JP2000192370A - Lactic acid-based resin monofilament - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lactic acid-based resin monofilament having excellent biodegradability, mechanical strength and storage stability and rich in formability, when secondarily processed, by melt-extruding and thermally drawing the lactic acid-based resin and then imparting a lipophilic lubricant to the drawn filament. SOLUTION: This monofilament is obtained by melt-extruding a lactic acid- based resin such as polylactic acid, heating and drawing the obtained filament, and then imparting a lipophilic lubricant, such as a petroleum-based lubricant consisting mainly of one or more oils selected from the group of a paraffinic oil, a naphthenic oil, a spindle oil, a freezer oil, a compressor oil, a dynamo oil, a turbine oil, a machine oil, a (marine)engine oil, a cylinder oil, a gear oil, an air plane lubricant, a jet engine lubricant and a hydraulic oil, to the obtained mononfilament.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to mechanical strength, heat resistance,
In addition, the present invention relates to a biodegradable lactic acid-based resin monofilament having excellent secondary workability when formed into a net, fishnet, or rope shape.

[0002]

2. Description of the Related Art In general, polymer materials (mainly thermoplastic polymer materials) represented by polyolefins, polystyrenes, polyesters, polyamides, polyacrylates, polycarbonates, polyimides, etc., are in our daily lives. It is an indispensable material. However, these ordinary polymer materials have completed their mission of use, and when disposed of, are hardly decomposed in the natural environment. Therefore, when they are buried, they remain semi-permanently in the ground and are incinerated. In this case, there are problems such as air pollution by waste gas and shortening of the life of the incinerator due to incineration heat energy. Furthermore, since ordinary polymer materials are hardly decomposed in the natural environment, they damage the landscape, pollute the environment by elution of additives such as plasticizers, destroy the living environment of marine life, There are many environmental issues and new materials are needed.

[0003] From such a background, degradability and / or biodegradability (in the specification of the present application, the function of decomposing under the action of microorganisms in a natural environment and the function of decomposing in vivo by the action of enzymes and the like) As a thermoplastic resin having polylactic acid, a copolylactic acid having a lactic acid component as a main component (for example, a copolymer of lactic acid and another aliphatic hydroxycarboxylic acid), a polylactic acid and another aliphatic polyester. (For example, a mixture of polylactic acid and polybutylene succinate) has attracted attention. In particular, polylactic acid is 100% biodegradable in the body of animals within several months to one year, and when left in wet conditions such as soil or seawater, its strength starts to decrease in about a few weeks and from about one year It is characteristic in that it disappears without retaining its original form in about several years, and that the decomposition product has the property of becoming lactic acid and / or carbon dioxide and water harmless to the human body. Lactic acid, which is a raw material of polylactic acid, is produced by a fermentation method or a chemical synthesis method. Recently, L-lactic acid has been produced in a large amount by the fermentation method, and the price has become low. Development of various applications utilizing characteristics of polylactic acid having transparency and rigidity is being promoted.

The present invention relates to a monofilament made of a lactic acid-based resin, and several techniques relating to this have already been disclosed. For example, a polylactic acid fiber comprising a blend of poly-L-lactic acid and poly-D-lactic acid (Japanese Patent Application Laid-Open No. 63-264913), a yarn containing polylactic acid as a constituent material (Japanese Patent Application Laid-Open No. 3-183428), A method for producing a polylactic acid-based resin filament using at least two or more stretching steps (Japanese Patent Application Laid-Open No. 10-60733) is known. However, although these technologies are certainly technologies that can produce filaments,
There are a number of problems in the subsequent processing of nets, fishing nets and ropes.

[0005] For example, when secondary processing is performed into a net, fishing net, or rope, the yarns are entangled due to static electricity due to friction between the filament and rolls, hooks, braces, and the like of a loom or knitting machine, and the filament cannot be formed. It may be scratched or cut. Further, the device may be damaged due to wear between the filament and the device. To solve such problems, for example, a technique for avoiding the above-described problems due to friction and wear by applying a lubricant such as a fatty acid ester or an emulsifier, a surfactant, or an antistatic agent to the surface of the monofilament is considered. Can be

However, when such a technique is applied to the monofilament made of a lactic acid-based resin shown in the present invention, the yarn wound on a bobbin or a paper roll may be cut during storage, or the yarn may be cut off during bobbin processing. The yarn may be broken when the yarn is fed from the reel. Furthermore, the thread breakage due to the friction and abrasion may not be avoided depending on the medicine. As described above, according to the conventional technology, there is no technology for obtaining a monofilament having sufficient mechanical strength and substantially satisfying the secondary processing property in secondary processing into a net, a fishnet, or a rope. It is.

[0007]

Accordingly, the present invention has substantially sufficient mechanical strength, has excellent storage stability when wound into a paper roll, and is knitted or woven into a net, fish net, rope, or the like. It is an object of the present invention to develop a lactic acid-based resin monofilament having excellent moldability in the case of secondary processing.

[0008]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have satisfied the above problems by applying a lipophilic lubricant to the surface of a monofilament made of a lactic acid-based resin. It has been found that a monofilament that can be used is obtained, and the present invention has been completed.

That is, the present invention provides the following [1] to [1]
0]. [1] A monofilament obtained by melt-extruding a lactic acid-based resin, the monofilament having an excellent lipophilic lubricant obtained by applying a lipophilic lubricant to the surface of the filament. [2] The monofilament excellent in secondary workability according to [1], wherein the lipophilic lubricant is a petroleum-based lubricant. [3] Petroleum-based lubricating oils include paraffinic oil, naphthenic oil, spindle oil, refrigerating machine oil, compressor oil, dynamo oil, turbine oil, machine oil, engine oil,
The secondary processing according to [2], wherein the secondary processing is an oil mainly containing one or a mixture of two or more kinds selected from cylinder oil, marine engine oil, gear oil, aviation lubricating oil, jet engine lubricating oil, and hydraulic oil. Monofilament with excellent properties. [4] The monofilament according to [1] to [3], wherein the lactic acid-based resin is polylactic acid. [5] A method for producing a monofilament, comprising: a step of melt-extruding a lactic acid-based resin to obtain a strand; a step of heating and stretching the strand in one or more steps to obtain a monofilament; and a step of winding the drawn monofilament. A method for producing a monofilament excellent in secondary workability, characterized by applying a lipophilic lubricant to the surface of a filament in any step before winding.

[6] A monofilament excellent in secondary workability, comprising a composition obtained by adding a lipophilic lubricant to a lactic acid-based resin. [7] The monofilament excellent in secondary workability according to [6], wherein the lipophilic lubricant is a petroleum-based lubricant. [8] Petroleum lubricating oils include paraffinic oil, naphthenic oil, spindle oil, refrigerating machine oil, compressor oil, dynamo oil, turbine oil, machine oil, engine oil,
The secondary processing according to [7], wherein the secondary processing is an oil mainly containing one or a mixture of two or more selected from cylinder oil, marine engine oil, gear oil, aviation lubricating oil, jet engine lubricating oil, and hydraulic oil. Monofilament with excellent properties. [9] The monofilament excellent in secondary workability according to [6] to [8], wherein the lactic acid-based resin is polylactic acid. [10] A secondary process comprising: a step of melt-extruding a composition obtained by adding a lipophilic lubricant to a lactic acid-based resin to obtain a strand; a step of heating and stretching the strand in one or more steps; and a step of winding a drawn monofilament. Manufacturing method of monofilament with excellent processability.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. [Lactic acid-based resin] In the present invention, the term "lactic acid-based resin" refers to a homopolymer or a copolymer in which the lactic acid component in all the monomer components constituting the resin is at least 50% by weight or more. (Eg, copolymer of lactic acid and glycolic acid, copolymer of lactic acid and caproic acid, block copolymer of polylactic acid and polycaproic acid), lactic acid and aliphatic polyhydric alcohol and aliphatic polycarboxylic acid (E.g., a copolymer of lactic acid and butanediol with succinic acid and adipic acid, a copolymer of lactic acid and ethylene glycol, and a copolymer of butanediol and succinic acid, a block copolymer of polylactic acid and polybutylene succinate, etc.),
And mixtures thereof. Further, a mixture of polylactic acid and an aliphatic polyester (for example, polycaproic acid, polybutylene succinate, polyethylene succinate, a copolymer of β-hydroxybutyric acid and β-hydroxyvaleric acid, etc.) is included. In the case of a mixture, a compatibilizer may be contained. When the lactic acid-based resin is a copolymer,
The mode of the arrangement of the copolymer may be any mode such as a random copolymer, an alternating copolymer, a block copolymer, and a graft copolymer. Furthermore, these may be at least partially cross-linked with a cross-linking agent such as xylylene diisocyanate, polyvalent isocyanate such as 2,4-tolylene diisocyanate or polysaccharide such as cellulose, acetyl cellulose or ethyl cellulose. At least a part thereof may have any structure such as a linear shape, a ring shape, a branched shape, a star shape, and a three-dimensional network structure, and there is no limitation.

In the lactic acid resin of the present invention, polylactic acid,
In particular, poly-L-lactic acid, a block copolymer of polylactic acid and poly-6-hydroxycaproic acid, particularly a block copolymer of poly-L-lactic acid and poly-6-hydroxycaproic acid, and a copolymer of polylactic acid and polybutylene succinate Block copolymers, especially block copolymers of poly-L-lactic acid and polybutylene succinate, copolymers of polylactic acid, β-hydroxybutyric acid and β-hydroxyvaleric acid, especially poly-L-lactic acid, β-hydroxybutyric acid and β- Preference is given to block copolymers with copolymers of hydroxyvaleric acid.

[Aliphatic hydroxycarboxylic acid] Specific examples of the aliphatic hydroxycarboxylic acid constituting the lactic acid resin in the present invention include, for example, glycolic acid, lactic acid, and lactic acid.
-Hydroxy drank acid, 4-hydroxy drank acid, 3-hydroxy valeric acid, 4-hydroxy valeric acid, 5-hydroxy valer lactic acid, 6-hydroxy caproic acid and the like. These may be one kind or a mixture of two or more kinds. When the aliphatic hydroxycarboxylic acid has an asymmetric carbon,
L-form, D-form, and a mixture thereof, that is, a racemic form may be used.

[Aliphatic polycarboxylic acid and its anhydride]
Specific examples of the aliphatic polycarboxylic acid constituting the lactic acid-based resin in the present invention, for example, oxalic acid, succinic acid,
Malonic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanoic acid,
Examples thereof include aliphatic dicarboxylic acids such as dodecane diacid and anhydrides thereof. These may be one kind or a mixture of two or more kinds.

[Aliphatic polyhydric alcohol] Specific examples of the aliphatic polyhydric alcohol constituting the lactic acid resin in the present invention include, for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 3-butanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,9-
Nonanediol, neopentyl glycol, tetramethylene glycol, 1,4-cyclohexanedimethanol and the like can be mentioned. These may be one kind or a mixture of two or more kinds.

[Polysaccharides] Specific examples of polysaccharides include, for example, cellulose, cellulose nitrate, cellulose acetate, methylcellulose, ethylcellulose, celluloid, viscose rayon, regenerated cellulose, cellophane, cupra, cuprammonium rayon, cuprophan, Bemberg , Hemicellulose, starch, amylopectin, dextrin, dextran, glycogen, pectin, chitin, chitosan, gum arabic, guar gum, locust bean gum, acacia gum, and the like, and derivatives thereof. Particularly, acetyl cellulose and ethyl cellulose are preferably used. Can be These may be one kind or a mixture of two or more kinds.

[Molecular weight of lactic acid-based resin] The molecular weight of the lactic acid-based resin used in the present invention is not particularly limited as long as it exhibits substantially sufficient mechanical properties when processed into a monofilament. . The molecular weight of the lactic acid-based resin is preferably from 1 to 3,000,000, more preferably from 3 to 2,000,000, more preferably from 5 to 1,000,000, still more preferably from 70 to 500,000, and more preferably from 9 to 3,000,000, as a weight average molecular weight.
100,000 is most preferred. If the weight average molecular weight is less than 10,000, the mechanical properties are not sufficient or the molecular weight is less than 30.
If it is larger than 10,000, handling may be difficult due to molding processing, and production cost may be uneconomical. The weight-average molecular weight and molecular weight distribution of the lactic acid-based resin used in the present invention, the type of solvent, the type and amount of catalyst, the reaction temperature, the reaction time, the method of embedding the solvent distilled off by azeotropic distillation, The desired conditions can be controlled by appropriately selecting the reaction conditions such as the degree of solvent drying in the reaction system.

[Method for Producing Lactic Acid Resin] The method for producing the lactic acid resin of the present invention is not particularly limited. For example, as a specific example of a method for producing polylactic acid and a lactic acid-based resin having lactic acid as a structural unit, a method as described in Production Example 2 described below with reference to the method disclosed in JP-A-6-65360. No. That is, it is a direct dehydration condensation method in which lactic acid or lactic acid and an aliphatic hydroxycarboxylic acid other than lactic acid, or an aliphatic diol and an aliphatic dicarboxylic acid are directly dehydrated and condensed in the presence of an organic solvent and a catalyst.

As another example of a method for producing a lactic acid-based resin having lactic acid as a structural unit, see, for example, JP-A-7-17326.
Production Example 4 described below with reference to the method disclosed in No. 6
The method shown in FIG. That is, this is a method in which a homopolymer of polylactic acid and at least one aliphatic polyester is copolymerized and transesterified in the presence of a polymerization catalyst. As another example of the method for producing polylactic acid, for example, a method as shown in Production Example 1 described below with reference to the method disclosed in US Pat. No. 2,703,316 is exemplified. That is, it is an indirect polymerization method in which lactic acid or lactic acid and a hydroxycarboxylic acid other than lactic acid are each once dehydrated to form a cyclic dimer, and then subjected to ring-opening polymerization.

[Lipophilic Lubricant] The lipophilic lubricant used in the present invention is a mold that can not be obtained by spinning of a lactic acid-based resin alone. It has the effect of improving various properties such as improvement of the properties, and further improving the formability in the case of secondary processing into nets, fishing nets and ropes. For that purpose, it is necessary to apply the lubricant to the surface of the monofilament of the lactic acid-based resin. Examples of the method of applying a lubricant to the surface of a lactic acid-based resin monofilament include (1) a method of melt-spinning a lactic acid-based resin composition obtained by adding the lubricant to a lactic acid-based resin, and (2) a method of melt-spinning a lactic acid-based resin. Extrusion step of obtaining a strand by doing, a stretching step of stretching the strand, a winding step of winding the stretched yarn, a method of applying the lubricant in any step up to, the method of the present invention, There are no restrictions.
In the case of the method (1), the lubricant bleeds out to the surface of the yarn in an extrusion step or a drawing step described below,
The effects of the present invention are exhibited. Therefore, it is preferable that the lubricant has low compatibility with the lactic acid-based resin.

The lipophilic lubricant used in the present invention includes:
For example, spindle oil, refrigerator oil, compressor oil,
Dynamo oil, turbine oil, machine oil, engine oil, cylinder oil, marine engine oil, gear oil, aviation lubricant oil,
A petroleum-based lubricating oil containing a lubricating oil for a jet engine, a hydraulic oil or the like as a main component is exemplified. In particular the kinematic viscosity of petroleum lubricating oil, better 1 to 500 mm ² / S at 40 ° C., preferably better 1 to 300 mm ² / S, more preferably from 1 to 10
0 mm ² / S is good, and most preferably 1 to 50 mm ² /
S is good. If the kinematic viscosity is greater than 500 mm ² / S, handling may be difficult, control of the amount of application when applying to the filament may be difficult, or uneconomical.

As such a petroleum-based lubricating oil, for example,
Product name of Idemitsu Kosan Co., Ltd., Diana Fresia G-
6, Diana Fresia W-8, Diana Fresia K
-8, Diana Fresia F-9, Diana Fresia
NR-9, Diana Fresia S-10, Diana Fresia S-32, Diana Fresia P-32), Diana Fresia P-90, Diana Fresia P-18
0, Diana Fresia P-430, Diana Fresia
N-28, Diana Fresia N-90, Diana Fresia N-150, Diana Fresia N-430, Diana Fresia U-46, Diana Fresia U-6
8, Diana Fresia U-130, Diana Fresia U-260 and the like. These may be one kind or a mixture of two or more kinds.

[Additives] The lactic acid-based resin or the lactic acid-based resin composition of the present invention extremely impairs the mechanical strength of the filament, the secondary workability of forming into a net, a fishnet, a rope, and the biodegradability. If not, various elastomers (SBR, NBR, SBS type ternary block copolymer thermoplastic elastomer, etc.) and additives (plasticizer, pigment, stabilizer, antistatic agent, ultraviolet absorber, antioxidant,
Flame retardants, release agents, lubricants, dyes, antibacterial agents) and impact modifiers (impact core / shell particles, impact modifiers, etc.) can be used as appropriate according to the purpose and application.

[Inorganic Filler] For example, an inorganic filler can be added for the purpose of improving the blocking resistance of the filament or improving the weather resistance.
Specific examples of the inorganic filler include, for example, carbon, talc, kaolinite, SiO ₂ , clay, calcium carbonate, titanium oxide, zinc oxide, barium sulfate and the like. Among them, carbon and titanium oxide are preferable. The particle size of the inorganic filler needs to be appropriately selected depending on the shape and diameter of the filament, but is generally from 10 nm to 100 μm.
m is good, 20 nm to 75 μm is more preferable, and 50 n
m to 50 μm are more preferred, and 50 nm to 10 μm are most preferred.

[Amount of Inorganic Filler] The amount of the inorganic filler to be added depends on the type of the inorganic filler, but includes mechanical strength of the filament, secondary workability into a net, fish net, rope, and biodegradability. There is no limitation as long as the amount does not extremely impair, but generally 0.01 to 10.0 parts by weight can be added to 100 parts by weight of the lactic acid-based resin,
Preferably 0.03-5.0 parts by weight, more preferably 0.05-3.0 parts by weight, even more preferably 0.1-1.
0 parts by weight. If the amount is less than 0.01 part by weight, the effect of the addition will not be exhibited, while if it is more than 10 parts by weight, the secondary workability and mechanical properties of the filament may be deteriorated.

[Production Method of Lactic Acid Resin Composition] [Mixing / Kneading / Kneading] In the present invention, the lactic acid-based resin is mixed with a lipophilic lubricant and optionally other additives. The lactic acid-based resin composition is obtained by kneading techniques known and publicly known, for example, a method of mixing each raw material with a Henschel mixer, a ribbon blender, or the like, or while directly adding to a molten polymer using an extruder or the like. A kneading method (side feed method) can be adopted.

[Molding of Lactic Acid Resin Monofilament] A method for producing a lactic acid resin monofilament will be described below. As the molding process of the lactic acid-based resin monofilament of the present invention, for example, a lactic acid-based resin is extruded from a die hole of a molding machine, and is extruded into a cooling water tank to obtain a strand. A method of applying the lipophilic lubricant in any step up to the step of winding the stretched monofilament, and a lactic acid-based resin composition to which the lipophilic lubricant is added, using a die of a molding machine. An extrusion step in which a molten strand is extruded from a hole and guided to a cooling water bath to obtain a strand, a stretching step in which the strand is stretched, and a method in which a filament is obtained by a winding step in which the stretched yarn is wound up can be exemplified.

[Extrusion Step] The extrusion temperature is set at 220 ° C. from the melting point (Tm) of the lactic acid-based resin or lactic acid resin composition, and the molten strand coming out of the die is cooled in a cooling water bath. The water temperature depends on the diameter of the monofilament,
The range is preferably from 0 to 80C, more preferably from 30 to 70C, even more preferably from 40 to 60C. When the water temperature is lower than 30 ° C., the strand becomes excessively hard, so that the strand is disturbed in running, or the disorder is propagated to the surroundings to adversely affect the shape of the strand. In addition, the disorder of the shape of the strand may cause the next stretching to be not uniform. When the water temperature is higher than 80 ° C., insufficient cooling of the strand occurs, and the strand is introduced into the next stretching step while being soft, which may cause poor winding by the take-up roller (stretching roller).

[Stretching Step] The term "stretching" as used in the present invention refers to an operation of mechanically stretching a monofilament at a temperature equal to or lower than the melting point of a material to orient molecules in a direction parallel to the tensile direction.
This operation significantly increases the tensile strength and increases the toughness. After the stretching process, if the film is reheated to a temperature higher than the stretching temperature, it tends to shrink to its original size. To stabilize the dimensions and strength, heat treatment at a temperature slightly lower than the stretching temperature (heat fixing, heat setting) May be performed. In the present invention, the strand obtained in the extrusion step is stretched by heating to a specific temperature. Stretching is performed at the speed ratio (drawing ratio) between the entrance-side take-up roller and the exit-side take-up roller.
The stretching ratio at this time is preferably 3 to 15 times. The heating method at the time of stretching may be any of a hot water tank, an oven, a hot roll and the like, and is not limited at all. However, a hot water tank is more preferable for more uniform heating and stretching.

Stretching using a hot water tank can be realized by arranging a water tank having a length and depth capable of adjusting the water temperature, and a take-up roller before and after the water tank. Stretching using an oven can be realized by arranging an electric heater (infrared heater) as a heat source in the longitudinal direction to adjust the temperature by arranging an oven having a length of several meters, and arranging a take-off roller before and after the oven. . In addition, stretching using a hot roll is realized by installing a plurality of heated and temperature-controlled take-off rollers with water pipes, oil pipes, electric heaters, etc. arranged inside, and adjusting the rotation speed of the rolls. It is possible.

The temperature conditions at the time of stretching include a hot water tank, an oven,
Regardless of which apparatus or method is selected, such as a hot roll, the surface temperature of the monofilament before stretching is changed from the glass transition temperature (Tg) of the lactic acid-based resin or the lactic acid-based resin composition to the melting point (Tm) of 60 to 130. ° C, Tg
To (Tm-30 ° C), more preferably Tg to (Tm-6).
0 ° C.) is more preferred. If the surface temperature is lower than Tg, stretching may be cut off or stretching three times or more may not be possible. On the other hand, when it exceeds Tm, the effect of strength development by stretching is reduced.

In the present invention, the stretching ratio is usually in the range of 3 to 15 times, preferably 4 to 14, and more preferably 5 to 13 times. If the stretching ratio is less than 3 times, the strength development by the stretching operation becomes insufficient, and a product having practical strength (2.0 g / d or more) as a monofilament may not be obtained. Conversely, at a draw ratio exceeding 15 times,
In some cases, troubles such as easy stretching breakage, whitening due to voids, and vertical cracking of the monofilament may occur. As a method of performing the stretching of 3 to 15 times, in addition to the method of performing the stretching in one step, these are appropriately combined to form a two-stage, three-stage to multi-stage configuration, and a small-magnification stretching is performed in each stage. A method in which the stretching ratio is 3 to 15 times can be adopted.

In the case of performing multi-stage stretching, the stretching ratio is sequentially changed, for example, from 1.1 to 10 times in the first stage, and from 1.5 to 10 times in the second stage. Magnification 3
Preferably, the heating temperature condition is set to be the lowest at the first stage in the above-mentioned temperature range, and the temperature is sequentially increased each time the number of stages is increased.

In the present invention, the stretched monofilament can be further heat-treated to suppress a change in physical properties (eg, shrinkage) at a high temperature. The method is carried out in a heating tank set at a temperature between the glass transition temperature (Tg) and the melting point (Tm) of the lactic acid-based resin or the lactic acid-based resin composition, preferably 70 to 120 ° C, more preferably 80 to 100 ° C. After being guided and subjected to a heat treatment (heat fixing), it is cooled in a cooling bath. As in the case of the stretching operation, any method such as a water tank, an oven, or a hot roll may be used for the heat treatment, and there is no limitation.
Cooling may be performed by either water cooling or air cooling, and there is no limitation.

[Winding Step] Finally, the stretched monofilament is taken up by a winding machine into a tubular paper, plastic,
It can be wound on a metal winding to obtain a monofilament winding.

The monofilament obtained by the production method of the present invention has a draw ratio of 3 to 15 times, a filament thickness of 50 to 2000 d, and a tensile strength of 2.0 to 10.0 g measured according to JIS Z8703. / D and a monofilament having a tensile elongation of 5 to 50% are obtained.

The monofilament obtained according to the present invention has substantially sufficient mechanical strength, has excellent storage stability in the state of being wound on a paper roll, and has a loom for secondary processing into a net, fishnet or rope. And knitting machine rolls, hooks,
It exhibits good formability and has high productivity without causing yarn breakage or yarn entanglement due to abrasion or friction with umbrellas. The secondary processed product shown in the present invention has, for example, a net shape, a rope shape, a net shape, and a combination thereof processed by a conventionally known knitting machine or loom, and has a size and a shape. There are no restrictions on the design. The types of netting when processing with a knitting machine or loom include knotty nets such as real nets, frog nets, double frog nets, Russell nets, maple nets,
There are no knitted nets such as woven nets and metallic fiber nets, but there is no limitation. .

The secondary processed product of the monofilament obtained by the present invention can be used for applications such as fishing materials, agricultural and forestry materials, civil engineering and construction materials, sports and leisure materials, and industrial materials. For example, as fishing materials,
Nori net, fishing line, bottoming net, gill net, trawl net, fixed net, winding net, fish net such as aquaculture net, aquaculture, rope for fishing boat, etc.
Materials for agriculture and forestry include insect-proof nets, wind-proof nets, shading nets, weed prevention nets, bird-proof nets, cue nets, flower nets, etc., and civil engineering and building materials include vegetation nets, sandbag nets, rockfall nets, Sports and leisure materials such as safety nets include golf, baseball, tennis, table tennis, volleyball, badminton, soccer, handalls, basketball, hockey, ice hockey, water polo and other sport nets, insect nets, and the like.

The secondary processed product such as a monofilament, a net or a rope obtained by the present invention is excellent in weather resistance by adding an inorganic filler such as carbon or titanium oxide for a relatively long period in a natural environment. Applicable to applications requiring stability.

[0040]

[Examples] Production examples, examples and comparative examples are shown below.
The present invention will be described in detail. Note that descriptions of synthesis examples, examples, comparative examples, aspects and the like in the specification of the present application are descriptions for assisting understanding of the contents of the present invention, and the description narrows the technical scope of the present invention. It is not of a nature to be interpreted.

The method for producing the lactic acid resin used in the examples and comparative examples is described below. All parts in the text are based on weight. The average molecular weight (weight average molecular weight Mw) of the polymer was measured by gel permeation chromatography using polystyrene as a standard under the following conditions. (1) Instrument: Shimadzu LC-IOAD (2) Detector: Shimadzu RID-6A (3) Column: Hitachi Chemical GL-S350DT-5, GL
-S370DT-5 (4) Solvent: chloroform (5) Concentration: 1% (6) Injection volume: 20 μl

Further, the glass transition temperature (Tg) and the melting point (Tm) are measured by a differential scanning calorimeter (manufactured by Shimadzu Corporation;
SC-50), the point at which the lactic acid-based resin changes into a rubbery state when the temperature is raised at a rate of 10 ° C./min is defined as a glass transition point (T
g), the peak of the melting peak was taken as the melting point (Tm).

Production Example 1 <Production of Polymer A (Poly L-lactide)> 100 parts of L-latatatide and stannous octoate 0.01
And 0.03 part of lauryl alcohol were sealed in a thick cylindrical polymerization vessel made of stainless steel equipped with a stirrer, degassed under vacuum for 2 hours, and then replaced with nitrogen gas. The mixture was heated at 200 ° C. for 3 hours with stirring under a nitrogen atmosphere. While maintaining the temperature as it is, gradually degas by a vacuum pump through an exhaust pipe and a glass receiver, and the inside of the reaction vessel was 3 mm.
The pressure was reduced to Hg. One hour after the start of degassing, the distillation of the monomer and low-molecular-weight volatiles disappeared. Therefore, the inside of the vessel was replaced with nitrogen, and the polymer was drawn out from the lower part of the vessel in the form of a strand, pelletized, and homopolymer of L-lactide (polymer A) was obtained. The yield was 78% and the weight average molecular weight Mw was 136,000.

Production Example 2 <Polymer B (poly L-lactic acid)
Production of 10% of 90% L-lactic acid at 150 ° C./5 in a 100-liter reactor equipped with a Dien-Stark trap
After distilling water while stirring at 0 mmHg for 3 hours, 6.2 g of tin powder was added, and the mixture was further added at 150 ° C / 30 mmHg for 2 hours.
Stir for hours to oligomerize. 28.8 g of tin powder and 21.1 kg of diphenyl ether were added to this oligomer,
An azeotropic dehydration reaction at 150 ° C./35 mmHg was performed, and the distilled water and the solvent were separated by a water separator, and only the solvent was returned to the reactor. Two hours later, the organic solvent to be returned to the reactor was passed through a column packed with 46 kg of molecular sieve 3A, and then returned to the reactor. A solution of polylactic acid was obtained. Diphenyl ether 44 dehydrated in this solution
After adding kg and diluting, the mixture was cooled to 40 ° C., and the precipitated crystals were filtered, washed three times with 10 kg of n-hexane, and dried at 60 ° C./50 mmHg. 0.5 N of this powder
-Add 12 kg of HCl and 12 kg of ethanol, and add 35
After stirring at 1 ° C. for 1 hour, the mixture was filtered and dried at 60 ° C./50 mmHg to obtain 6.1 kg of white polylactic acid (yield: 85%).
%). The weight average molecular weight Mw of this polylactic acid (Polymer B) was 145,000. The glass transition temperature of this polymer was 58 ° C and the melting point was 175 ° C.
The glass transition temperature of this polymer was 58 ° C and the melting point was 168 ° C.

Production Example 3 <Production of polymer C (polybutylene succinate / polylactic acid copolymer)> 50.5 g of 1,4-butanediol and 66.5 of succinic acid
g to 293.0 g of diphenyl ether and 2.02 to tin metal
g was added thereto, and the mixture was heated and stirred at 130 ° C./140 mmHg for 7 hours while distilling water out of the system to form an oligomer. to this,
Attach Dean-Stark trap, 140 ° C
After azeotropic dehydration at 30 mmHg for 8 hours, a tube filled with 40 g of molecular sieve 3A was attached, and the distilled solvent was returned to the reactor through the molecular sieve tube, and stirred at 130 ° C / 17 mmHg for 49 hours. did. The reaction mass was dissolved in 600 ml of chloroform, added to 4 liters of acetone and reprecipitated, and then a solution of HCl in isopropyl alcohol (hereinafter abbreviated as IPA) (H
(Cl concentration: 0.7 wt%) for 0.5 hour (three times), washed with IPA, and dried under reduced pressure at 60 ° C. for 6 hours to obtain polybutylene succinate. The weight average molecular weight Mw of this polymer was 138,000.

40. Polybutylene succinate obtained
0 g of polylactic acid 16 obtained by the same method as in Production Example 2.
0.0 g (weight average molecular weight Mw is 2,000,000), 800 g of diphenyl ether and 0.7 g of metal tin were mixed, and
The dehydration condensation reaction was performed at 30 ° C./17 mmHg for 20 hours. After completion of the reaction, post-treatment was carried out in the same manner as in Production Example 2 to give a copolymer 188 of polybutylene succinate and polylactic acid.
g (94% yield). This block copolymer of polybutylene succinate and polylactic acid (copolymer C)
Had a weight average molecular weight Mw of 14,000. The glass transition temperature of this polymer is 55 ° C. and the melting point is 162 ° C.
Met.

Production Example 4 <Production of polymer D (polycaproic acid / polylactic acid copolymer)> Same as Production Example 3, except that 6-hydroxycaproic acid was used instead of 1,4-butanediol and succinic acid. As a result, polycaproic acid (91% yield) was obtained. The weight average molecular weight Mw of this polymer was 158,000. To 40.0 g of the obtained polycaproic acid, 160.0 g of a polylactic acid obtained by the same method as in Production Example 2 (weight average molecular weight Mw is 20,000), and diphenyl ether 800
g, 0.7 g of metallic tin, and again 130 ° C./17 mm
A dehydration condensation reaction was performed at Hg for 20 hours. After the reaction, post-treatment was carried out in the same manner as in Production Example 2 to obtain 192 g of a copolymer of polycaproic acid and polylactic acid (96% yield). The weight average molecular weight Mw of the block copolymer (copolymer D) of polycaproic acid and polylactic acid was 150,000. The glass transition temperature of this polymer was 56 ° C and the melting point was 158 ° C.

Production Example 5 <Production of Polymer E (Copolymer of β-hydroxybutyric acid and β-hydroxyvaleric acid / polylactic acid copolymer)> Biopol D was used as a copolymer of β-hydroxybutyric acid and β-hydroxyvaleric acid. To 40.0 g of -311G (trade name, manufactured by Monsanto Co.), 160.0 g of polylactic acid obtained by the same method as in Production Example 2 (weight average molecular weight Mw is 2.
0,000), 800 g of diphenyl ether, 0.7 g of metal tin
, And again subjected to a dehydration condensation reaction at 130 ° C./17 mmHg for 20 hours. After completion of the reaction, post-treatment was carried out in the same manner as in Production Example 2 to obtain 190 g (yield: 95%) of a copolymer of β-hydroxybutyric acid and β-hydroxyvaleric acid and a copolymer of polylactic acid. The weight average molecular weight Mw of the block copolymer (copolymer E) of this copolymer of β-hydroxybutyric acid and β-hydroxyvaleric acid and polylactic acid is 1
It was 47,000. The glass transition temperature of this polymer is 5
The melting point was 5 ° C and the melting point was 157 ° C.

[Evaluation of Physical Properties] The conditions for evaluating the physical properties of the monofilaments produced in Examples and Comparative Examples using the lactic acid-based resins obtained in Production Examples 1 to 5 are as follows. (1) Mechanical strength According to JIS Z8703, tensile speed 300 mm / mi
The tensile strength and the elongation were measured at m and a distance between spans of 200 mm. (2) Storage test The state of the yarn was observed after storage at 40 ° C for 3 months in a state where a 30,000 m filament was wound on a paper roll having a length of 40 cm and φ10 cm. 〇: No change ×: Some thread breakage was observed

(3) Secondary workability The workability when the filament was formed into a net shape by a knitting machine using a netting type of Russell net was evaluated for the following items. * The occurrence of thread entanglement 〇: No thread entanglement is observed. ×: Thread entanglement occurs and molding is difficult. * The situation of thread rupture 〇: Thread was not broken and molding was possible.

Example 1 Polymer A100 obtained in Production Example 1 as a lactic acid-based resin
The parts by weight are set to the twin screw extruder cylinder set temperature of 170 to 19
Pelleted at 0 ° C. This pellet is heated at 80 ° C / 4H
After drying, set the cylinder temperature of the extruder equipped with a gear pump to 170 to 200 ° C. and the diameter of the die hole to 1.5 m.
At 90 m, 90 strands were extruded, guided into a water bath set at 45 ° C. provided immediately below the dies, and cooled to obtain strands. The obtained strand was set at a temperature of 60 to 80 ° C. and 90 to 100 ° C. as a first and second stretching heating tanks 2
It was guided to two water tanks and stretched with the respective draw ratios of 5.0 times and 2.5 times by the speed ratio of the stretching rollers arranged before and after each water tank. Subsequently, the atmosphere temperature near the surface of this filament was led to an oven set at 100 ° C. to perform heat treatment (thermal fixation), and then cooled in a cooling water bath adjusted to a water temperature of 30 ° C., and the heat-treated monofilament was further cooled. Diana Fresia W- as lubricant
8 (trade name, manufactured by Idemitsu Kosan Co., Ltd.), and then wound into a paper roll by a winder. The moldability at this time was good without breaking the yarn during stretching or winding. Also, the obtained monofilament has a thickness of 500d,
The tensile strength was 7.0 g / d and the tensile elongation was 25%.
In addition, a storage test was performed at 40 ° C. for 3 months in a state in which the obtained monofilament was wound around a paper roll.
There was no change in intensity. Next, the obtained monofilament was knitted in a net shape by a knitting machine using a netting type of Russell net as a type of netting. As a result, it was possible to form the yarn satisfactorily without causing entanglement or yarn breakage.

Examples 2 to 8 The results obtained in the same manner as in Example 1 except that the lactic acid-based resin, the first and second stretching magnifications during stretching, and the type of the lubricant were changed, are shown in Table 1. See 2).

[0053]

[Table 1]

[0054]

[Table 2] Comparative Examples 1-9 Performed in the same manner as in Example 1, except that the lactic acid-based resin, the first and second stretching magnifications during stretching were changed, and no lubricant was used or the lubricant was changed to a hydrophilic one. Table 2 (Tables 3 and 4)
Shown in

[0055]

[Table 3]

[0056]

[Table 4]

Example 9 Polymer A100 obtained in Production Example 1 as a lactic acid-based resin
Parts by weight, Diana Fresia W- as a lipophilic lubricant
8 (trade name, manufactured by Idemitsu Kosan Co., Ltd.) was sufficiently mixed with a Henschel mixer, and then pelletized at a cylinder setting temperature of 170 to 190 ° C. of a twin-screw extruder. After the pellets were dried at 80 ° C. for 4 hours, the cylinder set temperature of the extruder equipped with a gear pump was set to 170 to 170 ° C.
90 strands were extruded at a temperature of 200 ° C. and a die hole diameter of 1.5 mm, guided into a water bath set at 45 ° C. provided directly below the dies, and cooled to obtain strands. The obtained strands are used as first and second stretching heating tanks at a temperature of 60 to 8
It was led to two water tanks set at 0 ° C. and 90 to 100 ° C., and the respective draw ratios were set to 5.0 times and 2.5 times according to the speed ratio of the rolling rollers arranged before and after each water tank.
Subsequently, the obtained monofilament is introduced into an oven in which the ambient temperature in the vicinity of the surface is set to 100 ° C., heat-treated (heat-fixed), and then cooled in a cooling water tank adjusted to a water temperature of 30 ° C. and wound up. The paper was wound into a paper roll. The moldability at this time was good without breaking the yarn during stretching or winding. The obtained monofilament had a thickness of 500 d, a tensile strength of 7.0 g / d, and a tensile elongation of 25%. A storage test was carried out at 40 ° C. for 3 months with the obtained monofilament wound on a paper roll. As a result, there was no change in both appearance and strength. Next, the obtained monofilament was used to form a net into a net shape with a knitting machine, using a netting type of Russell net. As a result, it was possible to form the net well without any trouble.

Examples 10 to 16 In the same manner as in Example 9 except that the type and amount of the lactic acid-based resin and the lipophilic lubricant, the thickness of the yarn, and the first and second draw ratios during drawing were changed. The results obtained are shown in Table 3 (Tables 5 and 6).

[0059]

[Table 5]

[0060]

[Table 6]

[0061]

Industrial Applicability The monofilament of the present invention has biodegradability, has substantially sufficient mechanical strength, has excellent storage stability in the state of being wound up on a paper roll, and has a net, fish net or rope shape. Excellent formability during subsequent processing.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) // C08L 67/04 C08L 67/04 (72) Inventor Yasuhiro Kitahara 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Chemicals, Inc. (72) Inventor Hisashi Aihara 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Inside of Mitsui Chemicals Co., Ltd. (72) Inventor Ikuki Yoshida 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Mitsui Chemicals Inc. (72) Inventor Nakata Tomoyuki 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa F-term (reference) 4J002 AE042 AE052 CF191 EA016 EA026 FA031 FD172 FD176 GK00 4J029 AA02 AB07 AC01 AC02 AE02 EA05 4L033 AA06 AB01 BA18 BB72 BB89 BB91 CC03 CC20 DD14 EE08 EE20 FF10 4L038 AA16 AA18 AB07 BA13 BB07 CA06 DA20

Claims (10)

[Claims] 1. A monofilament obtained by melt-extruding a lactic acid-based resin, wherein the monofilament has excellent secondary workability obtained by applying a lipophilic lubricant to the surface of the filament. 2. The monofilament excellent in secondary workability according to claim 1, wherein the lipophilic lubricant is a petroleum-based lubricant. 3. The petroleum-based lubricating oil is a paraffinic oil,
Selected from naphthenic oil, spindle oil, refrigerating machine oil, compressor oil, dynamo oil, turbine oil, machine oil, engine oil, cylinder oil, marine engine oil, gear oil, aviation lubrication oil, jet engine lubrication oil, hydraulic oil The monofilament excellent in secondary workability according to claim 2, which is an oil containing one or a mixture of two or more kinds as a main component. 4. The lactic acid-based resin is polylactic acid.
4. A monofilament excellent in secondary workability according to items 3 to 3. 5. A method for producing a monofilament comprising: a step of melt-extruding a lactic acid-based resin to obtain a strand; a step of heating and stretching the strand in one or more steps to obtain a monofilament; and a step of winding the drawn monofilament. A method for producing a monofilament having excellent secondary workability, comprising applying a lipophilic lubricant to the surface of the filament in any step before winding the monofilament. 6. A monofilament excellent in secondary workability, comprising a composition obtained by adding a lipophilic lubricant to a lactic acid-based resin. 7. The monofilament excellent in secondary workability according to claim 6, wherein the lipophilic lubricant is a petroleum-based lubricant. 8. The petroleum-based lubricating oil is a paraffinic oil,
Selected from naphthenic oil, spindle oil, refrigerating machine oil, compressor oil, dynamo oil, turbine oil, machine oil, engine oil, cylinder oil, marine engine oil, gear oil, aviation lubrication oil, jet engine lubrication oil, hydraulic oil The monofilament excellent in secondary workability according to claim 7, which is an oil containing one or a mixture of two or more kinds as a main component. 9. The lactic acid-based resin is polylactic acid.
9. A monofilament excellent in secondary workability according to any one of Items 8 to 8. 10. A step of obtaining a strand by melt-extruding a composition obtained by adding a lipophilic lubricant to a lactic acid-based resin, a step of heating and stretching the strand in one or more steps, and a step of winding a drawn monofilament. A method for producing a monofilament with excellent secondary workability.