JPS6234254B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyolefin composition for drawn filaments used as ropes, fishing nets, woven fabrics, etc. Stretched polyolefin resin products can be used for ropes,
It is widely used in fishing nets, general nets, woven fabrics, etc. and in large quantities. All of these products are polyolefin monofilaments with a thickness of about 200 to 600 ^De , so-called lined fibers made by connecting several monofilaments, relatively thick so-called thick denier monofilaments of about 1000 ^De or more, and this monofilament. It can be obtained by processing a so-called flat filament, which is a flattened filament, or a stretched tape. The biggest problem in this case is that a large number of fluffs occur on the surface of the monofilament during molding, and the surface gloss of the filament deteriorates, resulting in a significant deterioration of the quality of the product. Furthermore, powder is generated on the guide during the molding process and during the process of processing ropes, woven fabrics, etc., and this causes various troubles. This generation of fluff and powder is often seen when the molecular weight of polyolefin is increased to obtain particularly strong filaments, and when the stretching ratio during stretching is increased. This occurs when the extrusion temperature is increased to improve properties such as yarn properties, spinnability, and film-forming properties, or when the cooling rate after extrusion is slowed to prevent undrawn yarn from wobbling after extrusion. For this reason, attempts have been made to prevent the generation of fluff and powder by lowering the extrusion temperature or reducing the molecular weight of polyolefin, but there is currently no perfect method, and in some cases, However, such improvements can also cause other damage, such as deterioration of physical properties and operability. The inventors of the present invention conducted extensive studies in view of the above circumstances, and as a result, discovered that it is advantageous to add a certain type of compound to the polyolefin resin. The purpose of the present invention is to prevent fuzz that tends to occur during molding and secondary processing by blending specific additives with polyolefin resin, to provide a better surface gloss than conventional products, and to reduce the generation of powder during the process. Another object of the present invention is to provide a polyolefin composition for drawn filaments which can also prevent the above problems. Another object of the present invention is to provide a polyolefin composition for drawn filaments that can be formed into thick denier filaments or aligned fibers using commonly used processing means. The present invention for the above-mentioned purpose is characterized in that a thiobisphenol compound is blended in a polyolefin resin in an amount of 0.01 to 0.2 parts by weight. The polyolefin resin in the present invention refers to α-olefin homopolymers, copolymers, and mixtures thereof represented by the general formula CH ₂ =CHR (R is hydrogen or an alkyl group), such as polyethylene, polypropylene, ethylene propylene, etc. Examples include copolymers, ethylene-butene-1 copolymers, propylene-hexene-1 copolymers, and mixtures thereof. In addition, ethylene homopolymers and copolymers made by the so-called medium-low pressure method can be cited as preferred examples, and the flow rates measured at JISK6760 loads of 21.6 kg and 2.16 kg, respectively.
For polyethylene whose ratio HLMI/MI (hereinafter referred to as HL/MI) is 40 or less and MI1.5 or less, and for polyethylene that exceeds MI1.5,
The strength of the resulting monofilament, etc. is insufficient, and if the HL/MI is higher than 40, the resulting monofilament, etc. will not have sufficient linear strength or knot strength. Not suitable for filament use. In the present invention, a thiobisphenol compound is blended into the polyolefin resin, and the following can be used as effective thiobisphenol compounds. 4,4'-Thiobis-(6-tert-butyl-3-
methylphenol), 4,4'-thiobis-(6-tert-butyl-0-
cresol), dialkylphenol sulfide, 2,2'-thiobis-(6-tert-butyl-4-methylphenol), and 4,4'-thiobis-(6-tert-butyl-4-methylphenol).
Butyl-3-methylphenol) can be mentioned as a preferable example. In addition, the amount of thiobisphenol compound added to polyolefin resin is 100% of polyolefin resin.
It is 0.01 to 0.2 parts by weight per part by weight (hereinafter expressed in PHR units), preferably 0.01 to 0.12 PHR. If it is less than 0.01PHR, the improvement effect will be poor, and if it exceeds 0.12PHR, the effect will be saturated.
The color of the product also gradually deteriorates. Furthermore, if it exceeds 0.2 PHR, the effect will be completely saturated and it will become uneconomical, and the initial hue of the product will also be extremely poor, which is not preferable in terms of color change over time. In addition to the above-mentioned thiobisphenol compound, it is preferable to add an inhibitor and a stabilizer as necessary. As this stabilizer, tetrakis-(2.
4-ditertiary butyl phenyl) 4,4'-
Organic phosphite stabilizers such as biphenylene diphosphonite and distearyl pentaerythritol diphosphite. In addition, antioxidants added to assist the effect of adding thiobisphenol compounds include:
The following compounds may be mentioned. Sulfur-containing ester compounds such as dilaurylthiodipropionate, distearylthiopropionate, distearyl-β・β′-thiodibutyrate, laurylstearylthiodipropionate, dimyristylthiodipropionate, etc. system stabilizer. Tetrakis-(methylene-3-3'・5'di-3
-butyl 4'-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2,4,6-tris-(3,5-di-tert-butylbenzyl)benzene, 1,1,3-tris -(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 4,4'-butylidenebis-(3-methyl-6-
Among higher phenolic antioxidants such as tertiary-butylphenol, it is an antioxidant with relatively long oven life stability. Furthermore, auxiliary components such as known antioxidants, metal soaps, ultraviolet deterioration inhibitors, lubricants, and pigments can also be included. Thus, the polyolefin resin composition blended with the required amount of the above-mentioned thiobisphenol compound can be formed into a monofilament form by conventional means. To state this further,
It can be extruded from a nozzle at a relatively high temperature of 230 to 290°C, cooled with water through air gaps at appropriate intervals, and then stretched 5 to 6 times or more, in some cases more than ten times, to form a monofilament. As for the forming conditions for this monofilament, it is generally said that the spinning temperature, cooling temperature, drawing ratio, etc. are low, and the air gap is narrower, which is better in terms of fuzz suppression effect and powder generation prevention effect. With the composition, there is no need to be too particular about the molding conditions; even if there are some differences in the molding conditions, there is no fuzz, no decrease in gloss, and no generation of powder. Furthermore, the monofilament molded therein is stronger than conventional ones. The composition of the present invention can also be in the form of lined fibers. This arrangement refers to several monofilaments connected together, and when molding involves several nozzles connected through slits, several nozzles placed close together are used to form the monofilament using a balancing effect of the extruded resin. In addition, there are methods such as partially adhering extruded resin in a molten state using guides, etc., but no matter which molding method is used, fuzz and powder generation occur when molding ordinary monofilament. more remarkable than. However, with the composition according to the present invention, there is no fluffing, the gloss is good, and the generation of powder is suppressed, as in the case of monofilament. Furthermore, the composition of the present invention can be in the form of a thick denier monofilament or flat yarn. Thick denier monofilament is usually 200
It is a monofilament of ~600 ^De that has a thicker denier than about 1000 ^De , and its molding is the same as that of monofilament. Flat yarn is extruded from a round or flat nozzle, cooled with water, and then stretched. Sometimes embossing is performed after stretching, and generally 1000 ^De
It is more than 6000 ^De . These thick denier monofilaments and flat yarns also have poorer surface gloss than ordinary monofilaments, and are prone to fuzzing and powdering, but such phenomena are suppressed by the composition of the present invention. This also applies to stretched tapes manufactured using ordinary forming means, and when the composition of the present invention is applied,
This effect is exhibited not only in the above-mentioned monofilaments, aligned fibers, thick denier monofilaments, and flat yarns, but also in the form of tapes. Furthermore, the effects of the present invention include improving the gloss and aesthetic appearance of the product, suppressing deterioration of physical properties such as product strength and elongation, and improving the working environment and operability. Next, individual cases of the present invention will be shown as examples.

[Table] 1.1m/mφ nozzle spacing 0.2m/m, 5 in a row 36
Extruded from the block, water-cooled at 60 m/m in an air cap, and stretched at 120 m/m in boiling water at 100°C.
It was stretched 10 times at min. Based on a sample with a set magnification of 400 ^De x 5. Examples 1-8, 12 in the following table. Applicable to Comparative Examples 1 to 4 and 7. However, Example 12 and Comparative Example 7 are based on samples stretched to 8 times pp.

[Table] The material was extruded through a 1.2 m/mφ120 ^H nozzle, water cooled with an air gap of 50 m/m, and after water cooling, stretched 10 times at a stretching speed of 120 m/min in boiling water at 100°C. Setting magnification 400 ^De
According to the sample. Examples 9 and 10 in the following table. Comparative example 5 applies.

[Table] The sample was extruded through a 2.0 m/mφ40 ^H nozzle, cooled with water at an air gap of 80 m/m, and then stretched 8 times with boiling water at 100°C at a stretching speed of 100 m/min. Based on sample set magnification 1500 ^De . Example 11 in the following table. Comparative example 6 applies. In addition to the compositions listed in the table, each Example and Comparative Example also contained 0.08% higher phenol, 0.04% distearylthiopropionate, and calcium stearate.
0.1% of each was added. Next, the results of each Example are shown in the table below along with the results of Comparative Examples. In this table, the physical properties were measured under the following conditions. JIS L1073 Grasp interval 300m/m Take-up speed 300m/min Temperature 20℃ In addition, each item in the appearance of the molded product is judged visually, and the results are divided into the following categories and shown by grade. Filament surface gloss, resulting in filament fuzz. 1 Very good. 2 Good. 3 Normal. 4 Bad. 5 Very bad. Results of powder blowing in the spinning process (winder front guide) and powder blowing in the net making process (link twisting machine creel stand rear guide). 1 None. 2 Slight occurrence (tolerable limit). 3 Frequent occurrence during 24-hour operation of the spinning process Frequent occurrence during 8-hour operation of the rope-making process 4 Unable to operate unless treated during the spinning process 24-hour operation Unable to operate unless treated during the 8-hour operation of the rope-making process 5 Unable to operate

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Claims (1)

[Scope of Claims] 1. A polyolefin composition for drawn filaments, comprising a polyolefin resin and 0.01 to 0.2 parts by weight of a thiobisphenol compound. 2. The polyolefin composition for a drawn filament according to claim 1, wherein the polyolefin resin is polyethylene. 3 Polyolefin resin is HL/MI40 or less,
The polyolefin composition for a drawn filament according to claim 1, which is polyethylene having an MI of 1.5 or less. 4. The polyolefin composition for drawn filaments according to claim 1, which is in the form of thick denier filaments or lined fibers that are cooled and drawn after melt extrusion.