WO2019142920A1

WO2019142920A1 - Method for producing nonwoven fabric

Info

Publication number: WO2019142920A1
Application number: PCT/JP2019/001514
Authority: WO
Inventors: シティサラ; 畑野貴典
Original assignee: 株式会社カネカ
Priority date: 2018-01-22
Filing date: 2019-01-18
Publication date: 2019-07-25
Also published as: JPWO2019142920A1; JP7222923B2

Abstract

The present invention relates to a method for producing a nonwoven fabric, which comprises a step A for obtaining fibers by melt spinning a composition that contains a poly(3-hydroxyalkanoate) with use of a spinneret, a step B for obtaining a web by forming the fibers obtained in the step A into a web, and a step C for subjecting the web obtained in the step B to thermal bonding under pressure, and wherein the thermal bonding temperature under pressure in the step C is from (Tc - 45)°C to (Tc + 5)°C (inclusive) (wherein Tc is the crystallization temperature of the poly(3-hydroxyalkanoate)). Consequently, the present invention provides a production method which exhibits good formability of a nonwoven fabric that contains a poly(3-hydroxyalkanoate), and by which even a nonwoven fabric that substantially contains only a poly(3-hydroxyalkanoate) as the resin component is able to be produced.

Description

Method of manufacturing non-woven fabric

The present invention relates to a method of making a nonwoven comprising poly (3-hydroxyalkanoate) which is a biodegradable polyester.

In recent years, plastic waste has become a cause of imposing a large load on the global environment, such as the impact on ecosystems, the generation of harmful gases at the time of combustion, and global warming due to a large amount of combustion heat. As one of the solutions to such problems, development of biodegradable plastics has become active.

Among them, plant-derived biodegradable plastics do not increase carbon dioxide in the atmosphere because carbon dioxide emitted when the plant is burned is originally in the air. This is called carbon neutral, and it is considered important under the Kyoto Protocol that imposes a carbon dioxide reduction target value. Active use of plant-derived biodegradable plastics is desired.

Recently, aliphatic polyester resins have attracted attention as plant-derived plastics from the viewpoint of biodegradability and carbon neutrality, and in particular, polyhydroxyalkanoates (hereinafter sometimes referred to as PHA), and also PHAs. Poly (3-hydroxybutyrate), poly (3-hydroxybutyrate-co-3-hydroxyvalerate), poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (hereinafter referred to as P3HB3HH) And poly (3-hydroxyalkanoates) such as poly (3-hydroxybutyrate-co-4-hydroxybutyrate) (hereinafter sometimes referred to as P3HA) and polylactic acid etc. There is.

However, since the PHA is slow in crystallization and has a glass transition temperature (about 0 to 4 ° C.) lower than room temperature, it is necessary to extend the cooling time for solidification after heating and melting during molding processing, and productivity It is bad. In particular, when attempting to produce a non-woven fabric by melt-spinning PHA and forming a web and then applying pressure and heat to produce a non-woven fabric, the solidification of the resin is slow. This causes breakage, shrinkage of the web, etc., making it difficult to produce a stable non-woven fabric, and the quality of the obtained non-woven fabric also becomes low.

As means for solving these problems, a method of producing a nonwoven fabric of thermoplastic biodegradable polyester containing a butylene succinate unit added with a crystal nucleating agent is disclosed (see Patent Document 1 and Patent Document 2). According to the method, a web obtained by melt spinning a thermoplastic biodegradable polyester and forming it into a web is heated to a temperature (Tm) -5 ° C or lower of the thermoplastic biodegradable polyester (Patent Document 1), or a melting point It is described that when heat pressing is performed by a roll set to a temperature lower than the temperature by 10 ° C. or more (Patent Document 2), a non-woven fabric capable of holding the shape can be obtained.

Also, as another prior example, a web of core-sheath composite fiber comprising P3 HA resin as a core component and polybutylene succinate, polyethylene succinate or copolymer thereof as a sheath component has a temperature 30 ° C. lower than Tm and Tm A method of heat bonding at a temperature below is disclosed (see Patent Document 3).

Japanese Patent Application Publication No. 08-325916 Japanese Patent Laid-Open No. 09-095 848 JP 2000-160466 A

However,

Patent Documents

1 and 2 do not specifically describe a non-woven fabric using PHA as a thermoplastic biodegradable polyester, and when P3HA is used as a resin component,

Patent Documents

1 and 2 In the above method, it is difficult to produce a non-woven fabric. In the method disclosed in Patent Document 3, there is a problem that a non-woven fabric made only of P3HA such as P3HB3HV can not be formed.

Therefore, the present invention provides good moldability of the non-woven fabric containing poly (3-hydroxyalkanoate), and also produces non-woven fabric essentially containing only poly (3-hydroxyalkanoate) as a resin component. Provide a possible manufacturing method.

The present inventors diligently studied to solve such problems, and according to the manufacturing method including specific steps, the moldability of the non-woven fabric containing poly (3-hydroxyalkanoate) is good, and the resin component We have found that it is also possible to produce non-woven fabrics comprising essentially only poly (3-hydroxyalkanoate), as this completes the present invention.

That is, the present invention provides, for example, the following method for producing a nonwoven fabric in one or more embodiments.

[1] Step A of melt spinning a composition containing poly (3-hydroxyalkanoate) using a spinneret to obtain a fiber;
Step B: obtaining the web by converting the fibers obtained in step A into a web;
Subjecting the web obtained in step B to pressure heat adhesion treatment step C,
In the nonwoven fabric characterized in that the pressure heat adhesion treatment temperature in the step C is (Tc-45) ° C. or more and (Tc + 5) ° C. or less [Tc: crystallization temperature of poly (3-hydroxyalkanoate)] Production method.

[2] The method for producing a non-woven fabric according to [1], wherein the pressure heat adhesion treatment temperature is (Tc-40) ° C. or more and (Tc + 0) ° C. or less.

[3] The method for producing a non-woven fabric according to [1] or [2], wherein the discharge amount of the composition per single hole from the spinneret in step A is 0.2 to 1.2 g / min.

[4] The method for producing a non-woven fabric according to [3], wherein the discharge amount of the composition per single hole from the spinneret in step A is 0.2 to 0.7 g / min.

[5] The method for producing a non-woven fabric according to any one of [1] to [4], wherein web formation in step B is carried out by a spun bond method.

[6] The method for producing a nonwoven fabric according to any one of [1] to [5], wherein the melt-spinning temperature in step A is 145 to 190 ° C.

[7] The method for producing a non-woven fabric according to any one of [1] to [6], wherein the composition further contains a crystal nucleating agent.

[8] The method for producing a nonwoven fabric according to [7], wherein a content of the crystal nucleating agent is 0.05 to 12 parts by weight with respect to 100 parts by weight of poly (3-hydroxyalkanoate).

[9] The method for producing a non-woven fabric according to any one of [1] to [8], wherein the composition further contains a lubricant.

[10] The method for producing a non-woven fabric according to [9], wherein the content of the lubricant is 0.05 to 12 parts by weight with respect to 100 parts by weight of poly (3-hydroxyalkanoate).

[11] The poly (3-hydroxyalkanoate) is poly (3-hydroxybutyrate), poly (3-hydroxybutyrate-co-3-hydroxyvalerate), poly (3-hydroxybutyrate-co-) At least one selected from the group consisting of 3-hydroxyhexanoate) and poly (3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) [1] to [6] The manufacturing method of the nonwoven fabric as described in any one of 10].

Since the present invention has the above constitution, the moldability of the non-woven fabric containing poly (3-hydroxyalkanoate) is good, and the non-woven fabric essentially containing only poly (3-hydroxyalkanoate) as a resin component Production is also possible.

It is the schematic of the apparatus used for manufacture of the nonwoven fabric in the Example.

One or more embodiments of the present invention will now be described in detail. The present invention is not limited to the following embodiment.

The method for producing the nonwoven fabric of the present invention is a method including the following steps A to C as essential steps. The method for producing the non-woven fabric of the present invention may include other steps.
Step A: Melt spinning of a composition containing poly (3-hydroxyalkanoate) using a spinneret to obtain fibers Step B: Webizing the fibers obtained in Step A to obtain a web Step C : A step of applying pressure and heat adhesion to the web obtained in step B

[Step A]
In step A, a composition containing poly (3-hydroxyalkanoate) (hereinafter sometimes referred to as P3HA composition) is melt spun to obtain a fiber composed of the P3HA composition.

(P3 HA composition)
The P3HA composition is a composition containing P3HA as an essential component. P3HA used in the present invention is a polymer containing 3-hydroxyalkanoic acid (3HA) as an essential monomer component. Among them, P3HA is preferably a group represented by the formula (1): [-CHR-CH ₂ -CO-O-] (wherein R is an alkyl group represented by C _n H _{2n + 1} in the formula (1), n is 1 Or P15 HA (aliphatic polyester) containing a repeating unit represented by the following formula:

P3HA is generally classified into microorganism-produced P3HA and chemically synthesized P3HA obtained by chemical synthesis such as ring-opening polymerization of lactone. These P3HAs are different in structure, and the microorganism-produced P3HA has optical activity because its monomer structural unit consists only of D form (R form), whereas chemically synthesized P3 HA has D form (R form) and L form (L form) The monomer structural units derived from the S form are randomly bonded and optically inactive.

As P3HA, P3HA containing a 3-hydroxybutyrate unit is preferable, and as such PHA, for example, poly (3-hydroxybutyrate) (P3HB), poly (3-hydroxybutyrate-co-3-hydroxyl) Valerate (P3HB3HV), poly (3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) (P3HB3HV3HH), poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) Nooate) (P3HB3HH), poly (3-hydroxybutyrate-co-4-hydroxybutyrate) (P3HB4HB), poly (3-hydroxybutyrate-co-3-hydroxyoctanoate), poly (3-hydroxybutyrate) Butyrate-co-3-hydroxy octadeca Benzoate), etc., from the viewpoint industrial production is easy, preferably. Among these, P3HB, P3HB3HV, P3HB3HV3HH, P3HB3HH and P3HB4HB are more preferable, and P3HB3HH is more preferable.

When P3HA is a P3HA having a 3-hydroxybutyrate unit structure, the average composition ratio of repeating units (monomer structural units) is not particularly limited, but from the viewpoint of balance between flexibility and strength, poly (3-hydroxybutyrate The composition percentage of (rate) is preferably 80 to 99 mol%, more preferably 85 to 97 mol%.

P3HA can be produced by known or conventional methods. When P3HA is a microorganism-produced P3HA, the microorganism used for producing the P3HA is not particularly limited as long as it is a microorganism capable of producing P3HAs. For example, as P3HB-producing bacteria, Bacillus megaterium discovered in 1925 is the first to be used, as well as Capriavidus necator (old classification: Alcaligenes eutrophus (Alcaligenes eutrophus, Ralstonia eutropha), Natural microorganisms such as Alcaligenes latus are known, and in these microorganisms, P3HB is accumulated in the cells.

Moreover, as bacteria for producing copolymers containing hydroxybutyrate units and other hydroxyalkanoate units, P3HB3HV and P3HB3HH producing bacteria, Aeromonas caviae, P3HB4HB producing bacteria, Alkalinegenes eutrophus (Alcaligenes) eutrophus) etc. are known. In particular, with regard to P3HB3HH, Alkalinegenes eutrophus AC 32 strain (Alcaligenes eutrophus AC32, FERM BP-6038) into which a gene of P3HA synthetase group was introduced to increase the productivity of P3HB3HH (T. Fukui, Y. Doi, J. Bateriol) , 179, p 482 1-4830 (1997)) and the like, and microbial cells obtained by culturing these microorganisms under appropriate conditions and accumulating P3HB3HH in the cells are used. In addition to the above, genetically modified microorganisms into which various P3HA synthesis related genes have been introduced may be used according to the PHA to be produced, or culture conditions including the type of substrate may be optimized.

The molecular weight of P3HA is not particularly limited as long as it exhibits substantially sufficient physical properties in the intended application. If the molecular weight is too low, the strength of the resulting molded article may be reduced. On the other hand, if it is too high, the processability may be reduced and the molding may be difficult. Considering them, the range of weight average molecular weight of P3HA is preferably 50,000 to 3,000,000, and more preferably 100,000 to 1,500,000. In addition, the weight average molecular weight here refers to what was measured from the polystyrene conversion molecular weight distribution using the gel permeation chromatography (GPC) using chloroform eluent. As a column in the said GPC, a column suitable for measuring the said molecular weight may be used.

The melt flow rate of P3HA measured at 160 ° C. under a 5 kg load is preferably 0.1 to 100 g / 10 min, more preferably 1 to 50 g / 10 min, and 10 to 40 g / 10 min Is more preferred. When the melt flow rate is too low, the flowability of the molten resin is insufficient, and when it is too high, the flowability is too high, and in either case spinning of the fiber tends to be difficult.

As P3 HA, one type of P3 HA may be used alone, or two or more types may be used in combination. Also, for example, in the case of P3HB3HH, only one P3HB3HH may be used, and P3HB3HH may be a mixture of two or more different in composition percentage of 3HB.

The content of P3HA in the P3HA composition of the present invention is not particularly limited, but is preferably 80% by weight or more, more preferably 85% by weight or more, still more preferably 90% by weight or more, while the upper limit is 100% by weight For example, it may be 98 wt% or less or 95 wt% or less. By setting the content of P3HA to 80% by weight or more, the biodegradability of the obtained nonwoven fabric tends to be further improved. According to the method for producing the non-woven fabric of the present invention, even when the content of P3HA is considerably large such as 80% by weight or more, it is very advantageous in that the non-woven fabric can be produced with excellent formability.

The proportion of P3HA in the resin component contained in the P3HA composition of the present invention is not particularly limited, but is preferably 80 to 100% by weight, more preferably 90 to 100% by weight, still more preferably 95 to 100% by weight . According to the method for producing the nonwoven fabric of the present invention, it is possible to produce the nonwoven fabric with good formability even when the proportion of P3HA in the resin component is high (for example, 80% by weight or more).

The P3HA composition of the present invention preferably further comprises a nucleating agent. The crystal nucleating agent is not particularly limited as long as it is a compound having an effect of promoting the crystallization of P3HA, and, for example, boron nitride, titanium oxide, talc, layered silicate, calcium carbonate, chloride Inorganic substances such as sodium and metal phosphate; sugar alcohol compounds derived from natural products such as erythritol, galactitol, mannitol and arabitol; pentaerythritol; polyvinyl alcohol; chitin; chitosan; polyethylene oxide; aliphatic carboxylic acid amide; Carboxylic acid salts; aliphatic alcohols; aliphatic carboxylic acid esters; dicarboxylic acid derivatives such as dimethyl adipate, dibutyl adipate, diisodecyl adipate and dibutyl sebacate; C; O such as indigo, quinacridone, quinacridone magenta Cyclic compounds having in their molecule a functional group selected from H, S and O; sorbitol-based derivatives such as bisbenzylidenesorbitol and bis (p-methylbenzylidene) sorbitol; nitrogen-containing heteroaromatics such as pyridine, triazine and imidazole Examples thereof include compounds having a group nucleus; phosphoric acid ester compounds; bisamides of higher fatty acids and metal salts of higher fatty acids; branched polylactic acids; low molecular weight poly 3-hydroxybutyric acid and the like. Among them, pentaerythritol, a sugar alcohol compound, polyvinyl alcohol, chitin, chitosan and the like are preferable, and pentaerythritol is more preferable, from the viewpoint of the effect of improving the crystallization rate and mixing with fibers. One of these may be used alone, or two or more of these may be used in combination.

Pentaerythritol is not particularly limited as long as it is generally available, and reagent products or industrial products may be used. Examples of reagent products include Wako Pure Chemical Industries, Ltd., Sigma-Aldrich, Tokyo Chemical Industry Co., Ltd., Merck & Co., Ltd., and if it is an industrial product, the product of Koei Chemical Industry Co., Ltd. (trade name: Pentalitt) and Toyo Chemicals Co., Ltd. products may be mentioned, but the present invention is not limited thereto.

Some commonly available reagents and products include, as impurities, oligomers such as dipentaerythritol and tripentaerythritol produced by dehydration condensation of pentaerythritol. The above-mentioned oligomer has no effect on the crystallization of polyhydroxyalkanoate but does not inhibit the crystallization effect of pentaerythritol. Therefore, an oligomer may be contained.

The content of the crystal nucleating agent in the P3 HA composition is not particularly limited, but preferably 0.05 to 12 parts by weight, more preferably 0.1 to 10 parts by weight, and more preferably 0.5 to 8 parts by weight with respect to 100 parts by weight of P3 HA. Parts are more preferred, particularly preferably 1 to 5 parts by weight. By setting the content of the crystal nucleating agent to 0.05 parts by weight or more, a further excellent crystallization promoting effect can be obtained, and the productivity of the non-woven fabric tends to be improved. On the other hand, by setting the content of the crystal nucleating agent to 12 parts by weight or less, while maintaining a sufficient crystallization rate promoting effect, there is a tendency not to produce adverse effects such as viscosity reduction at the time of processing and fiber physical properties. is there.

Preferably, the P3 HA composition further comprises a lubricant. The lubricant is not particularly limited as long as it is a compound having an effect of imparting lubricity to PHA. For example, fatty acid amides such as behen acid amide, stearic acid amide, erucic acid amide and oleic acid amide; alkylene fatty acid amides such as methylenebisstearic acid amide and ethylenebisstearic acid amide; polyethylene wax; oxidized polyester wax; glycerin monostearate Glycerin mono fatty acid esters such as glycerin mono behenate and glycerol mono laurate; Organic acid mono glycerides such as succinic acid saturated fatty acid mono glyceride; sorbitan fatty acid esters such as sorbitan behenate, sorbitan stearate and sorbitan laurate; diglycerin stearate , Diglycerin laurate, tetraglycerin stearate, tetraglycerin laurate, decaglycerin stearate and decaglycerin Polyglycerol fatty acid esters such as Rinraureto; and higher alcohol fatty acid esters such as stearyl stearate and the like. One of these may be used alone, or two or more of these may be used in combination.

Among the above-mentioned lubricants, in particular, for example, fatty acid amides and polyglycerin fatty acid esters are preferable as the compound having the effect of imparting external lubricity. Examples of fatty acid amides include monoamides and bisamides of fatty acids. The fatty acid (fatty acid portion) constituting the fatty acid amide is preferably one having a carbon number of 12 to 30, more preferably 18 to 18 from the viewpoint of suppressing the deterioration of processability during melt processing because the melting point is appropriately high. 22 fatty acids, such as higher fatty acids such as erucic acid, palmitic acid, oleic acid and the like. Specific examples of the fatty acid amide include behenic acid amide, erucic acid amide, palmitic acid amide, oleic acid amide, stearic acid amide, methylenebisstearic acid amide, ethylenebisstearic acid amide, ethylenebisoleic acid amide, ethylenebis Erucic acid amide etc. are mentioned. Examples of polyglycerin fatty acid esters include monoesters of glycerin, diesters of glycerin, triesters of glycerin (eg, glycerin diacetomonolaurate, glycerin diacetomonoolate, glycerin diacetomonostearate, glycerin diacetomonocaprylate, glycerine dia And glycerin diacetomonoesters such as cetomonodecanoate etc. As a commercial product of polyglycerin fatty acid ester, for example, Rikemar PL-012 (manufactured by Riken Vitamin Co., Ltd.), DAIFATTY (manufactured by Daihachi Chemical Industry Co., Ltd.), etc. can be obtained. In addition, fatty acid amides and polyglycerin fatty acid esters are more preferable from the viewpoint of easy availability and high effects.

The content of the lubricant in the P3 HA composition is not particularly limited as long as friction between the polyhydroxyalkanoate and the metal surface of the extruder or spinning machine can be reduced and mutual adhesion of fibers can be prevented, for example, P3 HA 100 weight The amount is preferably 0.05 to 12 parts by weight, more preferably 0.1 to 10 parts by weight, still more preferably 0.5 to 8 parts by weight, and particularly preferably 3 to 10 parts by weight. By setting the content of the lubricant to 0.05 parts by weight or more, the friction in the extruder and the spinning machine is suppressed, the decomposition of P3HA due to shear heat generation is suppressed, and the fibers coming out of the nozzles are prevented from adhering to each other. It tends to be done. On the other hand, by setting the content of the lubricant to 12 parts by weight or less, P3HA in the extruder melts more efficiently, and as a result, fiber breakage is suppressed without becoming too hard, and productivity is further improved. There is a tendency to

The P3 HA composition further contains other components such as plasticizers, inorganic fillers, organic fillers (such as cellulose), antioxidants, ultraviolet absorbers, colorants such as dyes and pigments, and antistatic agents. It may be

The plasticizer is not particularly limited, but, for example, adipic acid ester compounds such as diethylhexyl adipate, dioctyl adipate and diisononyl adipate; polyether ester such as polyethylene glycol dibenzoate, polyethylene glycol dicaprylate and polyethylene glycol diisostearate Compounds; benzoate ester compounds; epoxidized soybean oil; epoxidized fatty acid 2-ethylhexyl; sebacic acid monoesters and the like. One of these may be used alone, or two or more of these may be used in combination.

Among the above-mentioned plasticizers, polyether ester compounds are preferred in view of easy availability and high degree of plasticizing effect. The content of the plasticizer in the P3HA composition is not particularly limited, and can be appropriately selected, for example, in the range of 3 to 25 parts by weight with respect to 100 parts by weight of P3HA.

Although the inorganic filler is not particularly limited, for example, titanium oxide, calcium carbonate, talc, clay, synthetic silicon, carbon black, barium sulfate, mica, glass fiber, whisker, carbon fiber, magnesium carbonate, glass powder, metal powder, kaolin , Graphite, molybdenum disulfide, zinc oxide and the like. One of these may be used alone, or two or more of these may be used in combination.

Among the above-mentioned inorganic fillers, titanium oxide and / or calcium carbonate are preferable in terms of the strength increase and the effect of promoting the biodegradability. The content of the inorganic filler in the P3HA composition is not particularly limited, and can be appropriately selected, for example, in the range of 1 to 10 parts by weight with respect to 100 parts by weight of P3HA.

The P3 HA composition may contain a resin component (other resin component) other than P3 HA. Other resin components include biodegradable resins such as petroleum derived resins such as polylactic acid, polybutylene adipate terephthalate, polybutylene succinate adipate and polybutylene succinate, and natural polymers such as starch and cellulose. Be Further, known thermoplastic resins (polyvinyl chloride resins, polystyrene resins, ABS resins, etc.), thermosetting resins (epoxy resins, etc.) can be added. In addition, general purpose engineering plastics such as polyethylene terephthalate resins, polybutylene terephthalate resins, polycarbonate resins and polyamide resins are also used as other resin components. The content of the other resin component is preferably 20% by weight or less, more preferably 10% by weight or less, still more preferably 5% by weight or less, based on the total amount (100% by weight) of the resin component. The other resin components may be used alone or in combination of two or more.

In the method for producing the non-woven fabric of the present invention, in the step A of melt spinning a composition containing at least poly (3-hydroxyalkanoate), the step B of forming the web obtained in the step A, and the step B A step C of subjecting the obtained web to pressure and heat adhesion treatment is included in this order, whereby PHA is used to produce a biodegradable non-woven fabric. As a method of processing non-woven fabric by adapting these steps, in a general method, for example, a spunbond method (fibers out of a spinneret are drawn through a portion such as an ejector called an ejector) and stretched And meltblown methods (methods of blowing fibers from a spinneret to form a web) and the like.

First, in step A, for example, a P3 HA composition is melted using a melt extruder, and continuously extruded from a spinneret (also called a spinning die) to form a fiber composed of the P3 HA composition. The melt extruder may be a general device as long as it can appropriately maintain the molecular weight and melt viscosity of P3HA used, and a compression extruder in which the melt portion is kept at a constant temperature or a screw type capable of continuous supply Either of the extrusion devices may be used. The former is suitable for small volume production and the latter is suitable for industrial production.

The cylinder temperature of the melt extruder and the die outlet temperature may be adjusted so that the melt viscosity of P3HA can be maintained appropriately depending on the molecular weight and monomer composition of P3HA used. The melt spinning temperature of the fiber is preferably 145 to 190 ° C., more preferably 150 to 190 ° C., and still more preferably 150 to 180 ° C. By setting the spinning temperature to 145 ° C. or more, the spinning tends to be further stabilized because the PHA composition can be sufficiently dissolved. On the other hand, by setting the spinning temperature to 190 ° C. or less, the thermal decomposition of the resin is suppressed, the spinning is further stabilized, and the physical properties of the obtained fiber tend to be further improved. In addition, melt-spinning temperature means the temperature of the highest temperature range among the temperatures added while P3HA composition is fiberized.

The P3 HA composition is melted and extruded from the spinning die while adjusting the flow rate to keep the discharge amount constant, and the opening area of the spinning die at this time is preferably 0.15 to 3.5 mm ² . By setting the opening area to 0.15 mm ² or more, breakage during spinning tends to be further suppressed. On the other hand, by setting the opening area to 3.5 mm ² or less, the time required for solidification does not become too long because the fibers do not become too thick, relaxation of the formed extension chain is suppressed, and processability and strength are improved. There is a tendency to improve further.

Although the discharge amount can be arbitrarily selected based on the finally required fiber diameter and the spinning speed at the time of production, the discharge amount (discharge amount of P3HA composition per single hole of spinneret) is 0. It is preferably 2 to 1.2 g / min, more preferably 0.2 to 0.7 g / min. By setting the discharge amount to 0.2 g / min or more, the fibers do not become too thin, and yarn breakage tends to be further suppressed. On the other hand, by setting the discharge amount to 1.2 g / min or less, the fibers do not become too thick, and the solidification of the fibers proceeds rapidly, and the mutual adhesion of the fibers tends to be suppressed.

Moreover, in order to suppress the decomposition of the resin due to the heat at the time of extrusion, the residence time of the resin inside the spinning machine is preferably 30 minutes or less, and more preferably 15 minutes or less.

The atmosphere temperature extruded from the spinneret is not particularly limited, and can be suitably adjusted, for example, in the range of 5 to 40.degree.

[Step B]
Next, in step B, the fibers composed of the P3HA composition extruded from the spinneret in step A, that is, the fibers obtained by melt-spinning the P3HA composition, are webbed to obtain a web. In this step, the fibers (spun filaments) composed of the P3HA composition are drawn to be a target fineness (become drawn filaments), and a collection surface such as a conveyor moving in the longitudinal direction (MD) Deposit on top to form a long fiber web.

In the case of producing a non-woven fabric by the spun bond method (that is, when the web formation in the step B is carried out by the spun bond method), air drawing and draw thinning are carried out using a suction device such as an ejector. For example, when using an ejector 3 as shown in FIG. 1, it is possible to adjust the spinning speed by adjusting the pressure of air traction. By increasing the air pressure, the spinning speed is increased. The air pressure is preferably 0.2 to 7.0 kgf / cm ² , more preferably 0.5 to 5.0 kgf / cm ² . When it is lower than 0.2 kgf / cm ² , a sufficient spinning speed is difficult to obtain, and when it is higher than 7 kgf / cm ^2, it tends to be higher than 7000 m / min which is a spinning speed at which stable spinning can be performed. The spinning speed by air drawing is preferably 500 to 7,000 m / minute, more preferably 700 to 7,000 m / minute, still more preferably 700 to 5,000 m / minute, and particularly preferably 700 to 3,000 m / minute. In this spinning speed range, solidification of fibers consisting of a P3 HA composition capable of ensuring spinnability is obtained. When the spinning speed is low, the produced non-woven fabric may shrink on cooling, and a homogeneous and good non-woven fabric may not be obtained. The upper limit value of the take-up speed is not particularly limited, but if it is larger than 7,000 m / min, the strength of the obtained fiber does not change, so there is no need to make it higher than 7,000 m / min. The longer the distance from the suction device to the collection surface, the better, and the distance is preferably 80 cm or more. By setting the diameter to 80 cm or more, the solidification of the fibers proceeds rapidly, the fibers are less likely to adhere to each other in the suction device, and the yarn breakage tends to be suppressed. Moreover, it is easy to reduce shrinkage | contraction of a web by attracting | sucking from under the collection surface.

In step B, before pulling and narrowing the fibers (spun filaments) extruded from the spinneret in step A, the straightening air is flowed with a device for giving a straightening air such as quench 2 as shown in FIG. It is preferable to give. The rectified air is also called quench air, and has the function of stabilizing the flow of yarn. It is also possible to cool the spinning filaments by using a cooled gas. The quench wind is preferably discharged through the net or mesh and uniformly sent to the yarn. In the case of the web manufacturing apparatus, it is preferable that the quenching air be blown from the same direction as the flow direction of the web forming conveyor, and the yarn may be blown from one side or both sides. The temperature of the quench air is preferably 5 to 40 ° C., more preferably 10 to 30 ° C. If the temperature is lower than 5 ° C., residual stress may occur in the fibers, and the fibers may be crimped. If the temperature is higher than 40 ° C., the solidification of the resin becomes insufficient and the fibers stick. The quenching air velocity is preferably 0.1 to 1.5 m / sec. If it is lower than 0.1 m / sec, the effect of rectification tends to be low, and if it is higher than 1.5 m / sec, the quench wind is too strong and conversely causes the disturbance of the yarn, causing the fibers to stick or break. May occur.

The fibers (drawn filaments) pulled by air by the ejector 3 are collected, for example, on the conveyor 4 as shown in FIG. 1, and a sheet-like web is formed as the conveyor travels. By suctioning from the inside of the collection surface of the conveyor, it is easy to reduce the shrinkage of the web. By changing the line speed, which is the operating speed of the conveyor, the basis weight of the non-woven fabric can be adjusted when the discharge amount during melt spinning is the same. By increasing the line speed, the basis weight becomes smaller, but if it is increased too much, there is a possibility that the shrinkage and the cutting of the web may occur.

[Step C]
Next, in step C, the web obtained in step B is subjected to pressure heat adhesion treatment. As a method of pressure heat bonding, for example, a heat embossing roll in which the surface of a pair of upper and lower rolls is engraved respectively, or a roll in which one roll surface is flat (smooth) and a surface of the other roll are engraved Applying thermocompression bonding with various rolls such as a heat embossing roll consisting of a combination of rolls and a heat calender roll consisting of a combination of upper and lower flat (smooth) rolls, and applying an air through system to pass hot air in the thickness direction of the nonwoven web It can. Above all, heat bonding using a heat embossing roll capable of maintaining appropriate air permeability while improving mechanical strength can be preferably employed.

The pressure heat adhesion treatment temperature in step C, that is, the surface temperature of the pressure heat adhesion roll is (Tc-45) ° C. or more, (Tc + 5) ° C. or less, (Tc-40) ° C. or more, (Tc + 0) ° C. The following are preferred. In addition, Tc is a crystallization temperature of P3HA measured by the below-mentioned method. By setting the pressure and heat adhesion treatment temperature to this temperature range, it is possible to adhere the fibers to one another while crystallizing the fibers made of the PHA composition and maintain the shape of the non-woven fabric, and peeling of the sheet and generation of fluff. It can be suppressed. On the other hand, if the pressure heat bonding is performed outside this temperature range, the fibers can not be solidified, and besides being stuck to the roll, the shape of the non-woven fabric can not be maintained, and the non-woven fabric shrinks or breaks.

Also, it is effective to apply a constant pressure between the two rolls of the pressure heat bonding roll. When using an embossing roll, it is general to use an embossing roll having a engraved roll surface and a rubber backup roll having a flat (smooth) roll surface. The pressure required for pressurization may be such that an engraving pattern can be applied to the non-woven fabric at an optimum temperature at which crystallization of P3HA proceeds, and mechanical strength can be maintained. The pressure between effective pressurized heat bonding rolls is preferably 20 to 60 Kg / cm, more preferably 30 to 50 Kg / cm. When the pressure of the pressure heat adhesive roll is lower than 20 kg / cm, an engraving pattern is difficult to be applied, and the strength may be lowered. On the other hand, when it is higher than 60 kg / cm, excessive stress is applied to the non-woven fabric, and the non-woven fabric may be broken.

The crystallization temperature of P3HA is a temperature measured by the following apparatus, conditions and method.
・ Measurement method: Differential scanning calorimetry (DSC, Differential Scanning Calorimetry)
・ Measurement equipment: EXSTAR6000 series DSC6200 made by Hitachi Hightex Science
Measurement sample: Put 5 to 10 mg of P3HA in an aluminum pan and crimp it with a lid.
Measurement conditions: After raising the temperature from 25 ° C. to 180 ° C. at 10 ° C./min, decrease the temperature to 25 ° C. at 10 ° C./min. During the measurement, flow 50 mL / min of nitrogen gas.
-Identification of crystallization temperature: The exothermic peak observed in the temperature lowering process is taken as the crystallization peak, and the peak top is taken as the crystallization temperature.

The shape of the engraving applied to the heat embossing roll is not particularly limited, and examples thereof include a circle, an ellipse, a square, a rectangle, a parallelogram, a rhomb, a regular hexagon, and an octagonal shape.

In the case of partially thermally bonding the fibers present in the embossed pattern portion using a heated embossing roll, it is preferable to set the pressing area ratio of the embossing roll to 5 to 50%. By setting the pressure contact area ratio to 5% or more, a certain point-like fused area is secured, so that the mechanical strength of the non-woven fabric tends to be improved, and good dimensional stability tends to be obtained. On the other hand, by setting the pressure contact area ratio to 50% or less, the rigidity of the non-woven fabric is suppressed, and the flexibility tends to be further improved.

Through step C, a non-woven fabric composed of the P3HA composition is obtained. The method for producing the non-woven fabric according to one or more embodiments of the present invention may include other steps in addition to the steps A to C as described above, and the other steps include, for example, before the step C. And the step of temporarily fixing the web obtained in step B. For example, as shown in FIG. 1, by installing the temporary fixing roll 5 on the conveyor, the flow of the web is stabilized, and the web can be guided to the pressure heat adhesive roll 6 in that state.

In the method of producing a nonwoven fabric according to one or more embodiments of the present invention, steps A to C may be performed continuously or may be performed discontinuously. In particular, it is preferable to continuously carry out the steps A to C in that the nonwoven fabric can be produced more efficiently. The speed at which the steps A to C are carried out is not particularly limited. For example, it is preferable to set the time from obtaining the fiber in the step A to the end of the step C to be 30 seconds to 3 minutes, more preferably 40 Seconds to 1 minute.

In one or more embodiments of the present invention, the nonwoven can be made, for example, with the apparatus shown in FIG.
First, in step A, a composition containing P3HA is melted and extruded from the spinneret 1, thereby melt spinning to obtain fibers a (spun filaments).
Next, in step B, the fibers a are formed into a web to obtain a web b. Specifically, first, the rectified air is applied to the fiber a at the quench 2. Next, the fiber a is pulled by air with the ejector 3 to draw and thin it to a predetermined fineness (stretched filament), and deposited on the conveyor 4 moving in the machine direction (MD) to form the long fiber web b Form.
Next, before carrying out the step C, the long fiber web b is passed through the temporary fixing roll 5 installed on the conveyor 4 and led to the pressure bonding roll 6.
Next, in step C, the long fiber web b is subjected to pressure heat bonding treatment at a predetermined temperature by the pressure heat bonding roll 6 to obtain a long fiber nonwoven fabric c. In the pressure heat bonding roll 6, one may be an embossing roll having a engraved roll surface, and the other may be a rubber backup roll having a flat (smooth) roll surface.
Thereafter, the obtained long fiber non-woven fabric c is wound by a winding roll 7.

The nonwoven fabric obtained by the manufacturing method of one or more embodiments of the present invention may be determined appropriately depending on the application, purpose, etc., but from the viewpoint of enhancing the strength, MD measured according to JIS L 1096 The tensile strength in the direction is preferably 8 N / 50 mm or more, more preferably 10 N / 50 mm or more, still more preferably 15 N / 50 mm or more, and particularly preferably 20 N / 50 mm or more. Further, the tensile strength in the CD direction measured according to JIS L 1096 is preferably 5 N / 50 mm or more, more preferably 10 N / 50 mm or more, still more preferably 15 N / 50 mm or more, and 20 N It is further more preferable that it is / 50 mm or more, and it is particularly preferable that it is 40 N / 50 mm or more.

The nonwoven fabric obtained by the manufacturing method according to one or more embodiments of the present invention may be determined appropriately depending on the application, purpose, etc., but from the viewpoint of enhancing the strength, MD measured according to JIS L 1096 The tear strength in the direction is preferably 3 N / 50 mm or more, more preferably 5 N / 50 mm or more, still more preferably 10 N / 50 mm or more, and particularly preferably 15 N / 50 mm or more. Further, the tear strength in the CD direction measured according to JIS L 1096 is preferably 2 N / 50 mm or more, more preferably 5 N / 50 mm or more, still more preferably 10 N / 50 mm or more, 15 N It is especially preferable that it is / 50 mm or more.

The non-woven fabric obtained by the method for producing a non-woven fabric according to the present invention can be used in various known or customary applications such as agriculture, fishery, forestry, clothing, non-clothing textiles (eg curtains, carpets, rugs etc), hygiene products, horticulture, automobiles It can be suitably used in components, construction materials, medical care, food industry, other fields and the like.

EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to the technical scope by these examples.

Production Example 1 Production of P3HB3HH For culture production of P3HB3HH, strain KNK-005 (see US Pat. No. 7,384,766) was used.

The composition of the seed culture medium is 1 w / v% Meat-extract, 1 w / v% Bacto-Tryptone, 0.2 w / v% Yeast-extract, 0.9 w / v% Na ₂ HPO ₄ · 12 H ₂ O, 0.1. It was 15 w / v% KH ₂ PO ₄ (pH 6.8).

The composition of the preculture medium is 1.1 w / v% Na ₂ HPO ₄ · 12 H ₂ O, 0.19 w / v% KH ₂ PO ₄ , 1.29 w / v% (NH ₄ ) ₂ SO ₄ , 0.1 w / V% MgSO ₄ · 7 H ₂ O, 0.5 v / v% trace metal salt solution (in 0.1 N hydrochloric acid, 1.6 w / v% FeCl ₃ · 6 H ₂ O, 1 w / v% CaCl ₂ · 2 H ₂ O , 0.02 w / v% CoCl ₂ · 6 H ₂ O, 0.016 w / v% CuSO ₄ · 5 H ₂ O, 0.012 w / v% NiCl ₂ · 6 H ₂ O). Palm oil was used as a carbon source, and this was added all together at a concentration of 10 g / L.

The composition of P3HB3HH production _{medium, 0.385w / v% Na 2 HPO} 4 · 12H 2 O, 0.067w / v% KH 2 PO 4, 0.291w / v% (NH 4) 2 SO 4, 0.1w / V% MgSO ₄ · 7 H ₂ O, 0.5 v / v% trace metal salt solution (in 0.1 N hydrochloric acid, 1.6 w / v% FeCl ₃ · 6 H ₂ O, 1 w / v% CaCl ₂ · 2 H ₂ O , 0.02 w / v% CoCl ₂ · 6 H ₂ O, 0.016 w / v% CuSO ₄ · 5 H ₂ O, 0.012 w / v% NiCl ₂ · 6 H ₂ O dissolved), 0.05 w / v % BIOSPUREX 200 K (defoamer: manufactured by Cognis Japan Ltd.).

First, a glycerol stock (50 μL) of strain KNK-005 was inoculated into a seed culture medium (10 mL) and cultured for 24 hours for seed mother culture. Next, the seed culture broth was inoculated at 1.0 v / v% into a 3 L jar fermenter (MDL-300, manufactured by Marubishi Bio Engineering Co., Ltd.) containing 1.8 L of preculture medium. The culture temperature was 33 ° C., the stirring speed was 500 rpm, the aeration amount was 1.8 L / min, and the culture was performed for 28 hours while controlling the pH between 6.7 and 6.8 for 28 hours, and preculture was performed. 14% ammonium hydroxide aqueous solution was used for pH control.

Next, 1.0 v / v% of the preculture liquid was inoculated into a 10 L jar fermenter (MDS-1000 manufactured by Marubishi Biotech) containing 6 L of a production medium. The culture temperature was 28 ° C., the stirring speed was 400 rpm, the aeration amount was 6.0 L / min, and the pH was controlled between 6.7 and 6.8. 14% ammonium hydroxide aqueous solution was used for pH control. Palm oil was used as a carbon source. The culture was performed for 64 hours, and after completion of the culture, the cells were collected by centrifugation and washed with methanol. It was then lyophilized.

To 1 g of the dried cells obtained above, 100 mL of chloroform was added, and stirred overnight at room temperature to extract P3HB3HH in the cells. After filtering off the cell residue, the mixture was concentrated by an evaporator to a total volume of 30 mL, 90 mL of hexane was gradually added, and the mixture was left for 1 hour while being slowly stirred. The precipitated P3HB3HH was separated by filtration and vacuum dried at 50 ° C. for 3 hours to obtain polyhydroxyalkanoate A1 (P3HB3HH).

The 3HH composition of the obtained P3HB3HH was analyzed by gas chromatography as follows. To 20 mg of P3HB3HH, 2 mL of a mixed solution of sulfuric acid-methanol (15:85) and 2 mL of chloroform were added, sealed tightly, and heated at 100 ° C. for 140 minutes to obtain a methyl ester of P3HB3HH decomposition product. After cooling, 1.5 g of sodium hydrogencarbonate was added little by little to neutralize it, and the mixture was left until carbon dioxide gas evolution ceased. Furthermore, 4 mL of diisopropyl ether was added, mixed well, centrifuged, and the monomer unit composition of the polyester degradation product in the supernatant was analyzed by capillary gas chromatography. The gas chromatograph used was GC-17A manufactured by Shimadzu Corporation, and the capillary column used was NEUTRA BOND-1 (column length 25 m, column inner diameter 0.25 mm, liquid film thickness 0.4 μm) manufactured by GL Science. He was used as a carrier gas, the column inlet pressure was 100 kPa, and 1 μL of the sample was injected. The temperature was raised to a temperature of 100 to 200 ° C. at a rate of 8 ° C./min, and further raised to a temperature of 200 to 290 ° C. at a rate of 30 ° C./min. As a result of analysis under the above conditions, it was confirmed that the obtained P3HB3HH was P3HB3HH in which the composition percentage ratio of the monomer of 3-hydroxyhexanoate (3HH) was 5.4 mol%. Further, the weight average molecular weight Mw measured by GPC was 350,000, the melting point was 141 ° C., and the crystallization temperature (Tc) was 80 ° C.

In addition, crystallization temperature (Tc) and melting | fusing point were measured by differential scanning calorimetry (DSC, Differential Scanning Calorimetry). The apparatus used EXSTAR6000 series DSC6200 manufactured by Hitachi High-Tex Science. A sample of 5 to 10 mg of P3HB3HH was put in an aluminum pan, covered, and crimped to obtain a measurement sample. The temperature was raised from 25 ° C. to 180 ° C. at 10 ° C./min, and then lowered to 10 ° C./min to 25 ° C. During the measurement, nitrogen gas was flowed at 50 mL / min. The endothermic peak observed in the temperature rising process was taken as the melting peak, and the peak top temperature was taken as the melting point. The exothermic peak observed in the temperature lowering process was taken as the crystallization peak, and the peak top temperature was taken as the crystallization temperature (Tc).

Examples 1 to 11 and Comparative Examples 1 to 3
To P3HB3HH (100 parts by weight) obtained in Production Example 1, 3 parts by weight of pentaerythritol (Neurizer P manufactured by Japan Synthetic Chemical Co., Ltd.), which is a crystal nucleating agent, and erucic acid amide (Nippon Seika Co., Ltd.) as a lubricant Dry blend of 5 parts by weight of Neutron S (manufactured by Nippon Steel Co., Ltd.) and 0.5 parts by weight of behenic acid amide (behenic acid amide, BNT-22H manufactured by Nippon Seika Co., Ltd.) as a lubricant The mixture was melt-kneaded and pelletized at 130 to 160 ° C. using an extruder (TEM 26 SS). The obtained pellet is melted by a single screw extruder with a screw diameter of 20 mm, the flow rate is adjusted by a gear pump, and as shown in Tables 1 and 2, a spinning hole with a melt spinning temperature of 170 ° C. and a diameter of 0.3 mm. Is extruded from a spinning die having 815 pieces at a discharge amount shown in Tables 1 and 2 and cooled using a cooling air flow at 25 ° C., and is then drawn by an ejector at a pressure described in Tables 1 and 2 to move the conveyor Deposited on top to form a web. The web was then subsequently partially heat bonded at the line speeds and pressure heat bond roll temperatures described in Tables 1 and 2.
The schematic of the apparatus used for manufacture of the nonwoven fabric above was shown in FIG.

(Examples 12 to 13)
To P3HB3HH (100 parts by weight) obtained in Production Example 1, 1.5 parts by weight of pentaerythritol (Neurizer P manufactured by Japan Synthetic Chemical Co., Ltd.), which is a crystal nucleating agent, and erucic acid amide (Nippon Seiyaku Co., Ltd.) as a lubricant. Dry blend of 0.5 parts by weight of Neutron S (manufactured by Chemical Industries, Ltd.) and 0.5 parts by weight of behenic acid amide (behenic acid amide, BNT-22H manufactured by Nippon Seika Co., Ltd.) as a lubricant The mixture was melt-kneaded at 130 to 160 ° C. and pelletized using a twin screw extruder (TEM 26 SS) manufactured by Toray Industries, Ltd. The obtained pellet is melted by a single screw extruder having a screw diameter of 20 mm, the flow rate is adjusted by a gear pump, and as shown in Table 1, the spinning holes having a diameter of 0.3 mm at a melt spinning temperature of 170 ° C. After discharging from the spinning die having individual pieces at a discharge rate described in the table and cooling using a cooling air flow of 25 ° C., it is drawn by an ejector at the pressure described in Table 1 and deposited on a moving conveyor to deposit the web. It formed. The web was then subsequently partially heat bonded at the line speeds and pressure heat bond roll temperatures described in Table 1.
The schematic of the apparatus used for manufacture of the nonwoven fabric above was shown in FIG.

(Formability of non-woven fabric)
In Examples and Comparative Examples, the formability of the non-woven fabric (presence or non-ability of non-woven fabric) was evaluated based on the following criteria by visually evaluating the shrinkage of the web on the conveyor and the state of sticking to the pressure thermal adhesive roll.
A (very good moldability): Non-shrinkage on the conveyor and sticking to the pressure heat bonding roll are not obtained, and a non-woven fabric can be taken.
B (good formability): Shrinks slightly on the conveyor, but does not stick to the pressure heat bonding roll, and a non-woven fabric can be taken.
C (improper formability): Shrinks on a conveyor, adheres to a pressure heat adhesive roll, and can not take off the non-woven fabric.

(Tensile elongation, tensile strength, tear strength of nonwoven fabric)
The obtained non-woven fabric is cut into 5 × 30 cm test pieces in the MD direction (the direction in which the non-woven fabric flows) and the CD direction (the direction in which the non-woven fabric flows) perpendicular to JIS L 1096, and a tensile tester (Shimadzu Corporation) The elongation at break and the breaking strength were measured five times under the conditions of a test speed of 100 mm / min, using “AUTOGRAPH AG2000A” manufactured by Akira, Ltd., and the averaged values were taken as the tensile elongation and the tensile strength. Moreover, based on the same standard, tear strength was measured by the single tongue method. A 10 cm cut was made in the center of the short side of the test piece of the same size at right angles to the short side, and the tear strength was measured five times at a tensile speed of 200 cm / min, and the averaged value was taken as the tear strength.

(Yarn diameter and weight of nonwoven fabric)
The obtained non-woven fabric was cut into test pieces of 25 × 20 cm based on JIS L 1096, the weight was measured, the weight per area was measured 5 times, and the averaged value was taken as the fabric weight. The non-woven fabric was observed with an optical microscope to measure the diameter of the fibers (diameter of yarn).

As can be seen from Table 1, in the examples, the moldability of the non-woven fabric containing P3HA was good, and a non-woven fabric essentially containing only P3HA as a resin component could be produced with good moldability.

On the other hand, as can be seen from Table 2, in Comparative Examples 1 and 3 in which the pressure heat adhesion treatment temperature in step C is less than Tc-45 ° C., the temperature of the pressure heat adhesion roll is low, so crystallization is insufficient. The nonwoven fabric adhered to the pressure heat adhesive roll, and the nonwoven fabric could not be obtained. In Comparative Example 2 in which the pressure heat adhesion treatment temperature in step C is higher than Tc + 5 ° C., the temperature of the pressure heat adhesion roll is high, so the resin is softened and the non-woven fabric adheres to the pressure heat adhesion roll. Could not get.

a Fiber b Web c Non-woven fabric 1 Spinneret 2 Quench 3 Ejector 4 Conveyor 5 Temporary fixing roll 6 Pressure heat bonding roll 7 Winding roll

Claims

Melt spinning a composition containing poly (3-hydroxyalkanoate) using a spinneret to obtain fibers, A
Step B: obtaining the web by converting the fibers obtained in step A into a web;
Subjecting the web obtained in step B to pressure heat adhesion treatment step C,
In the nonwoven fabric characterized in that the pressure heat adhesion treatment temperature in the step C is (Tc-45) ° C. or more and (Tc + 5) ° C. or less [Tc: crystallization temperature of poly (3-hydroxyalkanoate)] Production method.
The method for producing a non-woven fabric according to claim 1, wherein the pressure heat adhesion treatment temperature is (Tc-40) ° C or more and (Tc + 0) ° C or less.
The method for producing a non-woven fabric according to claim 1 or 2, wherein the discharge amount of the composition per single hole from the spinneret in step A is 0.2 to 1.2 g / min.
The method for producing a non-woven fabric according to claim 3, wherein the discharge amount of the composition per single hole from the spinneret in step A is 0.2 to 0.7 g / min.
The method for producing a nonwoven fabric according to any one of claims 1 to 4, wherein the web formation in step B is carried out by a spun bond method.
The method for producing a nonwoven fabric according to any one of claims 1 to 5, wherein the melt spinning temperature in step A is 145 to 190 ° C.
The method for producing a non-woven fabric according to any one of claims 1 to 6, wherein the composition further contains a crystal nucleating agent.
The method for producing a nonwoven fabric according to claim 7, wherein a content of the crystal nucleating agent is 0.05 to 12 parts by weight with respect to 100 parts by weight of poly (3-hydroxyalkanoate).
The method for producing a non-woven fabric according to any one of claims 1 to 8, wherein the composition further contains a lubricant.
The method for producing a non-woven fabric according to claim 9, wherein the content of the lubricant is 0.05 to 12 parts by weight with respect to 100 parts by weight of poly (3-hydroxyalkanoate).
The poly (3-hydroxyalkanoate) is poly (3-hydroxybutyrate), poly (3-hydroxybutyrate-co-3-hydroxyvalerate), poly (3-hydroxybutyrate-co-3-hydroxy) The compound according to any one of claims 1 to 10, which is at least one selected from the group consisting of hexanoate) and poly (3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate). The manufacturing method of the nonwoven fabric of a statement.