TWI337210B - Composite fiber made of polyoxymethylene resin - Google Patents

Description

139. The invention relates to a composite fiber in which a core and a sheath are formed of a specific two kinds of polyacetal copolymers and has excellent knot strength retention. [Prior Art] Polymethyl hydrazine resin is a polymer mainly having a polymer skeleton in which oxymethylene units are repeatedly formed. It is known to have high crystallinity and is excellent in rigidity, strength, chemical resistance, solvent property and the like. Further, since the crystallization rate is fast and the molding cycle is fast, it is mainly used as an injection molding material in the field of mechanical parts such as automobiles and electric machines. In addition, since the polyacetal resin has high crystallinity, it is known that it is possible to form a high-strength, high-elastic body by alignment crystallization by extension (for example, refer to the "High-strength/high-strength fiber" polymer society compilation, Co-published, p. 4 8, + 1 8 8 In this case, Polymethacrylate resin is a resin material with excellent properties, and it is expected to be used as a material for fibers. However, polymethyl hydrazine resin The crystallization property is difficult to process into fibers, and the fiber composed of the polyacetal resin exhibits excellent strength by crystallization due to elongation, but the knot strength is slightly low, and it is considered necessary to improve it for practical use. SUMMARY OF THE INVENTION An object of the present invention is to solve the problems as described above, and to provide fibers having excellent properties of a polymethyl resin and having high knot strength holding. The present inventors have made efforts to achieve the above object. The result is 312XP / invention manual (supplement) /94-09/94 Π 8543 medicine in the nail knot). However, when the fiber composed of the polyacetal resin is produced by the melt spinning method, the aldehyde ratio is 5 1337210, which is used as a composite fiber composed of a core and a sheath, and a core and a sheath are formed by using different specific polyacetal copolymers. Thereby, the workability in melt spinning is excellent, and the obtained composite weave is high in strength, high in elastic modulus, and excellent in knot strength, and the present invention has been attained.

摩尔的摩尔。 The conjugated fiber comprising a oxidized methylene unit in a polymer chain consisting of oxidized methylene units. The polyoxyalkylene copolymer having the oxidized alkylene unit represented by the following general formula (1) and having a melt index (1 90 ° C 'load 2 1 60 0 g) of 1 to 100 g / 10 min (a) a core composed of the following general formula (1) containing a ruthenium oxide unit in a polymer chain mainly composed of oxidized methylene units: 0.3 to 8 moles per 100 moles; a oxidized alkylene unit having a melt index (190 ° C, a load of 2,160 g) of 1 to 100 g / 10 minutes of a polyacetal copolymer (b); When the crystal melting temperature of the polyoxymethylene copolymer (a) and the polyacetal copolymer (b) is Tma (°C) and Tmb (°C), the following formula (2) is satisfied. —RC)m-o ^—

I

Rl (1) (wherein Ri'Rz is an organic group selected from the group consisting of hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkyl group having 1 to 8 carbon atoms, and an organic group having a stupid group, R, R2 may be the same or different. m represents an integer from 2 to 6.) 6 312XP/Invention Manual (supplement)/94-09/94118543 1337210

Tmb<Tma-3 (2) (T ma (°C): crystal melting temperature of polyacetal copolymer (a); T mb (°C crystallization melting temperature of oxymethylene copolymer (b)) According to the present invention, A fiber aggregate having a high specific strength of a polyacetal resin and having a high knot strength retention ratio, and a fiber aggregate such as a woven fabric or a nonwoven fabric can be obtained. [Embodiment] Hereinafter, the present invention will be described in detail. The composite fiber is characterized in that it is composed of a core and a sheath which are composed of two different specific polyoxymethylene copolymers. In addition, the fiber in the present invention is defined as also including a filament (fi 1 ament ).摩尔的摩尔。 The conjugated polyalkylene group in the polymer chain of the conjugated ruthenium oxide unit is 0.1 to 7. 5 moles per 100 moles. The oxidized alkyl group represented by the above one (1), and having a melt index (190 ° C, a load gram) of 1 to 100 g / 10 0 minutes. In the polymer (a), the proportion of the oxidized stretching base unit represented by the general formula (1) The oxymethylene unit is 0. 5-6 mol, and the ultra-fine mercapto unit is 1.0 to 5 mol per 100 mol. In the present invention, the polyoxymethylene of the core is formed. The crystal melting temperature of the copolymer (a) and the sheath polyoxymethylene copolymer (b) is important in that it has a constant temperature difference. For this reason, it is necessary to relatively adjust the introduction of the polyoxymethylene copolymer umbrella and the (b) oxidation stretching. The amount of the alkyl unit. The proportion of the oxidized and extended base unit of the polyoxymethylene copolymer (a) exceeds the above range and is excessive. 312XP/Invention Manual (Supplement)/94-09/94118543): Strength of the poly Said, it is called '(a) contains the general formula 2 160 aldehyde common oxidized part of the special J (a) guide,

1337210 becomes a crystal melting temperature lower, and it is difficult to form a crystal melting temperature difference with the polyoxymethylene (b) forming a sheath portion, and has a problem that the nodule strength is lowered, and is introduced in the polyoxymethylene copolymer (b) forming the sheath portion. When the ratio of the alkyl unit exceeds the range described later and is excessively large, the melting temperature may be lower than that of the polyacetal copolymer (a), but in this case, the core is 卩, sheath Each of them is formed of a polyacetal copolymer having an excessively large alkyl group, and has a problem that the fiber properties finally obtained and the strength after stretching become low. On the other hand, the proportion of the oxidized exudation unit introduced into the polyoxymethylene (a) is inferior to the above range, and the thermal stability is poor, and the workability of the fiber is lowered. Further, the polyacetal copolymer (a) is preferably a melt index (MI) of 1.2 to 90 g / ], and particularly preferably 1. 5 to 80 g / 10 min. The melt index (the polyoxymethylene copolymer (a) of Μ, because the melt viscosity becomes too high, the spinning load increases and it is difficult to push out. If the melt index (Μ I ) is too large, it is long due to drawdown, etc. The manufacture of the filament becomes unstable, and the molecular weight is lowered, and the strength of the filament is also lowered. In addition, the melt index (MI) of the polyacetal copolymer used in the present invention is based on 八五丁为0-于1 0 0 The measurement is carried out under the load of °C and 2 1 60 g, and the following is the same. Secondly, in the conjugate fiber of the present invention, the polymethylate (b) used for the sheath portion is mainly composed of repeating oxymethylene units. The poly(indenyl) group contains an oxyalkylene unit of the formula (1) per mole of the oxime group of 0.3 to 8 moles, and the melt index (1 90 ° C 2 1 60 g) It is 100 g / 10 0. In the polyacetal (b) used in the sheath, the proportion of the oxidative exudation unit represented by the general formula (1) is higher than that of the 312XP/invention specification (supplement)/94- 09/94118543 Copolymer. Another oxidized to crystal melting temperature unit ratio is less than the thermal copolymer 0 minutes I) when the resin is too small With the medium made 1 2 3 8, aldehyde copolymer chain, the above one, the load copolymer, the best oxygen 8 1337210

The method for producing the above polyacetal copolymers (a) and (b) used in the present invention is not particularly limited, and is generally a cyclic bond compound or a cyclic dimethanol of trioxane and a comonomer. A cyclic formal compound, which is mainly obtained by a block polymerization using a cationic polymerization catalyst, can be obtained. As the polymerization device, a known device such as a batch type or a continuous type can be used. Here, the introduction ratio of the alkylene oxide unit shown by the above general formula (Π) can be adjusted according to the amount of the copolymerized monomer to be copolymerized, and the melt index (Μ I ) can be based on the bond transfer agent used in the polymerization, for example. Adjusted by the addition amount of dimethicone (methy 1 a 1 ). Examples of the cyclic ether compound or the cyclic dimethanol formal compound used as a comonomer include ethylene oxide, propylene oxide, butylene oxide, oxetane, tetrahydrofuran, and trioxane. Trioxepane, 1,3 - two. Isopentane (l,3-dioxolane), propylene glycol acetal, diethylene glycol formal, triethylene glycol formal, 1,4-butanediol formal, 1,5-pentanediol formal, 1,6-hexanediol formal, etc., among which ethylene oxide, 1,3 dipentane, diethylene glycol formal, and 1,4-butanediol formal are preferred. Further, as the alkylene oxide unit represented by the general formula (1) which is formed by polymerization of a comonomer, oxyethylene, oxymethyleneene or tetramethylene oxide is preferred. Further, the polyoxymethylene copolymer used in the present invention may be introduced into a branching structure or a crosslinked structure by copolymerizing a bifurcation component and a polyfunctional component. Further, the polyoxymethylene copolymers (a) and (b) used in the present invention may be the same as or different from the above-mentioned comonomers used in the production thereof, and the oxidation results as shown in the above general formula (1) are formed as a result of the polymerization. The alkyl groups can also be the same or different. In the polyoxymethylene copolymers (a) and (b) used in the present invention, the aforementioned general formula (1) formed by the above-mentioned 11 312 XP/invention specification (supplement)/94-09/94118543 1337210 polymer. The alkylated alkyl unit shown is preferably dispersed uniformly in the molecular chain of the polymethylene copolymer, and the oxidized stretching unit represented by the above general formula (1) is two or more chain members. The ratio is preferably 5 mol% or less of the entire alkyl unit of the oxidized alkyl group.

The polyoxymethylene copolymer obtained by the polymerization is subjected to a catalyst deactivation treatment, removal of unreacted monomers and polymer washing, drying, stabilization of the terminal portion, and the like, and then stabilization with various stabilizers. Processing, etc., for practical use. Typical examples of the stabilizers include hindered phenol-based compounds, nitrogen-containing compounds, hydroxides of barium or soil-measuring metals, inorganic salts, and carboxylates. Further, in the polyoxymethylene copolymer used in the present invention, a thermoplastic additive may be used as a general additive such as a dye, a pigment, a coloring agent, a lubricant, a nucleating agent, a releasing agent, and an antistatic agent, as needed. One or more of a solvent, a surfactant, an organic polymer material, an inorganic or organic filament, a plate, or a particulate filler may be added without departing from the scope of the present invention. Next, a method for producing the conjugate fiber of the present invention comprising the polyoxymethylene copolymers (a) and (b) described above will be described. The conjugate fiber of the present invention can be plasticized by using two kinds of polyoxymethylene copolymers (a) and (b), and can be plasticized by two extruders to form a polyfurfural copolymer (a). The polyoxymethylene copolymer (b) is obtained as a sheath portion by melt spinning as a core portion. The structure of the melt spinning device used herein is not particularly limited, and for example, a spinning device composed of two single-shaft or double-shaft pomelo machine 'gear pumps, a composite spinning discharge nozzle, and 12 312XP/ Disclosure of the Invention (Supplement) / 94-09/941] SM3 1337210 The molten polymer discharged from the discharge nozzle is drawn into a fiber shape, and is formed by winding a roll. The polyacetal copolymers (a) and (b) of the raw materials are melted in such a melt spinning apparatus, and are discharged into a fiber shape by a discharge nozzle, and taken up by a roll. In this case, it is preferable to draw the fiber material discharged from the discharge nozzle while heating at an ambient temperature of 140 to 250 °C. If the ambient temperature of heating is less than 14 Ot, the curing speed of the fiber is fast and the productivity is deteriorated.

Further, it is difficult to obtain a fiber which can be stretched at a high stretching ratio, and it is difficult to obtain a fiber having high strength and high modulus of elasticity. On the other hand, when the ambient gas temperature is 250 ° C or more, the fiber is wound up on the roll in an insufficiently cured state, and the workability is deteriorated. The ambient temperature for heating the fibrous material discharged from the discharge nozzle is preferably from 1 4 0 to 2 2 0 °C. In the conjugate fiber of the present invention, the cross-sectional shape of the core portion is generally circular, and any shape such as a star shape or a polygonal shape may be used. The cross-sectional area ratio of the core portion and the sheath portion is not particularly limited. However, since the strength of the conjugate fiber tends to be largely dependent on the strength of the core portion, the ratio of the cross-sectional area occupied by the core portion in the total cross-sectional area of the fiber is 30% or more. Good, and better than 70%. The fiber obtained by the above spinning step is further subjected to an elongation step and can be continuously or discontinuously stretched. The stretching ratio can be adjusted by appropriately setting the speed ratio of the take-up roll to the take-up roll to obtain the fiber of the desired stretch ratio. The heating method at this time may be a method of heating gas, heating liquid, hot plate contact, far infrared ray heating, laser light heating, electromagnetic induction heating, or the like, and is not particularly limited. In the present invention, the crystal melting temperature of the polyoxymethylene copolymer (b) is higher than the glass transition temperature of the polyacetal copolymer (a), 13 3 ] 2XP / invention specification (supplement) / 94-09/94118M3 1337210 Extension at the following temperatures is preferred. As the temperature at the time of extension, the range of (the crystal melting temperature of the polyoxymethylene copolymer (a) - 5 0 ° C) ~ (the crystal melting temperature of the polyoxymethylene copolymer (b) - 5 ° C) is particularly preferable. When the heat is extended in a state of insufficient heat, the elongation stress is increased, and not only the productivity is lowered, but also the yarn breakage is likely to occur. Further, in the state of excessive heating, the polymer is in a molten state or in a state close to it, and the melt tension is lowered and the yarn is broken, which is not preferable.

Further, the stretching ratio is preferably set within the above range depending on the application. When the stretching ratio is set, it is considered that the strength of the elongated body obtained as the stretching ratio increases, and vice versa, the elongation is lowered, and the practical characteristics such as toughness and nodular elongation are lowered or the fiber itself exhibits an easy fibrillation behavior, and is considered for general use. In the case of the physical property balance, for example, a stretching ratio of about 5 times to about 10 times is preferable, and when it is required to use a high strength of a warp of a woven fabric or the like, it is preferably extended at a high stretching ratio of about 8 times to 20 times. The fiber obtained by the elongation step extension treatment is preferably subjected to a heat fixation treatment in a fixed molecular state in a heated state, thereby reducing the dimensional change of the extension. An example of the heat setting condition is heat setting at a temperature equal to or lower than (the crystal melting temperature of the polyoxymethylene copolymer (a) is -3 ° C). The conjugate fiber composed of the two kinds of polyoxymethylene copolymers of the present invention can be used in various applications such as excellent properties such as knot strength retention, high strength, high modulus of elasticity, solvent resistance, heat resistance, and bending fatigue resistance. By using this long fiber to form a crepe, a woven fabric, a braid, etc., it can be used for various industrial materials such as civil engineering and construction. 14 312XP/Invention Manual (supplement)/94-09/941丨8543

1337210 Further, depending on the purpose, the fiber may be appropriately cut into short fibers for use, and excellent properties such as high strength, high modulus of elasticity, solvent resistance, heat resistance, fatigue resistance, alkali resistance, high temperature rigidity, and the like may be used, for example, Reinforced or non-woven processing of various shapes (concrete 'mortar, synthetic resin, stone bone) and various other uses. (Embodiment) Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited thereto. (Examples 1 to 8) The polyacetal copolymer (a) 'polyacetal copolymer (b) was produced by the following method. A continuous mixing reactor equipped with a jacket through a hot (cold) medium, a barrel having a circularly overlapping shape, and a rotary shaft with a blade attached thereto, with two blades attached thereto The rotary shaft is rotated at 150 rpm, and is added to the liquid three-degree quenching, as a comonomer ether or cyclic dimethanol acetal (1,3-dioxane, 1,4-butanediol acetal). , diethylene glycol condensate tunneling'' will be used as a molecular weight regulator of dinonanol furfural, while simultaneously supplying 30 ppm of boron trifluoride (relative to all monomers) of the catalyst to the polymerization machine. The bulk polymerization is carried out, and the polymer obtained by modulating the amount of the comonomer (the ratio of the alkylene oxide units) shown in the table is rapidly introduced into the pulverizer while being added to the pulverizer. 0 5 wt% triethylamine in 60 ° C aqueous solution, let the catalyst coexist. After further separating, washing, and drying, a crude polyacetal copolymer was obtained, followed by 10 parts by weight of the crude polyacetal copolymer, 4 parts by weight of an aqueous solution of ethylamine 5 wt%, and pentaerythritol-肆[3- (3,5 - 2 312XP / invention manual (supplement) /94-09/94118543 素 布 不 15 15 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 13 Parts by weight were melt-kneaded at 2 1 0 °C by a twin-axis extruder to remove the unstable portion. Addition of pentaerythritol-indole [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate as a stabilizer to 100 parts by weight of the polyacetal copolymer obtained by the above method] 0.03 parts by weight and 0.15 parts by weight of melamine were melt-kneaded at 210 ° C by a biaxial extruder to obtain a pelletized resin composition using a polyoxymethylene copolymer as a matrix resin.

Using the two kinds of polyoxymethylene copolymers (a) and (b) obtained above, they are separately supplied to respective 25 mm uniaxial extruders, and plasticized and melted at a cylinder set temperature of 200 ° C. In a concentric circular core-sheath composite die having a diameter of 0.5 mm, 24 holes, and a circular hole, the polyoxymethylene copolymer (a) is used as a core, and the polyacetal copolymer (b) is supplied as a sheath. The composite die was continuously extruded and taken up at a pulling roll speed of 300 m / mi η. The ratio of the cross-sectional area of the core with respect to the cross-sectional area of the fiber was 72%. Next, it is continuously contacted with an extension plate which is heated in (the crystal melting temperature of the polyacetal copolymer (b) - 10 ° C) and extends in the longitudinal direction. The stretching ratio is adjusted by adjusting the winding speed ratio of the roll, specifically, the winding speed is controlled to 4 6 m / mi η, the take-up roll speed is controlled to 285 m/min, and the 6.2-fold extension is performed 6 (Comparative Example 1) ~ 9) The composite spun yarn outside the specification of the present invention was produced, and the unstretched body was prepared under the same conditions as in the examples, and the stretched yarn was further adjusted. The results of the evaluations in the same manner as in the examples are shown in Table 1. Further, the evaluation items, the measurement methods, the evaluation criteria, and the like in the examples and comparative examples are as follows. ] 6 312XP / invention manual (supplement) /94-09/941 ] 8543 1337210 [measuring melt index (Μ I )] under ASTM D - 1 2 3 8, under a load of 1 90 ° C, 2 1 60 ° Determination. [Polymer composition analysis] The polymer used for the evaluation of the physical properties was dissolved in hexafluoroisopropanol d2 and subjected to 1 Η - N M R measurement. Quantification is performed by the peak area corresponding to each unit. [Crystal melting temperature] The peak temperature of the crystal melting peak at a temperature of 10 ° C /min was measured by D S C .

According to J I S L 1 0 1 3, the knot strength evaluation of the filament monofilament was carried out, and the knot strength retention ratio with respect to the knot strength ratio of the fiber strength was calculated. Table 1

312XP/Invention Manual (supplement)/94-09/941丨8543 17 1337210 001

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Claims (1)

1337210 X. Patent application scope: 1. A composite fiber characterized in that: the polymer chain mainly composed of oxidized repeats contains oxymethylene units in the range of 0·1 to 7.5 m. The oxygen position represented by the formula (1), and the melt index (190 ° C, load 2 1 6 0 g) is a core composed of the polyfurfural copolymer (a) of 1 to 1 hour; The oxidized methylene unit of the deuterated methylene unit repeat is an oxyalkylene unit represented by 0.3 to 8 mol per 100 m of the molar alkyl group, and the melt index (1 9 (TC g) is 1 Formed from ~100 g/10 min of polyoxymethylene copolymer (b), and the decomposition temperature of polyacetal copolymer (a) and polyoxymethylene copolymer (b) is regarded as T ma ( ° C ) and T mb ( When the temperature is °C, the following formula (I Ri (wherein R, R 2 is selected from the group consisting of hydrogen, 1 to 8 carbon atoms, 1 to 8 alkyl groups, organic groups, stupid groups, and benzene) R2 may be the same or different, m represents an integer of 2 to 6;) 3<Tma-Tmb^ 10 (2) (T ma (°C): crystal melting temperature of polyacetal copolymer (a) ; Crystallization of furfural copolymer (b) Solve the temperature. 2, as claimed in the scope of claim 1, the oxidized alkyl unit is selected from the group consisting of oxime and ethyl, 94118543 0CT 0 7 2010 _ exchange of methylene units per 100 The ear alkyl group is 0 0 g / 10 0 in the chain containing £ general formula (1) • the load 2 1 6 0 constitutes the sheath; the other crystal melts 2); has a carbon number base, R1, T Mb (°C): 3⁄4 , general formula (1) oxidized triammonium 19 1337210 base, oxidized tetradecylene group. 94118543 20