JPS6140766B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyolefin composition for drawn filaments used as ropes, fishing nets, textiles, 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 in order to improve properties such as yarn properties, spinnability, and film-forming properties, or when the cooling rate after extrusion is slowed to prevent yarn wobbling of the drawn yarn after extrusion. For this reason, attempts have been made to prevent the generation of fuzz and powder by lowering the extrusion temperature, increasing the cooling rate after extrusion, and reducing the molecular weight of polyolefin, but these efforts are not yet complete. In some cases, such improvements may cause other problems 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, provide a better surface gloss than conventional products, and also prevent powder blowing during the process. It is an object of the present invention to provide a polyolefin composition for drawn filaments which not only has a good initial silver hue and does not discolor over time. Another object of the present invention is to provide a polyolefin composition for drawn filaments that can be formed into not only monofilaments but also thick denier filaments, lined fibers, etc. using commonly used processing means. There are also things to do. The present invention achieves the above object by adding a sulfur-containing ester compound to a polyolefin resin containing a thiobisphenol compound to prevent the above-mentioned fluffing and also to prevent powder blowing during the process. The main idea is that the initial hue and discoloration over time are improved by adding an antioxidant. Therefore, the polyolefin resin used 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, Examples include polypropylene, ethylene-propylene copolymer, ethylene-α-olefin copolymer of ethylene-butene-1 copolymer, propylene-hexene-1 copolymer, and mixtures thereof. In addition, ethylene homopolymers and copolymers produced by the so-called medium-low pressure method can be cited as preferred examples, but more preferably, the ratio HLMI to HLMI and MI of the flow rates measured under JISK6760 loads of 21.6 kg and 2.16 kg, respectively. /MI (hereinafter
HLMI/MI) is 40 or less and MI1.5 or less. If the polyethylene exceeds MI1.5, the strength of the monofilament etc. obtained is insufficient, and if the HLMI/MI exceeds 40, the monofilament produced there. Not only is it not possible to obtain sufficient linear strength and knot strength, etc., but also the stringability and drawability are poor, making it undesirable for use in drawn filaments. Examples of thiobisphenol compounds include thiobisalkylphenol compounds such as 4,4'-thiobis-(6-tert-butyl-3-
methylphenol) 4,4'-thiobis-(6-tert-butyl-O-
cresol) 2,2'-thiobis-(6-tert-butyl-4methylphenol), and 4,4'-thiobis-(6-tert-butyl-4-methylphenol) is particularly preferable.
(6-tert-butyl-3-methylphenol). The amount of the thiobisalkylphenol compound added to the polyolefin resin is 0.01 to 0.2 parts by weight (hereinafter expressed in PHR units) per 100 parts by weight of polyolefin, preferably 0.01 to 0.12 PHR.
It is. 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 fuzz will gradually disappear. 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 become extremely poor, making it undesirable in terms of color change over time. In order to fully exhibit the effects of the present invention,
As the sulfur-containing ester compound added together with the above thiobisalkylphenol compound, a sulfur compound represented by the following general formula is used. R: Alkyl group having 8 to 30 carbon atoms. n: an integer of 1-4. is particularly preferable, and pentaerythol tetrakis (3-laurylthiopropionate) shown below is particularly preferable. The amount of the sulfur-containing ester compound added is determined depending on the amount of the thiobisalkylphenol compound added, and must satisfy the following formula. Polyolefin resin (A) 100 parts by weight Thiobisalkylphenol compound (B)
Under conditions of 0.01 to 0.2 parts by weight, sulfur-containing ester compound (C)
C = α (2 to 10) x (B) parts by weight, preferably when (α) is in the range of 2 to 5, the most synergistic effect can be expected, and when (α) is in the range of 5 to 10, the most synergistic effect can be expected. When the effect approaches saturation and exceeds 10, not only does it become uneconomical, but the synergistic effect with the thiobisalkylphenol compound may even decrease. In the polyolefin composition to which the above-mentioned thiobisalkylphenol compound and sulfur-containing ester compound are added, these additives suppress fluffing during the process, and powder blowing caused by the fluffing is suppressed by these additives. Prevented. However, thiobisalkylphenol compounds can cause problems in initial hue and color change over time in polyolefin compositions. This problem becomes a very serious problem depending on the application of the drawn filament. Therefore, in the present invention, when it is required to improve the initial hue and eliminate discoloration over time, a phosphorus antioxidant is added. This antioxidant has the general formula (In the formula, R ₁ and R ₂ each represent the same or different alkyl, cycloalkyl, aryl, or arylalkyl group.) For example, distearyl pentaerythritol diphosphite or tetrakis (2-4- ditertiary butyl phenyl), 4,4'-biphenylene diphosphonite, and the like. Further, the amount of the phosphorus antioxidant added is also determined by the amount of the thiobisalkylphenol compound added, as in the case of the sulfur-containing ester compound, and must satisfy the following formula. Polyolefin resin (A) 100 parts by weight Thiobisalkylphenol compound (B)
0.01-0.2 parts by weight sulfur-containing ester compound (C)
Under the condition of α (2 to 10) × (B) parts by weight, the phosphorus antioxidant (D) is D = β (1 to 3) × (B) parts by weight, and (β) is less than 1. When it is low, the hue improving effect is small, and when (β) exceeds 3, the effect is saturated and not only becomes uneconomical, but also may cause various harmful effects. As already mentioned, the thiobisalkylphenol compound and the sulfur-containing ester compound have a very remarkable fuzz-inhibiting effect and a dust-preventing effect, and the hue-improving effect of the phosphorus antioxidant is also remarkable. Furthermore, by using a required amount of a thiobisalkylphenol compound and an amount of a sulfur-containing ester compound determined from the amount of the thiobisalkylphenol compound added,
Although satisfactory results can be obtained, the following stabilizers and antioxidants can be added to further assist the effects of the above additives. Dilaurylthiopropionate, distearylthiopropionate, distearyl-β・β′-
Sulfur-based stabilizers such as sulfur-containing compounds such as thiocybutyrate, lauryl stearyl thiodipropionate, dimyristyl thiodipropionate, etc. Tetrakis-[methylene-3-(3'・5'di-3-
-butyl 4'-hydroxyphenyl)propionate] methane, 1,3,5-trimethyl-2,4.
6-tris-(3,5-di-tert-butyl-4-
hydroxybenzyl)benzene, 1,1,3-tris-(2-methyl-4hydroxy-5-tertiary)
Among higher phenolic antioxidants such as butyl (butyl phenyl) butane, it is an antioxidant with relatively long oven life stability. The polyolefin composition may contain commonly used auxiliary agents such as antioxidants, metal soaps, ultraviolet deterioration inhibitors, lubricants, and pigments. Thus, the polyolefin resin composition of the present invention can be formed into a monofilament form using conventional means. That is, it can be extruded through a nozzle at a relatively high temperature of 230 DEG to 290 DEG C., cooled with water, 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, and even if there are some differences in the molding conditions, there is no fluffing, no reduction in gloss, the hue is improved, and no powder is generated. 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, and due to the 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, in the case of the composition according to the present invention, as in the case of monofilament, there is no fluffing, the gloss is good, the hue is improved, and the generation of powder is suppressed. 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 through a round or flat nozzle, water-cooled, and then stretched. Sometimes embossing is performed after stretching and forming, and generally the yarn is 1000 ^De or more and 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 filaments, aligned fibers, thick denier filaments, and flat yarns, but also in the form of tapes. 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 with an air gap of 60 m/m, and after water-cooled, stretched at 120 m/m in boiling water at 100°C.
It was stretched 10 times at n. Based on a sample with a set magnification of 400 ^De x 5. Examples 1-7, 12-15 in the following table. Comparative examples 1 to 5, 9
Corresponding, however, Example 12 and Comparative Example 9 are based on samples of polypropylene (PP) stretched 8 times.

[Table] The material was extruded through a 1.2 m/mφ20 hole nozzle, water cooled with an air gap of 50 m/m, and after water cooling, stretched 10 times at a drawing speed of 120 m/m in boiling water at 100°C. Setting magnification
Based on a sample of 400 ^De . Examples 8 and 9 in the following table. Comparative example 6 applies.

[Table] It was extruded through a 20 m/mφ, 40-hole nozzle, water-cooled with an air gap of 80 m/m, and after water-cooled, it was stretched 8 times with 100°C boiling water at a stretching speed of 100 m/min. Setting magnification
Based on a sample of 1500 ^De . Examples 10 and 11 in the following table. Comparative examples 7 and 8 apply. The thiobisalkylphenol compounds and sulfur-containing ester compounds used in the above Examples and Comparative Examples are as follows. Examples 1 to 12 and each comparative example Γ4·4'-thiobis-(6-tert-butyl-3-methylphenol) Γpentaerythrityl β-mercaptolauryl propionate Example 13 Γ4·4'-thiobis-(6 -tert-butyl-0-
Cresol) Γ Pentaerythrityl β-mercaptrauryl propionate Example 14 Γ2・2′-Thiobis-(6-tert-butyl-4-methylphenol) Γ Pentaerythrityl β-mercaptrauryl propionate Example 15 Γ4・4 '-Thiobis-(6-tert-butyl-3-methylphenol) Γpentaerythrityl β-mercaptostearylpropionate Also, as an organic phosphite stabilizer,
Distearylpentaerythritol diphosphite was used. In addition, in each Example and Comparative Example, in addition to the items listed in the table, tetrakis [methylene-3-(3', 5' di-tert-butyl 4' hydroxyphenyl) propionate] methane 0.08, distearylthiopropionate
0.04PHR and calcium stearate 0.1PHR are 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. JISL1073 Grasp interval 300m/m Take-up speed 300mm/min Temperature 20°C In addition, the appearance of the molded product is visually judged for gloss, fluffing, and powdering, and the results are divided into the following categories and indicated 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 rope making process (link twister creel stand rear guide). 1 None. 2 Slight occurrence (tolerable limit) 3 Frequent occurrence during 24-hour operation of the spinning process. This occurred frequently during the 8-hour operation of the rope making process. 4 The spinning process cannot be operated unless it is processed 24 hours a day. The rope manufacturing process cannot be operated unless it is processed for 8 hours. 5 Unable to operate Regarding the initial hue, the white index was measured using a color difference meter. In general, the relationship between white index and sensory evaluation is as follows: 50 or more Very good 40-50 Good 30-40 Discoloration 20-30 Widespread discoloration, unusable Less than 20 Not acceptable After being left for 30 days, the white index was measured using a color difference meter.

【table】

【table】

Claims (1)

[Claims] 1 For 100 parts by weight of polyolefin resin (A)
Contains 0.01 to 0.2 parts by weight of a thiobisalkylphenol compound, and the sulfur-containing ester compound (C) is added to the thiobisalkylphenol compound (B), (C) = α (2 to 10). x (B) parts by weight, and if necessary, phosphorous antioxidant (D), (D) = β (1 to
3) Polyolefin composition for drawn filament blended in the range of x (B) parts by weight. 2 The above thiobisalkylphenol compounds are 4,4'-thiobis-(6-tert-butyl-alkylphenol), 4,4'-thiobis-(6-
2.2'-Thiobis-(6-tert-butyl-4-methylphenol) The polyolefin composition for drawn filaments according to claim 1, which comprises 2,2'-thiobis-(6-tert-butyl-4-methylphenol).