JP4664167B2 - Biodegradable resin filament with controlled biodegradability and method for producing the same - Google Patents

Description

  The present invention relates to biodegradable resin filaments with controlled biodegradability, in particular, polyglycolic acid resin filaments and methods for producing the same, and more particularly, the balance between biodegradability and physical properties and the biodegradation rate are controlled. Polyglycol that is suitably biodegraded and disappears, does not cause environmental pollution or natural destruction, has high tensile strength and knot strength, and has a suitable elongation, especially as a fishery material for catching fish The present invention relates to an acid resin filament and a production method unique to the filament.

Biodegradable synthetic resin materials have long been known as one of highly functional resin materials, and have been widely used as materials for surgical sutures and artificial skin in the medical field for a long time. Etc. are constantly being made.
Biodegradation is a general term for in-vivo degradation and degradation in nature of resin materials. In the natural world, it is degraded by the action of hydrolysis and degradation by microorganisms, becoming a harmless monomer for living organisms, consumption by microorganisms, etc. However, biodegradable resin materials include natural resins such as starch, biodegradable polyester resins such as polyvinyl alcohol resin, polyglycolic acid resin, polylactic acid resin or polycaprolactone, polyethylene carbonate, etc. It is over.
The field of application has been greatly expanded, and even if it is left and dumped in the mountains, fields, or cities after use, it uses a sustained-release fertilizer container that uses its gradually disappearing properties, and its natural degrading properties. In order to prevent environmental pollution and natural destruction, civil engineering materials such as ropes and cement decorative frames (see Patent Document 1) and agricultural materials such as nursery nets and greenhouse films (see Patent Document 2), and more recently In addition, it has been used for daily goods such as magnetic cards and packaging materials or golf course members such as markers.

  Recently, as one of the serious environmental pollutions, the natural world caused by abandonment and disposal of large amounts of used fishing lines (tegus) and discarded fishnets on the coast, ocean, rivers and lakes by fishermen and fishermen. In particular, fishing lines and fishnets that are dumped on the coast or drifted to the ocean are often transparent and difficult to see. In addition, fishing lines and fish nets are entangled with divers in the sea and injured, wrapped around the screw of the ship and hindering the operation of the ship, or deposited on the sea floor and seaweed and fish Even problems that hinder the breeding of mosquitoes are derived.

Therefore, in order to prevent such environmental problems such as fishing lines and discarded fish nets from remaining in the natural world forever, and to protect natural creatures, recently, the field of fishery materials In Japan, the use of biodegradable resin materials that naturally decomposes and disappears over time after use has been attracting attention and has become necessary, and technical development has been undertaken.
However, in conventional fishery materials such as fishing lines, physical properties (physical properties) such as tensile strength and elongation at break are strongly emphasized, and polyamide resins have been used exclusively in the past. And in the polyamide resin, such strength in water decreases, water settling (sedimentation in water) is low, and yellowing with time, so importance is also placed on transparency and sedimentation in water, Instead of polyamide resin, polyolefin resin such as polypropylene resin, polyester resin, or polyvinylidene fluoride resin has come to be used frequently. Especially, polyester resin or polyvinylidene fluoride resin has been heavily used. Even if a biodegradable resin is used, it is generally very difficult to have both moderate biodegradability, appropriate spinnability, and various performances of conventional fishing lines.

Nevertheless, many attempts to use biodegradable resin materials for marine products have been presented until recently, and improvements have recently been made in the development and modification of resin materials, fiber coating, cross-sectional structures, and handling of filaments. Wide range of special performance.
A typical example of disclosure is to use a biodegradable resin material as a fishing line, using polyglycolic acid or a mixture of it and other degradable polymers as its constituent material, and further increasing the intrinsic viscosity and cutting strength. The specific degradable fishing line, and a method for producing a degradable fishing line that performs specific heat drawing and relaxation heat treatment after melt spinning (see Patent Document 3), after maintaining sufficient tensile strength during use and after being abandoned in water Is a hydrolyzable polyester fiber having a repeating structural unit having at least a glycolic acid unit and / or a lactic acid unit in the polymer molecular structure, or the hydrolyzable polyester fiber, in order to reduce the strength gradually by hydrolysis. A degradable polymer comprising twists and / or braids of non-hydrolyzable fibers, and the surface of the fibers is less hydrolyzable than the hydrolyzable polyester. Fishing line (see Patent Document 4), a biodegradable fishing line that has a good balance between strength and elongation and is easy to perform fishing operations, and the fishing line body has an initial elongation of less than 2.0 g / d. Is 10% or more, the elongation in the range of tensile force 2.0 to 4.5 g / d is smaller than the initial elongation, the elongation at break is 40% or less, A biodegradable fishing line having a second region having a strength of 4.5 g / d or more (see Patent Document 5), a raw material having a practically sufficient initial strength and capable of controlling the biodegradation rate. Biodegradable polyester fiber comprising a composition containing 0.5 to 10% by weight of an alkaline inorganic compound in an aliphatic polyester resin and having a tensile strength of 3 g / d or more (patented) (Ref. 6) It is shown.
However, in these disclosed technologies, in Patent Document 3, no special device or specific manufacturing method has been made just by using a biodegradable polyglycolic acid resin as a fishing line, and the material is hard and brittle and has a knot strength. It cannot be said that the performance as a fishing line is low, and even in Patent Document 4, it is difficult to say that the material is hard and brittle and the balance between strength and biodegradation speed is balanced. No contrivance has been made, and Patent Document 6 also realizes a good balance in physical properties and biodegradability, such as free control of the biodegradation speed or strength, even though it has sufficient strength for practical use. Both are not good.

  In addition, as an effort to achieve a good balance between physical properties such as strength and biodegradability, aliphatics with specified melt index and melting point to combine basic performance as a fishing line with an appropriate biodegradation rate A biodegradable fishing line that has polyester as a main component, tensile strength of 5.0 g / d or more, knot strength of 4.0 g / d or more, and a specified degree of orientation of the surface layer and overall orientation. Later, after cooling and solidifying in an inert liquid at 60 ° C. or lower, the first stage stretching is subsequently performed at a magnification of 2.5 to 5.0 times, and then the total stretching ratio is 6.0 times or more. Monofilament with excellent balance between biodegradability and mechanical properties as a fiber for use in marine materials or various industrial material applications (see Patent Document 7). In particular, in order to provide a fishing line, at least one polyalkylene dicarboxylate having a melting point of 70 ° C. or more is used as a core component, a polylactic acid resin or the like is used as a sheath component, and the weight ratio of the core component / sheath component is as follows: A biodegradable monofilament that exhibits a mechanical property of 95/5 to 40/60 and has a tensile strength of 4.0 g / d or more and a knot strength of 3.0 g / d or more (see Patent Document 8), A biodegradable composite monofilament with excellent balance of degradability and mechanical properties and improved adhesion at the core-sheath or sea-island interface, especially a core-sheath or sea-island type biodegradable composite monofilament to provide fishing line And one component has a polyalkylene dicarboxylate having a melting point of 70 ° C. or higher, and the other component has a melting point composed of an aromatic dicarboxylic acid / aliphatic dicarboxylic acid and an aliphatic diol. Many biodegradable composite monofilaments using a copolyester of 90 ° C. or higher (see Patent Document 9) have been disclosed, and various ingenuity has been made in each. In addition, the balance between biodegradability and various physical properties is not necessarily satisfactory.

JP 2002-21324 A (summary) JP 2000-238194 A (summary) Japanese Patent Laid-Open No. 3-259029 (Claims 1, 2 and upper left column on page 2) JP-A-4-108331 (Claims 1 and upper right column on page 2) JP-A-8-196175 (Summary) Japanese Patent Laid-Open No. 9-41220 (Abstract and Claim 1) Japanese Patent Laid-Open No. 9-74661 (summary) JP-A-10-102323 (summary) Japanese Patent Laying-Open No. 2005-187968 (Abstract)

  In view of the importance of the utilization of such biodegradable resin materials in various industrial fields, as outlined in paragraphs 0002 to 0006 as background art of the present invention, and the need for environmental pollution control and nature protection. Furthermore, in particular, from the above viewpoint, the application of biodegradable resin materials is strongly requested by society, and the development of application is not yet sufficient, and the biodegradation speed is particularly flexible. In light of the fact that control or biodegradability functions and various physical properties as marine materials are not controlled and provided in a well-balanced manner, the present invention can be applied to biotechnology in various technical fields such as civil engineering and agriculture. It is useful as a degradable material, has excellent biodegradable functions and various physical properties, can control the balance between biodegradable functions and various physical properties and biodegradation speed, and is particularly useful as a fishery material There, to develop biodegradable resin material, it is an issue to be solved invention.

By the way, the inventors of the present invention have been conducting research to develop biodegradable resin materials that have a well-balanced control of biodegradable functions and various physical properties. In glycolic acid resins, the amount of residual monomer with respect to the polymer is closely related to the balance between biodegradable function and various physical properties, and if the amount of residual monomer is specified specially, practical properties such as tensile strength and knot strength can be achieved. It has been found that a polyglycolic acid-based resin having excellent and appropriate biodegradability can be obtained, and has been filed as an earlier invention (Japanese Patent Application No. 2004-78854).
This prior invention comprises (i) a polyglycolic acid resin having a residual monomer amount of less than 0.5% by weight, a tensile strength of 750 MPa or more, and a knot strength of 600 MPa or more. Resin melt, and (ii) polyglycolic acid resin having a residual monomer content of less than 0.5 wt%, melt-spun, quenched in a liquid bath at 10 ° C. or lower, and then liquid at 60 to 83 ° C. This is a method for producing a polyglycolic acid resin filament, which comprises amorphous stretching in a bath.

  In general, the smaller the amount of residual monomer, the higher the polymer purity and the higher its physical properties. In polyglycolic acid resins, the lower the residual monomer amount, the higher the physical properties and the lowering of hydrolysis function and biodegradability. However, when the inventors of the present invention have continued research on the application and improvement of the prior invention, the residual monomer amount is 0.5% by weight or more. In the case of the biodegradable resin, particularly polyglycolic acid resin, if a special stretching treatment and heat treatment after melt spinning in the invention of the prior application are adopted, the amount of residual monomer is equivalent to less than 0.5% by weight. It has excellent physical properties such as tensile strength and knot strength, and the biodegradability is a polyglycol with a residual monomer content of 0.5% by weight or more due to the hydrolysis function that strongly affects it. Recognize that the rate of decomposition increases when compared with the case of less than 0.5% by weight, but rather when it is left in nature or dumped in nature. I was able to.

  Even if the specified condition of the residual monomer amount in the polyglycolic acid resin in the prior application invention is changed from less than 0.5% by weight to 0.5% by weight or more, the residual monomer amount is less than 0.5% by weight. Excellent physical properties such as tensile strength and knot strength can be provided, and the biodegradability is less than 0.5% by weight when the residual monomer amount is 0.5% by weight or more. However, the new recognition that the rate of decomposition and disappearance is more appropriate when the material is left in the natural environment after being used or discarded after use of the material, especially in polyglycolic acid resins, The balance between biodegradability and physical strength can be controlled (and the biodegradation rate can be controlled more appropriately) and the biodegradability function and various physical properties can be provided in a well-balanced manner according to the prescribed conditions for residual monomer amount. It is one that enables the fact should be noted recognized by From this point of view.

  And the above new recognition as a result of continuous research for application and improvement in the invention of the prior application will form a new present invention in the present application. Developed biodegradable resin materials that are useful as biodegradable materials in each technical field of the present invention, and in particular, have a well-balanced control of biodegradable functions and various physical properties as fishery materials " It led to solving the problem which should be solved.

From the above paragraphs 0010 to 0012, the present invention can be provided with excellent physical properties such as tensile strength and knot strength equivalent to the invention of the prior application. A biodegradable resin filament characterized by comprising 0.5% by weight or more of biodegradable resin, having a tensile strength of 750 MPa or more and a knot strength of 600 MPa or more.
It is useful as a biodegradable material in various technical fields such as civil engineering and agriculture, and has a well-balanced biodegradable function and various physical properties as a fishery material. And the biodegradation rate can be controlled by the amount of residual monomer, and can be controlled and set to a necessary and appropriate biodegradation rate according to the use form in the air or water in nature.
In addition, the present invention more specifically specifies the function and use of the polyglycolic acid resin having a residual monomer amount of 0.5% by weight or more, more preferably a residual monomer amount of 0.8% by weight or more. A civil engineering material or an agricultural material, wherein the tensile strength is 750 MPa or more and the knot strength is 700 MPa or more, and the balance between biodegradability and physical strength and the biodegradation rate are controlled by the amount of residual monomer, or It is also a biodegradable polyglycolic acid resin filament used as a fishery material.

  Furthermore, in the present invention, additionally, the specification in the type of monomer in which the type of the resin material and the residual amount in the polyglycolic acid resin are specified, the use of the form of the filament and the fishing line, and the adjustment of the residual monomer amount In accordance with the method of controlling the biodegradability and physical strength and the method of controlling the biodegradation rate, or the polyglycolic acid resin filament manufacturing method in the prior invention, rapid cooling and amorphous drawing after melt extrusion The manufacturing method of the polyglycolic acid resin filament of the present invention having the above-mentioned features is also an invention unit.

In addition, in each paragraph and other patent documents as the prior art in the paragraphs 0002 to 0007 described as the background art of the present invention, the main thing is simply to use the biodegradable polyglycolic acid resin. Degradable fishing line (refer to claims and upper left column to upper right column in Patent Document 3), tensile strength and breaking strength are specified in g / d units, and elongation is specified in% units. Decomposable resin material has no specific fishing line (refer to claims and paragraphs 0010 to 0012 in Patent Document 5), the basic performance as a fishing line, and an appropriate biodegradation rate. In addition, biodegradable fishing lines (see the abstract in Patent Document 7), in which knot strength is specified in units of g / d and numerical values for a specific degree of orientation are also required.
On the other hand, since the present invention has new and unique constituent requirements such as residual monomer amount and various physical properties summarized in paragraph 0013 and characteristic actions such as control of biodegradation rate, the above is representative. It is obvious that the prior literature description does not suggest or suggest the present invention.

  In the above, since the background of the creation of the present invention, its configuration and the features of the operation, etc. have been outlined, the overview of the present invention will be overviewed here, and the entire configuration will be described clearly. [1] and [2] Further, the invention of [8] is a basic invention, and other inventions embody the basic invention or form an embodiment. It is. (The invention group as a whole is collectively referred to as “the present invention”.)

[1] A biodegradable resin filament comprising a biodegradable resin having a residual monomer amount of 0.5% by weight or more, a tensile strength of 750 MPa or more, and a knot strength of 600 MPa or more.
[2] A polyglycolic acid resin having a residual monomer amount of 0.8% by weight or more, a tensile strength of 750 MPa or more and a knot strength of 700 MPa or more, and a balance between biodegradability and physical strength depending on the amount of residual monomer And a biodegradable polyglycolic acid resin filament used as a civil engineering material, an agricultural material or a fishery material, wherein the biodegradation rate is controlled.
[3] The polyglycolic acid-based resin filament according to [1] or [2], wherein the polyglycolic acid-based resin is a resin obtained by polymerizing glycolic acid or glycolide, and the residual monomer is glycolic acid or glycolide .
[4] The polyglycolic acid resin is a resin obtained by copolymerizing glycolic acid or glycolide and another polymerizable monomer, or a mixture of a polyglycolic acid resin and another polyester resin, [3 ] The polyglycolic acid type resin filament in].
[5] The polyglycolic acid resin filament according to [1] or [2], wherein the filament is a monofilament and is used for biodegradable fishery materials.
[6] A fishing line formed from the polyglycolic acid resin filament according to any one of [1] to [5].
[7] The balance between biodegradability and physical strength and the biodegradation rate are controlled by adjusting the amount of residual monomer. The amount of residual monomer is adjusted by the polymerization conditions of the polyglycolic acid resin or by heating and drying the polymer after polymerization. And / or vacuum drying, wherein the polyglycolic acid resin filament according to any one of [1] to [6] is a method for controlling the balance between biodegradability and physical strength and the biodegradation rate.
[8] If necessary, other components are added to the polyglycolic acid resin whose residual monomer amount is adjusted to 0.5% by weight or more, melt-extruded at a temperature of 230 ° C. or higher, spun, and spun at a temperature of 10 ° C. or lower. Any one of [1] to [6], comprising rapid cooling in a refrigerant, then amorphous stretching in a medium of 60 to 83 ° C. by 3 times or more, and if necessary, two-stage stretching and thermal relaxation. A method for producing a polyglycolic acid resin filament in

  The biodegradable polyglycolic acid-based resin filament of the present invention is useful as a biodegradable material in various technical fields such as civil engineering and agricultural use for the purpose of suppressing environmental pollution and protecting nature, and particularly for marine products. It is very useful because it has an appropriate biodegradable function and excellent physical properties in a well-balanced manner. In addition, the balance between biodegradability and physical strength can be controlled and the biodegradation rate can be controlled by adjusting the amount of residual monomer.

  Although the present invention has been described in accordance with the basic configuration of the present invention as means for solving the problems of the invention, in the following, the embodiment of the invention of the present invention group described above will mainly be described as a residual. Polyglycolic acid resin with specified monomer amount and various physical properties, method for controlling balance between biodegradability and physical strength by adjusting residual monomer amount, and rapid cooling and amorphous after melt extrusion The method for producing the polyglycolic acid resin filament of the present invention having characteristics such as stretching will be specifically described in detail.

1. Biodegradable Resin Filament (1) Basic Structure The biodegradable resin of the present invention, particularly the polyglycolic acid resin filament, is composed of a polyglycolic acid resin having a residual monomer amount of 0.5% by weight or more and is tensile. A biodegradable resin filament characterized by having a strength of 750 MPa or more and a knot strength of 600 MPa or more.

(2) Biodegradable resins In general, biodegradable resins are classified into i) chemical synthesis systems, ii) microorganism production systems, and iii) natural product resins.
Examples of chemical synthesis systems include polyglycolic acid, polylactic acid, polycaprolactone, cellulose acetate, polybutylene adipate, polybutylene succinate, polyethylene carbonate, polyethylene succinate, and a copolymer obtained by combining monomers in each of the above polymers. Examples of the polymer include polyethylene succinate / terephthalate copolymer, polyvinyl alcohol, polyethylene glycol, and polypropylene glycol.
Examples of microbial production systems include poly-3-hydroxybutyrate, poly-3-hydroxyvalerate, and copolymers of monomers in these polymers.
Examples of natural products include starch, silk, chitin, chitosan and the like. However, since no residual monomer is produced, the present invention is not a single biodegradable resin.
As the biodegradable resin of the present invention, the above-mentioned chemical synthesis system or microbial production system resin may be used, and these resins may be combined, or the chemical synthesis system and microbial production system resin may be combined. These resins and natural products may be used in combination.
Among them, the polyglycolic acid resin is known as a resin particularly excellent in biodegradability.
The polyglycolic acid resin exclusively used in the present invention is basically a polyglycolic acid resin, which is produced by condensation polymerization of glycolic acid, but is usually a bimolecular condensate of glycolic acid due to the ease of polymerization. Is produced by ring-opening polymerization of glycolide, and the unit of the polymer is represented by — (OCH ₂ CO) _n —.

The polyglycolic acid resin may be a resin obtained by copolymerizing glycolic acid or glycolide and another polymerizable monomer, or a mixture of a polyglycolic acid resin and another polyester resin.
As the other polymerizable monomer to be copolymerized, an arbitrary monomer is used, but a monomer that forms a biodegradable polymer is preferable, carbonates such as lactic acid, lactones, or trimethylene carbonate, 3-hydroxypropane, and the like. Representative examples include acids, 3-hydroxybutanoic acid and esters of these acids, ethylene oxalate, and the like. These monomers can also be used in combination.
The repeating unit of glycolic acid in the polyglycolic acid resin is 55% by weight or more, preferably 70% by weight or more, particularly preferably 90% by weight or more.
If the repeating unit of glycolic acid is less than 55% by weight, it will be difficult to obtain high physical properties in the polyglycolic acid resin, and the balance between biodegradability and physical strength will be controlled by adjusting the residual monomer amount. It is also difficult to control the biodegradation rate.

In a mixture of a polyglycolic acid resin and another polyester resin, as the other polyester resin, a polyester system having a biodegradability polymerized from a polyester monomer exemplified and described in paragraph 0022. A polymer is used.
Instead of the form of a mixture (blend composition), it can also be used in the form of a laminated filament having a core-sheath structure.

(3) Residual monomer In the present invention, the amount of residual monomer is specified to be 0.5% by weight or more, but is a set rule in relation to the specification of less than 0.5% by weight in the prior invention. As described in paragraphs 0010 to 0011, even if the specified condition of the residual monomer amount is changed from less than 0.5% by weight to 0.5% by weight or more, the residual monomer amount is less than 0.5% by weight. It has excellent physical properties such as tensile strength and knot strength equivalent to the case, and the biodegradability is less than 0.5% by weight when the residual monomer amount is 0.5% by weight or more, The speed becomes faster, but there is also an advantage that a more appropriate decomposition and disappearance speed is obtained when the material is left in the natural world after being used or discarded.
The method for measuring the residual monomer amount is described as a test method in the following Examples (paragraph 0035).

(4) Physical properties
Various physical properties (physical properties; so-called mechanical properties) in the polyglycolic acid resin filament of the present invention are defined as tensile strength and knot strength as particularly excellent performance, and the tensile strength is 750 MPa or more, preferably 800 MPa. As described above, the knot strength is 600 MPa or more, preferably 700 MPa or more. These are particularly important performances as fishing lines in fishery materials.
A biodegradable polyglycolic acid resin filament comprising a polyglycolic acid resin having a residual monomer amount of 0.5% by weight or more, a tensile strength of 750 MPa or more, and a knot strength of 600 MPa or more is conventionally known. It is a filament that is not known.
The methods for measuring these physical properties are described as test methods in the following examples (paragraph 0037). Specific data are listed in Table 2 in Example-1.

  The biodegradable polyglycolic acid resin filament of the present invention can have a high tensile elastic modulus equal to or higher than that of an aromatic polyester resin (PET) filament known as a high-rigidity filament, and has a high rigidity of 600 MPa or more. Having a very high knot strength is only obtained at least with some degree of filament surface flexibility and surface elongation, and the biodegradability of the present invention is not found in conventional filament materials. This is one of the characteristic properties of polyglycolic acid resin filaments.

(5) Filament The use form of the biodegradable polyglycolic acid resin of the present invention is specified as a filament and is a monofilament or a multifilament and can be processed into a rope or a net. It is a form suitable for use. The filament in the present invention is formed by extrusion spinning a polyglycolic acid resin from an extruder or the like in a molten state, and is mainly used in the form of a monofilament.
Although the diameter of a filament is not specifically limited, 0.05-4.0 mm is used as a fishing line, and about 0.05-2.0 mm is preferable.

(6) Additives In the polyglycolic acid resin of the present invention, it is normally used in polyester resins as various additives for enhancing physical properties and adding other various physical properties. Plasticizers, nucleating agents, antioxidants, UV absorbers, dyes, pigments, heat stabilizers, light stabilizers, fillers, internal mold release agents, matting agents, conductivity imparting agents, charge control agents, charging Inhibitors, lubricants, and other processing aids can be added.

(7) Specific Aspect in Polyglycolic Acid Resin Filament As another specific aspect of the filament with respect to the basic constitution in the polyglycolic acid resin filament of the present invention described in paragraph 0020, “residual monomer amount is It consists of a polyglycolic acid resin of 0.5 wt% or more, more preferably 0.8 wt% or more of residual monomer, has a tensile strength of 750 MPa or more and a knot strength of 700 MPa or more. A biodegradable polyglycolic acid resin filament used as a civil engineering material, agricultural material, or marine material, characterized in that the balance between property and physical strength and the biodegradation rate are controlled is embodied.
This embodiment is an embodiment in which the amount of residual monomer is set higher in the basic configuration, the nodule strength is specified to be higher, and the functions and uses are clarified. It is what.

2. Control of the balance between biodegradability and physical strength As one of the characteristics of the polyglycolic acid resin filament of the present invention, the balance between biodegradability and physical properties (physical strength) and the biodegradation rate are controlled. You can also.
By adjusting the amount of residual monomer, the hydrolyzability of polyglycolic acid resins in the air (such as Yamano and Tabata) and in water (such as the ocean and rivers) is adjusted, thereby increasing the biodegradation rate at which the resin is decomposed into monomers. Can be controlled. Note that the biodegradation rate is faster in water than in air.
Specifically, taking into consideration both the pot life of the biodegradable material (the necessary date and time that can be used) and the time required for biodegradation and disappearance (month and day), which is suitable for nature conservation while avoiding environmental pollution. In addition, the optimum biodegradation rate can be set and controlled in consideration of the amount of residual monomer capable of obtaining as many physical properties as possible. As a result, the balance between biodegradability and physical properties can be controlled, and even if the purchaser (consumer) opens the moisture-proof container and leaves it in the air after purchase, it can be used for a considerable period (several months). Can hold the possible state.
The residual monomer amount can be adjusted by polymerization conditions of the polyglycolic acid resin or by heat drying and / or vacuum drying of the polymer after polymerization.

3. Applications in biodegradable polyglycolic acid resin filaments Applications in the polyglycolic acid resin filaments of the present invention include civilian materials mainly in various usage forms such as monofilaments, nets, ropes, resin wires, fibers and woven fabrics. Or it is used as agricultural material or fishery material. In particular, it is suitable as a fishing line or fish net in fishery materials.

4). Production of Biodegradable Polyglycolic Acid Resin Filament (1) Melt Extrusion The filament of the present invention has other components added to the polyglycolic acid resin whose residual monomer amount is adjusted to 0.5% by weight or more as required. It is melt-extruded and spun at a temperature of 230 ° C. or higher, rapidly cooled in a refrigerant at a temperature of 10 ° C. or lower, then amorphous stretched in a medium of 60 to 83 ° C. three times or more. Manufactured by making relaxation.
It is preferable to knead and pelletize with a heat stabilizer before extrusion melting. Preferable examples of the heat stabilizer include phosphate esters and phosphate alkyl esters having a pentaerythritol skeleton structure. 3 parts by weight or less, preferably 0.003 to 1 part by weight is added to 100 parts by weight of the biodegradable polyglycolic acid resin.
The melt extrusion temperature is preferably 230 to 290 ° C, more preferably 240 to 280 ° C. If it is less than 230 ° C., it is difficult to extrude the resin due to the motor overload of the screw of the extruder, and if it exceeds 290 ° C., thermal decomposition of the resin occurs.

(2) Rapid cooling and amorphous stretching Rapid cooling is carried out in a water bath or oil bath at a temperature of 10 ° C. or less, and when the temperature exceeds 10 ° C., the cooling rate of the polyglycolic acid resin is slowed and crystallization proceeds. Then, subsequent amorphous stretching becomes difficult.
Stretching after quenching is performed at 60 to 83 ° C., preferably 70 to 80 ° C. in a liquid bath of water, alcohols, silicone oil, polyethylene glycol, or the like. Below 60 ° C., the degree of softening of the polyglycolic acid resin is low. If the desired high magnification stretching is insufficient and the temperature exceeds 83 ° C., the crystallization of the resin cannot be ignored. Similarly, the high magnification stretching becomes difficult, and orientation defects are caused by the generated crystal nuclei, resulting in high physical properties. The filament is not obtained.
Stretching is performed in an amorphous state of the polyglycolic acid resin, and high-strength stretching of 3 times or more, particularly 4 to 8 times is preferable. High physical properties cannot be obtained unless amorphous stretching is performed.
Continuously or after cooling, if the second and subsequent stages are stretched and the overall stretch ratio is increased to 4.5 times or more, particularly 5 to 10 times, high strength can be expected. Thereafter, relaxation treatment may be performed within a range of about 0.99 to 0.8 times as necessary.

  In the following, while disclosing examples of the present invention and contrasting comparative examples, the present invention will be specifically disclosed in more detail, the configuration of the present invention will be further clarified, and each requirement of the configuration of the present invention will be clarified. Demonstrate rationality and significance and superiority over the prior art.

[Measuring method]
i) Residual monomer amount About 300 mg of a sample is dissolved in about 6 g of dimethyl sulfoxide (DMSO) by heating, cooled to room temperature, and filtered. A certain amount of 4-chlorobenzophenone and acetone as internal standard substances are added to the filtrate. The solution was injected into a gas chromatography apparatus and the residual monomer amount was measured.

ii) Gel chromatography analysis
Apparatus: Shimadzu GC-2010 Column: TC-17 (0.25 mm × 30 mm) Column temperature: held at 150 ° C. for 5 minutes, then heated to 270 ° C. at 20 ° C./min and held at 270 ° C. for 3 minutes. Temperature: 200 ° C Detector: FID (hydrogen flame ion detector) Temperature: 300 ° C

iii) Tensile strength and knot strength In accordance with JISL1013, using "Tensilon UTM-III-100 type tensile tester" manufactured by Orientec Co., Ltd. The tensile strength was measured at min, measurement number = 5. In addition, the nodule strength was measured by measuring the strength at the time of cutting under the same tensile condition by forming a nodule at the center between the grips of the sample.

iv) Tensile elongation and knot elongation Using the tester described in Paragraph 0037, measurement was performed under the same measurement conditions and measurement method.

v) Change with time In a room controlled at 23 ° C and 65RH%, leave it in a state where it is wound on a bobbin, and sample it after the elapse of a predetermined period, and obtain the strength retention and elongation retention by the above tensile test. It was.

[Raw materials]
Raw material (1) Polyglycolic acid resin Melt viscosity; 2,790 Pa · s (Capillograph 240 ° C. · 122 / sec) Residual monomer amount: 0.18 wt%
Raw material (2) Polyglycolic acid resin Melt viscosity; 2,560 Pa · s (Capillograph 240 ° C. · 122 / sec) Residual monomer amount: 0.8 wt%
Raw material (3) Polylactic acid resin Shimadzu Corporation (trade name Lacty) melt viscosity: 1,350 Pa · s (capillograph 220 ° C. · 100 / sec)

[Reference Example-1]
The raw material (1) was melt extruded in a φ35 mm extruder using L / D: 24, full flight type screw, φ1.3 × 6 hole single layer nozzle under conditions of extrusion temperature 260 ° C. and nozzle temperature 230 ° C. After that, it was quenched (rapidly cooled) under conditions of an air gap of 6.5 cm, a water cooling temperature of 5 ° C., and a take-up speed of 4.5 m / min, and then stretched 6.0 times in a glycerol bath at 80 ° C. A 24 mm monofilament was obtained.
The obtained monofilament has a tensile strength of 1,190 MPa, a tensile elongation of 34%,
The nodule strength was 930 MPa and the nodule elongation was 28%.

[Example-1]
Raw material (2) was melt extruded in a φ35 mm extruder using L / D: 24, full flight type screw, φ1.3 × 6 hole single layer nozzle under conditions of extrusion temperature 260 ° C. and nozzle temperature 230 ° C. After that, it was quenched (rapidly cooled) under conditions of an air gap of 6.5 cm, a water cooling temperature of 5 ° C., and a take-up speed of 4.5 m / min, and then stretched 6.0 times in a glycerol bath at 80 ° C. A 17 mm monofilament was obtained.
The obtained monofilament had a tensile strength of 790 MPa, a tensile elongation of 55%, a knot strength of 750 MPa, and a knot elongation of 52%.

[Comparative Example-1]
Raw material (3) is taken out in a φ35 mm extruder using L / D: 24, full flight type screw, φ1.3 × 6 hole single layer nozzle, extrusion temperature and nozzle temperature 220 ° C, quench temperature 40 ° C An undrawn yarn was produced by spinning at a speed of 5 m / min, and subsequently drawn 4.0 times in a first stage 85 ° C. hot water bath, and then 1.75 times in a second stage 98 ° C. hot water bath. And a total of 7.0 times to obtain a monofilament having a diameter of 0.2 mm.
The obtained monofilament had a tensile strength of 590 MPa and a tensile elongation of 35%.

[Measurement of change over time]
Tables 1 to 3 show changes in knot strength, tensile strength, knot elongation, and tensile elongation with time in Reference Example-1, Example 1, and Comparative Example 1. Further, the measurement results are shown in FIG. 1 and FIG. 2 as change graph diagrams.
Reference Example-1: Polyglycolic acid resin (residual monomer amount = 0.18% by weight)

Example-1: Polyglycolic acid resin (residual monomer amount = 0.8 wt%)

Comparative Example-1: Polylactic acid resin

[Consideration of results of Examples and Comparative Examples]
In the biodegradable polyglycolic acid resin filaments of the present invention, by contrasting the above reference examples with Examples and Comparative Examples according to Tables 1 to 3 and FIGS. At the beginning of production, strengths close to the values of the knot strength and tensile strength of the invention of the prior application were obtained, and it was proved that the physical properties equivalent to those of the invention of the prior application could be obtained even if the regulation of the residual monomer amount was changed. ing.
With each change in strength and elongation, the decrease in strength and the like of the present invention is faster than in the invention of the previous application, and the filaments left or dumped on the mountain or coast after use are quickly decomposed and lost. It has been shown that it can contribute more to environmental pollution control and nature conservation. In addition, since it does not change so much for several months from the time of manufacture, even if it is sold as a product of biodegradable material, it does not bring a disadvantage of deterioration in product performance particularly to the purchaser.
In the conventional example of the comparative example, polylactic acid resin is used, and further, the manufacturing conditions do not satisfy the requirements of the present invention. Therefore, compared with the present invention, the initial tensile strength is inferior and the change with time is very high. Since it is low, filaments that are left or dumped in the mountains or on the beach after use are difficult to decompose and disappear, and it has been shown that they cannot contribute to environmental pollution control and nature protection.
From the results of the reference examples and the present invention, it can be seen that in the present invention, the biodegradation rate can be controlled by adjusting the residual monomer amount, and the balance between biodegradability and physical properties can also be controlled.
From the above data results and discussion, the rationality and significance of the constituent requirements of the present invention have been demonstrated, and it has been clarified that the present invention has a significant advantage over the prior art. I can say that.

It is a graph which shows a time-dependent change of the intensity | strength retention in a reference example, an Example, and a comparative example. It is a graph which shows a time-dependent change of the elongation retention in a reference example, an Example, and a comparative example.

Claims (7)

It consists of a polyglycolic acid resin with a residual monomer content of 0.8% by weight or more and a tensile strength of 75
It is used as civil engineering material, agricultural material or fishery material, characterized in that it has 0 MPa or more and nodule strength is 700 MPa or more, and the balance of biodegradability and physical strength and biodegradation rate are controlled by the amount of residual monomer. Biodegradable polyglycolic acid resin filament. The polyglycolic acid resin filament according to claim 1, wherein the polyglycolic acid resin is a resin obtained by polymerizing glycolic acid or glycolide, and the residual monomer is glycolic acid or glycolide. The polyglycolic acid resin is a resin obtained by copolymerizing glycolic acid or glycolide and another polymerizable monomer, or a mixture of a polyglycolic acid resin and another polyester resin. Polyglycolic acid resin filaments. The polyglycolic acid resin filament according to claim 1, wherein the filament is a monofilament and is used for biodegradable fishery materials. A fishing line formed from the polyglycolic acid resin filament according to any one of claims 1 to 4. The balance between biodegradability and physical strength and the biodegradation rate are controlled by adjusting the residual monomer amount. The residual monomer amount is adjusted by the polymerization conditions of the polyglycolic acid resin or by heating and drying the polymer after polymerization. The method for controlling the balance between biodegradability and physical strength and the biodegradation rate in the polyglycolic acid resin filament according to any one of claims 1 to 5, wherein the method is performed by vacuum drying. If necessary, other components are added to the polyglycolic acid resin whose residual monomer amount is adjusted to 0.5% by weight or more, melt-extruded at a temperature of 230 ° C. or higher, spun and spun in a refrigerant at a temperature of 10 ° C. or lower. 6. The method according to any one of claims 1 to 5, comprising quenching, then, amorphous stretching in a medium of 60 to 83 ° C by 3 times or more, and optionally performing two-stage stretching and thermal relaxation. A method for producing a polyglycolic acid resin filament.

Images