JPH08296119A - High strength biodegradable polylactoneamide multifilament and its production - Google Patents

Abstract

PURPOSE: To obtain a high strength and biodegradable polylactoneamide multifilament capable of being biodegraded, improved in strength and toughness, excellent in heat resistance and capable of being supplied to practical uses as a general industrial material. CONSTITUTION: This biodegradable multifilament comprises a polylactoneamide copolymer comprising 5-80wt.% of polyamide units and 20-95wt.% of polylactone units and have a melting point (Tm) of >=90 deg.C and a linear tensile strength of >=4.0d/g. The birefringence of the multifilaments is preferably >=35×10<-3> . The biodegradable multifilaments are produced by a method comprising melt- spinning the polylactoneamide copolymer (relative viscosity of >=0.5), cooling the melt-spun multifilaments in a <=60 deg.C inert gas, subjecting the cooled multifilaments to the first stage drawing treatment in a drawing ratio of 60-85% based on the whole drawing ratio and subsequently subjecting the first drawn multifilaments to the wholly drawing treatment so as to give the multifilaments having a birefringence of >=35×10<-3> after drawn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polylactone amide multifilament having biodegradability, strength properties and heat resistance, and a process for producing the same.

[0002]

2. Description of the Related Art Conventionally, fibers having excellent strength and weather resistance have been required as fibers for industrial materials used for fishing, agriculture and civil engineering, and those mainly composed of polyamide, polyester, vinylon, polyolefin and the like have been demanded. in use. Since these fibers are not self-degradable, there is a problem in that they cause various pollution when left in the sea or mountains after use.

This problem can be solved by treating it by incineration, landfilling or recovery after use. However, since such treatment requires a great deal of money, it is actually left in the sea or mountains, and birds and It has become entangled with marine life, divers, etc., causing death, and entangled with the boat's screw, causing ship accidents.

As a method for solving such a problem, it can be considered to manufacture the fibers for industrial materials by using a material which is naturally decomposed or decomposed by light or microorganisms.

Heretofore, as naturally degradable polymers, polysaccharides such as cellulose, proteins such as regenerated collagen, and synthetic aliphatic polyesters such as polycaprolactone have been well known.

Particularly, the polycaprolactone polymer is a completely biodegradable synthetic polymer, and is gradually decomposed when placed in an environment in which microorganisms such as a living body or soil inhabits. It has been proposed to fiberize the coalescence.

For example, Japanese Unexamined Patent Publication (Kokai) No. 5-59612 describes a multifilament made of polycaprolactone which is relatively inexpensive and has a strength such that it can be put to practical use, and a method for producing the same.

[0008]

However, the polycaprolactone multifilament disclosed in Japanese Patent Laid-Open No. 5-59612 is a multifilament which is considerably excellent as a technique for improving strength, but the melting point of the polymer is around 60 ° C. Therefore, its heat resistance is poor and its use is limited. For example, materials for fisheries and materials for civil engineering, when exposed to high temperatures due to the storage environment, have a drastic decrease in strength and, in some cases, a problem of fusing. Further, there is a problem that the strength is greatly reduced due to heat generated by rubbing during use.

Therefore, the present invention eliminates the above-mentioned drawbacks of the prior art, has high strength and good heat resistance, and is a biodegradable polylactone amide mulch which can be put to practical use in general industrial material applications. The main purpose is to provide filaments.

[0010]

In order to solve the above problems, the high-strength biodegradable polylactone amide multifilament of the present invention comprises a poly (polyamide unit) of 5 to 80% by weight and a polylactone unit of 20 to 95% by weight. A multifilament comprising a lactone amide copolymer,
3. Melting point (Tm) is 90 ° C. or higher, and linear tensile strength is 4.
It is characterized by being 0 g / d or more.

Further, the method for producing the high-strength biodegradable polylactone amide multifilament of the present invention is 5-80% by weight of polyamide unit and 20-95% by weight of polylactone unit.
A polylactone amide copolymer having a relative viscosity of 0.5 or more is melt-spun, is cooled and solidified with an inert gas at 60 ° C. or less, and is then multistage-stretched.

The present invention will be described in detail below.

The multifilament of the present invention is a multifilament composed of a polylactone amide copolymer comprising 5 to 80% by weight of a polyamide unit and 20 to 95% by weight of a polylactone unit, and comprises a polyamide-forming compound and a dicarboxylic acid. And polylactone diol. Among them, the copolymerization ratio is preferably 10 to 70% by weight of the polyamide unit and 30 to 90% by weight of the polylactone unit. If the polyamide unit is too small, the heat resistance will not be sufficient, and conversely if it is too large, the biodegradability will be insufficient.

As the polyamide-forming compound, an aminocarboxylic acid having 4 to 12 carbon atoms, a lactam having 4 to 12 carbon atoms, and a dicarboxylic acid having 4 to 12 carbon atoms and 4 to 12 carbon atoms.
One or more compounds selected from nylon salts consisting of 12 diamines may be used.

Specifically, as the aminocarboxylic acid having 4 to 12 carbon atoms, ω-aminobutyric acid, ω-aminovaleric acid, ω-aminocaproic acid, ω-aminoenanthic acid,
ω-aminocaprylic acid, ω-aminoberargonic acid, ω-
Examples include aminoundecanoic acid and ω-aminododecanoic acid, and among them, ω-aminocaproic acid and ω-
Aminoundecanoic acid and ω-aminododecanoic acid are preferred.

As the lactam having 4 to 12 carbon atoms, γ-
Examples thereof include butyrolactam, ε-caprolactam, enantolactam, caprylotactam, laurolactam and the like, of which ε-caprolactam and laurolactam are preferable.

The dicarboxylic acid having 4 to 12 carbon atoms includes
Aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, sebacic acid, azelaic acid and dodecanedioic acid, alicyclic dicarboxylic acids such as hydrogenated terephthalic acid and hydrogenated isophthalic acid, terephthalic acid ,
Examples thereof include aromatic dicarboxylic acids such as isophthalic acid and phthalic acid. Among them, aliphatic dicarboxylic acids are preferable, and adipic acid and sebacic acid are particularly preferable.

Examples of the diamine having 4 to 12 carbon atoms include tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, undecamethylenediamine and dodecamethylenediamine. Aliphatic diamines, cyclohexanediamine, alicyclic diamines such as methylcyclohexanediamine, aromatic diamines such as xylenediamine, and the like. Among these, aliphatic diamines are preferable, and hexamethylenediamine is particularly preferable. .

The dicarboxylic acid to be reacted with the above polyamide-forming compound is a dicarboxylic acid having 4 to 54 carbon atoms, and includes succinic acid, glutaric acid, adipic acid, pimelic acid, speric acid, sebacic acid and azelaic acid. , Aliphatic dicarboxylic acids such as, dodecanedioic acid, dimer acid,
Alicyclic dicarboxylic acids such as hydrogenated terephthalic acid and hydrogenated isophthalic acid, and aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and phthalic acid can be mentioned. Among them, aliphatic dicarboxylic acids are preferable, and Adipic acid and sebacic acid are preferred.

Further, the polylactone diol to be reacted with the above polyamide-forming compound and dicarboxylic acid is a polylactone diol having an average molecular weight of 500 to 4000, and a glycol compound is used as a reaction initiator to form a lactone having 3 to 12 carbon atoms. Derived from the compound. Examples of the lactone compound include β-propiolactone, β-ptyrolactone, δ-valerolactone, ε-caprolactone, enanthlactone, caprylolactone, laurolactone, and the like. Caprolactone diol is preferred.

The polylactone amide multifilament of the present invention has a different melting point depending on the copolymerization ratio of polyamide and polylactone, but in order to obtain a polylactone amide multifilament having high strength and biodegradability, a melting point of 90 ° C. or higher is required. It costs.

When used as a fishery material, an agricultural material, or a general industrial material, those having a low melting point and poor heat resistance have a limited range of use. For example, polycaprolactone has excellent biodegradability, but its melting point is low at around 60 ° C and its heat resistance is poor. Therefore, when the material is exposed to high temperature during transportation or storage, the strength is greatly reduced, and sometimes fusing occurs. there's a possibility that. In addition, heat may be generated due to rubbing during use and the strength may be reduced. Therefore, it has a melting point of 90 ° C. or higher,
Filaments for fishery materials, agricultural materials, and general industrial materials with improved heat resistance are important.

The polylactone amide multifilament of the present invention has a linear tensile strength of 4.0 g / d or more.

The polylactone amide multifilament of the present invention, which is tough and biodegradable, is an optimum material for fishery materials, agricultural materials and general industrial materials from the viewpoint of durability. A filament having a linear tensile strength of less than 4.0 g / d lacks toughness and has a limited range of use, resulting in poor practicality.

Therefore, the birefringence is preferably 35 × 10 ⁻³ or more. The birefringence of 35 × 10 ⁻³ or more means that the molecular chains are highly oriented in the fiber axis direction, and can contribute to the development of high tensile strength.

The relative viscosity of the polylactone amide copolymer to be subjected to melt spinning is the value of the relative viscosity measured by an Ostwald viscometer in a 25% atmosphere of a polymer solution having a concentration of 0.5% using orthochlorophenol as a solvent. Yes, 0.5
The above is necessary. In particular, the range of 0.7 to 3.0, and further the range of 0.8 to 2.5 are preferable from the viewpoint of spinnability. If the relative viscosity is less than 0.5, the degree of polymerization is too low, so even if high-strength drawing is performed to obtain a high-strength multifilament, yarn breakage frequently occurs and sufficient toughness cannot be obtained. A strong multifilament cannot be obtained.

On the other hand, when the relative viscosity is so high as to exceed 3.0, melt fracture and discharge unevenness during spinning are likely to occur, and thus fineness unevenness in the length direction of the filament is apt to occur and strength and the like are increased. Since unevenness in the physical properties of the fiber is likely to occur, it becomes difficult to obtain a high-strength polylactone amide multifilament satisfying the practical quality.

In the present invention, such a polylactone amide copolymer having a high degree of polymerization is melt-spun and the melt-spun multifilament is treated with an inert gas (for example, 60 ° C. or lower, preferably 40 ° C. or lower). After cooling and solidifying in air, nitrogen gas, etc.), it was succeeded in obtaining a biodegradable polylactone amide multifilament with extremely high strength, which has never been known so far, by multistage drawing under specific conditions. is there.

If the cooling temperature exceeds 60 ° C., the solidification of the filament is slow and the fusion between the yarns is likely to occur, the yarn production becomes unstable, and normal yarn production becomes difficult. In addition, wire diameter unevenness occurs, which causes a decrease in strength.

An example of the manufacturing method of the present invention will be specifically described below, but the invention is not limited thereto.

In the present invention, first, the polylactone amide copolymer is melt-spun, but the spinning temperature may be selected as an optimum condition depending on the copolymerization ratio. If the spinning temperature is too low, melt fracture will occur and smooth melt extrusion will be difficult, and if it is too high, the decomposition of the polymer will be remarkably increased, and it will be difficult to produce a yarn on an industrial scale.

Immediately after melt spinning, a heating zone filled with an inert gas may be provided, or a heat retaining zone without heating may be provided.

The melt-spun unstretched yarn is cooled and solidified with an inert gas at 60 ° C. or lower, an oil agent is added thereto, the yarn speed is controlled by a take-up roll, and then the yarn is once wound. It is stretched or continuously enters the stretching process without being wound.

As the oil agent, an ordinary antistatic agent and one containing a lubricant as a main component may be used.

The spinning speed is not limited to a low value such as a decrease in productivity and a high cost, and a high speed such that a yarn is easily broken without spinnability, except conditions such as a copolymerization ratio and a relative viscosity of the polymer. The optimum spinning speed may be selected according to

The stretching is carried out by carrying out a two-stage stretching or a multi-stage stretching of three or more pairs with three or more pairs of Nelson type rolls, followed by heat treatment between the following Nelson rolls.

The heat medium may be selected from a method of directly heating the rolls, a method of installing the heat medium between the rolls, a combination thereof and the like.

The stretching temperature is preferably a temperature not exceeding the melting point of the polylactone amide multifilament when using a liquid heat medium, a vapor heat medium or a contact heat medium having high heat efficiency, and a dry heat gas having low heat efficiency is used. In such a case, a temperature that greatly exceeds the melting point of the polylactone amide multifilament is acceptable.

When a liquid heat medium, a vapor heat medium, or a contact heat medium having a high heat efficiency is used and the drawing temperature is higher than the melting point, fusing occurs frequently, and it is difficult to produce yarn.

The melting point (Tm) (° C.) of this polylactone amide multifilament is SSC520 (manufactured by Seiko Denshi Kogyo Co., Ltd.)
Crystal melting peak temperature when measured at a temperature rising rate of 10 ° C / min using a 0-type differential scanning calorimeter (however, when several melting peaks overlap, the peak temperature of the highest calorific value) (° C) is meant.

The draw ratio for obtaining the high-strength polylactone amide multifilament of the present invention varies depending on the copolymerization ratio, the relative viscosity, the spinning conditions, etc., but in the first drawing, the neck generation position can be fixed, In addition, it is important to draw at a draw ratio that does not cause single yarn breakage. Therefore, it is preferable that the first stage drawing is performed at a draw ratio of 60% or more and 85% or less of the total draw ratio. The remaining stretching is performed from the second stage onward. The total draw ratio is 35 × 10 ^{−3 in} birefringence.
It is preferable to stretch the film at the above ratio. The total draw ratio is the product of the draw ratios in multi-stage drawing.

If the draw ratio of the first stage does not exceed 60% of the total draw ratio, the neck position cannot be fixed, and multifilaments containing unstretched portions are likely to occur. Further, when drawn at a draw ratio of more than 85% of the total draw ratio, a single yarn breakage occurs due to a rapid change in the fiber structure, and it becomes difficult to obtain a high strength polylactone amide multifilament.

The stretching from the second stage onward may be carried out in two or more stages as long as the stretching ratio and the stretching temperature are satisfied. In this case, the total draw ratio is the product of the first draw ratio and the draw ratio of the second and subsequent draws divided into two or more steps. It is also possible to provide a constant length or relaxing heat treatment step between the first stage stretching and the second stage stretching.

After completion of the multi-stage drawing, a heat treatment is carried out to wind the film in order to form a more stable fiber structure. The heat treatment temperature is preferably a temperature that does not exceed the melting point of the polylactone amide multifilament from room temperature when a liquid heat medium, a vapor heat medium, or a contact heat medium having high heat efficiency is used, and a dry heat gas having low heat efficiency is used. In such a case, a temperature that greatly exceeds the melting point of the polylactone amide multifilament is acceptable.

According to this manufacturing method, mulch having high strength characteristics suitable for industrial materials use, that is, linear tensile strength of 4.0 g / d or more, excellent heat resistance, and sufficient biodegradability. A filament can be obtained.

The polylactone amide multifilament of the present invention contains additives such as a paste, a dye, a heat-resistant agent, an ultraviolet absorber, an antioxidant, a crystallization inhibitor and a plasticizer within a range that does not impair the effects of the present invention. It can also be contained within.

[0047]

In the present invention, it is important that a specific polymer is used, cooled at a specific cooling temperature, and subjected to multistage stretching under specific conditions. If necessary, first stage stretching and second stage stretching are performed. It is preferable to perform heat treatment under specific conditions between the two, and this manufacturing method in which heat treatment under specific conditions is carried out after completion of drawing gives an unprecedented excellent multifilament that is biodegradable, has high strength, and satisfies heat resistance. be able to.

[0048]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples.

The physical properties of the obtained polylactone amide multifilament were measured by the following measuring methods.

(A) Linear tensile strength and knot strength: JI
According to the method of S-L1017. That is, a sample is taken in the shape of a slab and left in a temperature / humidity control room at 20 ° C. and 65% RH for 24 hours, and then “TENSILON” UTM- manufactured by Orientec Co., Ltd.
Using a 4-100 type tensile tester, the test length is 250 mm and the tensile speed is 300 mm / min.

(B) Heat resistance: After being left in an oven at a temperature of 80 ° C. for 30 minutes in a drip state, it was left standing at 20 ° C. in a 65% RH temperature / humidity control room for 4 hours, and then measured, and the strength retention rate was evaluated. . A heat retention of 90% or more is considered good heat resistance.

(C) Microbial degradability: 6 samples were placed in soil
It is buried for a month and taken out, and the multifilament has lost its shape or the tensile strength retention rate is 50%.
The following cases are considered to have good biodegradability.

(D) Birefringence: Determined by an ordinary Berek compensator method using a POH type polarizing microscope manufactured by Nippon Kogaku Co., Ltd. with a D line (monochromatic light, Na lamp) as a light source.

Examples 1 to 6 and Comparative Examples 1 to 5 Polylactone amide copolymers having a relative viscosity of 1.0 (copolymerization ratio: N6 / polylactone = 50/50) (Tm: 145
C.) was fed to an extruder type melt spinning machine, melt spinning was carried out at a spinning temperature of 200.degree. C., and cooled by cold air (air) of 25.degree.

Then, after applying the oil agent, the yarn speed was controlled by a take-up roll rotating at a speed of 70 m / min, and then continuous drawing was performed without once winding.

Stretching is performed by 3 pairs of Nelson type rolls to 2
After the multi-stage drawing, 5% of relaxation was given between the following Nelson rolls and the film was wound up.

The take-up roll temperature was set at 40 ° C., one-stage drawing was performed between the take-up roll and the first drawing roll heated to 70 ° C. at a draw ratio of 5.0 times, and then the first drawing roll Two-stage stretching was performed between the second stretching roll heated to 100 ° C. and the stretching ratio such that the total stretching ratio was 8.1 times.

The next Nelson roll was heated to 50 ° C. and used for adjusting the tension after stretching.

The resulting multifilament was 60 filaments, 400d, and had a tensile strength of 5.81 g /
d, the birefringence was 48.3 × 10 ⁻³ .

The yarn-forming property was good, the heat resistance was good, and the biodegradability was good.

Multifilaments were produced in the same manner as above except that the polymer composition, polymer viscosity, cooling temperature, first stage drawing conditions and second stage drawing conditions were changed as shown in Tables 1-2. Examples 2-6 and Comparative Examples 1-5).

The conditions of Examples 1 to 6 are shown in Table 1, the conditions of Comparative Examples 1 to 5 are shown in Table 2, and Table 3 shows the conditions of Examples 1 to 6 and Comparative Examples 1 to 5. The physical properties of the multifilament are described below.

[0063]

[Table 1]

[0064]

[Table 2]

[0065]

[Table 3]

[0066]

EFFECTS OF THE INVENTION According to the present invention, while being biodegradable, the strength and toughness are improved, the heat resistance is excellent, and the high strength and heat resistance that can be put to practical use for general industrial materials are provided. A biodegradable polylactone amide multifilament can be provided.

As a result, this polylactone amide multifilament can be used for fishery materials, agricultural materials, and general industrial materials, and after use, if left in an environment where microorganisms are present for a certain period of time. Since it is decomposed later, use of this multifilament makes it possible to prevent pollution of the waste multifilament without requiring special waste treatment.

Claims (6)

[Claims] 1. A multifilament comprising a polylactone amide copolymer comprising 5 to 80% by weight of a polyamide unit and 20 to 95% by weight of a polylactone unit,
3. Melting point (Tm) is 90 ° C. or higher, and linear tensile strength is 4.
High-strength biodegradable polylactone amide multifilament characterized by being 0 g / d or more. 2. The high-strength biodegradable polylactone amide multifilament according to claim 1, wherein the birefringence of the multifilament is 35 × 10 ⁻³ or more. 3. The polylactone amide copolymer is
Polyamide unit 10 to 70% by weight and polylactone unit 3
The high-strength biodegradable polylactone amide multifilament according to claim 1 or 2, which is a copolymer composed of 0 to 90% by weight. 4. A polylactone amide copolymer having a relative viscosity of 0.5 or more, which is a copolymer composed of 5 to 80% by weight of a polyamide unit and 20 to 95% by weight of a polylactone unit, is melt-spun and the temperature is 60 ° C. or lower. A method for producing a high-strength biodegradable polylactone amide multifilament, which comprises cooling in an inert gas as described above, and then performing multi-stage drawing. 5. The method for producing a high-strength biodegradable polylactone amide monofilament according to claim 4, wherein the polylactone amide copolymer has a relative viscosity of 0.8 to 3.0. 6. The first stage drawing is carried out at a draw ratio of 60 to 85% of the total draw ratio, and the total draw ratio is such that the birefringence of the drawn multifilament is 35 × 10 ⁻³ or more. The method for producing a high-strength biodegradable polylactone amide multifilament according to claim 4 or 5, wherein