JPH0813237A - Elastic fiber - Google Patents

Abstract

PURPOSE:To obtain an elastic fiber, comprising a hydrogenated block copolymer and an olefin-based polymer and excellent in oil, heat and weather resistances, flexibility and mechanical strength. CONSTITUTION:This elastic fiber is obtained by carrying out the hydrogenation treatment of a butadiene-polyisoprene-polybutadiene type block copolymer comprising a polybutadiene block with <=30% bonded vinyl content and at least one or more copolymer blocks at (100/0) to (20/80)wt.% ratio of isoprene/ butadiene, providing a hydrogenated block copolymer containing >=70% hydrogenated unsaturated bond in the block chain, adding 0-500 pts.wt. olefin-based polymer such as high-density polyethylene or low-density polyethylene or polypropylene to 100 pts.wt. resultant hydrogenated block copolymer and melt spinning the prepared thermoplastic resin composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elastic fiber having excellent oil resistance, flexibility, heat resistance, mechanical strength and weather resistance.

[0002]

2. Description of the Related Art Hydrogenated products of block copolymers composed of conjugated dienes and vinyl aromatic compounds are known.
JP-B-42-4704, JP-B-42-8933, JP-B-48-3555, JP-A-46-72
No. 91 publication and the like. The elastic fiber using such a hydrogenated block copolymer is inferior in solvent resistance to an organic solvent as compared with polyurethane-based elastic fiber, for example, commercially available spandex, and therefore its current application is limited. Is.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an elastic fiber having excellent oil resistance, flexibility, heat resistance, mechanical strength and weather resistance.

[0004]

As a result of intensive studies by the present inventors, the above-mentioned object of the present invention comprises a block copolymer comprising at least a polymer block A and at least one polymer block B, Hydrogenated block copolymer 10 in which 70% or more of unsaturated bonds in the block chain are hydrogenated
An elastic fiber containing 0 to 500 parts by weight of an olefin polymer with respect to 0 parts by weight, provided that polymer block A: polybutadiene block having a vinyl bond content of 30% or less Polymer block B: isoprene / butadiene = 100 /
Achieved by (co) polymer blocks consisting of 0-20 / 80% by weight.

The hydrogenated block copolymer used in the elastic fiber of the present invention is a polymer block A composed of at least one butadiene having a vinyl bond content of 30% or less.
And at least one isoprene / butadiene = 100 /
(Co) polymer block B consisting of 0 to 20/80% by weight
And a hydrogenated block copolymer having 70% or more of the unsaturated bonds in the block chain is hydrogenated.

The polymer block A has a vinyl bond content of 30.
It must be a butadiene block that is less than or equal to%. The block A becomes a block having a crystalline polyethylene-like structure when hydrogenated. The vinyl bond content of the block A has a great influence on the crystallinity of the block A after hydrogenation, and when it is more than 30%, the oil resistance and spinnability of the target elastic fiber are inferior and the obtained elasticity is low. The disadvantage is that the mechanical strength of the fiber is poor. More preferably, the vinyl bond content is 20% or less.

The polymer block B must be a (co) polymer block composed of isoprene / butadiene = 100/0 to 20/80% by weight. When the butadiene content exceeds 80% by weight, the flexibility and rubber elasticity of the block B of the hydrogenated block copolymer obtained are poor, and the elastic fiber targeted by the present invention cannot be obtained, which is not preferable.

When isoprene and butadiene are copolymerized and used as the polymer block B, the ratio is isoprene / butadiene = 80 to 20/20 to 80 (% by weight).
Is preferable, and more preferably isoprene / butadiene = 65-40 / 35-60 (% by weight).

Further, when copolymerizing isoprene and butadiene in the polymer block B, the copolymer may be in the form of a random block copolymer or a tapered block copolymer, but isoprene and butadiene are random. Copolymers are preferred.

The vinyl bond content of the block B is not particularly limited, but in order that the desired elastic fiber has excellent rubber elasticity and low-temperature characteristics, the vinyl bond content in the block B is set to be the same. Has a glass transition temperature (Tg) of 2
It is preferable to control the temperature to be 0 ° C. or lower. For example, when the component of the block B is used alone as isoprene, its vinyl bond content is preferably 80% or less.

In the present invention, the vinyl bond amount means the total amount of 1,2-bond isoprene and 3,4-bond isoprene in the case of isoprene, and 1,2-bond in the case of butadiene. Is represented by butadiene.

The ratio of block A to block B in the block copolymer differs depending on the intended use of the elastic fiber, but the ratio of block A is preferably 5 to 75% by weight, more preferably 10 to It is 60% by weight.

The hydrogenated block copolymer containing the polymer block A and the polymer block B has a hydrogenation ratio of 7
It is necessary to be 0% or more, preferably 80% or more, and more preferably 90% or more. Hydrogenation rate is 70
If it is less than%, the crystallinity of the polymer block A is inferior, the oil resistance of the hydrogenated block copolymer and the elastic fiber obtained, and the spinnability in the spinning step for obtaining the elastic fiber are inferior. . Furthermore, a hydrogenated block copolymer with a residual unsaturated double bond, and the heat resistance of the resulting elastic fiber,
The weather resistance is remarkably deteriorated, which is not preferable.

In the present invention, the number average molecular weight of the hydrogenated block copolymer is not particularly limited, but from the viewpoint of moldability, it is usually 10,000 to 400,000, more preferably 20,000 to 200,000. .

As the bonding form of the hydrogenated block copolymer,
A-B, A-B-A, B-A-B, (A-B) n-X,
(A-B-A) n-X (n is an integer of 2 to 10, X represents a coupling agent residue) and the like, but from the viewpoint of mechanical strength and molding processability of the target elastic fiber. , A-B or A-B-A are preferred.

The hydrogenated block copolymer used in the present invention may contain a functional group such as a carboxyl group, a hydroxyl group, an acid anhydride, an amino group or an epoxy group in the molecular chain or at the molecular end. These functional groups are introduced by using an unsaturated carboxylic acid such as maleic anhydride or glycidyl methacrylate or a derivative thereof in a solution state or a molten state of the hydrogenated block copolymer with or without a radical initiator. Can be done by It can also be carried out by synthesizing a living polymer by anionically polymerizing butyllithium as a polymerization initiator and adding carbon dioxide, ethylene oxide, propylene oxide or the like to the active terminal of the polymer.

In the present invention, the precursor polymer of the hydrogenated block copolymer can be easily obtained by known anionic polymerization. As a synthesis example thereof, a method of sequentially polymerizing butadiene, isoprene or / and butadiene using an alkyllithium compound as an initiator, or a method of sequentially polymerizing isoprene or / and butadiene or butadiene using a dilithium compound as an initiator, and further an alkyllithium compound A method in which butadiene, isoprene, and / or butadiene are sequentially polymerized using as an initiator and then coupled with a coupling agent can be used. Further, the vinyl bond amount in the block copolymer can be controlled by adding a vinylating agent before or during the polymerization. Examples of the alkyl lithium include alkyl compounds having an alkyl residue having 1 to 10 carbon atoms, and ethyl lithium, n-propyl lithium, sec-butyl lithium, and tert-butyl lithium are particularly preferable. Examples of dilithium compounds include hexamethylene dilithium, naphthalenedilithium, oligostildilithium, dilithiostilbenzene and the like. Examples of coupling agents include diethyl adipate, divinylbenzene, silicon tetrachloride, tin tetrachloride,
1,2-dibromoethane, 1,4-chloromethylbenzene and the like can be mentioned. Examples of the vinylating agent include tetramethylenediamine, tetrapropanediamine, tetrahydrofuran, diethyl ether, 1,4-dioxane and the like. The amount used is 1 total monomer used for polymerization.
0.01 to 0.3 part by weight of each initiator, 0.04 to 0.8 part by weight of coupling agent, and 0.0
5 to 15 parts by weight is suitable.

Examples of the organic solvent that can be used during the polymerization include butane, pentane, n-hexane, isopentane, heptane, octane and other aliphatic hydrocarbons, cyclopentane,
Examples thereof include alicyclic hydrocarbons such as methylcyclopentane, cyclohexane and methylcyclohexane, and aromatic hydrocarbons such as benzene, toluene and xylene.

Polymerization is carried out at -20 in any polymerization method.
It is carried out in a temperature range of -80 ° C for 1-50 hours.

The block copolymer is prepared by adding the polymerization solution to a poor solvent such as methanol and solidifying it, followed by heating or drying under reduced pressure, or dropping the polymerization solution into boiling water to azeotrope the solvent. After that, it is obtained by heating or drying under reduced pressure.

The block copolymer obtained is hydrogenated according to a known method. Recommended methods include hydrogenation reaction and a method of reacting molecular hydrogen in a state in which the block copolymer is dissolved in a solvent inert to the hydrogenation catalyst. Examples of the hydrogenation catalyst include precious metal catalysts such as platinum and palladium, Raney-nickel, organic nickel compounds, organic cobalt compounds, or composite catalysts of these compounds and other organic metal compounds. In the hydrogenation reaction, the hydrogen pressure is atmospheric pressure to 200 kg / cm ² , and the reaction time is 0.1.
~ 100 hours. After the hydrogenation reaction, the block copolymer is coagulated with methanol or the like and then heated or dried under reduced pressure, or the polymerization solution is dropped into boiling water and azeotropically distilled with a solvent, and then heated or dried under reduced pressure. Is obtained by

Next, the olefin polymer which can be used in the present invention is a polymer containing an α-monoolefin having 2 to 8 carbon atoms as a main monomer component. Specific examples of the olefin polymer include low density polyethylene, high density polyethylene, linear low density polyethylene, polypropylene, ethylene-propylene random copolymer, ethylene-propylene block copolymer, polymethylpentene, polybutene-1. And so on. These may be used alone or in combination of two or more. A particularly preferred olefin polymer is a polymer having ethylene or propylene as a main monomer component, and specifically, various polyethylenes, polypropylenes, ethylene-vinyl acetate random copolymers, ethylene- (meth) acrylic acid. Random copolymers, ethylene-based random copolymers such as ethylene-glycidyl methacrylate random copolymers, propylene-based random or propylene-based block copolymers, and mixtures thereof.

The amount of the olefin polymer used is required to be 0 to 500 parts by weight based on 100 parts by weight of the hydrogenated block copolymer. Hydrogenated block copolymer 10
The amount of the olefin polymer used is 0 to 500 parts by weight.
If the amount is more than the weight part, there is a drawback that the obtained fiber is inferior in flexibility and rubber elasticity. The hydrogenated block copolymer and the olefin polymer may be kneaded by any method known in the prior art. In order to obtain the most homogeneous composition, it is preferable to knead the raw materials in a heat-melted state using a kneading machine such as a single-screw extruder, a twin-screw extruder, a Banbury mixer, a Brabender, an open roll and a kneader.

Prior to melt-kneading, these components are dry-blended in advance using a mixer such as a Henschel mixer and a tumbler, and the resulting blend is melt-kneaded to obtain a homogeneous composition.

The olefinic polymer 0 to 500 is added to 100 parts by weight of the hydrogenated block copolymer obtained by the above method.
The composition containing parts by weight, before fiberizing, further improves the fluidity during molding by adding a mineral oil softener called paraffin oil or naphthenic oil, if necessary, Flexibility can be imparted to the composition. Also, depending on the purpose, calcium carbonate, talc, carbon black, titanium oxide, silica,
Inorganic fillers such as clay, barium sulphate and magnesium carbonate can be mixed. Furthermore, it is possible to mix inorganic or organic fibrous substances such as glass fibers and carbon fibers depending on the purpose. In addition, a heat stabilizer, an antioxidant, a light stabilizer, a flame retardant, a tackifier, an antistatic agent, a foaming agent and the like can be added.

The composition thus obtained can be made into fibers by melt spinning. When spinning, mixed spinning with other thermoplastic polymers and composite spinning are also possible. The melt spinning apparatus used here may be substantially the same as the apparatus used for melt spinning a thermoplastic polymer such as polyamide, polyester, polyolefin, polyvinyl chloride, or polyvinylidene chloride. For example, a screw extruder may be combined with a gear pump. The denier composition of the fiber to be produced can be variously changed depending on the spinning temperature, the spinning extrusion pressure, the extrusion rate, the spinneret pore diameter, and the winding speed, but in this respect, it is the same as in the ordinary melt spinning of synthetic fibers. Is. However, in order to prevent sticking between the wound fibers, apply a surfactant aqueous solution or an aqueous solution in which finely divided talc, calcium carbonate, etc. are dispersed to the spun yarn before winding. It is good to leave. The spinning temperature is usually 180 to 250 ° C., the spinning draft is 5 to 200, and the winding speed is 20 to 10
A range of 00 m / min is generally preferred.

The fibers thus wound may be stretched as in the case of ordinary thermoplastic synthetic fibers, but they may not be stretched and the heat treatment step may be omitted. . Therefore, the yarn making process is extremely simple and economical.

The thickness of the fiber obtained by the present invention is several denier or more, as in the case of the usual thermoplastic synthetic fiber, and can be arbitrarily selected from this. Therefore, it can be used as a multifilament, a monofilament, and a staple. The cross-sectional shape of the obtained fiber may be a flat cross section, a polygonal cross section, a multilobal cross section, a hollow cross section, or the like, in addition to an ordinary round cross section. When it is a composite fiber, its cross-sectional shape is concentric core-sheath type, eccentric core-sheath type,
It may be of a multi-core sheath type, a bimetal type, a multi-layer laminated type or the like. In the case of composite spinning or mixed spinning, it is preferable that the ratio of the hydrogenated block copolymer is 40% by weight or more based on the total polymer constituting the fiber, from the viewpoint of imparting flexibility and elasticity.

The elastic fibers of the present invention can also be used directly in making various nonwoven fabrics. For example, a direct molding method usually called melt blown, that is, melt spinning,
It is also possible to obtain various non-woven fabrics by changing the amount of polymer discharged and the amount of jetting fluid by collecting the non-woven fabric after collecting it in a sheet form to obtain a non-woven fabric after making this into a fiber stream by high-speed gas. Further, any known method in which spinning-bonding, melt spinning, spinning-lacing and the like are combined can be adopted.

The elastic fiber of the present invention containing a specific amount of the olefin-based polymer with respect to the hydrogenated block copolymer has excellent elasticity as shown in the following examples, and if necessary, other It is also used as a general industrial material such as rubber string, rubber thread for socks, net materials such as bras, foundation materials such as corsets, sports equipment materials, ropes, belts and sheets. It is widely used.

[0031]

EXAMPLES Hereinafter, the concrete constitution of the elastic fiber of the present invention will be explained based on examples, and the physical properties of the elastic fiber will be explained in comparison with those of the elastic fiber of the comparative example.

The properties of the hydrogenated block copolymer and the physical properties of the elastic fiber were measured as follows. (A) Molecular weight The number average molecular weight was measured using gel permeation chromatography (GPC). (B) Microstructure A block copolymer before hydrogenation is dissolved in deuterated toluene and a 500 MHz nuclear magnetic resonance apparatus (NM
The amount of 1,2-bond was calculated by measuring the chemical shift of ¹ H using R). (C) Hydrogenation rate The hydrogenated block copolymer after hydrogenation was dissolved in deuterated toluene, and a 500 MHz nuclear magnetic resonance apparatus (N
The hydrogenation rate was calculated by measuring the chemical shift of ¹ H using MR). (D) Restoration rate A sample having a sample length (L ₀ ) was stretched 100% at a speed of 10 cm / min, held in that state for 10 minutes, opened, and the sample length (L ₁ ) after 10 minutes was measured. It was calculated by the following formula.

Recovery rate (%) = (2-L ₁ / L ₀ ) × 100 (e) Oil resistance 5 g of the obtained elastic fiber was added to 100 ml of toluene at room temperature for 7 hours.
After soaking for a day, the insoluble matter was filtered off, and the weight after vacuum drying was measured to calculate the weight loss rate. [Preparation of hydrogenated block copolymer] (1) Preparation of hydrogenated block copolymer (I) In a pressure vessel equipped with a stirrer, 60 kg of cyclohexane, 2.25 kg of butadiene and 185 g of n-butyllithium were added, and the mixture was heated at 50 ° C. Polymerize for 60 minutes, then Isoprene 1
Add 0.5 kg for 60 minutes, then butadiene 2.25
A polybutadiene-polyisoprene-polybutadiene type block copolymer was obtained by adding kg and polymerizing for 60 minutes. After obtaining a 10 wt% cyclohexane solution of this block copolymer, it was degassed under reduced pressure and then replaced with hydrogen.
Add 5 wt% / polymer palladium catalyst 10kg / cm
The hydrogenation reaction was carried out in the hydrogen atmosphere of ² to obtain a hydrogenated block copolymer (I) having a hydrogenation rate of 98%.

The molecular properties of the block copolymer (I) are shown in Table 1. (2) Preparation of hydrogenated block copolymer (II) In a pressure vessel equipped with a stirrer, 60 kg of cyclohexane, 7.5 kg of butadiene and 200 g of n-butyllithium were added, polymerized at 50 ° C for 60 minutes, and then used as a vinylating agent. Tetrahydrofuran was added and then isoprene 7.5
kg was added for 60 minutes, and then 2.25 kg of butadiene was added and polymerized for 60 minutes to obtain a polybutadiene-polyisoprene type block copolymer. This block copolymer was obtained according to the method for producing the hydrogenated block copolymer (I) described above to obtain a hydrogenated block copolymer (II) shown in Table 1. (3) Preparation of hydrogenated block copolymers (III), (IV) and (VII) Type of monomer, amount of monomer, amount of polymerization initiator, polymerization temperature, polymerization time, hydrogenation temperature, hydrogenation time, etc. In accordance with the method for producing the hydrogenated block copolymer (I) described above, the hydrogenated block copolymers (III) and (IV) shown in Table 1 are changed.
And (VII) were obtained. (4) Preparation of hydrogenated block copolymers (V) and (VI) Type and order of addition of monomers, amount of monomers, amount of polymerization initiator, amount of vinylating agent, polymerization temperature, polymerization time, hydrogenation temperature The hydrogenation block copolymers (V) and (VI) shown in Table 1 were obtained by changing the hydrogenation time and the like according to the method for producing the hydrogenated block copolymer (II).

[0035]

[Table 1]

[Preparation of thermoplastic resin composition] (1) Preparation of thermoplastic resin composition (No. 1) The hydrogenated block copolymer (I) was formed into a strand at 180 ° C. by a screw type extruder. After melt-extruding into a pellet, it was pelletized with a strand cutter.

Pellets 4 of hydrogenated block copolymer (I)
A polypropylene resin “Mitsubishi Yuka Co., Ltd .: MA-3 (homopolypropylene, MI = 11 g / 10 min)” 60% by weight as an olefin polymer was dry blended with 0% by weight, and then a twin-screw extruder was used. (Toshiba Machine Co., Ltd .: TEM
-35), temperature 200 ℃, screw rotation speed 20
Kneading and pelletization were performed under the condition of 0 rpm to obtain a thermoplastic resin composition (No. 1). (2) Preparation of thermoplastic resin composition (No. 2 to 7) The hydrogenated block copolymers (II to VII) and the olefin polymer were subjected to the preparation method of the thermoplastic resin composition (No. 1). Then, the thermoplastic resin composition (No. 2 to 7) was obtained by kneading and pelletizing the ingredients shown in Table 2. (3) Production of thermoplastic resin composition (No, 8) Commercially available styrene-based thermoplastic elastomer "Kuraray Co., Ltd .: Septon 2002; styrene content 30% by weight, molecular weight Mn 50000" based on 60% by weight of olefin resin Polypropylene resin as "Mitsubishi Petrochemical Co., Ltd .: MA
-3 (homopolypropylene, MI = 11 g / 10
Min) ”40% by weight after dry blending, using a twin-screw extruder (Toshiba Machinery Co., Ltd .: TEM-35) at a temperature of 20.
Kneading and pelletization were carried out under the conditions of 0 ° C. and a screw rotation speed of 200 rpm to obtain a thermoplastic resin composition (No. 8).

[0038]

[Table 2]

[Preparation of Elastic Fiber] Example 1 The hydrogenated block copolymer (I) was used at 200 ° C. using a conventional spinning machine in which a screw type extruder was combined with a gear pump.
In the above, an elastic fiber was obtained by spinning at a spinning speed of 500 m / min. The physical properties of the obtained elastic fiber are shown in Table 3.

Reference Example 1 Commercially available styrene thermoplastic elastomer "Septon 20"
02 ”was obtained by using the same spinning machine as in Example 1 and changing the spinning speed. The physical properties of the obtained elastic fiber are shown in Table 3.

Examples 2 to 8, Comparative Examples 1 to 6 and Reference Example 2 Hydrogenated block copolymers (II to VII) shown in Table 1 and thermoplastic resin compositions (No. 1 to No. 1) By using 8) and changing the spinning temperature and spinning speed, elastic fibers were obtained in the same manner as in Example 1. The physical properties of the obtained elastic fiber are shown in Table 3.

Examples 1 to 4 are elastic fibers made of a hydrogenated block copolymer, and as can be seen from Table 3, all have excellent oil resistance, rubber elasticity, and good mechanical strength. Elastic fibers are obtained. Examples 5-8
Is an elastic fiber composed of a hydrogenated block copolymer and an olefin polymer, and as can be seen from Table 3, all have excellent oil resistance, rubber elasticity, and good mechanical strength.
The desired elastic fiber is obtained.

The hydrogenated block copolymer VI of Comparative Example 1 was inferior in spinnability and no fiber was obtained. The fiber obtained in Comparative Example 2 has oil resistance, but is inferior in rubber elasticity, which is not preferable.

The elastic fibers obtained in Comparative Examples 3, 4 and 6 are not preferable because they have rubber elasticity but are poor in oil resistance.

The elastic fiber obtained in Comparative Example 5 is excellent in mechanical strength, but is inferior in oil resistance and rubber elasticity, which is not preferable.

The elastic fibers obtained in Reference Examples 1 and 2 are
It has excellent rubber elasticity and mechanical strength, but is inferior in oil resistance.

[0047]

[Table 3]

[0048]

EFFECTS OF THE INVENTION The conventional fiber made of a hydrogenated product of a block copolymer composed of a vinyl aromatic compound and a conjugated diene has a drawback that it is inferior in oil resistance to an organic solvent.

However, since the elastic fiber provided by the present invention is excellent in oil resistance and is also excellent in flexibility, heat resistance, mechanical strength and weather resistance, it is possible to make use of the characteristics of the elastic fiber for daily use such as clothing and packaging. It can be used in various fields such as materials, industrial products, food products, etc., and is particularly preferably used for a portion which comes into direct contact with an organic solvent or a vapor of its components.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mizuho Maeda 36 Towada, Kamisu-cho, Kashima-gun, Ibaraki Prefecture Kuraray Co., Ltd.

Claims (1)

[Claims] 1. A block copolymer comprising at least one polymer block A and at least one polymer block B shown below, wherein 70% or more of the unsaturated bonds in the block chain are water. Olefin-based polymer 0-500 to 100 parts by weight of the hydrogenated block copolymer added
An elastic fiber containing parts by weight. Polymer block A: polybutadiene block having a vinyl bond content of 30% or less Polymer block B: isoprene / butadiene = 100 /
(Co) polymer block consisting of 0 to 20/80% by weight