WO2024058076A1

WO2024058076A1 - Stained p3hb3hh-based fibers, fiber aggregate including same, and methods for manufacturing these

Info

Publication number: WO2024058076A1
Application number: PCT/JP2023/032906
Authority: WO
Inventors: 大関達郎; 藤田正人
Original assignee: 株式会社カネカ
Priority date: 2022-09-14
Filing date: 2023-09-08
Publication date: 2024-03-21

Abstract

The present invention addresses the problem of staining, with excellent stain adhesion, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)-based fibers while reducing the amount of energy required for staining.　The present invention provides stained poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)-based fibers, a fiber aggregate, and methods for manufacturing these, characterized by including a step for staining poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)-based fibers, and further characterized in that the staining is carried out at a temperature of 85°C or lower using a dye.

Description

Dyed P3HB3HH fibers, fiber aggregates containing the same, and methods for producing them

The present invention relates to dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) fibers, fiber aggregates containing the same, and methods for producing them.

Conventionally, polyester fibers composed of aromatic polyesters such as polyethylene terephthalate have been widely used in various textile products such as clothing, carpets, and pile fabrics. In recent years, from the viewpoint of environmental protection, biodegradable aliphatic polyester fibers that decompose in the natural environment have been used. For example, Patent Document 1 describes a fiber structure containing polylactic acid fibers. Further, Patent Document 2 describes a fabric containing an aliphatic polyester multifilament having a melting point of 130° C. or higher.

Japanese Patent Application Publication No. 2003-253575 Japanese Patent Application Publication No. 2003-138450

Polyester fibers are usually dyed under pressure at 130°C, or if a carrier is used, they are often dyed at 100°C under normal pressure. Patent Documents 1 and 2 also dye aliphatic polyester fibers using a disperse dye at a temperature of 90° C. or higher, which poses a problem in that the energy required for dyeing is high. In the following, when there is no mention of pressure, normal pressure is meant.

In order to solve the above-mentioned conventional problems, the present invention aims to dye poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)-based fibers with good dyeability while reducing the energy required for dyeing. A method for producing a dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)-based fiber, and a dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)-based fiber. A method for producing a fiber aggregate containing fibers, a dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) fiber, and a fiber aggregate containing the same are provided.

One or more embodiments of the invention include dyeing poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)-based fibers using a dye at a temperature of 85° C. or less. The present invention relates to a method for producing dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) fibers.

One or more embodiments of the present invention provide a method of making a fiber assembly comprising dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)-based fibers, the method comprising: The present invention relates to a method for producing a fiber aggregate, comprising a step of dyeing (co-3-hydroxyhexanoate) based fibers with a dye, the dyeing being carried out at a temperature of 85° C. or lower.

In one or more embodiments of the present invention, the maximum temperature T2 of the dyeing process calculated based on a thermomechanical analysis (TMA) curve measured from 30 to 180°C is 88°C or less, and the T2 is: Corresponds to the intersection of the straight line A passing through the two points of 30°C and 40°C on the TMA curve and the tangent line B whose tangent point is the point on the TMA curve that shows a heat shrinkage rate of 25% compared to the heat shrinkage rate at 120°C. The present invention relates to dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) fibers having a temperature of

One or more embodiments of the present invention relate to a fiber assembly comprising the dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)-based fibers.

According to the present invention, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)-based fibers can be dyed with good dyeability while reducing the energy required for dyeing.
According to the present invention, a fiber assembly includes dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) fibers that have good dyeability while reducing the energy required for dyeing. can be obtained.

1 is a TMA curve obtained by thermomechanical analysis of an example of dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) fiber.

The present inventors have made extensive studies in order to solve the above problems. As a result, we found that by using poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (also referred to as "P3HB3HH") fiber as the aliphatic polyester fiber and dyeing at 85°C or lower, It was possible to obtain dyed P3HB3HH fibers with good dyeability while reducing the required energy. In particular, when a disperse dye was used, dyed P3HB3HH fibers with good dyeability could be suitably obtained by low-temperature dyeing at 85° C. or lower without using a carrier.
Furthermore, in one or more embodiments of the present invention, P3HB3HH-based fibers obtained by low-temperature dyeing and fiber aggregates containing the same have excellent soil degradability and ocean degradability, and are resistant to hydrolysis. In addition, the color fastness to washing is also good.

In this specification, when a numerical range is indicated by "~", the numerical range includes both end values (upper limit and lower limit). For example, a numerical range of "X to Y" is a range that includes both end values of X and Y. Furthermore, in this specification, when a plurality of numerical ranges are described, a numerical range that is a combination of the upper and lower limits of different numerical ranges as appropriate is included.

In this specification, biodegradability refers to properties that can be differentiated to the molecular level through the action of microorganisms and eventually become water and carbon dioxide, and marine degradability refers to properties that can be differentiated to the molecular level by the action of microorganisms in the ocean, It means the property of being differentiated down to the molecular level and eventually becoming water and carbon dioxide. Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) is widely used as a biodegradable bioplastic that is degradable in the ocean, and P3HB3HH fibers and fiber aggregates containing them are also highly degradable in soil. It can also have ocean degradability.

(Dyed P3HB3HH fiber and its manufacturing method)
In the following, unless otherwise indicated, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) fibers dyed with dyes, that is, containing dyes, will be referred to as "dyed P3HB3HH fibers" and simply P3HB3HH. When it is written as a P3HB3HH type fiber, it means a P3HB3HH type fiber that does not contain dye.

Dyed P3HB3HH fibers can be produced by dyeing P3HB3HH fibers with a dye at a temperature of 85° C. or lower. That is, the dyed P3HB3HH fiber is a P3HB3HH fiber dyed at a temperature of 85° C. or lower. P3HB3HH fibers dyed at a low temperature of 85° C. or lower can be confirmed by TMA (thermo-mechanical analysis), as described below. Further, the residual shrinkage rate when dyed P3HB3HH fibers are heat treated at a specific temperature can be estimated from the TMA heat shrinkage curve.

<P3HB3HH fiber>
The P3HB3HH-based fiber preferably contains P3HB3HH in an amount of 80% by weight or more, more preferably 85% by weight or more, even more preferably 90% by weight or more, and even more preferably 95% by weight or more.

The monomer composition of P3HB3HH is not limited, but from the viewpoint of excellent strength and low-temperature dyeing properties, 50 to 98 mol% of 3-hydroxybutyrate (3HB) and 2 to 50 mol of 3-hydroxyhexanoate (3HH). %, and more preferably 50 to 97 mol% of 3HB and 3 to 50 mol% of 3HH. One kind of P3HB3HH may be used alone, or two or more kinds having different molar contents of 3HB may be used in combination.

The composition ratio of monomers in P3HB3HH can be measured as follows. Add 2 mL of sulfuric acid-methanol mixture (volume ratio, sulfuric acid: methanol = 15:85) and 2 mL of chloroform to approximately 20 mg of the sample, seal it tightly, and heat it at 100°C for 140 minutes to convert the methyl ester of the polyester decomposition product. obtain. After cooling, 1.5 g of sodium hydrogen carbonate is added little by little to neutralize it, and the mixture is left to stand until the generation of carbon dioxide gas stops. After adding 4 mL of diisopropyl ether and mixing well, centrifugation was performed, and the composition of the hydroxyalkanoic acid methyl ester of the polyester decomposition product in the supernatant was analyzed by capillary gas chromatography. ).

P3HB3HH is not particularly limited and can be produced by a known method, but from the viewpoint of easily obtaining P3HB3HH with high marine degradability, it is preferably produced by a production method using microorganisms. As the production method using microorganisms, known methods can be used. The microorganism is not particularly limited as long as it has the ability to produce P3HB3HH. Examples of microorganisms capable of producing P3HB3HH include Aeromonas caviae, Cupriavidus necator, Ralstonia eutropha, and Alcaligenes ratus. enes latus), etc. In addition, in order to increase the productivity of P3HB3HH, the Alcaligenes eutrophus AC32 strain (FERM BP-6038) into which genes for the P3HB3HH synthase group were introduced (J. Bateriol., 179, p4821-4830) (1997) ) etc. may be used. Furthermore, as P3HB3HH, a commercially available product such as biodegradable polymer GP (Green Planet) (registered trademark) manufactured by Kaneka Corporation may be used.

The weight average molecular weight of P3HB3HH is not particularly limited, but from the viewpoint of moldability and strength, it is preferably 100,000 to 3,000,000, more preferably 150,000 to 1,500,000. In this specification, the weight average molecular weight refers to that measured from polystyrene equivalent molecular weight distribution using gel permeation chromatography (GPC) using chloroform as an eluent. As a column in the GPC, a column suitable for measuring the molecular weight may be used.

The melt flow rate (MFR) of P3HB3HH is not particularly limited, but according to JIS K 7210-1:2014, the melt flow rate (MFR) measured under the conditions of a temperature of 165°C and a load of 5 kg (49 N) is 0.1. It may be ~100 g/10 minutes, it may be 1-50 g/10 minutes, it may be 10-40 g/10 minutes. When the melt flow rate is within the above-mentioned range, the fluidity of the molten resin will be within an appropriate range, and fiberization will be good. Note that, if fiberization is possible, the melt flow rate (MFR) of P3HB3HH may exceed 100 g/10 minutes.

The P3HB3HH fiber may contain a crystal nucleating agent from the viewpoint of fiber properties and productivity. The crystal nucleating agent is not particularly limited as long as it is a compound that has the effect of promoting crystallization of P3HB3HH. For example, from the viewpoint of improving crystallization rate and inclusion in fibers, sugar alcohol compounds, polyvinyl alcohol, chitin, chitosan, etc. are preferred, sugar alcohol compounds are more preferred, and pentaerythritol is even more preferred. One type of crystal nucleating agent may be used alone, or two or more types may be used in combination.

The content of the crystal nucleating agent in the P3HB3HH fiber is not particularly limited, but for example, it is preferably 0.05 to 12 parts by weight, more preferably 0.1 to 10 parts by weight, based on 100 parts by weight of P3HB3HH. The amount is preferably 0.5 to 8 parts by weight, more preferably 0.5 to 8 parts by weight, and particularly preferably 1 to 5 parts by weight. When the content of the crystal nucleating agent is 0.05 part by weight or more, the crystallization promoting effect tends to be improved and the productivity of fibers tends to be improved. Further, by setting the content of the crystal nucleating agent to 12 parts by weight or less, it is easy to suppress a decrease in the viscosity of P3HB3HH, a decrease in fiber physical properties, etc. during processing while maintaining a sufficient effect of accelerating the crystallization rate.

The P3HB3HH fiber may contain a lubricant from the viewpoint of productivity and fiber properties. The lubricant is not particularly limited as long as it is a compound that has the effect of imparting lubricity to P3HB3HH. Examples include fatty acid amide, alkylene fatty acid amide, glycerin monofatty acid ester, organic acid monoglyceride, sorbitan fatty acid ester, polyglycerin fatty acid ester, and higher alcohol fatty acid ester.

Among the above-mentioned lubricants, compounds having the effect of imparting external lubricity, specifically fatty acid amides, glycerin fatty acid esters, and the like are preferred. Examples of fatty acid amides include monoamides and bisamides of fatty acids. The fatty acid (fatty acid moiety) constituting the fatty acid amide preferably has a carbon number of 12 to 30, and more preferably has a carbon number of 12 to 30, from the viewpoint of giving the resin composition a suitably high melting point and suppressing deterioration of processability during melt processing. Preferably it is 18-22. Specifically, fatty acid amides include behenic acid amide, erucic acid amide, palmitic acid amide, oleic acid amide, stearic acid amide, methylene bis stearic acid amide, ethylene bis stearic acid amide, ethylene bis oleic acid amide, and ethylene bis oleic acid amide. Examples include biserucic acid amide. Examples of glycerin fatty acid esters include monoesters of fatty acids and glycerin, diesters of fatty acids and glycerin, and triesters of fatty acids and glycerin. Examples of glycerin triesters include glycerin diacetomonoesters such as glycerin diacetomonolaurate, glycerin diacetomonooleate, glycerin diacetomonostearate, glycerin diacetomonocaprylate, and glycerin diacetomonodecanoate. One type of lubricant may be used alone, or two or more types may be used in combination.

The content of the lubricant in the P3HB3HH fiber is not particularly limited, but for example, it is preferably 0.05 to 12 parts by weight, more preferably 0.1 to 10 parts by weight, based on 100 parts by weight of P3HB3HH. , more preferably 0.5 to 8 parts by weight, particularly preferably 1 to 5 parts by weight. By having a lubricant content of 0.05 parts by weight or more, friction between P3HB3HH and the metal surface inside the extruder or spinning machine during fiberization is suppressed, and decomposition of P3HB3HH due to shear heat generation is suppressed, and the nozzle It is also easy to prevent the fibers extruded from sticking to each other. In addition, by having a lubricant content of 12 parts by weight or less, P3HB3HH melts more efficiently in the extruder, and as a result, fiber breakage is suppressed without making the fiber too hard, further improving productivity. It's easy to do.

If necessary, the P3HB3HH fibers may contain plasticizers, inorganic fillers, organic fillers (cellulose, etc.), antioxidants, ultraviolet absorbers, antistatic agents, etc. within the range that does not impede the effects of the present invention. It may also contain other additive components. The amount of other additive components added may be 5 parts by weight or less, or 1 part by weight or less with respect to 100 parts by weight of P3HB3HH.

The P3HB3HH-based fibers may contain resin components other than P3HB3HH (other resin components), if necessary, within a range that does not impede the effects of the present invention. As other resin components, biodegradable resins are preferred. Examples of other biodegradable resins include petroleum-derived resins such as polylactic acid, polycaprolactone, polybutylene adipate terephthalate, polybutylene succinate adipate, and polybutylene succinate, and natural polymers such as starch and cellulose. Can be mentioned. The content of other resin components 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 components. One type of other resin components can be used alone, or two or more types can be used in combination.

P3HB3HH-based fibers can be obtained, for example, by fiberizing a resin composition containing P3HB3HH. The resin composition is not particularly limited, but preferably contains 80% by weight or more of P3HB3HH, more preferably 85% by weight or more, and even more preferably 90% by weight or more. On the other hand, the upper limit may be 100% by weight, but may be, for example, 98% by weight or less or 95% by weight or less. By setting the P3HB3HH content to 80% by weight or more, the biodegradability and marine degradability of the P3HB3HH fiber and the fiber aggregate containing the same tend to be further improved.

Although the resin composition is not particularly limited, from the viewpoint of productivity and fiber properties, it is preferable that the resin composition further contains a crystal nucleating agent. As the crystal nucleating agent, those mentioned above can be used as appropriate, and pentaerythritol is particularly preferred. One type of crystal nucleating agent may be used alone, or two or more types may be used in combination.

The content of the crystal nucleating agent in the resin composition is not particularly limited, but for example, it is preferably 0.05 to 12 parts by weight, and preferably 0.1 to 10 parts by weight, based on 100 parts by weight of P3HB3HH. The amount is more preferably 0.5 to 8 parts by weight, and particularly preferably 1 to 5 parts by weight. When the content of the crystal nucleating agent is 0.05 part by weight or more, the crystallization promoting effect tends to be improved and the productivity of fibers tends to be improved. Furthermore, by setting the content of the crystal nucleating agent to 12 parts by weight or less, while maintaining a sufficient effect of accelerating the crystallization rate, it is easy to suppress a decrease in the viscosity of the resin composition and a decrease in fiber physical properties during processing.

Although the resin composition is not particularly limited, it is preferable from the viewpoint of productivity that it further contains a lubricant. As the lubricant, those mentioned above can be used as appropriate, and fatty acid amides are particularly preferred.

The content of the lubricant in the resin composition is not particularly limited, but for example, it is preferably 0.05 to 12 parts by weight, more preferably 0.1 to 10 parts by weight, based on 100 parts by weight of P3HB3HH. The amount is preferably 0.5 to 8 parts by weight, more preferably 0.5 to 8 parts by weight, and particularly preferably 1 to 5 parts by weight. When the content of the lubricant is 0.05 parts by weight or more, friction between the resin composition and the metal surface inside the extruder or spinning machine is suppressed, the decomposition of P3HB3HH due to shear heat generation is suppressed, and the P3HB3HH is extruded from the nozzle. It is also easy to prevent the fibers from sticking to each other. In addition, by having a lubricant content of 12 parts by weight or less, P3HB3HH melts more efficiently in the extruder, and as a result, fiber breakage is suppressed without making the fiber too hard, further improving productivity. It's easy to do.

The resin composition may optionally contain a plasticizer, an inorganic filler, an organic filler (cellulose, etc.), an antioxidant, an ultraviolet absorber, an antistatic agent, etc., within a range that does not impede the effects of the present invention. It may also contain other additive components. The amount of other additive components added may be 5 parts by weight or less, or 1 part by weight or less with respect to 100 parts by weight of P3HB3HH.

The above resin composition may contain resin components other than P3HB3HH (other resin components), if necessary, within a range that does not impede the effects of the present invention. As other resin components, biodegradable resins are preferred. Examples of other biodegradable resins include petroleum-derived resins such as polylactic acid, polycaprolactone, polybutylene adipate terephthalate, polybutylene succinate adipate, and polybutylene succinate, and natural polymers such as starch and cellulose. It will be done. The content of other resin components 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 components. One type of other resin components can be used alone, or two or more types can be used in combination.

P3HB3HH fibers can be obtained by melt spinning the resin composition. First, a pellet-shaped resin composition obtained by melt-kneading the above resin composition is melted using a melt extruder, and the molten resin composition is continuously extruded from a nozzle to form fibers. Spun filaments (undrawn filaments) can be produced. The melt spinning temperature is not particularly limited as long as it is higher than the melting point of the resin composition and lower than the thermal decomposition temperature, but for example, when the melting point of the resin composition is Tm, it is [Tm+5°C] to [Tm+40°C]. It may be [Tm+10°C] to [Tm+30°C]. More specifically, the temperature may be 145 to 180°C, 150 to 180°C, or 150 to 170°C. By setting the melt spinning temperature to 145° C. or higher, the resin composition can be sufficiently dissolved, so that spinning can be easily stabilized. Further, by setting the spinning temperature to 180° C. or lower, thermal decomposition of P3HB3HH is suppressed, the spinning is easily stabilized, and the physical properties of the resulting fiber tend to be further improved. Note that the melt spinning temperature refers to a temperature in the highest temperature range among the temperatures applied while the resin composition is fiberized.

The resin composition is not particularly limited, but for example, from the viewpoint of moldability and fiber strength, the weight average molecular weight is preferably 100,000 to 3,000,000, and preferably 150,000 to 1,500,000. It is more preferable that

The environmental temperature when extruding the molten resin composition from the spinneret is not particularly limited, and when the glass transition temperature of the resin composition is Tg, it may be [Tg + 5 ° C] to [Tg + 50 ° C], [ [Tg+10°C] to [Tg+40°C]. More specifically, the temperature can be adjusted as appropriate within the range of, for example, 5 to 40°C. It is preferable to apply rectified air to the fibers (spun filaments) extruded from the spinneret. 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 spun filaments by using cooled gas as quench air. The temperature of the quench air is preferably 5 to 40°C, more preferably 10 to 30°C. When the temperature is 5°C or higher, it is easy to suppress generation of residual stress in the fibers. When the temperature is 40° C. or lower, the resin is sufficiently solidified, and it is easy to prevent the fibers from sticking. The wind speed of the quench air is not particularly limited, but is preferably 0.1 to 3.0 m/sec, for example. When it is 0.1 m/sec or more, the rectifying effect is easily exhibited, and when it is 3.0 m/sec or less, the quenching wind is not too strong and the yarns are not disturbed, causing sticking of fibers to each other and yarn breakage. It is restrained from doing so. In this specification, the glass transition temperature, crystallization temperature, melting point, and thermal decomposition temperature of the resin or resin composition can be measured as described in the Examples.

Next, the spun filaments can be drawn to obtain drawn filaments (multifilaments). By drawing, fibers with a desired fineness can be obtained and the strength of the fibers can be increased. Stretching is not particularly limited, and may be carried out by a two-step spinning/drawing method or by a direct spinning/drawing method. In the two-stage spinning and drawing method, drawing is performed after the spun filament is wound up. In the direct spinning/drawing method, spinning and drawing are performed continuously without winding the spun filaments. Further, the stretching step may be performed in multiple stages by combining a plurality of roll pairs. The surface temperatures and speeds of the multiple rolls may be the same or different. The stretching temperature, specifically the surface temperature of the roll, is not particularly limited, but may be, for example, 30 to 100°C, or 40 to 90°C. The stretching ratio may be, for example, 1.5 to 20 times. When the stretching ratio is 1.5 times or more, the strength of the fiber can be further increased. Before stretching, an oil agent may be applied to the spun filaments as necessary.

The single fiber tensile strength of the drawn filament is preferably 0.5 to 10 cN/dtex, more preferably 0.7 to 10 cN/dtex, and still more preferably 1.0 to 10 cN/dtex. When the single fiber tensile strength of the drawn filament is within the above-mentioned range, crimp can be easily imparted. In this specification, the single fiber tensile strength of the drawn filament can be measured based on JIS L 1013:2021.

A dyed P3HB3HH fiber may be obtained by dyeing the drawn filament as described below.

P3HB3HH short fibers can be obtained by crimping the drawn filaments and then cutting them into a predetermined length. The crimping process is not particularly limited, and can be performed by, for example, a known crimping method such as a gear crimp method or a stuffing box method. As a result, the obtained P3HB3HH fiber has crimps, specifically mechanical crimps.

The crimping process may be performed using a stuffing box after preheating the drawn filament. The drawn filament may be preheated by, for example, wet heat treatment or dry heat treatment. The moist heat treatment can be performed using, for example, steam. The dry heat treatment may be performed using, for example, a hot air oven or an electric heater. The preheating temperature of the drawn filament is preferably 60 to 120°C, more preferably 60 to 110°C, even more preferably 70 to 100°C, even more preferably 80 to 90°C. . The stuffing box pressure is more preferably 0.001 to 0.08 MPa, even more preferably 0.001 to 0.06 MPa, even more preferably 0.001 to 0.04 MPa.

The fiber length of the P3HB3HH short fibers is not particularly limited, but for example, from the viewpoint of suitability for use in spun yarn, it may be 20 to 176 mm, 25 to 138 mm, or 28 to 110 mm. good.

From the viewpoint of texture, the P3HB3HH fiber has a single fiber fineness of preferably 0.1 to 100 dtex, more preferably 0.5 to 50 dtex, even more preferably 1.0 to 25 dtex, and 1. Even more preferably it is .0 to 15 dtex.

From the viewpoint of mechanical strength, the P3HB3HH short fibers preferably have a tensile strength of 0.3 to 6.0 cN/dtex, more preferably 0.5 to 6.0 cN/dtex, and even more preferably It is 1.0 to 6.0 cN/dtex. In this specification, the tensile strength of P3HB3HH short fibers can be measured based on JIS L 1015:2021.

The weight average molecular weight of the P3HB3HH fiber is not particularly limited, but is preferably 100,000 to 3,000,000, more preferably 120,000 to 3,000,000, and even more preferably 150,000 to 3,000,000. ,000 to 1,500,000, more preferably 200,000 to 500,000. In this specification, the weight average molecular weight of a fiber can be measured as a polystyrene equivalent molecular weight using gel permeation chromatography (GPC) using chloroform as an eluent.

From the viewpoint of dimensional stability during dyeing and processing, the P3HB3HH fiber preferably has a hot water shrinkage rate at 85°C of 15% or less, more preferably 10% or less, and even more preferably 5% or less. It is particularly preferably 3% or less. In this specification, the hot water shrinkage rate of a fiber is defined as the length of the fiber before the hot water treatment and the length of the fiber after the hot water treatment when the fiber is immersed in hot water at a predetermined temperature for 60 minutes. The length can be measured and calculated using the following formula (1). The hot water may be a dye solution. When measuring the length of a fiber, the fiber is held at both ends with tweezers and stretched into a straight line. Note that the hot water shrinkage rate of the fibers in the spun yarn is measured by untwisting the spun yarn and taking out only the P3HB3HH short fibers.
Hot water shrinkage rate (%) = (L0-L1)/L0×100 (1)
In the above formula (1), L0 is the length of the fiber before hot water treatment, and L1 is the length of the fiber after hot water treatment.

From the viewpoint of dimensional stability during dyeing and processing, the P3HB3HH fiber preferably has a hot water shrinkage rate at 80°C of 10% or less, more preferably 5% or less, and even more preferably 3% or less. It is.

<Dyeing>
Dyed P3HB3HH fibers can be obtained by immersing P3HB3HH fibers in a dye solution containing a dye at a temperature of 85° C. or lower. By dyeing at a temperature of 85° C. or lower, the energy required for dyeing can be reduced. The dye may be a synthetic dye or a natural dye. Synthetic dyes are not particularly limited, and include, for example, disperse dyes, direct dyes, vat dyes, and metal-containing dyes (also referred to as metal complex dyes). One or more commercially available dyes can be appropriately selected and used depending on the desired color and the like. When using a disperse dye, the dyeing solution may contain a carrier from the viewpoint of improving low-temperature dyeability, and may not contain a carrier from the viewpoint of reducing the environmental load due to waste liquid treatment. For example, dyed P3HB3HH fibers can be obtained by dyeing P3HB3HH fibers using a disperse dye without using a carrier at a temperature of 85° C. or lower.

The dye concentration of the dye solution may be appropriately set depending on the desired hue and is not particularly limited. For example, the dye concentration may be 0.0001 to 4% by weight (% o.w.f.) based on the weight of the P3HB3HH fiber from the viewpoint of hue, cost, and color fastness.

The bath ratio is not particularly limited, but may be 1:10 or more, and from the viewpoint of reducing costs and environmental impact due to waste liquid treatment, it is preferably 1:30 or less, and 1:20 or less. More preferred.

The dyeing temperature (temperature of the dyeing solution) may be 85°C or lower and is not particularly limited, but from the viewpoint of dyeability, it is preferably 30°C or higher, more preferably 40°C or higher, and 50°C or higher. It is more preferable that the temperature is at least ℃. Furthermore, from the viewpoint of more effectively reducing the energy required for dyeing, the dyeing temperature (temperature of the dyeing solution) is preferably 80°C or lower, more preferably 75°C or lower, and 70°C or lower. The temperature is even more preferably 65°C or lower, even more preferably 60°C or lower, and particularly preferably 60°C or lower.

The staining time is not particularly limited, but for example, from the viewpoint of productivity and suppression of staining spots, it may be 30 to 120 minutes or 60 to 120 minutes.

P3HB3HH fibers may be dyed (yarn dyed) in the form of fibers or spun yarns, or may be dyed (piece dyed) in the form of cloth. Piece dyeing is preferable from the viewpoint of reducing costs. Since P3HB3HH fibers have good low-temperature dyeability at temperatures of 85° C. or lower, they can be piece-dyed even in the case of fabrics that use cellulose fibers in combination.

<Dyed P3HB3HH fiber>
The dyed P3HB3HH fiber has a maximum dyeing temperature T2 of 88°C or lower, which is calculated based on a thermomechanical analysis (TMA) curve that measures the thermal shrinkage rate from 30 to 180°C, and the T2 is 30°C on the TMA curve. This is the temperature corresponding to the intersection of a straight line A passing through the two points ℃ and 40℃ and a tangent line B whose tangent point is a point on the TMA curve that shows a thermal contraction rate of 25% with respect to the thermal contraction rate at 120℃. .
The present inventors determined that when P3HB3HH fibers were dyed to produce dyed P3HB3HH fibers, the dyeing temperature T1 in the manufacturing process and the heat shrinkage rate of the obtained dyed P3HB3HH fibers from 30 to 180°C were measured. The maximum temperature T2 of the dyeing process calculated based on the mechanical analysis (TMA) curve satisfies the following relational expression (I), that is, the relational expression (II), and more specifically, the following relational expression (III). I found something that satisfies me.
T1+5℃≧T2+2℃≧T1-5℃ (I)
T1+3℃≧T2≧T1-7℃ (II)
T1+3℃≧T2≧T1-2℃ (III)
Therefore, whether dyed P3HB3HH fibers are obtained by dyeing P3HB3HH fibers at a temperature of 85°C or lower is based on whether the T2 of the dyed P3HB3HH fibers satisfies 88°C or lower. It can be confirmed that one or more dyed P3HB3HH fibers of the present invention have a T2 of 88°C or less. Specifically, T2 can be measured and calculated as described in the Examples.

From the viewpoint of more effectively reducing the energy required for dyeing, T2 of the dyed P3HB3HH fiber is preferably 85°C or lower, more preferably 80°C or lower, and even more preferably 75°C or lower. The temperature is preferably 70°C or lower, even more preferably. Further, from the viewpoint of dyeability, T2 of the dyed P3HB3HH fiber is preferably 53°C or higher, more preferably 55°C or higher, and even more preferably 60°C or higher.

The single fiber fineness of the dyed P3HB3HH fiber is not particularly limited, and can be appropriately set depending on the purpose, use, etc. When used for daily necessities such as clothing and bedding products, from the viewpoint of texture, the single fiber fineness is preferably 0.1 to 100 dtex, more preferably 0.5 to 50 dtex, and 1.0 to 25 dtex. More preferably, it is 1.0 to 15 dtex, and even more preferably 1.0 to 15 dtex. In this specification, single fiber fineness can be measured by an autobibroscopy method.

The dyed P3HB3HH fibers may be filaments or short fibers. From the viewpoint of mechanical strength, the dyed P3HB3HH filament has a single fiber tensile strength of preferably 0.5 to 10 cN/dtex, more preferably 0.7 to 10 cN/dtex, and still more preferably 1.0 to 10 cN/dtex. It is. Thereby, the physical properties of the fiber aggregate using dyed P3HB3HH filaments can be improved. In this specification, the single fiber tensile strength of the dyed P3HB3HH filament can be measured based on JIS L 1013:2021. From the viewpoint of mechanical strength, the dyed P3HB3HH short fibers preferably have a tensile strength of 0.3 to 6.0 cN/dtex, more preferably 0.5 to 6.0 cN/dtex, and even more preferably is 1.0 to 6.0 cN/dtex. In this specification, the tensile strength of dyed P3HB3HH short fibers can be measured based on JIS L 1015:2021.

From the viewpoint of excellent washing durability, dyed P3HB3HH fibers have a knitted fabric made of 100% by mass of dyed P3HB3HH fibers as a measurement sample, and the dyeing fastness determined by the discoloration grade specified in JIS L 0844 No. A-2: 2011. The degree is preferably 3rd class or higher, more preferably 3-4th class or higher, and even more preferably 4th class or higher.

From the viewpoint of excellent washing durability, dyed P3HB3HH fibers are measured using a knitted fabric consisting of 100% by mass of dyed P3HB3HH fibers, and the color fastness determined by the contamination grade specified in JIS L 0844 No. A-2: 2011. is preferably 3rd grade or higher, more preferably 3-4th grade or higher.

From the viewpoint of biodegradability and hydrolysis resistance, the dyed P3HB3HH fiber preferably has a weight average molecular weight of 100,000 to 3,000,000, more preferably 120,000 to 3,000,000. Yes, more preferably 150,000 to 1,500,000, even more preferably 200,000 to 500,000.

From the viewpoint of excellent biodegradability, dyed P3HB3HH fibers preferably have a weight loss rate (decomposition rate) of 5% or more after being buried in soil at a temperature of 25°C or higher for 10 days, and 8% or more. It is more preferable that the amount is at least 12%, and even more preferably 12% or more.

From the viewpoint of excellent biodegradability, particularly marine degradability, the dyed P3HB3HH fiber preferably has a weight loss rate (decomposition rate) of 3% or more after being immersed in seawater at a temperature of 19° C. or higher for 4 weeks. , more preferably 4% or more, and still more preferably 5% or more.

From the viewpoint of excellent hydrolysis resistance, dyed P3HB3HH fibers must have a weight average molecular weight retention rate of 60% or more after being left in a high humidity environment of 80°C and 90% RH (relative humidity) for 82 hours. is preferable, more preferably 65% or more, and still more preferably 70% or more.

From the viewpoint of excellent hydrolysis resistance, the dyed P3HB3HH fibers preferably have a number average molecular weight retention rate of 60% or more after being left in a high humidity environment of 80° C. and 90% RH for 82 hours, and 65%. It is more preferably at least 70%, even more preferably at least 70%.

From the viewpoint of excellent hydrolysis resistance, the dyed P3HB3HH fiber preferably has a z-average molecular weight retention rate of 60% or more after being left in a high humidity environment of 80° C. and 90% RH for 82 hours, preferably 65%. It is more preferably at least 70%, even more preferably at least 70%.

From the viewpoint of dimensional stability, the dyed P3HB3HH fiber preferably has a hot water shrinkage rate at 85°C of 15% or less, more preferably 10% or less, still more preferably 5% or less, and particularly Preferably it is 3% or less. The lower the hot water shrinkage rate at 85°C is, the better, but from the viewpoint of practicality, it may be 1% or more.

From the viewpoint of dimensional stability, the dyed P3HB3HH fiber preferably has a hot water shrinkage rate at 80° C. of 10% or less, more preferably 5% or less, and even more preferably 3% or less. The lower the hot water shrinkage rate at 80°C is, the better, but from the viewpoint of practicality, it may be 1% or more.

From the viewpoint of dimensional stability, the dyed P3HB3HH fiber preferably has a dry heat shrinkage rate at 85° C. of 15% or less, more preferably 10% or less, still more preferably 5% or less, and particularly Preferably it is 3% or less. The lower the dry heat shrinkage rate at 85°C is, the better, but from the viewpoint of practicality, it may be 1% or more. In this specification, the dry heat shrinkage rate of a fiber is defined as the length of the fiber before the dry heat treatment and the length of the fiber after the dry heat treatment when the fiber is left in a circulating air dryer at a predetermined temperature for 60 minutes and subjected to dry heat treatment. It can be calculated using the following formula (2). When measuring the length of a fiber, the fiber is held at both ends with tweezers and stretched into a straight line. The dry heat shrinkage rate of the fibers in the spun yarn is measured by untwisting the spun yarn and taking out only the dyed P3HB3HH short fibers.
Dry heat shrinkage rate (%) = (L2-L3)/L2×100 (2)
In the above formula (2), L2 is the length of the fiber before the dry heat treatment, and L3 is the length of the fiber after the dry heat treatment.

From the viewpoint of dimensional stability, the dyed P3HB3HH fiber preferably has a dry heat shrinkage rate at 80° C. of 10% or less, more preferably 5% or less, and still more preferably 3% or less. The lower the dry heat shrinkage rate at 80°C is, the better, but from the viewpoint of practicality, it may be 1% or more.

From the viewpoint of dimensional stability, the dyed P3HB3HH fiber preferably has a residual dry heat shrinkage rate at 85°C of 15% or less, more preferably 10.5% or less, and still more preferably 5% or less. It is even more preferably 3% or less, particularly preferably 1.5% or less. The lower the residual dry heat shrinkage rate at 85°C, the better, but from the viewpoint of practicality, it may be 0.5% or more. In this specification, the residual dry heat shrinkage rate of dyed P3HB3HH fibers can be measured by thermomechanical analysis (TMA).

From the viewpoint of dimensional stability, the dyed P3HB3HH fiber preferably has a residual dry heat shrinkage rate at 80° C. of 10% or less, more preferably 7% or less, and even more preferably 5% or less, Even more preferably it is 3% or less, particularly preferably 1.5% or less. The lower the residual dry heat shrinkage rate at 80° C., the better, but from the viewpoint of practicality, it may be 0.5% or more.

(Fiber aggregate and its manufacturing method)
The fiber aggregate may be manufactured using dyed P3HB3HH fibers, but from the perspective of reducing costs, in the fiber aggregate containing P3HB3HH fibers, the P3HB3HH fibers may be manufactured using a dye at a temperature of 85°C or lower. Preferably, it is produced by dyeing. The P3HB3HH fibers in the fiber assembly containing the P3HB3HH fibers can be dyed in the same manner as the P3HB3HH fibers described above, and the explanation will be omitted here.

The fiber aggregate may contain dyed P3HB3HH fibers, and the content of dyed P3HB3HH fibers is not particularly limited. The fiber aggregate preferably contains 10% by weight or more of dyed P3HB3HH fibers, more preferably 20% by weight or more, still more preferably 30% by weight or more, from the viewpoint of increasing biodegradability such as marine degradability. Still more preferably 40% by weight or more, even more preferably 50% by weight or more, even more preferably 60% by weight or more, even more preferably 70% by weight or more, even more preferably 80% by weight or more, Even more preferably it contains 90% by weight or more, even more preferably 95% by weight or more. The fiber aggregate may be composed of 100% by weight of dyed P3HB3HH fibers.

The fiber aggregate may contain other fibers in addition to the dyed P3HB3HH fibers. Other fibers are not particularly limited, and include synthetic fibers, natural fibers, recycled fibers, and the like. From the viewpoint of biodegradability, the other fibers are preferably biodegradable fibers. Examples of biodegradable synthetic fibers include synthetic fibers containing aliphatic polyesters other than P3HB3HH, and examples of aliphatic polyesters other than P3HB3HH include polylactic acid, polycaprolactone, polybutylene adipate terephthalate, and polybutylene succinate. Examples include adipate and polybutylene succinate. Examples of natural fibers include natural cellulose fibers and natural animal fibers. Examples of natural cellulose fibers include cotton fibers, kapok fibers, flax fibers, hemp fibers, ramie fibers, jute fibers, Manila hemp fibers, and kenaf fibers. Examples of natural animal fibers include wool fibers, mohair fibers, cashmere fibers, camel fibers, alpaca fibers, and angora fibers. Examples of regenerated fibers include regenerated cellulose fibers such as rayon, polynosic, cupro, and lyocell, and regenerated protein fibers such as regenerated collagen fibers.

The fiber assembly may, for example, contain 10-95% by weight of dyed P3HB3HH fibers and 5-90% by weight of other fibers, 20-90% by weight of dyed P3HB3HH fibers and 10-80% by weight of other fibers, 30-80% by weight of dyed P3HB3HH fibers and 20-70% by weight of other fibers, 40-70% by weight of dyed P3HB3HH fibers and 30-60% by weight of other fibers, or 50-70% by weight of dyed P3HB3HH fibers and 30-50% by weight of other fibers.

The form of the fiber aggregate is not particularly limited, and examples include thread, cloth, and nonwoven fabric. The yarn may be a multifilament or a spun yarn. The cloth may be knitted or woven. Fabrics include plain weave, oblique weave, satin weave, variable plain weave, variable oblique weave, variable satin weave, variable weave, patterned weave, single layer weave, double weave, multiple weave, warp pile weave, weft pile weave, and Examples include twine weave. Knitted fabrics (also referred to as knits) include circular knitting, weft knitting, warp knitting, pile knitting, etc., as well as flat knitting, jersey knitting, rib knitting, smooth knitting (double-sided knitting), rubber knitting, pearl knitting, and denby knitting. Examples include tissue, cord tissue, atlas tissue, chain tissue, and insertion tissue. The jersey knit and ribbed knit have an excellent texture as a product. The nonwoven fabric may be a long fiber nonwoven fabric or a short fiber nonwoven fabric.

The fiber aggregate can be used for various textile products. Examples of textile products include clothing, daily necessities, interior goods, and the like. Examples of clothing include jackets, underwear, sweaters, vests, pants, gloves, socks, mufflers, hats, and the like. Examples of daily necessities include bedding, pillows, cushions, stuffed animals, and hygiene materials. Examples of the interior include curtains, carpets, etc.

In the fiber aggregate, other fibers may be dyed or may not be dyed. It may be set as appropriate depending on the purpose, use, etc. Further, the dyed P3HB3HH fiber and other fibers may be dyed in the same color or may be dyed in different colors.

Fiber aggregates such as spun yarn and cloth containing dyed P3HB3HH fibers and cellulose fibers have excellent ocean degradability and moisture absorption and quick drying properties, so they can be suitably used for daily necessities such as clothing and bedding products. The cellulose fibers may be natural cellulose fibers or regenerated cellulose fibers. As the natural cellulose fibers and regenerated cellulose fibers, those mentioned above can be used as appropriate. The fiber aggregate may contain 10 to 95% by weight of dyed P3HB3HH fibers, 5 to 90% by weight of cellulose fibers, and 20 to 90% by weight of dyed P3HB3HH fibers, from the viewpoint of excellent marine degradability and moisture absorption and quick drying properties. %, may contain 10 to 80% by weight of cellulose fibers, 30 to 80% by weight of dyed P3HB3HH fibers, 20 to 70% by weight of cellulose fibers, 40 to 70% by weight of dyed P3HB3HH fibers, It may contain 30 to 60% by weight of cellulose fibers, 50 to 70% by weight of dyed P3HB3HH fibers, and 30 to 50% by weight of cellulose fibers. From the viewpoint of excellent biodegradability, especially marine degradability, the weight loss rate (decomposition rate) after immersing a fiber aggregate containing dyed P3HB3HH fibers and cellulose fibers in seawater at a temperature of 19°C or higher for 4 weeks is It is preferably 10% or more, more preferably 15% or more, and even more preferably 20% or more.

When the fiber assembly contains cellulose fibers in addition to P3HB3HH fibers, the cellulose fibers in the fiber assembly may be dyed with a dye at a temperature of 85° C. or lower. By performing dyeing at a temperature of 85° C. or lower, the energy required for dyeing can be reduced. Natural dyes or synthetic dyes may be used for dyeing cellulose fibers. Examples of synthetic dyes include reactive dyes, direct dyes, vat dyes, basic dyes, naphthol dyes, sulfur dyes, and special disperse dyes. In this specification, the dyeing of cellulose fibers is not particularly limited, and can be carried out in the same manner as usual dyeing of cellulose fibers.

From the viewpoint of excellent washing durability, the fiber aggregate preferably has a color fastness of grade 3 or higher, as determined by the discoloration/fading grade specified in JIS L 0844 A-2: 2011, and is grade 3-4 or higher. It is more preferable that it is, and it is still more preferable that it is 4th grade or higher.

From the viewpoint of excellent washing durability, the fiber aggregate preferably has a color fastness of grade 3 or higher as determined by the contamination grade specified in JIS L 0844 No. A-2: 2011, and preferably has a color fastness of grade 3-4 or higher. It is more preferable that there be.

From the viewpoint of processability, the spun yarn preferably has a tensile strength of 100 gf or more, more preferably 150 gf or more, even more preferably 200 gf or more, and even more preferably 250 gf or more. Further, from the viewpoint of process stability during fabric manufacturing, the tensile strength of the spun yarn may be 500 gf or less.

The thickness of the spun yarn is not particularly limited, but when used for clothing, it may be 2 to 50 or 5 to 40 in English cotton count.

The weight per unit area (fabric weight) of the fiber aggregate is not particularly limited and may be determined as appropriate depending on the use and purpose, and may be, for example, 10 to 2000 g/m ² . When used for clothing, the fabric weight may be 100 to 800 g/m ² , in the case of lace fabric or long fiber nonwoven fabric, the fabric weight may be 10 to 100 g/m ² , and in the case of pile fabric, the fabric weight may be 100 to 2000 g/m 2 ² is fine.

Dyed P3HB3HH fibers and fiber aggregates and textile products using them biodegrade if left in an environment where microorganisms exist, so they do not require special disposal and are environmentally friendly.

Hereinafter, one or more embodiments of the present invention will be described in more detail based on Examples. Note that the present invention is not limited to these examples.

The measurement methods and evaluation methods used in the Examples and Comparative Examples are as follows.

(Shrinkage rate during dyeing of fiber)
The length of the fibers in the dyed object before dyeing and the length of the fibers in the dyed object after dyeing were measured, and the shrinkage rate of the fibers during dyeing was calculated using the following formula (3). When measuring the length of the fiber, the fiber was held at both ends with tweezers and stretched into a straight line. The shrinkage rate of the fibers in the spun yarn during dyeing was measured by untwisting the spun yarn and taking out only the P3HB3HH short fibers.
Shrinkage rate during staining (%) = (Ls0-Ls1)/Ls0×100 (3)
In the above formula (3), Ls0 is the length of the P3HB3HH fiber in the dyed object before dyeing, and Ls1 is the length of the dyed P3HB3HH fiber in the dyed object after dyeing.

(Thermomechanical analysis of fibers)
The dyed spun yarn was twisted back to take out only the dyed P3HB3HH short fibers, and the thermal shrinkage rate of the dyed P3HB3HH short fibers was measured using a thermomechanical analyzer TMA-7100 manufactured by Hitachi High-Technology Co., Ltd. . Take 10 dyed P3HB3HH short fibers with a length of 4 mm or more, apply a load of 3 mN at a measurement length of 5 mm, and measure the heat shrinkage rate of the dyed P3HB3HH short fibers ( The residual dry heat shrinkage rate) was measured. In the obtained TMA curve, the horizontal axis shows the temperature, and the left vertical axis shows the dimensional change rate. ” means that it is shrinking, and the numerical value means the shrinkage rate. The maximum dyeing temperature (maximum processing temperature experienced during dyeing) T2 of the dyed P3HB3HH short fibers was calculated by the following procedure.
(1) A straight line connecting 30°C and 40°C of the TMA curve was drawn to define straight line A.
(2) When the thermal shrinkage rate at 120° C. on the TMA curve is assumed to be 100%, a tangent line with a point showing a thermal contraction rate of 25% as a tangent point was drawn to define tangent line B.
(3) The temperature corresponding to the intersection of straight line A and tangent line B was determined, and was determined as the maximum temperature for dyeing process T2.
FIG. 1 is a TMA curve obtained by thermomechanical analysis of a dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) fiber of one example (Example 3).
(1) A straight line connecting 30°C and 40°C of the TMA curve was drawn to define straight line A(1).
(2) If the heat shrinkage rate at 120°C (2) on the TMA curve is 100%, draw a tangent line with the point (3) showing a 25% heat shrinkage rate as tangent line B (4). did.
(3) The temperature corresponding to the intersection point (5) of the straight line A (1) and the tangent line B (4) was determined and set as the maximum temperature T2 for the dyeing process.

(Dyeability)
The dyeability of the measurement sample (fiber or fiber aggregate) was visually evaluated based on the following criteria. Note that dyeability is one of the indicators for evaluating dyeability, and indicates how much dye has been adsorbed by the fiber.
A: Sufficiently colored B: Colored C: Not colored

(Energy required for dyeing)
Measure the power required to heat the water from 30°C to the dyeing temperature, and use the power required to heat the water from 30°C to 100°C as the reference value and calculate the relative value to the standard value. The value (%) was calculated, and the degree of reduction in the energy required for staining was evaluated based on the following criteria.
A: The relative value is 60% or less, and the reduction rate of the energy required for dyeing is quite good. B: The relative value is more than 60% and 80% or less, and the reduction rate of the energy necessary for dyeing is good. C: The relative value exceeds 80%, and the effect of reducing the energy required for staining is poor.

(color measurement)
The lightness and chromaticity of the measurement sample (fiber or fiber aggregate) in the L ^* a ^* b ^* color space were determined using a spectrophotometer ("CM3600d" manufactured by Konica Minolta). A smaller L ^* value means that the sample is more deeply dyed, a larger a ^* means a stronger red meat, and a larger b ^* means a stronger yellow tinge. In addition, in the colorimetry, specular reflection light removal (SCI, for visual color management) and total reflection light (SCE, for material management) were measured.

(color fastness)
Discoloration, fading, and staining (cotton) were determined in accordance with JIS L 0844:2011 A-2 (test method for dye fastness to washing). A nylon fabric was used as a comparison sample. A score of 3 or higher for both discoloration and staining (cotton) is within the acceptable range. In the case of Example 2 or Comparative Example 2, dyed P3HB3HH short fibers were knitted with a flat knitting machine into a knit (rib knit) with a basis weight of about 300 g/m ² , and Examples 3 to 5 and Comparative Example 2 In the case of ~4, a knit (rib knit) with a basis weight of approximately 300 g/m ² was knitted from the dyed spun yarn using a flat knitting machine, and in the case of Example 6, the dyed knit was used as the measurement sample as it was. Using.

(Seawater decomposition test)
The measurement sample (fiber) was placed in a mesh bag and immersed in seawater (Takasago, Hyogo Prefecture) for decomposition. The water temperature during the test period varied between 19 and 25°C. After drying the measurement sample at 60° C. for 12 hours before immersion, the weight (W0) was measured. Measurement samples (n=2) were collected every week after immersion, thoroughly washed with running water, dried at 120° C. for 1.5 hours, and then weighed (W1). The decomposition rate of the measurement sample in seawater was calculated using the following formula (4).
Decomposition rate in seawater (%) = (W0-W1)/W0×100 (4)
In the above formula (4), W0 is the dry weight of the measurement sample before being immersed in seawater, and W1 is the dry weight of the measurement sample after being immersed in seawater for a predetermined time.

(soil decomposition test)
The fibers of the measurement sample were placed in a mesh bag, buried in culture soil (manufactured by Takii Seeds), and water was poured over it to cause it to decompose. During the test period, the temperature of the culture soil remained between 25 and 35°C, and the pH between 6 and 7. After drying the measurement sample at 60° C. for 12 hours before embedding, the weight was measured (W2). Measurement samples (n=2) were recovered 10 days after burial, thoroughly washed with running water, dried at 120° C. for 1.5 hours, and then weighed (W3). The decomposition rate of the measurement sample in soil was calculated using the following formula (5).
Decomposition rate in soil (%) = (W2-W3)/W2×100 (5)
In the above formula (5), W2 is the dry weight of the measurement sample before being buried in the soil, and W3 is the dry weight of the measurement sample after being buried in the soil for a predetermined time.

(Tensile strength and elongation rate)
The tensile strength and elongation rate of the spun yarn were measured according to JIS L 1095:2010, and the tensile strength and elongation rate of the multifilament were measured according to JIS L 1095:2010.

(uneven thread)
The yarn unevenness of the spun yarn was measured according to JIS L 1095:2010.

(An endurance test)
An accelerated test for humidity effects was conducted under constant temperature and humidity conditions of 80° C. and RH 90%. The weight average molecular weight (Mw), number average molecular weight (Mn), and z average molecular weight (Mz) of the measurement sample before and after the accelerated test were measured using gel permeation chromatography (GPC). Using chloroform as an eluent, it was measured as a polystyrene equivalent molecular weight. In addition, the molecular weight retention rate was calculated using the following formulas (6) to (8).
Mw retention rate (%) = Mwa/Mwb×100 (6)
Mn retention rate (%) = Mna/Mnb×100 (7)
Mz retention rate (%) = Mza/Mzb×100 (8)
In the above formula (6), Mwa is the weight average molecular weight of the measurement sample after the accelerated test, and Mwb is the weight average molecular weight of the measurement sample before the acceleration test.
In the above formula (7), Mna is the number average molecular weight of the measurement sample after the accelerated test, and Mnb is the number average molecular weight of the measurement sample before the acceleration test.
In the above formula (8), Mza is the z-average molecular weight of the measurement sample after the accelerated test, and Mzb is the z-average molecular weight of the measurement sample before the acceleration test.

(Manufacturing example 1)
[Multifilament]
As P3HB3HH, 100 parts by weight of a copolymer resin (manufactured by Kaneka Corporation) with a monomer composition ratio of 3HB units/3HH units of 94/6, Mw of 350,000, and MFR (165°C, 5 kg) of 12 g/10 minutes. and 1.0 parts by weight of pentaerythritol (manufactured by Nippon Gosei Kagaku Co., Ltd., "Neurizer P") as a crystal nucleating agent, and 0.5 parts by weight of erucic acid amide and 0.5 parts by weight of behenic acid amide as lubricants. were dry blended, and the mixture was melt-kneaded using an extruder at 150°C to pelletize, to obtain a pellet-shaped resin composition. The resulting pellet-shaped resin composition had a glass transition temperature of 2°C, a crystallization temperature of 100°C, a melting point of 146°C, a thermal decomposition temperature of 180°C, and a weight average molecular weight of 350,000. The glass transition temperature, crystallization temperature, melting point, and thermal decomposition temperature of the pelletized resin composition were measured using a differential scanning calorimeter (manufactured by TA Instruments, model number "DSC25") within the measurement temperature range of 0 to 0. The weight average molecular weight of the pellet-shaped resin composition was measured by differential scanning calorimetry under the conditions of 180°C, a temperature increase rate of 10°C/min, and a cooling rate of 10°C/min, using chloroform as an eluent. It was measured from polystyrene equivalent molecular weight distribution using gel permeation chromatography (GPC).
The obtained resin composition (pellets) was melted using a kneading extruder (single-screw extruder, screw diameter 25 mm). The obtained melt was discharged from a spinning nozzle (temperature: 175° C., shape of discharge hole: circular, diameter of discharge hole: 0.3 mm, number of discharge holes: 368) to obtain a spun filament. The flow rate of the melt was adjusted to 3.6 kg/h using a gear pump. Next, in the spinning cylinder, air at 20° C. was blown onto the spun filaments discharged from the circumferential direction at a speed of 0.7 m/s.
The cooled spun filament is taken up by a first take-up roll section (speed: 536 m/min) and transported in order by the first to fourth transport roll sections (speed: 562 m/min), and then the first winding is carried out. It was wound up with a take-up roll (speed: 546 m/min) and stored at room temperature (5 to 35°C) for 18 hours to obtain an undrawn filament with a single fiber fineness of 5.47 dtex.
Next, the spun filament (undrawn filament) is taken up from the first take-up roll part by a second take-up roll part (speed: 50 m/min, roll temperature: 30°C), and the drawing roll part (115 m/min, roll Temperature: 90°C), conveyed by a take-off roll section (heat treatment roll section) (speed: 115 m/min, roll temperature: 90°C), and wound by a second winding roll section (speed: 106 m/min). By taking the filament, a drawn filament having a fineness of 2.53 dtex, a tensile strength of 2.58 cN/dtex, and a hot water shrinkage rate (80° C.) of 11.5% was obtained. The stretching ratio was 2.3 times.
In addition, as the take-up roll part and the conveyance roll part, a roll part comprised of two rolls each having the same speed and the same temperature was used.

(Manufacturing example 2)
[Short fiber]
The drawn filaments obtained in the same manner as in Production Example 1 were mixed to an appropriate fineness, preheated with steam to 100°C, and then fed to a stuffing box at a conveyance speed of 8.7 m/min, and the nip pressure P3HB3HH staple fibers were obtained by applying crimping under the conditions of 2.0 Kg/cm ² and stuffing pressure of 0.04 MPa, and cutting the obtained crimped yarn using a tow cutter so that the fiber length was 51 mm. Obtained. The obtained P3HB3HH short fibers had a single fiber fineness of 2.5 dtex, a single fiber tensile strength of 1.51 cN/dtex, an 80°C hot water shrinkage rate of 11.5%, a melting point of 146°C, and a softening point of 125°C. there were. The melting point and softening point of the P3HB3HH short fibers were determined using a differential scanning calorimeter (manufactured by TA Instruments, model number "DSC25") at a temperature range of 0 to 180°C, a heating rate of 10°C/min, and a cooling rate of 10°C. It was measured by differential scanning calorimetry under the conditions of ℃/min.

(Manufacturing example 3)
[Spun yarn]
Using short fibers (single fiber fineness 2.5 dtex, fiber length 51 mm) obtained in the same manner as in Production Example 2, a spun yarn A having an English cotton count of 21/1 was obtained by ring spinning.

(Manufacturing example 4)
[Spun yarn]
50 parts by weight of short fibers (single fiber fineness 2.5 dtex, fiber length 51 mm) obtained in the same manner as in Production Example 2, Lyocell fiber (“TENCEL (registered trademark)” manufactured by Lenzing, single fiber fineness 1.4 dtex, 50 parts by weight (fiber length: 38 mm) were mixed and blended by ring spinning to obtain a spun yarn B having an English cotton count of 30/1.

(Manufacturing example 5)
[knitting]
Using the spun yarn A obtained in the same manner as in Production Example 3, a knit A (rib knit) having a basis weight of about 300 g/m ² was produced using a flat knitting machine.

(Manufacturing example 6)
[knitting]
Using the spun yarn B obtained in the same manner as in Production Example 4, a knit B (rib knit) having a basis weight of about 300 g/m ² was produced using a flat knitting machine.

(Example 1)
The P3HB3HH multifilament obtained in Production Example 1 was used as an object to be dyed, and a dyeing solution (solution temperature: 60° The object to be dyed was placed in a bath (bath ratio 1:20) and dyed at 60°C for 60 minutes, then washed with water and hot water (40-50°C warm water). I got the filament. Note that the dyeing solution did not contain a dispersing agent, a leveling agent, and an auxiliary dye (carrier). Further, as treatments after dyeing, soaping using a surfactant and reduction cleaning using caustic soda, hydrosulfite, and a surfactant were not performed.

(Example 2)
Dyeing was carried out in the same manner as in Example 1 except that the P3HB3HH short fibers of Production Example 2 were used as the dyed material to obtain P3HB3HH short fibers dyed in blue.

(Example 3)
Dyeing was carried out in the same manner as in Example 1, except that the spun yarn A made of P3HB3HH short fibers of Production Example 3 was used as the object to be dyed, and a spun yarn made of P3HB3HH short fibers dyed blue was obtained.

(Example 4)
A spun yarn made of P3HB3HH short fibers dyed blue was obtained in the same manner as in Example 3, except that the temperature of the dyeing solution was adjusted to 80° C. and dyeing was carried out at 80° C. for 60 minutes.

(Example 5)
A spun yarn made of P3HB3HH short fibers dyed blue was obtained in the same manner as in Example 3, except that the temperature of the dyeing solution was adjusted to 85° C. and dyeing was carried out at 85° C. for 60 minutes.

(Example 6)
Dyeing was carried out in the same manner as in Example 1, except that spun yarn B containing the P3HB3HH short fibers and Lyocell fibers of Production Example 4 was used as the material to be dyed, and the P3HB3HH short fibers were dyed blue, and the Lyocell fibers were not dyed. No spun yarn was obtained.

(Example 7)
In the same manner as in Example 6, a spun yarn was obtained in which the P3HB3HH short fibers were dyed and the Lyocell fibers were not dyed.
The obtained spun yarn, in which only the P3HB3HH short fibers were dyed blue, was used as a material to be dyed, and 1% by weight of blue reactive dye (Sumifix (registered trademark) Br.Blue R 150% gran. , manufactured by Sumika Chemtex), 40 g/L of sodium sulfate, and 15 g/L of sodium carbonate (bath ratio 1:20), and dyeing at 60°C for 60 minutes. Lyocell fibers were dyed with this method to obtain a spun yarn dyed entirely blue.

(Example 8)
Dyeing was carried out in the same manner as in Example 1, except that knit A of Production Example 5 was used as the object to be dyed, to obtain a knit in which P3HB3HH short fibers were dyed blue.

(Example 9)
Dyeing was carried out in the same manner as in Example 1, except that knit B of Production Example 6 was used as the dyed material, to obtain a knit in which only the P3HB3HH short fibers were dyed blue and the Lyocell fibers were not dyed.

(Example 10)
In the same manner as in Example 9, a knit was obtained in which the P3HB3HH short fibers were dyed and the Lyocell fibers were not dyed.
Lyocell fibers were dyed in the same manner as in Example 7, except that a knit in which only the obtained P3HB3HH short fibers were dyed blue was used to obtain a knit dyed entirely in blue.

(Comparative example 1)
Same as Example 1 except that 100% polylactic acid fiber spun yarn (100% polylactic acid spun yarn Terramac (registered trademark) manufactured by Unitika Co., Ltd., English cotton count 21/1) was used as the material to be dyed. Dispersion staining was performed.

(Comparative example 2)
Dyeing was carried out in the same manner as in Example 3, except that the dyeing temperature was 90° C., to obtain a spun yarn made of P3HB3HH short fibers dyed blue.

(Comparative example 3)
Dyeing was carried out in the same manner as in Example 3, except that the dyeing temperature was 95° C., to obtain a spun yarn made of P3HB3HH short fibers dyed blue.

(Comparative example 4)
Dyeing was carried out in the same manner as in Example 3 except that the dyeing temperature was 100° C. to obtain a spun yarn made of P3HB3HH short fibers dyed blue.

The hue and dyeability of Examples 1 to 10 and Comparative Examples 1 to 4 are shown in Table 1 below. In addition, the energy required for dyeing was evaluated as described above, and the results are shown in Table 2 below.

As can be seen from the results in Tables 1 and 2 above, in the examples, both yarn-dyed and piece-dyed P3HB3HH fibers were dyed at low temperatures of 85°C or lower while efficiently reducing the energy required for dyeing. It was possible to dye with good dyeability.
On the other hand, as can be seen from the results of Comparative Example 1, PLA fibers could not be dyed at 60°C. Furthermore, in Comparative Examples 2 to 4, P3HB3HH fibers could be dyed with good dyeability, but the energy required for dyeing could not be efficiently reduced.

In the Examples and Comparative Examples, measurement of shrinkage during dyeing and thermomechanical analysis were performed as described above, and the results are shown in Table 3 below. In the Examples and Comparative Examples, color measurements were performed as described above, and the results are shown in Table 4 below. In addition, the color fastness to washing, yarn properties, sea degradability, and soil degradability were evaluated as described above, and the results are shown in Tables 4 to 6. In addition, a durability test was conducted as described above, and the yarn physical properties and molecular weight were evaluated after the durability test, and the results are shown in Tables 7 to 9.

As can be seen from Table 3 above, in Comparative Examples 2 to 4, which were dyed at a temperature of 90°C or higher, the P3HB3HH fibers showed greater heat shrinkage during dyeing than in Examples 3 to 5, which were dyed at a temperature of 85°C or lower. There is. Therefore, the spun yarns containing P3HB3HH fibers dyed at a temperature of 90°C or higher in Comparative Examples 2 to 4 have a better texture than the spun yarns containing P3HB3HH fibers dyed at a temperature of 85°C or lower in Examples 3 to 5. Inferior. Furthermore, the dyed P3HB3HH fibers of the examples have low residual dry heat shrinkage at 85° C. and 80° C. and have excellent dimensional stability.

In addition, as can be seen from Table 3 above, the dyeing temperature T1 when dyeing P3HB3HH fibers and the maximum temperature T2 for dyeing processing calculated based on the TMA curve obtained by thermomechanical analysis of dyed P3HB3HH fibers are: The following relational expression (I), that is, the following relational expression (II) is satisfied, and more specifically, the following relational expression (III) is satisfied.
T1+5℃≧T2+2℃≧T1-5℃ (I)
T1+3℃≧T2≧T1-7℃ (II)
T1+3℃≧T2≧T1-2℃ (III)

From the color measurement results in Table 4 above, it can be seen that Comparative Example 1 has a high L value and is insufficiently dyed. Furthermore, in any of the P3HB3HH fibers (short fibers) of Example 2, the spun yarns made of 100% by weight of P3HB3HH short fibers of Examples 3 to 5, and the knit made of 100% by weight of P3HB3HH short fibers of Example 8. The color fastness to washing was good.

Low-temperature dyeing It can be seen that the influence on the strength (tensile strength) of the yarn is low.
On the other hand, the spun yarn of Comparative Example 4 dyed at 100° C. has a larger fiber diameter than the heat-shrinkable P3HB3HH staple fiber, and has an inferior texture.

From the results in Table 6 above, it can be seen that P3HB3HH fibers are excellent in both seawater decomposition and soil decomposition. Furthermore, it can be seen that when P3HB3HH fibers are used in combination with cellulose fibers, the sea degradability is also excellent.

As can be seen from Tables 7 to 9 above, P3HB3HH fibers and fiber aggregates containing them are resistant to hydrolysis, and even when left in a high humidity environment of 80°C and 90% RH for 82 hours, the strength (tensile strength) ) and the decrease in molecular weight is suppressed.
On the other hand, PLA fibers have poor durability (hydrolysis) and cannot maintain their strength and shape when left in a high humidity environment of 80° C. and 90% RH for 82 hours.

Although the present invention is not particularly limited, it is desirable to include, for example, the following embodiments.

[1] Including the step of dyeing poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)-based fibers,
A method for producing dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) fiber, characterized in that the dyeing is carried out at a temperature of 85° C. or lower using a dye.
[2] The dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) according to [1], wherein the dye contains at least one selected from the group consisting of synthetic dyes and natural dyes. Method for producing fibers.
[3] The dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) according to [2], wherein the synthetic dye contains at least one selected from the group consisting of disperse dyes and direct dyes. ) method for producing fibers.
[4] The dyed poly(3-hydroxybutyrate-coated) according to any one of [1] to [3], wherein the dyeing is performed using a disperse dye without using a carrier at a temperature of 85°C or lower. 3-Hydroxyhexanoate)-based fiber manufacturing method.
[5] A method for producing a fiber aggregate containing dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) fibers, comprising:
Including the process of dyeing poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)-based fibers with a dye,
A method for producing a fiber aggregate, characterized in that the dyeing is carried out at a temperature of 85° C. or lower.
[6] The method for producing a fiber aggregate according to [5], wherein the dye includes at least one selected from the group consisting of synthetic dyes and natural dyes.
[7] The method for producing a fiber aggregate according to [6], wherein the synthetic dye includes at least one selected from the group consisting of disperse dyes and direct dyes.
[8] The method for producing a fiber aggregate according to any one of [5] to [7], wherein the dyeing is performed using a disperse dye without using a carrier at a temperature of 85° C. or lower.
[9] The method for producing a fiber aggregate according to any one of [5] to [8], wherein the fiber aggregate includes one or more selected from the group consisting of yarn, woven fabric, knitted fabric, and nonwoven fabric.
[10] The fiber aggregate further includes cellulose fibers, and includes a step of dyeing the cellulose fibers with a dye at a temperature of 85° C. or lower, according to any one of [5] to [9]. Method for producing fiber aggregate.
[11] The maximum temperature T2 of the dyeing process calculated based on the thermomechanical analysis (TMA) curve that measured the heat shrinkage rate from 30 to 180°C is 88°C or less, and the T2 is equal to 30°C and 40°C of the TMA curve. This is the temperature corresponding to the intersection of a straight line A passing through two points of ℃ and a tangent line B whose tangent point is a point on the TMA curve showing a heat shrinkage rate of 25% with respect to the heat shrinkage rate at 120℃. Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) fiber.
[12] A fiber assembly comprising the dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) fiber according to [11].

1 straight line A
2 Point on the TMA curve corresponding to 120°C 3 Point on the TMA curve corresponding to a shrinkage rate of 25% of the shrinkage rate at 120°C 4 Tangent line B
5 Intersection of straight line A and tangent B

Claims

Including a step of dyeing poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)-based fiber,
A method for producing dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) fiber, characterized in that the dyeing is carried out at a temperature of 85° C. or lower using a dye.
The dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) fiber according to claim 1, wherein the dye includes at least one selected from the group consisting of synthetic dyes and natural dyes. Production method.
The dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) fiber according to claim 2, wherein the synthetic dye includes at least one selected from the group consisting of disperse dyes and direct dyes. manufacturing method.
The dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) fiber according to claim 1, wherein the dyeing is carried out using a disperse dye without using a carrier at a temperature of 85° C. or lower. Production method.
A method for producing a fiber aggregate including dyed poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) fibers, the method comprising:
Including the process of dyeing poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)-based fibers with a dye,
A method for producing a fiber aggregate, characterized in that the dyeing is carried out at a temperature of 85° C. or lower.
The method for producing a fiber aggregate according to claim 5, wherein the dye includes at least one selected from the group consisting of synthetic dyes and natural dyes.
The method for producing a fiber aggregate according to claim 6, wherein the synthetic dye includes at least one selected from the group consisting of disperse dyes and direct dyes.
The method for producing a fiber aggregate according to claim 5, wherein the dyeing is performed at a temperature of 85° C. or lower using a disperse dye without using a carrier.
The method for producing a fiber aggregate according to any one of claims 5 to 8, wherein the fiber aggregate includes one or more selected from the group consisting of yarn, woven fabric, knitted fabric, and nonwoven fabric.
The method for producing a fiber aggregate according to claim 9, wherein the fiber aggregate further includes cellulose fibers, and includes a step of dyeing the cellulose fibers using a dye at a temperature of 85° C. or lower.
The maximum temperature T2 of the dyeing process calculated based on the thermomechanical analysis (TMA) curve that measured the heat shrinkage rate from 30 to 180°C is 88°C or less, and the T2 is equal to 2 of 30°C and 40°C of the TMA curve. The dyed poly(3 -hydroxybutyrate-co-3-hydroxyhexanoate) type fiber.
A fiber assembly comprising the poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) fiber according to claim 11.