Patent Application
20240263387
The present invention relates to a synthetic fiber treatment agent and to a synthetic fiber.
Synthetic fibers are produced, for example, by performing a spinning step of spinning an acrylic resin or the like into fibers.
A synthetic fiber treatment agent may be used in the spinning step to improve the bundling property of the fibers that have undergone the spinning step (also referred to hereinafter as spun fiber bundling property).
Patent Document 1 discloses a synthetic fiber treatment agent that contains a nonionic surfactant and a smoothing agent.
When the spun fiber bundling property is improved, for example, winding around a roller in the process of producing synthetic fibers can be suppressed to enable the production of synthetic fibers to be performed efficiently. Further, a contribution to quality improvement of the synthetic fibers can also be made. Further improvement of the spun fiber bundling property is thus being demanded of a synthetic fiber treatment agent.
A synthetic fiber treatment agent for solving the above problem contains an amine derivative (A) and a smoothing agent (B).
The amine derivative (A) is a compound in which an alkylene oxide with not less than 2 and not more than 4 carbon atoms is added at a ratio of not less than 1 mole and not more than 30 moles in total to 1 mole of the total of an amine compound (A1) having a hydrocarbon group with not less than 8 and not more than 20 carbon atoms and an amine compound (A2) having a hydrocarbon group with not less than 8 and not more than 20 carbon atoms that differs in the number of carbon atoms from the hydrocarbon group of the amine compound (A1).
In the synthetic fiber treatment agent, the alkylene oxide preferably contains an ethylene oxide.
In the synthetic fiber treatment agent, the smoothing agent (B) preferably includes an amino-modified silicone.
If the sum of contents of the amine derivative (A) and the smoothing agent (B) is taken as 100% by mass, the synthetic fiber treatment agent preferably contains the amine derivative (A) at a ratio of not less than 3% by mass and not more than 50% by mass and the smoothing agent (B) at a ratio of not less than 50% by mass and not more than 97% by mass.
The synthetic fiber treatment agent preferably further contains a (poly)oxyalkylene derivative (C).
The (poly)oxyalkylene derivative (C) is a compound in which an alkylene oxide with not less than 2 and not more than 4 carbon atoms is added at a ratio of not less than 1 mole and not more than 30 moles in total to 1 mole of a monohydric aliphatic alcohol having a hydroxy group at a β-position of an alkyl chain with not less than 4 carbon atoms.
If the sum of contents of the amine derivative (A), the smoothing agent (B), and the (poly)oxyalkylene derivative (C) is taken as 100% by mass, the synthetic fiber treatment agent preferably contains the amine derivative (A) at a ratio of not less than 3% by mass and not more than 40% by mass, the smoothing agent (B) at a ratio of not less than 20% by mass and not more than 94% by mass, and the (poly)oxyalkylene derivative (C) at a ratio of not less than 3% by mass and not more than 50% by mass.
In the synthetic fiber treatment agent, the synthetic fiber is preferably a carbon fiber precursor.
A synthetic fiber for solving the above problem has the synthetic fiber treatment agent adhered thereto.
The present invention succeeds in improving the spun fiber bundling property of synthetic fibers.
A first embodiment in which a synthetic fiber treatment agent according to the present invention (also simply referred to hereinafter as treatment agent) is embodied will now be described.
The treatment agent contains an amine derivative (A) and a smoothing agent (B).
The amine derivative (A) is a compound in which an alkylene oxide with not less than 2 and not more than 4 carbon atoms is added at a ratio of not less than 1 mole and not more than 30 moles in total to 1 mole of the total of an amine compound (A1) having a hydrocarbon group with not less than 8 and not more than 20 carbon atoms and an amine compound (A2) having a hydrocarbon group with not less than 8 and not more than 20 carbon atoms that differs in the number of carbon atoms from the hydrocarbon group of the amine compound (A1).
By the treatment agent containing the amine derivative (A) and the smoothing agent (B), the spun fiber bundling property of the synthetic fibers can be improved.
The hydrocarbon group with not less than 8 and not more than 20 carbon atoms in the above amine compound (A1) is not particularly limited and may be a straight chain hydrocarbon group or a hydrocarbon group with a branched chain. It may also be a saturated hydrocarbon group or an unsaturated hydrocarbon group.
Specific examples of the straight chain hydrocarbon group include an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, and an icosyl group.
Specific examples of the saturated hydrocarbon group with a branched chain include an isooctyl group, an isononyl group, an isodecyl group, an isoundecyl group, an isododecyl group, an isotridecyl group, an isotetradecyl group, an isopentadecyl group, an isohexadecyl group, an isoheptadecyl group, an isooctadecyl group, and an isoicosyl group.
The unsaturated hydrocarbon group may be an alkenyl group having one double bond as an unsaturated carbon bond or may be an alkadienyl group or an alkatrienyl group having two or more double bonds. It may also be an alkynyl group having one triple bond as an unsaturated carbon bond or may be an alkadiynyl group having two or more triple bonds. Specific examples of the unsaturated straight chain hydrocarbon group having one double bond in the hydrocarbon group include an octenyl group, a nonenyl group, a decenyl group, an undecenyl group, a dodecenyl group, a tridecenyl group, a tetradecenyl group, a pentadecenyl group, a hexadecenyl group, a heptadecenyl group, a octadecenyl group, and an icosenyl group.
Specific examples of the unsaturated hydrocarbon group with a branched chain having one double bond in the hydrocarbon group include an isooctenyl group, an isononenyl group, an isodecenyl group, an isoundecenyl group, an isododecenyl group, an isotridecenyl group, an isotetradecenyl group, an isopentadecenyl group, an isohexadecenyl group, an isoheptadecenyl group, an isooctadecenyl group, and an isoicosenyl group.
The amine compound (A1) may be any of a primary amine, secondary amine, or tertiary amine. Among these, it is preferably a primary amine.
The amine compound (A2) has the hydrocarbon group with not less than 8 and not more than 20 carbon atoms that differs in the number of carbon atoms from the hydrocarbon group of the amine compound (A1). With the exception of being different in the number of carbon atoms of the hydrocarbon group, the same compounds as those given as examples for the amine compound (A1) can be used.
The amine compound (A2) is not restricted to one type and a plurality of types of the amine compounds (A2) may be used. That is, a plurality of types of the amine compounds (A2) each having a hydrocarbon group with not less than 8 and not more than 20 carbon atoms that differs in the number of carbon atoms from the hydrocarbon group of the amine compound (A1) may be used. The plurality of types of the amine compounds (A2) preferably differ from each other in the number of carbon atoms of the hydrocarbon group. The plurality of types of the amine compounds (A2) may be those that are the same as each other in the number of carbon atoms of the hydrocarbon group but differ in chemical formula.
Preferably two or more types, more preferably three or more types, and even more preferably five or more types of the amine compound (A2) are used.
Blending ratios of the amine compound (A1) and the amine compound (A2) are not particularly limited. For example, as the mass ratio, amine compound (A1)/amine compound (A2) is preferably not less than 1/99 and not more than 99/1 and more preferable not less than 5/95 and not more than 95/5.
Examples of the alkylene oxide with not less than 2 and not more than 4 carbon atoms include ethylene oxide, propylene oxide, and butylene oxide. Among these, it is preferable for ethylene oxide to be contained.
The polymerization sequence of the alkylene oxide is not particularly limited and may be of a random adduct or a block adduct.
One type of the alkylene oxide with not less than 2 and not more than 4 carbon atoms may be used alone or two or more types may be used in combination.
The smoothing agent (B) is not particularly limited, and a known smoothing agent that is used in a treatment agent can be used. Examples of the known smoothing agent include a silicone oil, a mineral oil, a polyolefin, and an ester compound. One type of the smoothing agents may be used alone or two or more types may be used in combination. Among these, the smoothing agent (B) preferably includes a silicone oil.
Specific examples of the silicone oil include a dimethyl silicone, phenyl-modified silicone, amino-modified silicone, amide-modified silicone, polyether-modified silicone, aminopolyether-modified silicone, alkyl-modified silicone, alkylaralkyl-modified silicone, alkylpolyether-modified silicone, ester-modified silicone, epoxy-modified silicone, carbinol-modified silicone, and mercapto-modified silicone. Among these, the silicone oil preferably includes an amino-modified silicone.
By the smoothing agent (B) containing an amino-modified silicone, when carbon fibers are prepared by the synthetic fibers being made flame-resistant and further being carbonized, the strength of the carbon fibers can be further improved.
Specific examples of the smoothing agent (B) include an amino-modified silicone with a kinematic viscosity at 25° ° C. of 650 mm2/s and an amino equivalent of 1800 g/mol, an amino-modified silicone with a kinematic viscosity at 25° C. of 90 mm2/s and an amino equivalent of 5000 g/mol, an amino-modified silicone with a kinematic viscosity at 25° C. of 4500 mm2/s and an amino equivalent of 1200 g/mol, an amino-modified silicone with a kinematic viscosity at 25° ° C. of 8000 mm2/s and an amino equivalent of 1000 g/mol, a dimethyl silicone with a kinematic viscosity at 25° ° C. of 350 mm2/s, and a didodecyl ester of a 2 mole ethylene oxide adduct of bisphenol A.
One type of the silicone oil may be used alone or two or more types may be used in combination.
The kinematic viscosity at 25° C. of the smoothing agent (B) can be measured by a known method using a Cannon-Fenske viscometer under a condition of 25° C.
There are no limits in content ratios of the amine derivative (A) and the smoothing agent (B) in the treatment agent. If the sum of the contents of the amine derivative (A) and the smoothing agent (B) is taken as 100 parts by mass, the treatment agent preferably contains the amine derivative (A) at a ratio of not less than 3% by mass and not more than 50% by mass and the smoothing agent (B) at a ratio of not less than 50% by mass and not more than 97% by mass.
The treatment agent preferably further contains a (poly)oxyalkylene derivative (C).
The (poly)oxyalkylene derivative (C) is a compound in which an alkylene oxide with not less than 2 and not more than 4 carbon atoms is added at a ratio of not less than 1 mole and not more than 30 moles in total to 1 mole of a monohydric aliphatic alcohol having a hydroxy group at a β-position of an alkyl chain with not less than 4 carbon atoms.
By the treatment agent containing the (poly)oxyalkylene derivative (C), the spun fiber bundling property can be further improved.
The monohydric aliphatic alcohol is not particularly limited and may be a straight chain aliphatic alcohol or may be an aliphatic alcohol with a branched chain. It may also be a saturated aliphatic alcohol or an unsaturated aliphatic alcohol.
It may also be any of a primary alcohol, secondary alcohol, and tertiary alcohol. Among these, it is preferably a primary alcohol.
The number of carbon atoms of the alkyl chain of the monohydric aliphatic alcohol is preferably not less than 10 and more preferably not less than 12. Also, the number of carbon atoms of the alkyl chain of the monohydric aliphatic alcohol is preferably not more than 18 and more preferably not more than 16.
Specific examples of the alkyl chain include the same as those cited for the hydrocarbon group of the amine compound (A1) used in the amine derivative (A).
Examples of the alkylene oxide with not less than 2 and not more than 4 carbon atoms include the same as those cited for the alkylene oxide used in the amine derivative (A).
Specific examples of the (poly)oxyalkylene derivative (C) include a compound in which 5 moles of ethylene oxide are added to 1 mole of 2-dodecanol and a compound in which 9 moles of ethylene oxide are added to 1 mole of 2-tetradecanol.
One type of the (poly)oxyalkylene derivative (C) may be used alone or two or more types may be used in combination.
There are no limits in content ratios of the amine derivative (A), the smoothing agent (B), and the (poly)oxyalkylene derivative (C) in the treatment agent. If the sum of the contents of the amine derivative (A), the smoothing agent (B), and the (poly)oxyalkylene derivative (C) is taken as 100 parts by mass, the treatment agent preferably contains the amine derivative (A) at a ratio of not less than 3% by mass and not more than 40% by mass, the smoothing agent (B) at a ratio of not less than 20% by mass and not more than 94% by mass, and the (poly)oxyalkylene derivative (C) at a ratio of not less than 3% by mass and not more than 50% by mass.
A second embodiment in which a synthetic fiber according to the present invention is embodied will now be described. The synthetic fiber of the present embodiment includes the treatment agent of the first embodiment adhered thereto. The synthetic fiber is not particularly limited, and specific examples thereof include (1) polyethylene terephthalate, polypropylene terephthalate, polylactic acid ester, and other polyester fibers, (2) nylon 6, nylon 66, and other polyamide fibers, (3) polyacrylic, modacrylic, and other polyacrylic fibers, (4) polyethylene, polypropylene, and other polyolefin fibers, (5) a cellulose fiber, and (6) a lignin fiber.
The synthetic fiber is preferably a synthetic fiber that is made of resin and becomes a carbon fiber by undergoing a carbonization step described below. In other words, the synthetic fiber is preferably a carbon fiber precursor.
The resin constituting the synthetic fiber is not particularly limited and examples thereof include an acrylic resin, polyethylene resin, phenol resin, cellulose resin, lignin resin, and pitch.
The proportion of the treatment agent of the first embodiment to be adhered to the synthetic fiber is not particularly limited, and the treatment agent (not including solvent) is preferably adhered such as to be not less than 0.1% by mass and not more than 2% by mass and more preferably adhered such as to be not less than 0.3% by mass and not more than 1.2% by mass with respect to the synthetic fiber.
The form of the treatment agent of the first embodiment when adhering the treatment agent to the synthetic fiber is, for example, an organic solvent solution or an aqueous liquid.
The method for adhering the treatment agent to the synthetic fiber may be a method of using, for example, an aqueous liquid containing the treatment agent of the first embodiment and water or using a further diluted aqueous solution to adhere by a known method such as an immersion method, a spray method, a roller method, or a guide lubricating method using a metering pump.
The method for producing carbon fibers using the synthetic fibers of the present embodiment will now be described.
The method for producing carbon fibers preferably undergoes the first to third steps described below.
First step: a spinning step of spinning synthetic fibers that are to be a carbon fiber precursor and adhering the treatment agent of the first embodiment.
Second step: a flame-resisting processing step of converting the carbon fiber precursor obtained in the first step to flame-resistant fibers in an oxidizing atmosphere of not less than 200° C. and not more than 300° C. and preferably not less than 230° C. and not more than 270° C.
Third step: a carbonization step of carbonizing the flame-resistant fibers obtained in the second step in an inert atmosphere of not less than 300° C. and not more than 2000° C. and preferably not less than 300° ° C. and not more than 1300° C.
It is deemed that a baking step is constituted of the second and third steps.
The spinning step preferably further includes a wet spinning step of dissolving a resin in a solvent and spinning it into fibers, a dry and densification step of drying and densifying the wet-spun synthetic fibers, and a drawing step of drawing the dry densified synthetic fibers. The treatment agent of the first embodiment is preferably adhered between the wet spinning step and the dry and densification step.
The temperature of the dry and densification step is not particularly limited, and the synthetic fibers that have undergone the wet spinning step are preferably heated, for example, at not less than 70° C. and not more than 200° C. The timing at which the treatment agent is adhered to the synthetic fibers is not particularly limited, and it is preferably between the wet spinning step and the dry and densification step.
The oxidizing atmosphere in the flame-resisting processing step is not particularly limited, and, for example, an air atmosphere can be used.
The inert atmosphere in the carbonization step is not particularly limited, and, for example, a nitrogen atmosphere, an argon atmosphere, or a vacuum atmosphere can be used.
The following effects can be obtained by the treatment agent and the synthetic fiber of the embodiments.
(1) The treatment agent of the present embodiment contains the amine derivative (A) and the smoothing agent (B). Therefore, the spun fiber bundling property of synthetic fibers can be improved. Also, a flame-resistant bundling property of the synthetic fibers and, when carbon fibers are prepared by carbonizing the synthetic fibers, the strength of the carbon fibers can be improved.
(2) The smoothing agent (B) includes at least one selected from among the amino-modified silicone and the polyether-modified silicone. Therefore, at least either of the flame-resistant bundling property of the synthetic fibers and the strength of the carbon fibers when the carbon fibers are prepared by carbonizing the synthetic fibers can be further improved.
(3) The smoothing agent (B) includes the amino-modified silicone. Therefore, the strength of the carbon fibers can be further improved.
(4) By the treatment agent containing the (poly)oxyalkylene derivative (C), the spun fiber bundling property can be further improved.
The above-described embodiments can be modified as follows. The above-described embodiments and the following modifications can be implemented upon being combined with each other within a range that is not technically inconsistent.
Examples will now be given below to describe the features and the effects of the present invention more specifically, but the present invention is not limited to these examples. In the following description of working examples and comparative examples, parts means parts by mass and % means % by mass.
The respective ingredients shown in Table 1 were used and added to a beaker such that blending ratios are 15 parts of an amine derivative (A-1), 50 parts of a smoothing agent (B-1), and 35 parts of a (poly)oxyalkylene derivative (C-1). These were mixed well by stirring. While continuing to stir, ion exchanged water was added gradually to achieve a solids concentration of 25% and thereby prepare a 25% aqueous liquid of a synthetic fiber treatment agent of Example 1.
Respective carbon fiber precursor treatment agents of Examples 2 to 24 and Comparative Examples 1 to 3 were prepared using the respective ingredients shown in Table 1 and by the same method as Example 1.
The type and content of the amine derivative (A), the type and content of the smoothing agent (B), and the type and content of the (poly)oxyalkylene derivative (C) in each example are as respectively indicated in the “Amine derivative (A)” column, the “Smoothing agent (B)” column, and the “(Poly)oxyalkylene derivative (C)” column of Table 1.
Details of the amine derivatives (A), the smoothing agents (B), and the (poly)oxyalkylene derivatives (C) in Table 1 are as follows.
The types and blending ratios of the amine compound (A1) and the amine compound (A2) and the types and numbers of added moles of the alkylene oxides with not less than 2 and not more than 4 carbon atoms in each of the amine derivatives (A) in Table 1 are respectively indicated in the “Types and blending ratios (parts by mass) of amine compounds” column and the “Types and numbers of added moles of alkylene oxides” column of Table 2.
In Table 2, “C8” means an amine compound in which the number of carbon atoms of the hydrocarbon group is 8. Also, “C16:1” means an amine compound in which the number of carbon atoms of the hydrocarbon group is 16 and having one unsaturated bond and the same shall apply to others.
Entries with “*” added to an upper right side of a numeral mean amine compounds (A1) and all other entries mean amine compounds (A2). However, with Example 25, an amine compound of an amine derivative (A-9) shall be an amine compound (A1), and an amine compound of an amine derivative (A-10) shall be an amine compound (A2). EO means ethylene oxide, and PO means propylene oxide.
Amine derivatives (A-1) and (A-3) to (A-8) were each prepared by adding EO to a mixed liquid of 1 mole of the total of the amine compound (A1) and amine compounds (A2).
An amine derivative (A-2) was prepared by block addition of EO and PO in that order to a mixed liquid of 1 mole of the total of the amine compound (A1) and amine compounds (A2). As all amine derivatives (A-1) to (A-10), primary amines each having a straight chain hydrocarbon group were used.
The method for preparing the amine derivatives (A-1) to (A-8) is not restricted to a method in which an alkylene oxide is added to a mixed liquid of amine compounds. Preparation may instead be performed by adding an alkylene oxide to each amine compound individually and thereafter mixing these.
Synthetic fibers and carbon fibers were produced using the aqueous liquid of the synthetic fiber treatment agents prepared in Experimental Part 1.
First, as the first step, an acrylic resin was wet spun. Specifically, a copolymer of 1.80 limiting viscosity constituted of 95% by mass acrylonitrile, 3.5% by mass methyl acrylate, and 1.5% by mass methacrylic acid was dissolved in dimethylacetamide (DMAC) to prepare a spinning dope with a polymer concentration of 21.0% by mass and a viscosity at 60° ° C. of 500 poise. The spinning dope was discharged at a draft ratio of 0.8 from a spinneret with 12,000 holes of 0.075 mm hole diameter (inner diameter) into a coagulation bath of a 70% by mass aqueous solution of DMAC maintained at a spinning bath temperature of 35° C.
The coagulated yarn was drawn by 5 times at the same time as being desolvated in a rinse tank to prepare acrylic fiber strands (raw material fibers) in a water-swollen state. To these acrylic fiber strands, the synthetic fiber treatment agents prepared in Experimental Part 1 were each applied such that a solids adhesion amount would be 1% by mass (not including the solvent). Application of each synthetic fiber treatment agent was performed by an immersion method using a 4% ion exchanged water solution of the synthetic fiber treatment agent. Thereafter, the acrylic fiber strands were subject to dry and densification by a heating roller set at 130° C., further subject to drawing by 1.7 times between heating rollers set at 170° C., and thereafter wound around a spool using a winding device.
Next, as the second step, yarns were unwound from the wound carbon fiber precursor and, after being subject to flame-resisting processing for 1 hour under an air atmosphere in a flame-resisting processing furnace having a temperature gradient of not less than 230° C. and not more than 270° C., were wound around a spool to obtain flame-resistant yarns (flame-resistant fibers).
Next, as the third step, yarns were unwound from the wound flame-resistant yarns and, after conversion to carbon fibers by baking under a nitrogen atmosphere in a carbonizing furnace having a temperature gradient of not less than 300° C. and not more than 1300° C., were wound around a spool to obtain the carbon fibers.
Regarding each of the treatment agents of Examples 1 to 24 and Comparative Examples 1 to 3, the spun fiber bundling property, the flame-resistant bundling property, and the strength of the carbon fibers were respectively evaluated by procedures described below.
The bundling state when the acrylic fiber strands with the synthetic fiber treatment agent applied thereto passed through the heating roller set at 130° C. in the first step of Experimental Part 2 was checked visually and evaluated based on criteria given below. The evaluation results are shown in the “Spun fiber bundling property” column of Table 1.
⊚ (satisfactory): The fibers are bundled, a yarn width is relatively narrow, there is no winding around the heating roller, and there are no problems at all in operability.
◯ (fair): Although the fibers are somewhat unraveled and the yarn width is slightly wide, there is no winding around the heating roller, and there are no problems in operability.
x (poor): There are much unraveling of yarns, the yarn width is wide, yarn breakage occurs frequently due to winding around the heating roller, and operability is affected.
With the flame-resistant fibers on which the flame-resisting processing was performed in the second step of Experimental Part 2, the bundling state before being wound around the spool was checked visually and evaluated based on criteria given below. The evaluation results are shown in the “Flame-resistant bundling property” column of Table 1.
◯ (fair): Although the fibers are bundled, there are no spaces inside fiber bundles.
x (poor): The fibers are not bundled, there are spaces inside the fiber bundles, and a tow width is wide.
The carbon fibers obtained in the third step of Experimental Part 2 were used to measure a strength of the carbon fibers in accordance with JIS R7606 (corresponding international standard: ISO 11566:1996). Evaluation was performed based on criteria given below. The evaluation results are shown in the “Strength” column of Table 1.
⊚ (satisfactory): The strength is not less than 4.0 GPa but less than 4.5 GPa.
◯ (fair): The strength is not less than 3.5 GPa but less than 4.0 GPa.
x (poor): The strength is less than 3.5 GPa.
Based on the results of Table 1, the present invention succeeds in improving the spun fiber bundling property of the synthetic fibers. Also, the flame-resistant bundling property can be improved and the strength of the carbon fibers can be improved.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2021-094516 | Jun 2021 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2022/022417 | 6/2/2022 | WO |
