloration, and ×, which changed color to pink or yellow. The heat resistance life is calculated from the time it takes for the yarn to generate heat using a thermocouple inserted into the sample yarn by placing 18 g of sample yarn bundle in a metal cylindrical container with a diameter of 5 cm and depth of 6 cm with 30 holes of 10 mm diameter. I asked for it. For comparison, siple yarns were similarly formed without using the stabilizer combination of the present invention, and the gas colorability and heat resistance life were measured, and the results are also listed in Table 1. 【table】

Claims (1)

[Scope of Claims] 1. A color-fast polyolefin composition comprising 100 parts by weight of polyolefin and the following compounds (a), (b) and (c). (a) Di-(2,2,6,6-tetramethyl-4-
piperidyl) sebacate or succinic acid and N-
(2-Hydroxyethyl)-2,2,6,6-tetramethyl-4-hydroxypiperidine condensate 0.01 to 1 part by weight (b) Distearylpentaerythritol diphosphite or tris(2,4-di-t -butylphenyl) phosphite 0.01 to 1 part by weight (c) Distearylthiodipropionate or dilaurylthiodipropionate 0.01 to 1 part by weight