Artificial fur and manufacturing method thereof

Abstract

The present invention relates to an artificial fur and a method for manufacturing the same, and aims to provide an artificial fur which has sufficient moisture absorption performance and can reduce the energy consumption required for manufacturing. The artificial fur according to the present invention contains artificial protein fibers.

Description

[0001] This application is a divisional application. The international application number of the original application is PCT / JP2020 / 024902, the international application date is June 24, 2020, the Chinese national application number is 202080046551.5, the entry date into China is December 24, 2021, and the invention title is "Artificial Fur and Method for Manufacturing the Same". Technical Field

[0002] This invention relates to an artificial fur and a method for manufacturing the same. Background Technology

[0003] In the past, artificial fur has been used as a substitute for natural fur. For example, as described in Patent Document 1, artificial fur is constructed using synthetic fibers such as acrylic fibers.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 63-6133 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] Unlike natural fur, which has a limited supply, artificial fur can be mass-produced artificially. Therefore, in recent years, it has been more widely used in clothing, backpacks, accessories, carpets, plush toys, and other applications. Furthermore, traditional artificial fur is mostly made from acrylic fibers, which are both lightweight and warm, similar to soft wool.

[0009] However, artificial fur to date lacks moisture absorption due to its synthetic fiber composition, and because it is derived from petroleum, it cannot avoid the problem of huge energy consumption in production.

[0010] To address or mitigate these issues, one approach is to use protein fibers to produce artificial fur. However, some protein fibers shrink upon contact with water, and artificial fur made from such fibers may experience significant dimensional changes upon contact with water.

[0011] In addition, most artificial fur is made of acrylic fibers, which not only have a high environmental impact, but are also susceptible to moisture and water damage, especially the problem that the fibers may stretch due to washing.

[0012] The present invention was made against the background described above, and its first objective is to provide an artificial fur having sufficient moisture absorption properties while reducing the energy consumption required for manufacturing, and a method thereof for manufacturing the same.

[0013] The second objective of this invention is to provide an artificial fur that has sufficient moisture absorption properties and can reduce the energy consumption required for manufacturing while minimizing dimensional changes caused by contact with water.

[0014] The third objective of this invention is to provide an artificial fur with excellent functional properties such as water resistance.

[0015] The fourth objective of this invention is to provide an artificial fur with excellent water resistance.

[0016] The fifth objective of this invention is to provide a method for advantageously manufacturing artificial fur that has sufficient moisture absorption properties while reducing the energy consumption required for manufacturing.

[0017] The sixth objective of this invention is to provide a method for advantageously manufacturing artificial fur that has sufficient moisture absorption properties and can reduce the energy consumption required for manufacturing while minimizing dimensional changes caused by contact with water.

[0018] Methods for solving problems

[0019] The present invention (the first invention) for solving the first problem mentioned above relates to, for example, the following inventions.

[0020] [1-1] An artificial fur containing artificial protein fibers.

[0021] [1-2] The artificial fur according to [1-1], wherein the artificial protein fiber contains artificial structural protein fiber.

[0022] [1-3] The artificial fur according to [1-2], wherein the artificial structural protein fiber contains modified silk core protein fiber.

[0023] [1-4] The artificial fur according to [1-3], wherein the modified silk core protein fiber contains modified spider silk core protein fiber.

[0024] [1-5] The artificial fur according to any one of [1-1] to [1-4], wherein the critical oxygen index (LOI) value is 26.0 or higher.

[0025] [1-6] The artificial fur according to any one of [1-1] to [1-5], wherein the maximum hygroscopic heat generation calculated by the following formula A is greater than 0.025℃ / g.

[0026] Formula A: Maximum hygroscopic heat generation = {(the highest temperature of the sample after it has been placed in a low humidity environment until its temperature reaches equilibrium, and then moved to a high humidity environment) - (the temperature of the sample after it has been placed in a low humidity environment until its temperature reaches equilibrium, and then moved to a high humidity environment)} (°C) / sample weight (g)

[0027] [In Formula A, a low humidity environment refers to an environment with a temperature of 20℃ and a relative humidity of 40%, while a high humidity environment refers to an environment with a temperature of 20℃ and a relative humidity of 90%.]

[0028] [1-7] The artificial fur according to [1-6], wherein the highest hygroscopic heat generation is 0.031℃ / g or higher.

[0029] [1-8] The artificial fur according to any one of [1-1] to [1-7], wherein the thermal insulation performance index calculated by the following formula B is greater than 0.18.

[0030] Formula B: Thermal insulation performance index = Thermal insulation rate (%) / Unit area weight of the sample (g / m²) 2 )

[0031] [In Formula B, the heat retention rate (%) refers to the heat retention rate measured using the dry contact method (temperature 30℃, wind speed 30cm / s), calculated as (1-a / b)×100. 'a' represents the heat released through the test piece, and 'b' represents the heat released without passing through the test piece.]

[0032] [1-9] The artificial fur according to [1-8], wherein the above-mentioned thermal insulation performance index is 0.22 or higher.

[0033] The present invention (the second invention) for solving the second problem mentioned above relates to, for example, the following inventions.

[0034] [2-1] An artificial fur containing shrink-resistant protein fibers.

[0035] [2-2] The artificial fur according to [2-1], wherein the shrinkage rate of the above-mentioned protein fibers when wetted, as defined by the following formula I, is 2% or more.

[0036] Shrinkage rate upon wetting = {1 - (length of protein fiber in wetted state after contact with water / length of protein fiber after spinning and before contact with water)} × 100 (%) ... (Equation I)

[0037] [2-3] The artificial fur according to [2-1] or [2-2], wherein the shrinkage rate of the above-mentioned protein fibers as defined by Formula II below is greater than 7% during drying.

[0038] Shrinkage during drying = {1 - (length of protein fiber in dry state / length of protein fiber after spinning and before contact with water)} × 100 (%) ... (Equation II)

[0039] [2-4] The artificial fur according to any one of [2-1] to [2-3], wherein the protein fibers contain modified silk protein.

[0040] [2-5] The artificial fur according to [2-4], wherein the modified silk core protein is modified spider silk core protein.

[0041] [2-6] The artificial fur according to any one of [2-1] to [2-5], wherein the critical oxygen index (LOI) value is 26.0 or higher.

[0042] [2-7] The artificial fur according to any one of [2-1] to [2-6], wherein the maximum hygroscopic heat generation calculated by the following formula A is greater than 0.025℃ / g.

[0043] Formula A: Maximum hygroscopic heat generation = {(the highest temperature of the sample after it has been placed in a low humidity environment until its temperature reaches equilibrium, and then moved to a high humidity environment) - (the temperature of the sample after it has been placed in a low humidity environment until its temperature reaches equilibrium, and then moved to a high humidity environment)} (°C) / sample weight (g)

[0044] [In Formula A, a low humidity environment refers to an environment with a temperature of 20℃ and a relative humidity of 40%, while a high humidity environment refers to an environment with a temperature of 20℃ and a relative humidity of 90%.]

[0045] [2-8] The artificial fur according to [2-7], wherein the highest hygroscopic heat generation is above 0.031℃ / g.

[0046] [2-9] The artificial fur according to any one of [2-1] to [2-8], wherein the thermal insulation performance index calculated by the following formula B is greater than 0.18.

[0047] Formula B: Thermal insulation performance index = Thermal insulation rate (%) / Unit area weight of the sample (g / m²) 2 )

[0048] [In Formula B, the heat retention rate (%) refers to the heat retention rate measured using the dry contact method (temperature 30℃, wind speed 30cm / s), calculated as (1-a / b)×100. 'a' represents the heat released through the test piece, and 'b' represents the heat released without passing through the test piece.]

[0049] [2-10] The artificial fur according to [2-9], wherein the above-mentioned thermal insulation performance index is 0.22 or higher.

[0050] The present invention (the third invention) for solving the third problem mentioned above relates to, for example, the following inventions.

[0051] [3-1] An artificial fur containing fibers and being endowed with functionality.

[0052] [3-2] The artificial fur according to [3-1], wherein the fibers contain protein fibers.

[0053] [3-3] The artificial fur according to [3-2], wherein the above-mentioned protein fibers contain modified silk core protein.

[0054] [3-4] The artificial fur according to [3-3], wherein the modified silk core protein is modified spider silk core protein.

[0055] [3-5] The artificial fur according to [3-1] to [3-4] contains a protein cross-linker, each of which has a plurality of the following substances: a polypeptide backbone; a first residue, which is a residue of a first reactive agent having two or more first reactive groups capable of reacting with the protein and forming a bond; a second residue, which is a residue of a second reactive agent having one second reactive group capable of reacting with the first reactive group and forming a bond; wherein at least one of the first residues is cross-linked with the polypeptide backbone, and at least one of the first residues is bonded to the polypeptide backbone at one end and to the second residue at the other end.

[0056] [3-6] The artificial fur according to [3-1] to [3-5], wherein it comprises a hydroxyl-modified polymer having functional groups bonded to a hydroxyl-containing polymer.

[0057] [3-7] The artificial fur according to any one of [3-1] to [3-6], wherein the critical oxygen index (LOI) value is 26.0 or higher.

[0058] [3-8] The artificial fur according to any one of [3-1] to [3-7], wherein the maximum hygroscopic heat generation calculated by the following formula A is greater than 0.025℃ / g.

[0059] Formula A: Maximum hygroscopic heat generation = {(the highest temperature of the sample after it has been placed in a low humidity environment until its temperature reaches equilibrium, and then moved to a high humidity environment) - (the temperature of the sample after it has been placed in a low humidity environment until its temperature reaches equilibrium, and then moved to a high humidity environment)} (°C) / sample weight (g)

[0060] [In Formula A, a low humidity environment refers to an environment with a temperature of 20℃ and a relative humidity of 40%, while a high humidity environment refers to an environment with a temperature of 20℃ and a relative humidity of 90%.]

[0061] [3-9] The artificial fur according to [3-8], wherein the highest hygroscopic heat generation is above 0.031℃ / g.

[0062] [3-10] The artificial fur according to any one of [3-1] to [3-9], wherein the thermal insulation performance index calculated by the following formula B is greater than 0.18.

[0063] Formula B: Thermal insulation performance index = Thermal insulation rate (%) / Unit area weight of the sample (g / m²) 2 )

[0064] [In Formula B, the heat retention rate (%) refers to the heat retention rate measured using the dry contact method (temperature 30℃, wind speed 30cm / s), calculated as (1-a / b)×100. 'a' represents the heat released through the test piece, and 'b' represents the heat released without passing through the test piece.]

[0065] [3-11] The artificial fur according to [3-10], wherein the above-mentioned thermal insulation performance index is 0.22 or higher.

[0066] The present invention (the fourth invention) used to solve the fourth problem mentioned above relates to, for example, the following inventions.

[0067] [4-1] An artificial fur containing fibers and a substance that imparts water resistance.

[0068] [4-2] The artificial fur according to [4-1], wherein the fibers contain protein fibers.

[0069] [4-3] The artificial fur according to [4-2], wherein the protein fibers contain modified silk core protein.

[0070] [4-4] The artificial fur according to [4-3], wherein the modified silk core protein is modified spider silk core protein.

[0071] [4-5] The artificial fur according to any one of [4-2] to [4-4], wherein the modified silk core protein is covalently bonded to the water-resistant material.

[0072] [4-6] The artificial fur according to [4-1] to [4-5], wherein the water-resistant material is selected from at least one of organosilicon polymers and fluoropolymers.

[0073] [4-7] The artificial fur according to any one of [4-1] to [4-6], wherein the critical oxygen index (LOI) value is 26.0 or higher.

[0074] [4-8] The artificial fur according to any one of [4-1] to [4-7], wherein the maximum hygroscopic heat generation calculated by the following formula A is greater than 0.025℃ / g.

[0075] Formula A: Maximum hygroscopic heat generation = {(the highest temperature of the sample after it has been placed in a low humidity environment until its temperature reaches equilibrium, and then moved to a high humidity environment) - (the temperature of the sample after it has been placed in a low humidity environment until its temperature reaches equilibrium, and then moved to a high humidity environment)} (°C) / sample weight (g)

[0076] [In Formula A, a low humidity environment refers to an environment with a temperature of 20℃ and a relative humidity of 40%, while a high humidity environment refers to an environment with a temperature of 20℃ and a relative humidity of 90%.]

[0077] [4-9] The artificial fur according to [4-8], wherein the highest hygroscopic heat generation is above 0.031℃ / g.

[0078] [4-10] The artificial fur according to any one of [4-1] to [4-9], wherein the thermal insulation performance index calculated by the following formula B is greater than 0.18.

[0079] Formula B: Thermal insulation performance index = Thermal insulation rate (%) / Unit area weight of the sample (g / m²) 2 )

[0080] [In Formula B, the heat retention rate (%) refers to the heat retention rate measured using the dry contact method (temperature 30℃, wind speed 30cm / s), calculated as (1-a / b)×100. 'a' represents the heat released through the test piece, and 'b' represents the heat released without passing through the test piece.]

[0081] [4-11] The artificial fur according to [4-10], wherein the above-mentioned thermal insulation performance index is 0.22 or higher.

[0082] The present invention (the fifth invention) for solving the fifth problem mentioned above relates to, for example, the following invention.

[0083] [5-1] A method for manufacturing artificial fur, comprising: a step of obtaining a plush fabric with pile protruding on one or both sides of the fabric using fibers containing artificial protein fibers; and a step of cutting the loops of the pile to form a cut pile.

[0084] The present invention (the sixth invention) for solving the sixth problem mentioned above relates to, for example, the following inventions.

[0085] [6-1] A method for manufacturing artificial fur, comprising: a step of obtaining a pile fabric with pile protruding on one or both sides of the fabric using shrink-resistant protein fibers; and a step of cutting the loops of the pile to form a cut pile.

[0086] [6-2] A method for manufacturing artificial fur includes: a step of obtaining a pile fabric with pile protruding on one or both sides of the fabric using a fiber containing protein fibers; a step of cutting the loops of the pile to form a cut pile; and a step of shrink-proofing the pile fabric.

[0087] Invention Effects

[0088] According to the first invention, an artificial fur can be provided that has sufficient moisture absorption properties while reducing the energy consumption required for manufacturing.

[0089] According to the second invention, an artificial fur can be provided that has sufficient moisture absorption properties and can reduce the energy consumption required for manufacturing while minimizing dimensional changes caused by contact with water.

[0090] According to the third invention, an artificial fur with excellent functional properties such as water resistance can be provided.

[0091] According to the fourth invention, an artificial fur with excellent water resistance can be provided.

[0092] According to the fifth invention, a method for advantageously manufacturing artificial fur can be provided, which has sufficient moisture absorption properties while reducing the energy consumption required for manufacturing.

[0093] According to the sixth invention, a method for advantageously manufacturing artificial fur can be provided, which has sufficient moisture absorption properties and can reduce the energy consumption required for manufacturing while minimizing dimensional changes caused by contact with water. Attached Figure Description

[0094] Figure 1 This is a schematic diagram illustrating an example of a modified domain sequence of filoprotein.

[0095] Figure 2 This is a graph showing the distribution of z / w (%) values ​​for naturally derived silken protein.

[0096] Figure 3 This is a graph showing the distribution of x / y (%) values ​​for naturally derived silk protein.

[0097] Figure 4 This is a schematic diagram illustrating an example of a modified domain sequence of filoprotein.

[0098] Figure 5This is a schematic diagram illustrating an example of a modified domain sequence of filoprotein.

[0099] Figure 6 This is an illustrative diagram schematically showing an example of a spinning apparatus used to produce protein fibers (filaments).

[0100] Figure 7 This is a chart showing the results of an evaluation of the water shrinkage rate of the manufactured protein fibers.

[0101] Figure 8 This is an example chart showing the results of a moisture absorption and heat generation performance test.

[0102] Figure 9 This is a picture showing the surface of the artificial fur produced in Experimental Example 13.

[0103] Figure 10 This is a picture showing the side view of the artificial fur produced in Experimental Example 13. Detailed Implementation

[0104] The specific embodiments of the present invention will be described in detail below. However, the present invention is not limited to the following embodiments.

[0105] <First Implementation>

[0106] The artificial fur involved in the first embodiment of the first invention includes artificial protein fibers.

[0107] Synthetic protein fibers are fibers spun from proteins as the main raw material. Proteins can be categorized as natural proteins and recombinant proteins (synthetic proteins). Recombinant proteins can be any protein that can be produced on an industrial scale, including industrially applicable proteins, medically applicable proteins, and structural proteins. Specific examples of industrially or medically applicable proteins include enzymes, regulatory proteins, receptors, peptide hormones, cytokines, membrane or transport proteins, antigens used for immunization, vaccines, antigen-binding proteins, immunostimulatory proteins, allergens, full-length antibodies or antibody fragments or derivatives. Specific examples of structural proteins include spider silk, silkworm silk, keratin, collagen, elastin, arthropod elastin, and proteins derived from them. Furthermore, due to their excellent thermal insulation, moisture absorption and heat dissipation, and / or flame retardant properties, modified silk core proteins are preferred, and modified spider silk core proteins are more preferred. When the protein is modified silk core protein (preferably modified spider silk core protein), the artificial fur involved in this embodiment can be further endowed with heat-insulating properties, moisture-absorbing and heat-generating properties and / or flame-retardant properties, and its value as artificial fur can be further improved.

[0108] In addition, in this specification, fibers spun from structural proteins, modified silk core proteins, and modified spider silk core proteins will be referred to as artificial structural protein fibers, modified silk core protein fibers, and modified spider silk core protein fibers, respectively.

[0109] The modified silk protein involved in this embodiment comprises formula 1: [(A)] n Motif - REP m Or formula 2: [(A)] n Motif - REP m -(A) n A protein whose domain sequence is represented by a motif. Modified filoproteins can have amino acid sequences (N-terminal and C-terminal sequences) further appended to either the N-terminal or C-terminal side of the domain sequence. The N-terminal and C-terminal sequences are not limited to these; typically, they are regions that do not have the characteristic amino acid motif repeating in filoproteins and consist of approximately 100 amino acid residues.

[0110] In this specification, "modified silk core protein" refers to artificially manufactured silk core protein (artificial silk core protein). Modified silk core protein can be a silk core protein whose domain sequence differs from the amino acid sequence of naturally derived silk core protein, or it can be a silk core protein with the same amino acid sequence as naturally derived silk core protein. In this specification, "naturally derived silk core protein" also includes Formula 1: [(A)] n Motif - REP m Or formula 2: [(A)] n Motif - REP m -(A) n Proteins whose domain sequences are represented by motifs.

[0111] "Modified silk core protein" can be a silk core protein that directly utilizes the amino acid sequence of a naturally derived silk core protein, or a silk core protein whose amino acid sequence is modified based on the amino acid sequence of a naturally derived silk core protein (e.g., a silk core protein obtained by modifying the amino acid sequence of a cloned naturally derived silk core protein). In addition, it can also be a silk core protein that is artificially designed and synthesized without relying on a naturally derived silk core protein (e.g., a silk core protein with the desired amino acid sequence obtained by chemically synthesizing a nucleic acid that encodes the designed amino acid sequence).

[0112] In this specification, "domain sequence" refers to the crystalline region specific to the formation of filamentin (typically, equivalent to amino acid sequence (A)). n The amino acid sequence of the motif and the amorphous region (typically, equivalent to the REP of the amino acid sequence) refers to Formula 1: [(A)] nMotif - REP m Or formula 2: [(A)] n Motif - REP m -(A) n The amino acid sequence represented by the motif. Here, (A) n The motif represents an amino acid sequence dominated by alanine residues, ranging from 2 to 27 residues. (A) n The number of amino acid residues in the motif can be an integer from 2 to 20, 4 to 27, 4 to 20, 8 to 20, 10 to 20, 4 to 16, 8 to 16, or 10 to 16. Furthermore, as long as (A) n The proportion of alanine residues in the motif relative to the total number of amino acid residues should be 40% or more; however, it can be 60%, 70%, 80%, 83%, 85%, 86%, 90%, 95%, or even 100% (meaning it consists solely of alanine residues). Multiple (A) residues present in the domain sequence... n At least seven of the motifs may consist of only alanine residues. A REP represents an amino acid sequence consisting of 2–200 amino acid residues. A REP may also consist of an amino acid sequence consisting of 10–200 amino acid residues. m represents an integer from 2 to 300, and may be an integer from 10 to 300. Two or more (A) exist. n Motifs can be the same amino acid sequence or different amino acid sequences. Multiple REPs can have the same amino acid sequence or different amino acid sequences.

[0113] The modified filamentin involved in this embodiment can be obtained by modifying the gene sequence of cloned naturally derived filamentin by, for example, altering the amino acid sequence to correspond to substitution, deletion, insertion, and / or addition of one or more amino acid residues. The substitution, deletion, insertion, and / or addition of amino acid residues can be performed using methods well known to those skilled in the art, such as site-directed mutagenesis. Specifically, it can be performed according to methods described in publications such as Nucleic Acid Res. 10, 6487 (1982) and Methods in Enzymology, 100, 448 (1983).

[0114] Naturally derived silken protein contains formula 1: [(A)] n Motif - REP m Or formula 2: [(A)] n Motif - REP m -(A) n Proteins whose motifs represent domain sequences, specifically, for example, include filoproteins produced by insects or spiders.

[0115] Examples of silk proteins produced by insects include those from silkworms such as the domestic silkworm (Bombyx mori), wild mulberry silkworm (Bombyx mandarina), wild silkworm (Antheraea yamamai), tussah silkworm (Anteraea pernyi), maple silkworm (Eriogynapyretorum), castor silkworm (Pilosamia Cynthia ricini), ailanthus silkworm (Samia cynthia), camphor silkworm (Caligurajaponica), Indian tussah silkworm (Antheraea mylitta), and amber silkworm (Antheraea assama), as well as bee silk proteins produced by the larvae of brook bees (Vespa simillima xanthoptera).

[0116] As a more specific example of the silk core protein produced by insects, one can cite, for example, the silk core protein L chain (GenBank accession number M76430 (base sequence) and AAA27840.1 (amino acid sequence)).

[0117] As for the silk proteins produced by spiders, examples include those produced by spiders belonging to the order Araneae. More specifically, examples include spiders of the genus *Araneus* such as *Araneus macrocarpa*, *Araneus cruciformis*, *Araneus obliquus*, *Araneus pentaphyllum*, and *Araneus nojimai*; spiders of the genus *Neoscona* such as *Neoscona spp.*, *Neoscona hydrophila*, *Neoscona shrubinatus*, and *Neoscona spp.*; spiders of the genus *Pronus* such as *Pronus spp.*; spiders of the genus *Cyrtarachne* such as *Cyrtarachne spp.*; spiders of the genus *Gasteracantha* such as *Gasteracantha spp.*; and spiders of the genus *Gasteracantha spp.* such as *Gasteracantha spp.* and *Gasteracantha spp.*. Spiders belonging to the genus *Ordgarius*, such as the variegated spider; the golden spider (*Argiope*), such as the small golden spider (*Argiope*), and the horizontal-striped golden spider (*Argiope*); the two-peaked orb-tailed spider (*Arachnura*); the brown hanging leaf spider (*Acusilas*); the red clouded spider (*Cytophora*), the flower clouded spider (*Cytophora*), and the ugly cone-headed spider (*Poltys*); and the eight-headed spider (*Poltys*). Spiders belonging to the genus *Cyclosa*, such as the tuberculate spider, the four-pronged spider, the round-bellied spider, and the black-tailed spider, and spiders belonging to the genus *Chorizopes*, such as the Japanese bald spider, produce spider silk; spiders belonging to the genus *Tetragnatha*, such as the anterior-toothed octopus, the cone-shaped octopus, the straight-stretched octopus, and the scale-patterned octopus; spiders belonging to the genus *Leucauge*, such as the longitudinal-striped silver-scaled spider, the shoulder-spotted silver-scaled spider, and the small-shouldered silver-scaled spider; and spiders belonging to the genus *Nematophora*, such as the club-shaped nematophora and the spotted nematophora. Spiders belonging to the genus *Nephila*, such as the beautiful wheat spider (*Menosira*), the soft-skinned spider (*Dyschiriognatha*), the red-spotted spider (*Latrodectus*), the geometric spider (*Latrodectus*), and the brooding web spider (*Euprosthenops*) all produce spider silk proteins. Examples of spider silk proteins include, for instance, traction silk proteins such as MaSp (MaSp1 and MaSp2) and ADF (ADF3 and ADF4), MiSp (MiSp1 and MiSp2), AcSp, PySp, and Flag.

[0118] More specific examples of spider silk proteins produced by spiders include, for instance, fibroin-3 (adf-3) [from Araneus diadematus] (GenBank accession number AAC47010 (amino acid sequence), U47855 (base sequence)), fibroin-4 (adf-4) [from Araneus diadematus] (GenBank accession number AAC47011 (amino acid sequence), U47856 (base sequence)), dragline silk protein spidroin 1 [from Nephila clavipes] (GenBank accession number AAC04504 (amino acid sequence), U37520 (base sequence)), majorampullate spidroin 1 [from Latrodectus hesperus] (GenBank accession number ABR68856 (amino acid sequence), EF595246 (base sequence)), and dragline silk protein spidroin. 2 [from Nephila clavipes] (GenBank accession number AAL32472 (amino acid sequence), AF441245 (base sequence)), major ampullate spidroin 1 [from Eurosthenops australis] (GenBank accession number CAJ00428 (amino acid sequence), AJ973155 (base sequence)), and major ampullate spidroin 2 [Euprosthenops australis] (GenBank accession number CAM32249.1 (amino acid sequence), AM490169 (base sequence)), minor ampullate silk protein 1 [Nephila clavipes] (GenBank accession number AAC14589.1 (amino acid sequence)), minor ampullate silk protein 2 [Nephila clavipes] (GenBank accession number AAC14591.1 (amino acid sequence)), minor ampullate spidroin-like protein [Nephilengys cruentata] (GenBank accession number ABR37278.1 (amino acid sequence) etc.

[0119] More specific examples of naturally derived filamentin can be found in filamentin sequences registered in NCBI GenBank. For instance, they can be identified by extracting sequences from NCBI GenBank sequences containing INV as a classification code that include keywords such as spider silk protein, ampulla of Vater gland, filamentin, "silk and polypeptide," or "silk and protein" in their definition; by extracting the string for a specific product from CDS; and by extracting the string for a specific tissue type from the source.

[0120] The modified silk core protein involved in this embodiment can be modified silkworm silk core protein (silk core protein with modified amino acid sequence of silk protein produced by silkworms) or modified spider silk core protein (silk core protein with modified amino acid sequence of spider silk protein produced by spiders).

[0121] Specific examples of modified silk core proteins include modified silk core proteins derived from the large spinneret pulling silk protein produced by the large ampulla of Vater in spiders (modified silk core protein 1), modified silk core proteins with domain sequences having reduced glycine residue content (modified silk core protein 2), and modified silk core proteins with reduced (A) content. n Modification of motif content domain sequences in filoproteins (3rd modified filoprotein), reduction of glycine residue content, and (A) n Modified filamentin with increased motif content (modified filamentin 4), modified filamentin with domain sequences containing regions with high hydrophobicity (modified filamentin 5), and modified filamentin with domain sequences containing reduced glutamine residue content (modified filamentin 6).

[0122] As an example of the first modified silk protein, one can include formula 1: [(A)] n Motif - REP m The protein with the domain sequence shown. In the first modified filamentin, (A) n The number of amino acid residues in the motif is preferably an integer from 3 to 20, more preferably an integer from 4 to 20, further preferably an integer from 8 to 20, even more preferably an integer from 10 to 20, even more preferably an integer from 4 to 16, particularly preferably an integer from 8 to 16, and most preferably an integer from 10 to 16. In the first modified silk-core protein, the number of amino acid residues constituting REP in Formula 1 is preferably 10 to 200 residues, more preferably 10 to 150 residues, further preferably 20 to 100 residues, and even more preferably 20 to 75 residues. In the first modified silk-core protein, Formula 1: [(A)] n Motif - REPm The total number of glycine residues, serine residues, and alanine residues in the amino acid sequence shown is preferably 40% or more, more preferably 60% or more, and even more preferably 70% or more, relative to the total number of amino acid residues.

[0123] The first modified silk-core protein can be a polypeptide of the following type: Formula 1: [(A)] n Motif - REP m The unit of the amino acid sequence shown, and the C-terminal sequence is any one of the amino acid sequences shown in sequence numbers 1 to 3, or an amino acid sequence that has more than 90% homology with any one of the amino acid sequences shown in sequence numbers 1 to 3.

[0124] The amino acid sequence shown in sequence number 1 is identical to the amino acid sequence consisting of 50 residues from the C-terminus of the amino acid sequence of ADF3 (GI: 1263287, NCBI). The amino acid sequence shown in sequence number 2 is identical to the amino acid sequence after removing 20 residues from the C-terminus of the amino acid sequence shown in sequence number 1. The amino acid sequence shown in sequence number 3 is identical to the amino acid sequence after removing 29 residues from the C-terminus of the amino acid sequence shown in sequence number 1.

[0125] As a more specific example of the first modified spider silk protein, examples include modified spider silk proteins with an amino acid sequence that has more than 90% sequence identity with either (1-i) sequence number 4 (recombinant spider silk protein ADF3KaiLargeNRSH1) or (1-ii) sequence number 4. Preferably, the sequence identity is more than 95%.

[0126] The amino acid sequence shown in Serial No. 4 is obtained by adding a start codon, His10 tag, and HRV3C protease (Human rhinovirus 3C protease) recognition site (Serial No. 5) to the N-terminus of ADF3, thereby increasing the repeat region at positions 1-13 by approximately 2-fold, and terminating translation at amino acid residue 1154. The C-terminal amino acid sequence of the amino acid sequence shown in Serial No. 4 is identical to that of the amino acid sequence shown in Serial No. 3.

[0127] The modified filamentin (1-i) can be composed of the amino acid sequence shown in sequence number 4.

[0128] The second-modified filamentin has an amino acid sequence in which the content of glycine residues is reduced compared to that of naturally derived filamentin. Compared to naturally derived filamentin, the second-modified filamentin may have an amino acid sequence equivalent to at least one or more glycine residues in the REP being replaced with other amino acid residues.

[0129] Compared to naturally derived filamentin, the modified filamentin domain sequence in the REP may have an amino acid sequence in which at least one motif sequence selected from GGX and GPGXX (where G represents a glycine residue, P represents a proline residue, and X represents an amino acid residue other than glycine) is replaced with an amino acid residue equivalent to at least one or more of the motif sequences having one glycine residue replaced with another amino acid residue.

[0130] In the second modified silk core protein, the proportion of motif sequences in which the above-mentioned glycine residues are replaced by other amino acid residues can be more than 10% relative to the total motif sequence.

[0131] The second modified silk core protein includes Formula 1: [(A)] n Motif - REP m The domain sequence shown can also have the following amino acid sequence: when the (A) located on the C-terminus is removed from the above domain sequence. n The total number of amino acid residues in the sequence obtained after the motif extends to the C-terminus of the above-mentioned domain sequence, which consists of an amino acid sequence of XGX (where X represents an amino acid residue other than glycine), is denoted as z. The sequence from which (A) located closest to the C-terminus is removed from the above-mentioned domain sequence is also defined. n When the total number of amino acid residues in the sequence obtained after extending from the motif to the C-terminus of the aforementioned domain sequence is defined as w, z / w is 30% or more, 40% or more, 50% or more, or 50.9% or more. (A) n The number of alanine residues in the motif can be 83% or more of the total number of amino acid residues, preferably 86% or more, more preferably 90% or more, further preferably 95% or more, and even more preferably 100% (meaning it consists of only alanine residues).

[0132] The second modified silkcore protein preferably increases the proportion of the amino acid sequence composed of XGX by replacing one glycine residue in the GGX motif with another amino acid residue. In the second modified silkcore protein, the proportion of the amino acid sequence composed of GGX in the domain sequence is preferably 30% or less, more preferably 20% or less, further preferably 10% or less, even more preferably 6% or less, even more preferably 4% or less, and particularly preferably 2% or less. The proportion of the amino acid sequence composed of GGX in the domain sequence can be calculated using the same method as the method for calculating the proportion (z / w) of the amino acid sequence composed of XGX described below.

[0133] The calculation method for z / w is further explained in detail. First, in Equation 1: [(A)] n Motif - REP m In the filamentin (modified filamentin or naturally derived filamentin) with the domain sequence shown, the (A) domain located on the C-terminus side is removed from the domain sequence. n From all the REP sequences obtained after the sequence extends from the motif to the C-terminus of the domain sequence, amino acid sequences consisting of XGX residues are extracted. The total number of amino acid residues constituting XGX is z. For example, when 50 amino acid sequences consisting of XGX residues are extracted (without repetitions), z is 50 × 3 = 150. Furthermore, for example, as in the case of amino acid sequences consisting of XGXGX, when the X contained in two XGX sequences (the middle X) is present, the calculation is performed by subtracting the repetitive portion (5 amino acid residues when it is XGXGX). w is the number of amino acid residues removed from the domain sequence from the C-terminus (A). n The total number of amino acid residues contained in the sequence obtained after extending from the motif to the C-terminus of the domain sequence. For example, when... Figure 1 When the domain sequence is shown, w is 4+50+4+100+4+10+4+20+4+30=230 (excluding (A) located closest to the end of C). n (Modal). Then, by dividing z by w, z / w (%) can be calculated.

[0134] Here, the z / w ratio of naturally derived filamentin is explained. First, as described above, 663 filamentin proteins were extracted using a method exemplified by filamentin proteins whose amino acid sequence information is registered in NCBi GenBank (of which 415 are derived from spiders). Among all extracted filamentin proteins, those containing formula 1: [(A)] nFor amino acid sequences of naturally derived filamentin containing less than 6% of the domain sequence represented by the motif [REP]m and consisting of the GGX amino acid sequence from filamentin, the z / w ratio is calculated using the method described above. The results are as follows: Figure 2 As shown. Figure 2 The horizontal axis represents z / w (%), and the vertical axis represents frequency. Figure 2 It can be seen that the z / w ratio in naturally derived silk protein is less than 50.9% (the maximum is 50.86%).

[0135] In the modified silk core protein, the z / w is preferably 50.9% or more, more preferably 56.1% or more, even more preferably 58.7% or more, even more preferably 70% or more, and even more preferably 80% or more. There is no particular limit to the upper limit of the z / w, for example, it can be below 95%.

[0136] For example, a second modified silkcore protein can be obtained by replacing at least a portion of the base sequence encoding a glycine residue in the cloned gene sequence of a naturally derived silkcore protein, thereby encoding other amino acid residues. In this case, the modified glycine residue can be selected from either the GGX motif or the GPGXX motif, or it can be replaced by setting the z / w ratio to 50.9% or higher. Alternatively, for example, an amino acid sequence satisfying the above method can be designed based on the amino acid sequence of a naturally derived silkcore protein, and obtained by chemically synthesizing a nucleic acid encoding the designed amino acid sequence. In any case, in addition to modifications equivalent to replacing the glycine residue in the REP sequence of a naturally derived silkcore protein with other amino acid residues, further modifications equivalent to substitution, deletion, insertion, and / or addition of one or more amino acid residues can be performed on the amino acid sequence.

[0137] As for the other amino acid residues mentioned above, any amino acid residue other than glycine residues is acceptable and there are no particular restrictions. Preferably, hydrophobic amino acid residues such as valine (V) residues, leucine (L) residues, isoleucine (I) residues, methionine (M) residues, proline (P) residues, phenylalanine (F) residues, and tryptophan (W) residues, as well as hydrophilic amino acid residues such as glutamine (Q) residues, asparagine (N) residues, serine (S) residues, lysine (K) residues, and glutamic acid (E) residues are preferred. More preferably, valine (V) residues, leucine (L) residues, isoleucine (I) residues, phenylalanine (F) residues, and glutamine (Q) residues are preferred. Glutamine (Q) residues are even more preferred.

[0138] As a more specific example of the second modified silkcore protein, examples include modified silkcore proteins that have an amino acid sequence with more than 90% sequence identity to the amino acid sequences shown in (2-i) sequence number 6 (Met-PRT380), sequence number 7 (Met-PRT410), sequence number 8 (Met-PRT525) or sequence number 9 (Met-PRT799), or (2-ii) sequence number 6, sequence number 7, sequence number 8 or sequence number 9.

[0139] The modified filamentin (2-i) is described. The amino acid sequence represented by sequence number 6 is obtained by replacing all GGX in the REP sequence of sequence number 10 (Met-PRT313) of the naturally derived filamentin with GQX. The amino acid sequence shown in sequence number 7 is obtained by altering (A) from the N-terminus to the C-terminus in the amino acid sequence shown in sequence number 6. n Motifs are deleted every two motifs, and a further [(A)] is inserted near the C-terminal sequence. n The motif is obtained by [REP]. The amino acid sequence shown in sequence number 8 is derived from each (A) of the amino acid sequence shown in sequence number 7. n Two alanine residues are inserted at the C-terminus of the motif, and some glutamine (Q) residues are replaced with serine (S) residues. Additionally, some amino acids at the C-terminus are deleted to make the motif nearly identical in molecular weight to that of sequence number 7. The amino acid sequence shown in sequence number 9 is formed by repeating the region of the 20 domain sequences present in the amino acid sequence shown in sequence number 7 (where several amino acid residues at the C-terminus of this region are replaced) four times, and then adding a predetermined hinge sequence and a His tag sequence at the C-terminus.

[0140] The z / w value of the amino acid sequence shown in sequence number 10 (equivalent to naturally derived fibroin) is 46.8%. The z / w values ​​of the amino acid sequences shown in sequence numbers 6, 7, 8, and 9 are 58.7%, 70.1%, 66.1%, and 70.0%, respectively. Furthermore, the x / y values ​​of the serration ratios (described below) of the amino acid sequences shown in sequences 10, 6, 7, 8, and 9, ranging from 1:1.8 to 11.3, are 15.0%, 15.0%, 93.4%, 92.7%, and 89.8%, respectively.

[0141] The modified filamentin (2-i) can be composed of the amino acid sequences shown in sequence number 6, sequence number 7, sequence number 8 or sequence number 9.

[0142] The modified filamentin of (2-ii) comprises an amino acid sequence having more than 90% sequence identity with the amino acid sequences shown in sequence numbers 6, 7, 8, or 9. The modified filamentin of (2-ii) also contains formula 1: [(A)] n Motif - REP m The protein with the domain sequence shown. Preferably, the sequence identity is 95% or higher.

[0143] The modified silken protein of (2-ii) has more than 90% sequence identity with the amino acid sequences shown in sequence number 6, sequence number 7, sequence number 8 or sequence number 9, and when the total number of amino acid residues in the amino acid sequence consisting of XGX (where X represents amino acid residues other than glycine) contained in the REP is set as z, and the total number of amino acid residues in the REP in the above-mentioned domain sequence is set as w, z / w is preferably more than 50.9%.

[0144] The second type of modified filamentin can contain tag sequences at either the N-terminus or both the C-terminus. This allows for the isolation, immobilization, detection, and visualization of the modified filamentin.

[0145] As a tag sequence, for example, affinity tags that utilize specific affinity (binding, affinity) with other molecules can be listed. A specific example of an affinity tag is the histidine tag (His tag). The His tag is a short peptide composed of approximately 4 to 10 histidine residues, possessing the property of specifically binding to metal ions such as nickel, and therefore can be used for the separation of modified filamentin by chelating metal chromatography. A specific example of a tag sequence is, for example, the amino acid sequence shown in Serial No. 11 (an amino acid sequence containing the His tag sequence and the hinge sequence).

[0146] In addition, tag sequences such as glutathione S-transferase (GST), which binds specifically to glutathione, and maltose-binding protein (MBP), which binds specifically to maltose, can also be used.

[0147] Furthermore, "epitope tags" that utilize antigen-antibody reactions can be used. By adding a peptide (epitope) that displays antigenicity as a tag sequence, antibodies targeting that epitope can bind. Examples of epitope tags include HA (hypoglycine hemagglutinin peptide sequence), myc, and FLAG tags. By utilizing epitope tags, modified filamentin can be easily purified with high specificity.

[0148] Furthermore, tags obtained by excising the tag sequence using specific proteases can also be used. Modified filoproteins after tag sequence excision can also be recovered by treating proteins adsorbed via the tag sequence with proteases.

[0149] As a more specific example of a modified silkcore protein containing a tag sequence, examples include modified silkcore proteins that have an amino acid sequence that is more than 90% identical to the amino acid sequence shown in (2-iii) sequence number 12 (PRT380), sequence number 13 (PRT410), sequence number 14 (PRT525) or sequence number 15 (PRT799), or the amino acid sequence shown in (2-iv) sequence number 12, sequence number 13, sequence number 14 or sequence number 15.

[0150] The amino acid sequences shown in sequence number 16 (PRT313), sequence number 12, sequence number 13, sequence number 14 and sequence number 15 are respectively modified by adding the amino acid sequence shown in sequence number 11 (including the His tag sequence and hinge sequence) to the N-terminus of the amino acid sequences shown in sequence number 10, sequence number 6, sequence number 7, sequence number 8 and sequence number 9.

[0151] The modified filamentin of (2-iii) can be composed of the amino acid sequence shown in sequence number 12, sequence number 13, sequence number 14 or sequence number 15.

[0152] The modified silken protein of (2-iv) comprises an amino acid sequence having more than 90% sequence identity with the amino acid sequences shown in sequence numbers 12, 13, 14, or 15. The modified silken protein of (2-iv) also contains formula 1: [(A)] n Motif - REP m The protein with the domain sequence shown. Preferably, the sequence identity is 95% or higher.

[0153] The modified filamentin of (2-iv) has more than 90% sequence identity with the amino acid sequences shown in sequence numbers 12, 13, 14 or 15, and when the total number of amino acid residues in the amino acid sequence consisting of XGX (where X represents amino acid residues other than glycine) contained in the REP is set as z, and the total number of amino acid residues in the REP in the above-mentioned domain sequence is set as w, z / w is preferably more than 50.9%.

[0154] The second modified filamentin may contain a secretion signal for releasing proteins produced by the recombinant protein production system to the host. The sequence of the secretion signal can be appropriately configured according to the host species.

[0155] The third modified filamentin has a domain sequence that differs from that of naturally derived filamentin (A).n The amino acid sequence with reduced motif content. The third modified filoprotein domain sequence, compared to naturally derived filoprotein, may have an equivalent deletion of at least one or more (A) domains. n The amino acid sequence of the motif.

[0156] The third modified fibroin can have (A) equivalent to the loss of 10-40% from naturally sourced fibroin. n The amino acid sequence of the motif.

[0157] The third modified filoprotein domain sequence, compared to the naturally derived filoprotein, has at least 1 to 3 (A) domains from the N-terminus to the C-terminus. n One (A) is missing from the motif. n The amino acid sequence of the motif.

[0158] The third modified filoprotein domain sequence, compared to the naturally derived filoprotein, has at least two consecutive (A) repeats from the N-terminus to the C-terminus. n The absence of a motif and an (A) n Amino acid sequences with missing motifs.

[0159] The third modified filoprotein domain sequence can have deletions occurring at least every two domains from the N-terminus to the C-terminus (A). n The amino acid sequence of the motif.

[0160] The third modified silk core protein includes Formula 1: [(A)] n Motif - REP m The domain sequence shown can have the following amino acid sequence: comparing two adjacent [(A)] from the N-terminus to the C-terminus. n The number of amino acid residues in the REP of the motif-REP unit, when the number of amino acid residues in the REP with fewer amino acid residues is set to 1, and the ratio of the number of amino acid residues in the other REP is 1.8 to 11.3 between two adjacent [(A)] units. n When the maximum value obtained by adding the number of amino acid residues in the motif-REP unit is set as x, and the total number of amino acid residues in the domain sequence is set as y, x / y is greater than 20%, 30%, 40%, or 50%. (A) n The number of alanine residues in the motif can be 83% or more of the total number of amino acid residues, preferably 86% or more, more preferably 90% or more, further preferably 95% or more, and even more preferably 100% (meaning it consists of only alanine residues).

[0161] Reference Figure 1The calculation method for x / y will be explained in further detail. Figure 1 The domain sequence after removing the N-terminal and C-terminal sequences from the modified filamentin is shown. This domain sequence has (A) starting from the N-terminal side (left side). n Motif – 1st REP (50 amino acid residues) – (A) n Motif – 2nd REP (100 amino acid residues) – (A) n Motif – 3rd REP (10 amino acid residues) – (A) n Motif – 4th REP (20 amino acid residues) – (A) n Motif – 5th REP (30 amino acid residues) – (A) n A sequence of motifs.

[0162] Select two adjacent [(A)] sequentially from the N-terminal side to the C-terminal side without repetition. n [Modal - REP] unit. In this case, there may also be unselected [(A)] units. n [Basis sequence - REP] unit. Figure 1 The diagrams show Mode 1 (comparison between REP 1 and REP 2, and between REP 3 and REP 4), Mode 2 (comparison between REP 1 and REP 2, and between REP 4 and REP 5), Mode 3 (comparison between REP 2 and REP 3, and between REP 4 and REP 5), and Mode 4 (comparison between REP 1 and REP 2). In addition, other selection methods exist.

[0163] Next, for each pattern, compare the two adjacent selected [(A)] n The number of amino acid residues in each REP within the motif-REP unit is used for comparison. This is done by calculating the ratio of the number of amino acid residues in the REP with the fewer residues to the number of amino acid residues in the other REP when the REP with the fewer residues is set to 1. For example, when comparing REP 1 (50 amino acid residues) and REP 2 (100 amino acid residues), the ratio of the number of amino acid residues in REP 2 is 100 / 50 = 2 when REP 1 has the fewer residues. Similarly, when comparing REP 4 (20 amino acid residues) and REP 5 (30 amino acid residues), the ratio of the number of amino acid residues in REP 5 is 30 / 20 = 1.5 when REP 4 has the fewer residues.

[0164] Figure 1 In the figure, solid lines represent the ratio of the number of amino acid residues of the side with relatively fewer amino acid residues being 1 to 11.3, where the ratio of the number of amino acid residues of the other side is 1.8 to 11.3. [(A)] nGroups of motif-REP units. In this specification, this ratio is referred to as the sawtooth ratio. Dashed lines indicate [(A]] where, when the side with the relatively fewer amino acid residues is set to 1, the ratio of the amino acid residues of the other side is less than 1.8 or greater than 11.3. n Groups of motif-REP units.

[0165] In each pattern, the two adjacent [(A)] shown by the solid line are... n The number of amino acid residues in the motif-REP unit is summed (not just the number of REP residues, but also the number of amino acid residues in the (A)n motif). Furthermore, the sums are compared, and the sum of the pattern with the largest sum (the maximum sum) is set as x. Figure 1 In the example shown, mode 1 has the largest total value.

[0166] Next, x / y (%) can be calculated by dividing x by the total number of amino acid residues y in the domain sequence.

[0167] In the modified silk core protein of the third type, the x / y ratio is preferably 50% or more, more preferably 60% or more, further preferably 65% ​​or more, even more preferably 70% or more, even more preferably 75% or more, and particularly preferably 80% or more. There is no particular upper limit to the x / y ratio; for example, it can be below 100%. When the serration ratio is 1:1.9 to 11.3, the x / y ratio is preferably 89.6% or more; when the serration ratio is 1:1.8 to 3.4, the x / y ratio is preferably 77.1% or more; when the serration ratio is 1:1.9 to 8.4, the x / y ratio is preferably 75.9% or more; and when the serration ratio is 1:1.9 to 4.1, the x / y ratio is preferably 64.2% or more.

[0168] When the third modified filamentin contains multiple (A) sequences within its domain sequence. n When the modified filoprotein consists of at least 7 alanine residues in its motif, the x / y ratio is preferably 46.4% or more, more preferably 50% or more, further preferably 55% or more, even more preferably 60% or more, even more preferably 70% or more, and particularly preferably 80% or more. There is no particular upper limit to the x / y ratio; it can be 100% or less.

[0169] Here, the x / y ratio in naturally derived filamentin is explained. First, as described above, 663 filamentin proteins were extracted using a method exemplified by filamentin proteins whose amino acid sequence information is registered in NCBi GenBank (of which 415 were derived from spiders). Among all the extracted filamentin proteins, from Equation 1: [(A)] n Motif - REP mBased on the above calculation method, x / y is calculated from the amino acid sequence of the naturally derived silken protein, which consists of the represented domain sequence. Figure 3 This indicates the results when the sawtooth ratio is 1:1.9 to 4.1.

[0170] Figure 3 The horizontal axis represents x / y (%), and the vertical axis represents frequency. Figure 3 It can be seen that the x / y ratio in naturally derived silk protein is less than 64.2% (the maximum is 64.14%).

[0171] For example, the encoding (A) can be achieved by setting x / y to 64.2% or higher in the gene sequence of a cloned naturally derived filamentin. n One or more deletions in the motif sequence yield the third modified silkcore protein. Alternatively, for example, one or more (A) groups can be made by designing an amino acid sequence equivalent to that of naturally derived silkcore proteins, such that x / y is set to 64.2% or higher. n The amino acid sequence with a deleted motif is obtained by chemically synthesizing a nucleic acid encoding the designed amino acid sequence. In any case, except for deletions in the amino acid sequence of filocene from natural sources (A). n In addition to modifications equivalent to motifs, further modifications can be made to the amino acid sequence equivalent to substitutions, deletions, insertions, and / or additions of one or more amino acid residues.

[0172] As a more specific example of the third modified silkcore protein, examples include modified silkcore proteins that have an amino acid sequence with more than 90% sequence identity to the amino acid sequences shown in (3-i) sequence number 17 (Met-PRT399), sequence number 7 (Met-PRT410), sequence number 8 (Met-PRT525) or sequence number 9 (Met-PRT799), or (3-ii) sequence number 17, sequence number 7, sequence number 8 or sequence number 9.

[0173] The modified silken protein of (3-i) is described. The amino acid sequence shown in Serial No. 17 is modified by moving (A) from the N-terminus to the C-terminus in the amino acid sequence corresponding to Serial No. 10 (Met-PRT313) of the naturally derived silken protein. n Motifs are deleted every two motifs, and a further [(A)] is inserted near the C-terminal sequence. n The motif is obtained by [REP]. The amino acid sequence shown in sequence number 7, sequence number 8 or sequence number 9 is as described in the second modified silk core protein.

[0174] The serration ratio of the amino acid sequence shown in sequence number 10 (equivalent to naturally derived fibroin) is 15.0% in the range of 1:1.8–11.3. The x / y values ​​of the amino acid sequences shown in sequences number 17 and 7 are both 93.4%. The x / y value of the amino acid sequence shown in sequence number 8 is 92.7%. The x / y value of the amino acid sequence shown in sequence number 9 is 89.8%. The z / w values ​​of the amino acid sequences shown in sequences number 10, 17, 7, 8, and 9 are 46.8%, 56.2%, 70.1%, 66.1%, and 70.0%, respectively.

[0175] The modified filamentin (3-i) can be composed of the amino acid sequences shown in sequence number 17, sequence number 7, sequence number 8 or sequence number 9.

[0176] The modified filamentin of (3-ii) comprises an amino acid sequence having more than 90% sequence identity with the amino acid sequences shown in sequence numbers 17, 7, 8, or 9. The modified filamentin of (3-ii) also contains formula 1: [(A)] n Motif - REP m The protein with the domain sequence shown. Preferably, the sequence identity is 95% or higher.

[0177] The modified filoprotein of (3-ii) has more than 90% sequence identity with the amino acid sequences shown in sequence numbers 17, 7, 8 or 9, and the sequences are compared sequentially from the N-terminus to the C-terminus [(A)]. n The number of amino acid residues in the REP of the motif-REP unit, when the number of amino acid residues in the REP with fewer amino acid residues is set to 1, and the ratio of the number of amino acid residues in the other REP is 1.8 to 11.3 (zigzag ratio of 1:1.8 to 11.3) of the number of amino acid residues in two adjacent [(A)] units. n When the maximum value of the sum of the amino acid residues of the motif-REP unit is set as x, and the total number of amino acid residues of the domain sequence is set as y, x / y is preferably 64.2% or higher.

[0178] The third modified filamentin can contain the above tag sequence at either the N-terminus or both the C-terminus.

[0179] As a more specific example of a modified silkcore protein containing a tag sequence, examples include modified silkcore proteins that have an amino acid sequence that is more than 90% identical to the amino acid sequence shown in (3-iii) sequence number 18 (PRT399), sequence number 13 (PRT410), sequence number 14 (PRT525) or sequence number 15 (PRT799), or the amino acid sequence shown in (3-iv) sequence number 18, sequence number 13, sequence number 14 or sequence number 15.

[0180] The amino acid sequences shown in sequence numbers 18, 13, 14 and 15 are respectively modified by adding the amino acid sequence shown in sequence number 11 (including the His tag sequence and hinge sequence) to the N-terminus of the amino acid sequences shown in sequence numbers 17, 7, 8 and 9.

[0181] The modified filamentin of (3-iii) can be composed of the amino acid sequences shown in sequence number 18, sequence number 13, sequence number 14 or sequence number 15.

[0182] The modified silken protein of (3-iv) comprises an amino acid sequence having more than 90% sequence identity with the amino acid sequences shown in sequence numbers 18, 13, 14, or 15. The modified silken protein of (3-iv) also contains formula 1: [(A)] n Motif - REP m The protein with the domain sequence shown. Preferably, the sequence identity is 95% or higher.

[0183] The modified filoprotein of (3-iv) has more than 90% sequence identity with the amino acid sequences shown in sequence numbers 18, 13, 14 or 15, and the sequences are compared sequentially from the N-terminus to the C-terminus [(A)]. n The number of amino acid residues in the REP of the motif-REP unit, when the number of amino acid residues in the REP with fewer amino acid residues is set to 1, and the ratio of the number of amino acid residues in the other REP is 1.8 to 11.3 between two adjacent [(A)] units. n When the maximum value of the sum of the amino acid residues of the motif-REP unit is set as x, and the total number of amino acid residues of the domain sequence is set as y, x / y is preferably 64.2% or higher.

[0184] The third modified filamentin may contain a secretion signal for releasing proteins produced by the recombinant protein production system to the host. The sequence of the secretion signal can be appropriately configured according to the host species.

[0185] The fourth modification to filamentin involves altering its domain sequence compared to naturally derived filamentin, except for a reduction in (A). nIn addition to the motif content, the modified filamentin also possesses an amino acid sequence with reduced glycine residue content. The domain sequence of the fourth modified filamentin, compared to naturally derived filamentin, has at least one or more (A) domains. n In addition to motif deletion, it may also have an amino acid sequence equivalent to one or more glycine residues in at least REP being replaced by other amino acid residues. That is, the fourth modified filamentin is a modified filamentin that simultaneously possesses the characteristics of the second and third modified filamentins described above. Specific implementation methods are as described in the second and third modified filamentins.

[0186] As a more specific example of the fourth modified silk-core protein, examples include modified silk-core proteins comprising an amino acid sequence having more than 90% sequence identity with the amino acid sequences shown in (4-i) sequence number 7 (Met-PRT410), sequence number 8 (Met-PRT525), sequence number 9 (Met-PRT799), sequence number 13 (PRT410), sequence number 14 (PRT525), or sequence number 15, or (4-ii) sequence number 7, sequence number 8, sequence number 9, sequence number 13, sequence number 14, or sequence number 15. Specific embodiments of the modified silk-core protein comprising the amino acid sequences shown in sequence number 7, sequence number 8, sequence number 9, sequence number 13, sequence number 14, or sequence number 15 are described above.

[0187] The fifth modified filamentin domain sequence, compared to the naturally derived filamentin, may have an amino acid sequence equivalent to one or more amino acid residues in the REP being replaced with amino acid residues with high hydrophobicity indexes and / or one or more amino acid residues with high hydrophobicity indexes being inserted into the REP, and locally containing regions with high hydrophobicity indexes.

[0188] Regions with high local hydrophobicity are preferably composed of 2 to 4 consecutive amino acid residues.

[0189] The amino acid residues with high hydrophobicity are more preferably selected from isoleucine (I), valine (V), leucine (L), phenylalanine (F), cysteine ​​(C), methionine (M), and alanine (A).

[0190] Compared to naturally derived filamentin, the fifth modified filamentin, in addition to the modification of replacing one or more amino acid residues in the REP with amino acid residues with high hydrophobicity index and / or inserting one or more amino acid residues with high hydrophobicity index into the REP, can also be modified by altering the amino acid sequence of one or more amino acid residues by substitution, deletion, insertion and / or addition.

[0191] For example, a fifth-generation modified filamentin can be obtained by replacing one or more hydrophilic amino acid residues (e.g., amino acid residues with a negative hydrophobicity index) in the REP from the cloned natural filamentin gene sequence with hydrophobic amino acid residues (e.g., amino acid residues with a positive hydrophobicity index), and / or inserting one or more hydrophobic amino acid residues into the REP. Alternatively, it can be obtained by designing an amino acid sequence equivalent to replacing one or more hydrophilic amino acid residues in the REP from the natural filamentin sequence with hydrophobic amino acid residues, and / or inserting one or more hydrophobic amino acid residues into the REP, and then chemically synthesizing the nucleic acid encoding the designed amino acid sequence. In any case, in addition to modifications equivalent to replacing one or more hydrophilic amino acid residues in the REP from the natural filamentin sequence with hydrophobic amino acid residues, and / or inserting one or more hydrophobic amino acid residues into the REP, further modifications to the amino acid sequence equivalent to substitution, deletion, insertion, and / or addition of one or more amino acid residues can be performed.

[0192] The fifth modified silk core protein includes formula 1: [(A)] n Motif - REP m The domain sequence shown may have the following amino acid sequence: (A) removed from the C-terminal side of the above domain sequence. n In the sequence obtained after the motif up to the C-terminus of the above-mentioned domain sequence, the total number of amino acid residues in the region containing the region with an average hydrophobicity index of 2.6 or higher for four consecutive amino acid residues is defined as p. Then, the region containing residues (A) located closest to the C-terminus is removed from the above-mentioned domain sequence. n When the total number of amino acid residues in the sequence obtained after the sequence from the motif to the C-terminus of the above-mentioned domain sequence is set as q, the p / q ratio is 6.2% or higher.

[0193] Regarding the hydrophobicity index of amino acid residues, a well-known index (Hydropathy index: Kyte J, & Doolittle R (1982) "A simple method for displaying the hydropathic character of a protein", J. Mol. Biol., 157, pp. 105-132) is used. Specifically, the hydrophobicity index (HI) of each amino acid is shown in Table 1 below.

[0194] [Table 1]

[0195]

[0196] The calculation method for p / q is further explained in detail. In the calculation, equation 1 is used: [(A)] n Motif - REP m The domain sequence shown excludes (A) located at the C-end. n The sequence obtained after extending from the motif to the C-terminus of the domain sequence (hereinafter referred to as "Sequence A") is as follows: First, the average hydrophobicity index of four consecutive amino acid residues is calculated in all REPs contained in Sequence A. The average hydrophobicity index is obtained by dividing the sum of the HIs of each amino acid residue contained in the four consecutive amino acid residues by 4 (the number of amino acid residues). The average hydrophobicity index is calculated for all four consecutive amino acid residues (each amino acid residue is used for 1 to 4 average calculations). Next, regions where the average hydrophobicity index of four consecutive amino acid residues is 2.6 or higher are identified. Even if an amino acid residue belongs to multiple "four consecutive amino acid residues with an average hydrophobicity index of 2.6 or higher", it is included as one amino acid residue in the region. Moreover, the total number of amino acid residues contained in this region is p. Furthermore, the total number of amino acid residues contained in Sequence A is q.

[0197] For example, when 20 instances of "consecutive four amino acid residues with an average hydrophobicity index of 2.6 or higher" are extracted (without repetition), the region containing 20 instances of consecutive four amino acid residues with an average hydrophobicity index of 2.6 or higher contains 20 instances of consecutive four amino acid residues (without repetition), and p = 20 × 4 = 80. Furthermore, for example, if only one amino acid residue is repeated in two instances of "consecutive four amino acid residues with an average hydrophobicity index of 2.6 or higher", the region containing 7 amino acid residues with an average hydrophobicity index of 2.6 or higher contains 7 amino acid residues (p = 2 × 4 - 1 = 7, "-1" represents the subtraction of the repetition). For example, in Figure 4 In the case of the domain sequence shown, there are 7 instances of "4 consecutive amino acid residues with an average hydrophobicity index of 2.6 or higher" that are not repeated, therefore p = 7 × 4 = 28. Furthermore, for example, when... Figure 4 When the domain sequence is shown, q is 4+50+4+40+4+10+4+20+4+30=170 (excluding the last (A) located at the end of C). n (Modal). Then, by dividing p by q, p / q (%) can be calculated. Figure 4 In this case, 28 / 170 = 16.47%.

[0198] In the fifth modified silk core protein, the p / q ratio is preferably 6.2% or more, more preferably 7% or more, further preferably 10% or more, even more preferably 20% or more, and even more preferably 30% or more. There is no particular upper limit to the p / q ratio; for example, it can be 45% or less.

[0199] For example, for the cloned amino acid sequence of naturally derived filamentin, the modified filamentin can be obtained by replacing one or more hydrophilic amino acid residues (e.g., amino acid residues with negative hydrophobicity indices) in the REP with hydrophobic amino acid residues (e.g., amino acid residues with positive hydrophobicity indices), and / or inserting one or more hydrophobic amino acid residues into the REP to satisfy the above p / q conditions, and by modifying it to have an amino acid sequence containing a region with a high hydrophobicity index, thus obtaining the fifth modified filamentin. Alternatively, for example, an amino acid sequence satisfying the above p / q conditions can be designed based on the amino acid sequence of naturally derived filamentin, and obtained by chemically synthesizing the nucleic acid encoding the designed amino acid sequence. In any case, compared to naturally derived filamentin, in addition to modifications equivalent to replacing one or more amino acid residues in the REP with amino acid residues with high hydrophobicity indices, and / or inserting one or more amino acid residues with high hydrophobicity indices into the REP, further modifications equivalent to substitution, deletion, insertion, and / or addition of one or more amino acid residues can be performed.

[0200] There are no particular restrictions on the amino acid residues with high hydrophobicity, but isoleucine (I), valine (V), leucine (L), phenylalanine (F), cysteine ​​(C), methionine (M), and alanine (A) are preferred, and valine (V), leucine (L), and isoleucine (I) are even more preferred.

[0201] As a more specific example of the fifth modified silkcore protein, we can list modified silkcore proteins that have an amino acid sequence that has more than 90% sequence identity with the amino acid sequence shown in (5-i) sequence number 19 (Met-PRT720), sequence number 20 (Met-PRT665) or sequence number 21 (Met-PRT666), or (5-ii) sequence number 19, sequence number 20 or sequence number 21.

[0202] The modified filamentin (5-i) is described below. The amino acid sequence shown in sequence number 19 is relative to the amino acid sequence shown in sequence number 7 (Met-PRT410), with two 3-amino acid residues inserted every other REP (VLI), except for the terminal domain sequence on the C-terminus side. Furthermore, a portion of the glutamine (Q) residues are replaced with serine (S) residues, and a portion of the amino acids on the C-terminus side are deleted. The amino acid sequence shown in sequence number 20 is relative to the amino acid sequence shown in sequence number 8 (Met-PRT525), with one 3-amino acid residue inserted every other REP (VLI). The amino acid sequence shown in sequence number 21 is relative to the amino acid sequence shown in sequence number 8, with two 3-amino acid residues inserted every other REP (VLI).

[0203] The modified filamentin (5-i) can be composed of the amino acid sequences shown in sequence number 19, sequence number 20 or sequence number 21.

[0204] The modified silken protein of (5-ii) comprises an amino acid sequence having more than 90% sequence identity with the amino acid sequences shown in sequence numbers 19, 20, or 21. The modified silken protein of (5-ii) also contains formula 1: [(A)] n Motif - REP m The protein with the domain sequence shown. Preferably, the sequence identity is 95% or higher.

[0205] The modified filoprotein of (5-ii) has more than 90% sequence identity with the amino acid sequences shown in sequence numbers 19, 20 or 21, and preferably, the (A) from the C-terminus is removed from the domain sequence. n In the sequence obtained after the motif up to the C-terminus of the domain sequence, the total number of amino acid residues in the region containing four consecutive amino acid residues with an average hydrophobicity index of 2.6 or higher is defined as p. The region containing residues from the C-terminus (A) is removed from the domain sequence. n When the total number of amino acid residues in the sequence obtained after the sequence from the motif to the C-terminus of the domain sequence is set as q, the p / q ratio is greater than 6.2%.

[0206] The fifth modified filamentin can contain tag sequences at either the N-terminus or both the C-terminus.

[0207] As a more specific example of a modified silkcore protein containing a tag sequence, examples include modified silkcore proteins that have more than 90% sequence identity with the amino acid sequences shown in (5-iii) sequence number 22 (PRT720), sequence number 23 (PRT665) or sequence number 24 (PRT666), or (5-iv) sequence number 22, sequence number 23 or sequence number 24.

[0208] The amino acid sequences shown in sequence numbers 22, 23 and 24 are respectively modified by adding the amino acid sequence shown in sequence number 11 (including the His tag sequence and hinge sequence) to the N-terminus of the amino acid sequences shown in sequence numbers 19, 20 and 21.

[0209] The modified filamentin of (5-iii) can be composed of the amino acid sequences shown in sequence number 22, sequence number 23 or sequence number 24.

[0210] The modified filamentin of (5-iv) comprises an amino acid sequence having more than 90% sequence identity with the amino acid sequences shown in sequence numbers 22, 23, or 24. The modified filamentin of (5-iv) also contains formula 1: [(A)] n Motif - REP m The protein with the domain sequence shown. Preferably, the sequence identity is 95% or higher.

[0211] The modified filoprotein of (5-iv) has more than 90% sequence identity with the amino acid sequences shown in sequence numbers 22, 23 or 24, and preferably, the (A) from the C-terminus is removed from the domain sequence. n In the sequence obtained after the motif up to the C-terminus of the domain sequence, the total number of amino acid residues in the region containing four consecutive amino acid residues with an average hydrophobicity index of 2.6 or higher is defined as p. The region containing residues from the C-terminus (A) is removed from the domain sequence. n When the total number of amino acid residues in the sequence obtained after the sequence from the motif to the C-terminus of the domain sequence is set as q, the p / q ratio is greater than 6.2%.

[0212] The fifth modified filamentin may contain a secretion signal for releasing proteins produced by the recombinant protein production system to the host. The sequence of the secretion signal can be appropriately configured according to the host species.

[0213] The modified filamentin 6 has an amino acid sequence with reduced glutamine residue content compared to naturally derived filamentin.

[0214] The sixth modified silk core protein preferably contains at least one motif selected from the GGX motif and the GPGXX motif in the amino acid sequence of the REP.

[0215] When the modified filamentin in the REP includes the GPGXX motif, the GPGXX motif content is typically above 1%, but can also be above 5%, preferably above 10%. There is no particular upper limit to the GPGXX motif content; it can be below 50% or below 30%.

[0216] In this specification, "GPGXX motif content" is a value calculated using the following method.

[0217] In inclusion equation 1: [(A)] n Motif - REP m Or formula 2: [(A)] n Motif - REP m -(A) n In filamentin (modified filamentin or naturally derived filamentin) whose domain sequences are shown by the motif, the (A) terminator located on the C-terminus is removed from the domain sequence. n In the sequence obtained after the sequence from the motif to the C-end of the domain sequence, the number of GPGXX motifs in the region multiplied by 3 (i.e., the total number of G and P motifs in the GPGXX motif) is s, and the (A) located on the side closest to the C-end is removed from the domain sequence. n The sequence from the motif to the C-terminus of the domain sequence, excluding (A). n When the total number of amino acid residues of all REPs obtained after the motif is set as t, the GPGXX motif content is calculated as s / t.

[0218] In the calculation of GPGXX motif content, "the motif (A) located at the C-terminus is removed from the domain sequence". n The sequence obtained after the sequence from the motif to the C-terminus of the domain sequence is used as the object to exclude the following influence: "the sequence located on the side closest to the C-terminus (A)". n The sequence from the motif to the C-terminus of the domain (equivalent to the REP sequence) sometimes contains sequences with low correlation to the characteristic sequences of filamentin. When m is small (i.e., when the domain sequence is short), this can affect the calculation of the GPGXX motif content. In addition, when the "GPGXX motif" is located at the C-terminus of the REP, it is treated as the "GPGXX motif" even if "XX" is, for example, "AA".

[0219] Figure 5 This is a schematic diagram representing the modified domain sequence of the filoprotein. (See reference...) Figure 5 This section will explain in detail the method for calculating the GPGXX motif content. First, in... Figure 5 The modified filoprotein domain sequence shown is (“[(A)”). n Motif - REP m -(A) n In the "motif" type, all REPs are included in "removing the (A) from the domain sequence located at the C-end". n The sequence obtained after the sequence from the motif to the C-terminus of the domain sequence. Figure 5 In the sequence shown in "Region A", the number of GPGXX motifs used to calculate s is 7, and s is 7 × 3 = 21. Similarly, since all REPs are contained in "removing the (A) from the domain sequence located at the C-end", the number of GPGXX motifs used to calculate s is 7. n The sequence obtained after the sequence from the motif to the C-terminus of the domain sequence. Figure 5 In the sequence shown as "Region A" in the middle, therefore, (A) is further removed from this sequence. n The total number of amino acid residues t of all REPs obtained after the motif is 50 + 40 + 10 + 20 + 30 = 150. Next, by dividing s by t, the s / t (%) can be calculated. Figure 5 In the case of modified silk core protein, the result is 21 / 150 = 14.0%.

[0220] In the modified silk core protein of the 6th generation, the content of glutamine residues is preferably 9% or less, more preferably 7% or less, further preferably 4% or less, and particularly preferably 0%.

[0221] In this specification, the "glutamine residue content" is a value calculated using the following method.

[0222] In inclusion equation 1: [(A)] n Motif - REP m Or formula 2: [(A)] n Motif - REP m -(A) n In filamentin (modified filamentin or naturally derived filamentin) whose domain sequences are shown by the motif, the (A) terminator located on the C-terminus is removed from the domain sequence. n The sequence obtained after the sequence from the motif to the C-terminus of the domain sequence (equivalent to...) Figure 5 In all REPs contained in the sequence of “Region A”, when the total number of glutamine residues contained in that region is set to u, and the (A) located on the C-terminus side is removed from the domain sequence. n The sequence extending from the motif to the C-terminus of the domain sequence, further excluding (A). nWhen the total number of amino acid residues in all REPs obtained after the motif is set as t, the glutamine residue content is calculated as u / t. In the calculation of the glutamine residue content, it is expressed as "removing the (A) residues located from the C-terminus of the domain sequence". n The reason for considering the sequence obtained after the sequence from the motif to the C-terminus of the domain sequence as the object is the same as the reason mentioned above.

[0223] The modified filamentin domain sequence, compared to naturally derived filamentin, can have an amino acid sequence equivalent to the deletion or substitution of one or more glutamine residues in the REP with other amino acid residues.

[0224] "Other amino acid residues" can be any amino acid residue other than glutamine residues, preferably amino acid residues with a hydrophobicity index greater than that of glutamine residues. The hydrophobicity indexes of amino acid residues are shown in Table 1.

[0225] As shown in Table 1, amino acid residues with a hydrophobicity index greater than that of glutamine residues can be listed as amino acid residues selected from isoleucine (I), valine (V), leucine (L), phenylalanine (F), cysteine ​​(C), methionine (M), alanine (A), glycine (G), threonine (T), serine (S), tryptophan (W), tyrosine (Y), proline (P), and histidine (H). More preferably, amino acid residues selected from isoleucine (I), valine (V), leucine (L), phenylalanine (F), cysteine ​​(C), methionine (M), and alanine (A) are selected; even more preferably, amino acid residues selected from isoleucine (I), valine (V), leucine (L), and phenylalanine (F) are selected.

[0226] The hydrophobicity of the REP in the modified silk core protein of the sixth type is preferably -0.8 or higher, more preferably -0.7 or higher, even more preferably 0 or higher, even more preferably 0.3 or higher, and particularly preferably 0.4 or higher. There is no particular limit to the upper limit of the hydrophobicity of the REP, which can be 1.0 or lower, or 0.7 or lower.

[0227] In this specification, the "degree of hydrophobicity of REP" is a value calculated by the following method.

[0228] In inclusion equation 1: [(A)] n Motif - REP m Or formula 2: [(A)] n Motif - REP m -(A) n In filamentin (modified filamentin or naturally derived filamentin) whose domain sequences are shown by the motif, the (A) terminator located on the C-terminus is removed from the domain sequence.n The sequence obtained after the sequence from the motif to the C-terminus of the domain sequence (equivalent to...) Figure 5 In all REPs contained in the sequence of “Region A”, when the sum of the hydrophobicity indices of each amino acid residue in that region is set to v, and the sequence from which (A) located most closely to the C-terminus is removed from the domain sequence. n The sequence extending from the motif to the C-terminus of the domain sequence, further excluding (A). n The hydrophobicity of a REP is calculated as v / t when the total number of amino acid residues in all REPs following the motif is set as t. In the calculation of the hydrophobicity of a REP, the degree of hydrophobicity is expressed as "removing the (A) residues from the C-terminus of the domain sequence". n The reason for considering the sequence obtained after the sequence from the motif to the C-terminus of the domain sequence as the object is the same as the reason mentioned above.

[0229] Compared to naturally derived filamentin, the modified domain sequence of the sixth modified filamentin can be further modified by altering the amino acid sequence by replacing, deleting, inserting, and / or adding one or more amino acid residues, in addition to modifications equivalent to deleting one or more glutamine residues in the REP and / or replacing one or more glutamine residues in the REP with other amino acid residues.

[0230] For example, a modified sixth filamentin can be obtained by deleting one or more glutamine residues in the REP (residue receptor) of the cloned natural filamentin gene sequence, and / or by replacing one or more glutamine residues in the REP with other amino acid residues. Alternatively, it can be obtained by designing an amino acid sequence equivalent to deleting one or more glutamine residues in the REP of the natural filamentin gene sequence, and / or by replacing one or more glutamine residues in the REP with other amino acid residues, and then chemically synthesizing the nucleic acid encoding the designed amino acid sequence.

[0231] More specific examples of the 6th modified filamentin include (6-i) sequence numbers 25 (Met-PRT888), 26 (Met-PRT965), 27 (Met-PRT889), 28 (Met-PRT916), 29 (Met-PRT918), 30 (Met-PRT699), 31 (Met-PRT698), and 32 (Met-PRT918). Modified silkcore proteins containing amino acid sequences as shown in (6-ii) sequence number 41 (Met-PRT966), 41 (Met-PRT917), or 42 (Met-PRT1028), or modified silkcore proteins containing amino acid sequences having more than 90% sequence identity with the amino acid sequences shown in (6-ii) sequence number 25, 26, 27, 28, 29, 30, 31, 32, 41, or 42.

[0232] The modified filamentin of (6-i) is described below. The amino acid sequence shown in sequence number 25 is obtained by replacing all QQ with VL in the amino acid sequence (Met-PRT410) shown in sequence number 7. The amino acid sequence shown in sequence number 26 is obtained by replacing all QQ with TS and the remaining Q with A in the amino acid sequence shown in sequence number 7. The amino acid sequence shown in sequence number 27 is obtained by replacing all QQ with VL and the remaining Q with I in the amino acid sequence shown in sequence number 7. The amino acid sequence shown in sequence number 28 is obtained by replacing all QQ with VI and the remaining Q with L in the amino acid sequence shown in sequence number 7. The amino acid sequence shown in sequence number 29 is obtained by replacing all QQ with VF and the remaining Q with I in the amino acid sequence shown in sequence number 7.

[0233] The amino acid sequence shown in sequence number 30 is obtained by replacing all QQ with VL in the amino acid sequence (Met-PRT525) shown in sequence number 8. The amino acid sequence shown in sequence number 31 is obtained by replacing all QQ with VL in the amino acid sequence shown in sequence number 8, and replacing the remaining Q with I.

[0234] The amino acid sequence shown in sequence number 32 is obtained by repeating the region of the 20 domain sequences present in the amino acid sequence shown in sequence number 7 (Met-PRT410) twice, replacing all QQ with VF, and replacing the remaining Q with I.

[0235] The amino acid sequence represented by sequence number 41 (Met-PRT917) is obtained by replacing all QQ with LI and the remaining Q with V in the amino acid sequence represented by sequence number 7. The amino acid sequence represented by sequence number 42 (Met-PRT1028) is obtained by replacing all QQ with IF and the remaining Q with T in the amino acid sequence represented by sequence number 7.

[0236] The amino acid sequences shown in serial numbers 25, 26, 27, 28, 29, 30, 31, 32, 41 and 42 all contain less than 9% glutamine residues (Table 2).

[0237] [Table 2]

[0238]

[0239] The modified filamentin (6-i) can be composed of the amino acid sequences shown in sequence numbers 25, 26, 27, 28, 29, 30, 31, 32, 41 or 42.

[0240] The modified silken protein of (6-ii) comprises an amino acid sequence having more than 90% sequence identity with the amino acid sequences shown in sequence numbers 25, 26, 27, 28, 29, 30, 31, 32, 41, or 42. The modified silken protein of (6-ii) also comprises formula 1: [(A] n Motif - REP m Or formula 2: [(A)] n Motif - REP m -(A) n Proteins containing the domain sequence indicated by the motif. Preferably, the sequence identity is 95% or higher.

[0241] The content of glutamine residues in the modified filamentin of (6-ii) is preferably 9% or less. In addition, the content of the GPGXX motif in the modified filamentin of (6-ii) is preferably 10% or more.

[0242] The sixth modified filamentin can contain tag sequences at either the N-terminus or both the C-terminus. This enables the isolation, immobilization, detection, and visualization of the modified filamentin.

[0243] As more specific examples of modified silkcore proteins containing a tag sequence, examples include modified silkcore proteins that include the amino acid sequences shown in (6-iii) sequence numbers 33 (PRT888), 34 (PRT965), 35 (PRT889), 36 (PRT916), 37 (PRT918), 38 (PRT699), 39 (PRT698), 40 (PRT966), 43 (PRT917), or 44 (PRT1028), or modified silkcore proteins that include amino acid sequences having more than 90% sequence identity with the amino acid sequences shown in (6-iv) sequence numbers 33, 34, 35, 36, 37, 38, 39, 40, 43, or 44.

[0244] The amino acid sequences shown in sequences 33, 34, 35, 36, 37, 38, 39, 40, 43, and 44 were modified by adding the amino acid sequence shown in sequence 11 (containing the His tag sequence and hinge sequence) to the N-terminus of the amino acid sequences shown in sequences 25, 26, 27, 28, 29, 30, 31, 32, 41, and 42, respectively. Since only the tag sequence was added to the N-terminus, the glutamine residue content remained unchanged, and the glutamine residue content of the amino acid sequences shown in sequences 33, 34, 35, 36, 37, 38, 39, 40, 43, and 44 was all below 9% (Table 3).

[0245] [Table 3]

[0246]

[0247] The modified filamentin of (6-iii) can be composed of the amino acid sequence shown in sequence number 33, sequence number 34, sequence number 35, sequence number 36, sequence number 37, sequence number 38, sequence number 39, sequence number 40, sequence number 43 or sequence number 44.

[0248] The modified silken protein of (6-iv) comprises an amino acid sequence having more than 90% sequence identity with the amino acid sequences shown in sequence numbers 33, 34, 35, 36, 37, 38, 39, 40, 43, or 44. The modified silken protein of (6-iv) also comprises formula 1: [(A] n Motif - REP m Or formula 2: [(A)]n Motif - REP m -(A) n Proteins containing the domain sequence indicated by the motif. Preferably, the sequence identity is 95% or higher.

[0249] The content of glutamine residues in the modified filamentin of (6-iv) is preferably 9% or less. In addition, the content of the GPGXX motif in the modified filamentin of (6-iv) is preferably 10% or more.

[0250] The sixth modified filamentin may contain a secretion signal for releasing proteins produced by the recombinant protein production system to the host. The sequence of the secretion signal can be appropriately configured according to the host species.

[0251] The modified silk core protein can be a modified silk core protein that possesses at least two of the characteristics of the first modified silk core protein, the second modified silk core protein, the third modified silk core protein, the fourth modified silk core protein, the fifth modified silk core protein, and the sixth modified silk core protein.

[0252] As a modified silk core protein, it can be either hydrophilic or hydrophobic. In this specification, "hydrophilic modified silk core protein" refers to a modified silk core protein whose average HI (hydrophobicity index) is less than or equal to 0, obtained by summing the hydrophobicity indices (HI) of all amino acid residues constituting the modified silk core protein and then dividing this sum by the total number of amino acid residues. The hydrophobicity indices are shown in Table 1. Furthermore, "hydrophobic modified silk core protein" is a modified silk core protein with an average HI greater than 0. Hydrophilic modified silk core proteins exhibit particularly excellent flame-retardant properties. Hydrophobic modified silk core proteins exhibit particularly excellent hygroscopic heat dissipation and thermal insulation properties.

[0253] As hydrophilic modified silk core proteins, examples include modified silk core proteins that include the amino acid sequence shown in sequence number 4, the amino acid sequences shown in sequence number 6, 7, 8 or 9, the amino acid sequences shown in sequence number 13, 11, 14 or 15, the amino acid sequences shown in sequence number 18, 7, 8 or 9, the amino acid sequences shown in sequence number 17, 11, 14 or 15, and the amino acid sequences shown in sequence number 19, 20 or 21.

[0254] As a hydrophobic modified silk core protein, examples include modified silk core proteins containing the amino acid sequences shown in sequence numbers 27, 28, 29, 30, 31, 32, 33 or 43, and the amino acid sequences shown in sequence numbers 35, 37, 38, 39, 40, 41 or 44.

[0255] The modified filamentin involved in this embodiment can be prepared using a nucleic acid encoding the modified filamentin via conventional methods. The nucleic acid encoding the modified filamentin can be chemically synthesized based on base sequence information, or it can be synthesized using methods such as PCR.

[0256] For example, proteins can be dissolved in a soluble solvent to form a spinning solution, and then spun using known spinning methods such as wet spinning, dry spinning, wet-dry spinning, or melt spinning to obtain synthetic protein fibers. Examples of soluble protein solvents include dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), formic acid, and hexafluoroisopropanol (HFIP). Inorganic salts can be added to these solvents as solubilizing agents.

[0257] (Artificial fur)

[0258] Without impairing the effects of the present invention, the artificial fur involved in this embodiment may contain fibers other than artificial protein fibers. Examples of other fibers include, for instance, synthetic fibers such as nylon, polyamide, polyester, polyacrylonitrile, polyolefin, polyvinyl alcohol, polyethylene terephthalate, polytetrafluoroethylene, and acrylic resin; regenerated fibers such as cupro fiber, rayon, and lyocell; and natural fibers such as cotton, linen, silk, wool, and cashmere.

[0259] The artificial fur described in this embodiment may also contain other components besides fibers. Examples of such other components include colorants, smoothing agents, antioxidants, UV absorbers, dyes, fillers, crosslinking agents, matting agents, leveling agents, etc.

[0260] The artificial fur involved in this embodiment has a maximum hygroscopic heat generation rate calculated according to the following formula A that is greater than 0.025℃ / g.

[0261] Formula A: Maximum hygroscopic heat generation = {(the highest temperature of the sample after it has been placed in a low humidity environment until its temperature reaches equilibrium, and then moved to a high humidity environment) - (the temperature of the sample after it has been placed in a low humidity environment until its temperature reaches equilibrium, and then moved to a high humidity environment)} (°C) / sample weight (g)

[0262] In addition, in Formula A, a low humidity environment refers to an environment with a temperature of 20°C and a relative humidity of 40%, while a high humidity environment refers to an environment with a temperature of 20°C and a relative humidity of 90%.

[0263] The maximum hygroscopic heat generation of the artificial fur involved in this embodiment can be 0.026℃ / g or higher, or 0.027℃ / g or higher, or 0.028℃ / g or higher, or 0.029℃ / g or higher, or 0.030℃ / g or higher, or 0.031℃ / g or higher, or 0.035℃ / g or higher, or 0.040℃ / g or higher. There is no particular upper limit to the maximum hygroscopic heat generation, and it is usually below 0.060℃ / g.

[0264] The critical oxygen index (LOI) value of the artificial fur involved in this embodiment can be 18.0 or higher, or 20.0 or higher, or 22.0 or higher, or 24.0 or higher, or 26.0 or higher, or 28.0 or higher, or 29.0 or higher, or 30.0 or higher. In this specification, the above-mentioned LOI values ​​are based on the data from the Hazardous Materials Regulation Division of the Japanese Fire and Disaster Management Agency.

[0265] The values ​​measured by the test method for powdered or low-melting-point synthetic resins, as specified in Fire Safety Danger No. 50, dated May 31, 1995.

[0266] The thermal insulation performance index of the artificial fur involved in this embodiment, calculated according to the following formula B, can be greater than 0.18.

[0267] Formula B: Thermal insulation performance index = Thermal insulation rate (%) / Unit area weight of the sample (g / m²) 2 )

[0268] In this specification, the insulation rate refers to the insulation rate measured by the dry contact method using a Thermolab II test chamber (30 cm / s windward), and is the value measured by the method described in the examples described later.

[0269] The thermal insulation performance index of the artificial fur involved in this embodiment can be 0.20 or higher, 0.22 or higher, 0.24 or higher, 0.26 or higher, 0.28 or higher, 0.30 or higher, or 0.32 or higher. There is no particular limitation on the upper limit of the thermal insulation performance index; for example, it can be below 0.60 or below 0.40.

[0270] (Manufacturing method of artificial fur)

[0271] For example, the artificial fur involved in this embodiment can be obtained by the following steps: using the above-mentioned fibers (fibers including artificial protein fibers) to obtain a pile fabric with a large amount of pile protruding on one or both sides of the fabric (pile fabric manufacturing step); cutting the pile loops (shearing) to form cut pile (shearing step); combing the cut pile (shearing step) as needed (combing step); and / or washing the woven fabric that forms the cut pile (shearing step) (washing step).

[0272] The manufacturing process of fleece fabric can be carried out, for example, using methods such as fleece knitting or fleece weaving used in the manufacture of fleece fabrics, including woven fleece fabrics and knitted fleece fabrics. In the case of woven fleece fabrics, the fleece can be formed from warp yarns (warp-knitted fleece fabric) or from weft yarns (weft-knitted fleece fabric). The size of the fleece (loops) can be appropriately set according to the intended use of the artificial fur, for example, it can be 5mm or more and 50mm or less.

[0273] The shearing process can be carried out, for example, using methods commonly used in the manufacture of cut pile.

[0274] Furthermore, the fibers used in the manufacture of artificial leather according to this embodiment can be any synthetic protein fibers, and their form as yarn is not particularly limited. That is, for example, it can be a yarn made by bundling filaments, a twisted yarn made by twisting such a yarn bundle, or a spun yarn made from short fibers. The spun yarn can be any yarn that has been spun, or it can be a twisted yarn that has been further twisted. These yarns are manufactured according to known methods. For example, the spinning process can be obtained by including the following steps: a process of obtaining fibers by spinning fiber raw materials according to conventional methods (spinning process); a process of crimping the obtained fibers as needed (crimping process); a process of cutting the fibers to obtain short fibers (short fibers) (cutting process); a process of water treatment as needed (water treatment process); a process of opening and / or unwinding the short fibers as needed (opening process); and a process of spinning the short fibers (spinning process).

[0275] The spinning process can be carried out using conventional methods. The spinning method can be any one of wet spinning, dry spinning, wet-dry spinning, or melt spinning.

[0276] The crimping process can be implemented as needed, for example by mechanical crimping methods such as pressing, or by contacting short fibers with an aqueous medium to make them crimp (hereinafter sometimes referred to as "water-curing").

[0277] Aqueous medium refers to a liquid or gaseous (vapor) medium containing water (including water vapor). The aqueous medium can be water or a mixture of water and a hydrophilic solvent. Furthermore, volatile solvents such as ethanol and methanol, or their vapors, can be used as hydrophilic solvents. The aqueous medium can be a mixture of water and volatile solvents such as ethanol or methanol, preferably water or a mixture of water and ethanol. By using an aqueous medium containing volatile solvents or their vapors, the drying speed after water-induced curling can be increased, potentially imparting a soft texture to the final curled short fibers. The ratio of water to volatile solvent or its vapor is not particularly limited; for example, the mass ratio of water to volatile solvent or its vapor can be 10:90 to 90:10. The proportion of water is preferably 30% by mass or more, but can also be 40% by mass or 50% by mass or more.

[0278] The aqueous medium is preferably a liquid or gas containing water (including water vapor) at a temperature of 10–230°C. The temperature of the aqueous medium can be above 10°C, above 25°C, above 40°C, above 60°C, or above 100°C, or below 230°C, below 120°C, or below 100°C.

[0279] There is no particular limitation on the contact time with the aqueous medium, as long as it is more than 30 seconds, or more than 1 minute or more than 2 minutes. From a productivity point of view, it is preferable to be less than 10 minutes. Contact with the aqueous medium can be carried out under normal pressure or under reduced pressure (e.g., vacuum).

[0280] Methods involving contact with an aqueous medium include immersing short fibers in the aqueous medium, spraying short fibers with steam containing the aqueous medium, and exposing short fibers to an environment filled with steam containing the aqueous medium. When the aqueous medium is steam, contact between the aqueous medium and the short fibers can be achieved using a conventional steam setting device. Specific examples of steam setting devices include the FMSA type steam setting machine (manufactured by Fukushina Industrial Co., Ltd.) and the EPS-400 (manufactured by Tsujii Dyeing Machinery Co., Ltd.). A specific example of a method for curling short fibers using steam containing an aqueous medium includes accommodating short fibers in a predetermined chamber while simultaneously introducing steam containing the aqueous medium into the chamber, adjusting the temperature within the chamber to the predetermined temperature (e.g., 100°C to 230°C), and then contacting the steam with the short fibers.

[0281] Alternatively, the short fibers can be further dried after contact with an aqueous medium. The drying method is not particularly limited; drying can be natural drying, or drying with hot air or hot rollers. The drying temperature is not particularly limited; for example, it can be 20–150°C, preferably 40–120°C, and more preferably 60–100°C.

[0282] The cutting process can be performed using any device capable of cutting fibers. For example, a tabletop fiber cutting machine (S / NO. IT-160201-NP-300) can be cited as such a device. The length of the short fibers is not particularly limited; for example, it can be 20mm or more, 20-140mm, 70-140mm, or 20-70mm.

[0283] Water treatment processes can be implemented as needed, for example, using the same method as water-repellent curling.

[0284] The fiber opening process can be implemented as needed. For example, it can be implemented by opening or unwinding short fibers using a fiber opening machine or a fiber unwinding machine.

[0285] The spinning process can be carried out using known spinning methods. Examples of spinning methods include cotton spinning, carding spinning, and spinning. The apparatus used in these spinning methods is not particularly limited; commonly used apparatus can be used. Spinning can produce single yarns or blended yarns such as two-ply yarns (e.g., blends of synthetic protein fibers with the other fibers mentioned above).

[0286] <Second Implementation Method>

[0287] The artificial fur according to the second embodiment of the second invention comprises shrink-resistant protein fibers.

[0288] Protein fibers are fibers spun from protein as the main raw material. For example, the protein can be dissolved in a soluble solvent to form a spinning solution, and the fibers can be obtained by spinning using known spinning methods such as wet spinning, dry spinning, wet-dry spinning, or melt spinning. Examples of solvents that can dissolve proteins include dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), formic acid, and hexafluoroisopropanol (HFIP). Inorganic salts can be added to these solvents as solubility promoters.

[0289] Figure 6 This is an illustrative diagram schematically showing an example of a spinning apparatus used to prepare protein fibers. Figure 6 The spinning apparatus 1000 shown is an example of a spinning apparatus for wet and dry spinning, and includes an extrusion device 101, an undrawn yarn manufacturing device 102, a wet heat drawing device 103, and a drying device 104.

[0290] The spinning method using the spinning apparatus 1000 will be described. First, the spinning solution 106 stored in the storage tank 107 is extruded from the spinneret 109 by a gear pump 108. In laboratory-grade equipment, the spinning solution can also be filled into a cylinder and extruded from a nozzle using an injection pump. Next, the extruded spinning solution 106 is supplied through an air gap 119 to the coagulation liquid 111 in the coagulation liquid tank 120 to remove the solvent, coagulate the protein, and form a fibrous solid. Next, the fibrous solid is supplied to warm water 112 in the stretching bath 121 for stretching. The stretching ratio is determined by the speed ratio of the supply clamping roller 113 and the take-up clamping roller 114. Then, the stretched fibrous solid is supplied to the drying device 104 and dried in the yarn path 122 to obtain protein fibers 136 as a spool 105. 118a to 118g are yarn guides.

[0291] (Anti-shrink treatment)

[0292] As methods for preventing shrinkage of protein fibers, examples include: contacting the protein fibers with water after spinning to induce irreversible shrinkage (water-induced shrinkage); and heating the protein fibers after spinning to relax them and induce irreversible shrinkage (dry heat shrinkage). Either the water-induced shrinkage method or the dry heat shrinkage method can be applied to protein fibers before weaving artificial fur, or to artificial fur after weaving (either before or after cutting the pile loops).

[0293] For example, it is believed that irreversible shrinkage of protein fibers occurs due to the following reasons: one reason is the secondary or tertiary structure of the protein fibers, and another reason is the relaxation of residual stress in protein fibers that have residual stress due to stretching or other processes during manufacturing.

[0294] The water-shrinkage method includes a step (shrinkage step) in which, after spinning, the protein fibers, before contact with water, are brought into contact with water to undergo irreversible shrinkage. In this shrinkage step, the protein fibers shrink without external force through contact with water. The water in contact can be water in any state, whether liquid or gas. The method of contacting the protein fibers with water is not particularly limited; examples include: immersing the protein fibers in water, spraying the protein fibers with water at room temperature or heated steam, and exposing the protein fibers to a high-humidity environment filled with water vapor. Among these methods, immersing the protein fibers in water is preferred because it effectively shortens the shrinkage time and simplifies the processing equipment. Specifically, as a method of immersing the protein fibers in water, for example, one method involves placing the protein fibers (or artificial fur) into a container holding water at a predetermined temperature and bringing them into contact with the water.

[0295] The temperature of the water in contact with the protein fibers is not particularly limited; for example, a temperature below the boiling point is preferred. At such a temperature, workability and the workability of the shrinkage process can be improved. Furthermore, the upper limit of the water temperature is preferably 90°C or lower, more preferably 80°C or lower. The lower limit of the water temperature is preferably 10°C or higher, more preferably 40°C or higher, and even more preferably 70°C or higher. The temperature of the water in contact with the protein fibers can be adjusted according to the fibers constituting the protein fibers. Furthermore, during the contact between water and the protein fibers, the water temperature can be constant, or the water temperature can be adjusted to a predetermined temperature.

[0296] There is no particular limitation on the contact time between protein fibers and water; for example, it can be more than 1 minute. This time can be more than 10 minutes, more than 20 minutes, or more than 30 minutes. Furthermore, there is no particular upper limit to this time, but from the perspective of shortening the manufacturing process time and eliminating the possibility of protein fiber hydrolysis, it can be less than 120 minutes, less than 90 minutes, or less than 60 minutes.

[0297] In the water-shrunk process, after the shrinking process, a further step can be included: drying the protein fibers after contacting them with water (drying process).

[0298] There are no particular restrictions on the drying method used in the drying process; for example, it can be natural drying or forced drying using drying equipment. As for the drying temperature, there are no limitations as long as it is lower than the temperature at which the protein suffers heat damage. Generally, a temperature in the range of 20–150°C is preferred, with a range of 40–120°C being more preferably within the range of 60–100°C. Within this temperature range, the protein will not suffer heat damage, and the protein fibers can be dried more quickly and efficiently. The drying time is appropriately selected based on the drying temperature, for example, using a time that eliminates the impact of over-drying the protein fibers on the quality and physical properties of the woven fabric.

[0299] The dry heat shrinking method includes: a process of heating the protein fibers after spinning and before they come into contact with water (heating process); and a process of relaxing the heated protein fibers to cause irreversible shrinkage (relaxation shrinking process).

[0300] In the heating process, the heating temperature is preferably above the softening temperature of the protein used for the protein fibers. The protein softening temperature, as referred to in this specification, is the temperature at which the protein fibers begin to shrink due to stress relief. During heating relaxation shrinkage above the protein softening temperature, the fibers can shrink to a degree that cannot be achieved simply by removing moisture from the fibers, thereby sufficiently suppressing the shrinkage, i.e., dimensional change, that occurs when the obtained protein fibers come into contact with water. The heating temperature is preferably 80°C or higher, more preferably 180°C to 280°C, further preferably 200°C to 240°C, and even more preferably 220°C to 240°C.

[0301] From the viewpoint of fiber elongation after heat treatment, the heating time in the heating process is preferably 60 seconds or less, more preferably 30 seconds or less, and even more preferably 5 seconds or less. It is believed that the length of this heating time has little effect on stress.

[0302] In the relaxation and shrinkage process, the relaxation ratio is preferably greater than 1, more preferably 1.4 or more, even more preferably 1.7 or more, and particularly preferably 2 or more. The relaxation ratio can be, for example, determined as the ratio of the feed rate to the winding speed of the protein fiber.

[0303] (Protein fiber and protein)

[0304] The artificial fur according to the second embodiment prevents the protein fibers from shrinking by implementing the above-described anti-shrinkage treatment, thereby suppressing dimensional changes caused by contact with water. Therefore, the protein fibers (and proteins) used in the artificial fur can also be protein fibers that would otherwise undergo (significant) dimensional changes upon contact with water.

[0305] For example, the shrinkage rate of protein fibers upon wetting can be 2% or more. The shrinkage rate upon wetting can be 4% or more, or even 6% or more, or 8% or more, or even 10% or more, or 15% or more, or even 20% or more, or 25% or more, or even 30% or more. The upper limit of the shrinkage rate upon wetting is usually below 80%. Furthermore, the shrinkage rate upon wetting is defined by the following formula I.

[0306] Shrinkage rate upon wetting = {1 - (length of protein fiber in wetted state after contact with water / length of protein fiber after spinning and before contact with water)} × 100 (%) ... (Equation I)

[0307] Furthermore, for example, the shrinkage rate of protein fibers during drying can be greater than 7%. The shrinkage rate during drying can be 15% or more, or 25% or more, or 32% or more, or 40% or more, or 48% or more, or 56% or more, or 64% or more, or 72% or more. The upper limit of the shrinkage rate during drying is usually below 80%. Additionally, the shrinkage rate during drying is defined by Formula II below.

[0308] Shrinkage during drying = {1 - (length of protein fiber in dry state / length of protein fiber after spinning and before contact with water)} × 100 (%) ... (Equation II)

[0309] There are no particular restrictions on the protein used as the raw material for protein fibers; any protein can be used. Examples of proteins include natural proteins and recombinant proteins (artificial proteins). Examples of recombinant proteins include any protein that can be produced on an industrial scale, such as proteins that can be used industrially, proteins that can be used medically, and structural proteins. Specific examples of proteins that can be used industrially or medically include enzymes, regulatory proteins, receptors, peptide hormones, cytokines, membrane or transport proteins, antigens used for immunization, vaccines, antigen-binding proteins, immunostimulatory proteins, allergens, full-length antibodies or antibody fragments or derivatives. Specific examples of structural proteins include spider silk, silkworm silk, keratin, collagen, elastin, arthropod elastin, and proteins derived from them. Furthermore, since modified silk protein is preferred as the protein used due to its excellent heat retention, moisture absorption and heat generation properties, and / or flame retardant properties, modified silk core protein is more preferred. When the protein is modified silk core protein (preferably modified spider silk core protein), the artificial fur involved in this embodiment can be further endowed with heat retention and moisture absorption and heat generation properties.

[0310] And / or flame-retardant properties, further enhancing its value as artificial fur.

[0311] The modified silk protein used in the artificial fur according to this embodiment (the second embodiment) can be the same modified silk protein used in the artificial fur according to the first embodiment described above.

[0312] (Artificial fur)

[0313] Without impairing the effects of the present invention, the artificial fur according to this embodiment may contain fibers other than protein fibers. Examples of such fibers include those identical to those contained in the artificial fur according to the first embodiment described above.

[0314] The artificial fur described in this embodiment may also contain other components besides fibers. Examples of these other components include those found in the artificial fur described in the first embodiment described above.

[0315] The artificial fur described in this embodiment may also have the same maximum moisture absorption heat generation, critical oxygen index (LOI) value, and thermal insulation performance index as the artificial fur described in the first embodiment.

[0316] (Manufacturing method of artificial fur)

[0317] The artificial fur described in this embodiment can be obtained by the following steps: a step of obtaining a pile fabric with pile protruding on one or both sides of the fabric using the aforementioned fibers (fibers including protein fibers) (pile fabric manufacturing step); a step of cutting the pile loops (shearing) to form cut pile (shearing step); a step of performing anti-shrinkage treatment (anti-shrinkage step); a step of combing the cut pile (cutting step) as needed (combing step); and / or a step of washing the fabric formed with cut pile (cutting step) (washing step). Furthermore, the fibers used in the pile fabric manufacturing step can be any fibers containing protein fibers, and their form is not particularly limited. That is, for example, it can be a twisted yarn formed by twisting long filament bundles, or it can be a spun yarn composed of short fibers.

[0318] Specifically, for example, one embodiment of the manufacturing method includes a step of performing a shrink-proofing treatment on protein fibers (shrink-proofing step). Here, the protein fibers can be subjected to shrink-proofing treatment before bundling, before twisting, and before spinning (in filament or staple fiber state), or they can be subjected to shrink-proofing treatment after bundling, after twisting, and after spinning. Furthermore, the method of this embodiment includes: a step of obtaining a pile fabric with protruding pile on one or both sides of the fabric using shrink-proof protein fibers (pile fabric manufacturing step); and a step of cutting the pile loops to form a sheared pile (shearing step). If necessary, a combing step and / or a washing step may also be included.

[0319] Furthermore, other embodiments of the manufacturing method include: a step of obtaining a pile fabric with pile protruding on one or both sides of the fabric by using fibers containing protein fibers, for example, through pile weaving and pile knitting (pile fabric manufacturing step); a step of cutting the pile loops to form cut pile (shrinkage cutting step); and a step of performing a shrink-proof treatment on the pile fabric (shrinkage prevention step). If necessary, a combing step and / or a washing step may also be included. Furthermore, the shrinkage prevention step may be performed before or after the shearing step.

[0320] The anti-shrinkage process can be applied in the manner described in the anti-shrinkage treatment.

[0321] The plush fabric manufacturing process and the shearing process can, for example, be the same as the plush fabric manufacturing process and the shearing process used in the manufacture of artificial leather according to the first embodiment described above.

[0322] Spinning can be any yarn that has been spun, or it can be a twisted yarn that has been further twisted. For example, spinning can be achieved by including the following steps: a process of spinning fiber raw materials into fibers using conventional methods (spinning process); a process of crimping the obtained fibers as needed (cracking process); a process of cutting the fibers to obtain short fibers (short fibers) (cutting process); a process of opening and / or unwinding the short fibers as needed (opening process); and a process of spinning the short fibers (spinning process).

[0323] The spinning process can be carried out using conventional methods. The spinning method can be any one of wet spinning, dry spinning, wet-dry spinning, or melt spinning.

[0324] The curling process can be implemented as needed, for example, by mechanical curling methods such as pressing.

[0325] For example, the cutting, fiber opening, and spinning processes can be the same as those used in the manufacturing of artificial leather according to the first embodiment described above. The length of the short fibers obtained through the cutting process is not particularly limited; for example, it can be 20 mm or more, 20–140 mm, 70–140 mm, or 20–70 mm.

[0326] <Third Implementation Method>

[0327] The artificial fur involved in the third embodiment of the third invention comprises fibers and further endows them with functionality.

[0328] The fibers included in the artificial leather according to this embodiment (the third embodiment) may be synthetic fibers such as nylon, polyamide, polyester, polyacrylonitrile, polyolefin, polyvinyl alcohol, polyethylene terephthalate, polytetrafluoroethylene and acrylic resin, regenerated fibers such as cupro fiber, rayon and lyocell, natural fibers such as cotton, linen, silk, wool and cashmere, artificial fibers such as protein fibers, and composite fibers thereof.

[0329] The fiber preferably contains modified silk core protein, more preferably modified spider silk core protein. By including modified silk core protein (preferably modified spider silk core protein), the artificial fur can be endowed with functional properties such as heat insulation, moisture absorption and heat generation, and / or flame retardancy. The modified silk core protein can be included in the artificial fur as a modified silk core protein fiber (protein fiber) or a composite fiber of modified silk core protein fiber and other fibers. The modified silk core protein preferably included in the fiber providing the artificial fur according to this embodiment (third embodiment) can be the same modified silk core protein used in the artificial fur according to the aforementioned first and second embodiments.

[0330] In addition to ordinary fibers, the artificial fur involved in this embodiment can also be functionalized by including a functionalized substance (e.g., the predetermined protein crosslinker and hydroxyl-modified polymer in the second and third methods described later), or by including a functionalized fiber (e.g., the fiber containing modified silk core protein in the first method described later, and the fiber containing the predetermined protein crosslinker and hydroxyl-modified polymer in the second and third methods described later).

[0331] As a method for giving artificial fur functionality, examples include a method in which the artificial fur contains modified silk core protein (method 1), a method in which the artificial fur contains a predetermined protein cross-linker (method 2), and a method in which the artificial fur contains a hydroxyl-modified polymer with functional groups bonded to a hydroxyl-containing polymer (method 3), etc.

[0332] (Method 1)

[0333] In the first method, for example, functional artificial fur can be obtained by using fibers (protein fibers or composite fibers) containing modified silk core proteins as raw materials. Fibers containing modified silk core proteins can be spun from raw materials containing modified silk core proteins using conventional methods. The presence of modified silk core proteins in the fibers can impart functional properties such as heat insulation, moisture absorption and heat generation, and / or flame retardancy, thereby imparting these functional properties to the artificial fur according to this embodiment. Modified spider silk core proteins are preferred due to their superior functionality. Regarding modified silk core proteins, as described above...

[0334] (Method 2)

[0335] The predetermined protein crosslinker in the second method comprises a plurality of the following substances: a polypeptide backbone; a first residue, which is a residue of a first reactive agent having two or more first reactive groups capable of reacting with the protein and forming bonds; a second residue, which is a residue of a second reactive agent having one second reactive group capable of reacting with the first reactive group and forming bonds; wherein at least one of the first residues is crosslinked with the polypeptide backbone, and at least one of the first residues is a residue bonded to the polypeptide backbone at one end and to the second residue at the other end.

[0336] In the second method, for example, functional artificial fur can be obtained by using fibers containing a predetermined protein crosslink as raw material. Fibers containing the predetermined protein crosslink can be obtained, for example, by spinning the raw material containing the predetermined protein crosslink using conventional methods. Fibers containing the predetermined protein crosslink can also be obtained by spinning a protein-containing raw material using conventional methods to obtain protein fibrils or composite fibrils (precursors), and then reacting the fibrils (precursors) with a first reactant and a second reactant to crosslink the proteins in the fibrils to generate the predetermined protein crosslink. In the second method, for example, functional artificial fur can also be obtained by using a mixture of ordinary fibers and the predetermined protein crosslink as raw material.

[0337] More specifically, the second method comprises: a first step in which a protein-containing precursor is reacted with a first reactant having two or more first reactive groups capable of reacting with the protein and forming bonds, to obtain an intermediate; and a second step in which the intermediate is reacted with a second reactant having one second reactive group capable of reacting with the first reactive group and forming bonds, to obtain a shaped body. The "shaped body" in this method includes, for example, a predetermined protein crosslink itself (the precursor being the protein itself), or protein fibers or protein-containing composite fibers (the precursor being protein fibrils or protein-containing composite fibrils).

[0338] The first step is to react the protein-containing precursor with a first reactant. The first reactant is a multifunctional reactant having two or more first reactive groups capable of reacting with proteins and forming bonds. In the first step, the protein can be cross-linked by the first reactant.

[0339] Proteins have at least one reactive functional group selected from the group consisting of amide, hydroxyl, phenolic hydroxyl, amino, carboxyl, thiol, selenophenol, imidazole, indole, and guanidinyl. The first reactive group of the first reactant can be a group capable of reacting with the above-mentioned reactive functional groups to form a bond.

[0340] Electrophilic groups are preferred as the first reactive group. When the first reactive group is an electrophilic group, bonds can be easily formed through addition reactions with the reactive functional groups of the protein.

[0341] The first reactive group that serves as the electrophilic group is preferably a group represented by one of the following formulas (A-1), (A-2), (A-3), (A-4), (A-5), or (A-6). Furthermore, the wavy lines in each formula represent the bonds between the groups.

[0342]

[0343] In equation (A-1), X 1 Represents an oxygen atom (O) or a sulfur atom (S). As X 1 More preferably, oxygen atoms.

[0344] In equation (A-3), X 2 This refers to the leaving group. There are no particular limitations on the leaving group, as long as it is a group capable of nucleophilic substitution reactions through the reactive functional groups of a protein. Examples of leaving groups include halogen atoms (fluorine (F), chlorine (Cl), bromine (Br), iodine (I)) and sulfonate groups (-OSO2R). 1 ), carboxylic acid ester group (-OCOR) 2 ), Quaternary ammonium group (-NR)3 3) etc. R 1 For example, it can be a fluorine atom, alkyl, aryl, haloalkyl, or haloaryl. 2 For example, it can be alkyl, aryl, haloalkyl, or haloaryl. R 3 For example, it can be alkyl, aryl, haloalkyl, or haloaryl. R 1 R 2 and R 3 It may have substituents. Examples of such substituents include alkyl, alkenyl, aryl, and halogen atoms.

[0345] As X 2 More preferably, it is a chlorine atom, a bromine atom, an iodine atom, an ester group, or a sulfonate group; even more preferably, it is a bromine atom, an iodine atom, or a sulfonate group. As R 1 More preferably, it is a fluorine atom, an alkyl group (especially methyl, ethyl, benzyl, allyl), a perfluoroalkyl group (especially trifluoromethyl, pentafluoroethyl), an aryl group (especially phenyl, tolyl, naphthyl, fluorophenyl), etc. As R 2 More preferably, it is an alkyl group (especially methyl, ethyl, benzyl, allyl), a perfluoroalkyl group (especially trifluoromethyl, pentafluoroethyl), an aryl group (especially phenyl, tolyl, naphthyl, fluorophenyl), etc. As R 3 More preferably, it is alkyl (especially methyl, ethyl, benzyl, allyl), aryl (especially phenyl, tolyl, naphthyl, fluorophenyl), etc.

[0346] In equation (A-4), X 3 Oxygen (O) and sulfur (S) atoms are represented by -NR. 4 - indicates a group, or is represented by -C(R) 5 )2- represents the group. R 4 For example, it can be a hydrogen atom, alkyl, aryl, haloalkyl or haloaryl, arylsulfonyl, alkylsulfonyl, acyl, or carbamate group. 5 This indicates an electron-withdrawing group. Examples of electron-withdrawing groups include carbonyl, cyano, aryl, alkenyl, and alkynyl. (Two R's) 5 They can be the same as each other, or they can be different from each other. R 4 and R 5 It may have substituents. Examples of such substituents include alkyl, alkenyl, aryl, and halogen atoms.

[0347] As X3, oxygen atom is preferred. As R 4 More preferably, it is an arylsulfonyl group, an alkylsulfonyl group, an acyl group, a carbamate group, etc.

[0348] In equation (A-5), X 4 Y represents an oxygen atom (O) or a sulfur atom (S).1 Halogen atoms and hydroxyl groups are represented by -R. 6 The group to be represented is indicated by -OR 6 The group indicated, or represented by -OCOR 6 The group represented. R6 can be, for example, alkyl, aryl, haloalkyl, or haloaryl. 6 It may have substituents. Examples of such substituents include alkyl, alkenyl, aryl, and halogen atoms.

[0349] As X4, oxygen atom is preferred. As Y 1 More preferably, a halogen atom, using -OR 6 The group indicated, or represented by -OCOR 6 The group to be represented, etc. As R 6 More preferably, alkyl, aryl, etc.

[0350] In equation (A-6), X 5 Y represents an oxygen atom (O) or a sulfur atom (S). 2 Representing oxygen atoms (O), sulfur atoms (S), or using NR 7 The group indicated by R. 7 For example, it can be alkylsulfonyl, arylsulfonyl, acyl, carbamate, alkyl, aryl, haloalkyl, or haloaryl. R7 can have substituents. Examples of such substituents include alkyl, alkenyl, aryl, and halogen atoms.

[0351] As X 5 More preferably, an oxygen atom. As Y2, an oxygen atom is more preferred. As R 7 More preferably, it is alkylsulfonyl, arylsulfonyl, acyl, carbamate, etc.

[0352] The first reactant can be any compound having two or more first reactive groups. The number of first reactive groups in the first reactant is not particularly limited; for example, it can be 2 to 10,000, preferably 2 to 1,000.

[0353] The first step can be carried out, for example, by contacting a first reaction liquid containing a first reactant with a preform and heating it.

[0354] The first reaction solution can be solvent-free or may contain a solvent. The solvent for the first reaction solution is not particularly limited; for example, any solvent capable of dissolving the first reactant and not inhibiting the reaction between the reactive functional groups of the protein and the first reactive group is acceptable. When the first reactive group is an electrophilic group, preferred solvents for the first reaction solution include, for example, N,N-dimethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone, benzene, toluene, xylene, mesitylene, tetrahydrofuran, dimethyl sulfoxide, ethyl acetate, butyl acetate, and propylene glycol monomethyl ether acetate.

[0355] The reaction conditions in the first step are not particularly limited, as long as the conditions for the reaction between the reactive functional groups of the protein and the first reactive group are met.

[0356] In the first step, preferably, at least a portion of the first reactant cross-links the protein, and at least a portion of the first reactive group remains in the intermediate. That is, in the first step, preferably, an intermediate comprising a protein cross-linked by the first reactant and having the first reactive group is obtained.

[0357] For example, when the first reactant is a compound having two first reactive groups, a portion of the first reactant can cause the protein to cross-link (i.e., both first reactive groups react with the protein). Alternatively, another portion of the first reactive groups may react with the protein only through one of the first reactive groups, in which case the other first reactive group may not react and remain in the intermediate.

[0358] Furthermore, for example, when the first reactant is a compound having more than three first reactive groups, a portion of the first reactant can crosslink the protein through all the first reactive groups (i.e., all the first reactive groups react with the protein), while in another portion of the first reactant, some first reactive groups react with the protein, and other first reactive groups may not react and remain in the intermediate.

[0359] The reaction in the first step can also be described as a reaction in which, starting with the reactive functional groups of a protein, a cross-linked structure or side chains with the first reactive group is formed through a first reactant. The number of cross-linked structures and side chains can be adjusted by the amount of the first reactant used in the reaction. Reducing the amount of the first reactant tends to result in fewer side chains and more cross-linked structures, while increasing the amount of the first reactant tends to result in fewer cross-linked structures and more side chains.

[0360] Furthermore, the adjustment of the cross-linking structure and the number of side chains can be achieved, for example, in a pre-process before performing the first step, by reacting a portion of the first reactive groups of the first reactant with the second reactive groups of the second reactant. The number of first reactive groups remaining in the pre-process that do not react with the second reactive groups can be controlled by appropriately adjusting the amount of the second reactant relative to the first reactant used in such a pre-process. Therefore, in the first step, the amount of binding of the first reactive groups to the protein can be easily adjusted, and as a result, the cross-linking structure and the number of side chains of the protein can be easily controlled.

[0361] That is, the second method may further include: a preceding step, which, before the first step, causes a portion of the first reactant to react with a portion of the second reactant, and causes a portion of the first reactive group of the first reactant to react with a portion of the second reactive group of the second reactant.

[0362] By forming more cross-linked structures, the molded article tends to improve its water resistance (e.g., the ability to suppress shrinkage caused by contact with water, and the ability to suppress shrinkage during drying after contact with water), mechanical strength, and heat resistance. Furthermore, by forming more side chains, the molded article tends to improve its functionality (e.g., the texture described later). In the second method, the ratio of cross-linked structures to side chains can be appropriately adjusted according to the desired properties.

[0363] In the first step, an intermediate containing a reactant produced by the reaction of a protein with a first reactant is obtained. In this reactant, the protein is cross-linked by the first reactant, and unreacted first reactive groups may remain. That is, the reactant may contain a polypeptide backbone derived from the protein, a cross-linking portion that cross-links the polypeptide backbone, and a side chain portion that is bonded to the polypeptide backbone and has a first reactive group at its end.

[0364] The second step is a process in which the intermediate obtained in the first step reacts with a second reactant. The second reactant has a second reactive group capable of reacting with the first reactive group to form a bond. The second step can also be described as a process in which the first reactive group remaining in the intermediate reacts with the second reactant.

[0365] The second reactive group of the second reactant is not particularly limited and can be appropriately changed according to the type of the first reactive group. For example, if the first reactive group is an electrophilic group, the second reactive group is preferably a nucleophilic group.

[0366] As a secondary reactive group of a nucleophilic group, examples include hydroxyl, thiol, amino, and groups represented by formula (B-1).

[0367]

[0368] In equation (B-1), X 6 It represents an oxygen atom (O) or a sulfur atom (S).

[0369] As the group represented in formula (B-1), for example, the group represented in formula (B-1-1) can be listed below.

[0370]

[0371] In equation (B-1-1), Y 3 This indicates a monovalent group. Y 3 For example, it can be alkyl, alkenyl, alkynyl, aryl, alkoxy, alkyl thioether, aryl thioether, monosubstituted amino, disubstituted amino, etc., preferably alkyl, aryl, alkoxy, or monosubstituted amino. 3 It may have substituents. Examples of such substituents include alkyl, alkenyl, aryl, and halogen atoms.

[0372] The second reactant can be any compound having a second reactive group, and may also have a functional group that is inert to the reaction of the second step (the reaction between the first reactive group and the second reactive group). Based on such a second reactant, functional groups can be easily introduced into the molded article starting from the unreacted first reactive group in the intermediate.

[0373] There are no particular limitations on the functional groups. They can be groups that directly impart functionality to the molded body, or groups that impart reactivity between the molded body and other reactants.

[0374] As functional groups, examples include hydrocarbon groups such as alkyl, alkenyl, and alkynyl; groups with ring structures such as aryl and heterocyclic groups; reactive groups protected by protecting groups (hydroxyl, amino, thiol, etc.); carbonyl groups (-C(=O)-), groups with structures such as ether bonds (-O-), amide bonds (>NC(=O)-), urethane bonds (>NC(=O)O-), urea bonds (>N(C=O)N<), carbonate bonds (-OC(=O)O-); alkoxysilyl groups, sulfonyl groups (-S(=O)-), carboxyl groups (-C(=O)OH), sulfonic acid groups (-S(=O)2OH), and quaternary ammonium groups, etc.

[0375] For example, when the functional group is alkyl, the texture of the molded body is improved. Therefore, for example, in the case of a fibrous molded body, by using a second reactant having an alkyl group as a functional group, a material with excellent texture and good feel can be obtained.

[0376] When traditional protein materials are cross-linked to improve water resistance and strength, the material's feel deteriorates, and it is sometimes difficult to use them for applications involving contact with human skin. However, according to the second method, while maintaining the water resistance and mechanical strength induced by cross-linking, excellent texture and feel can be obtained through functional groups, and materials suitable for applications involving contact with human skin can also be obtained.

[0377] The second step can be carried out, for example, by contacting the second reaction liquid containing the second reactant with the intermediate and heating it.

[0378] The second reaction solution can be solvent-free or may contain a solvent. The solvent for the second reaction solution is not particularly limited; for example, any solvent capable of dissolving the second reactant and not inhibiting the reaction between the first and second reactive groups is acceptable. When the first reactive group is an electrophilic group and the second reactive group is a nucleophilic group, the solvent for the second reaction solution may preferably be, for example, N,N-dimethylacetamide, N,N-dimethylformamide, N-methylpyrrolidone, benzene, toluene, xylene, mesitylene, tetrahydrofuran, dimethyl sulfoxide, ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, etc.

[0379] In the second step, the amount of the second reactant is not particularly limited. For example, the amount of the second reactant can be greater than the amount of the first reactive group in the intermediate.

[0380] In the second step, some or all of the first reactive groups in the intermediate are consumed after reacting with the second reactive groups. Preferably, the first reactive groups do not remain in the molded body as much as possible. Therefore, in the second method, it is preferable that all of the first reactive groups are consumed after reacting with the second reactive groups or other side reactions.

[0381] The second process yields a molded body containing protein cross-links.

[0382] In the description of the second method, the first residue represents the remaining structure after removing the first reactive group from the first reactant. Furthermore, the second residue represents the remaining structure after removing the second reactive group from the second reactant.

[0383] The polypeptide backbone and the first residue are bonded by a bond formed by the reaction of the protein's reactive functional group with a first reactive group (e.g., a urea bond when the reactive functional group is an amino group and the first reactive group is an isocyanate group). Furthermore, the first residue and the second residue are bonded by a bond formed by the reaction of the first reactive group with a second reactive group (e.g., a carbamate bond when the first reactive group is an isocyanate group and the second reactive group is a hydroxyl group).

[0384] In the second method, the protein is cross-linked using a first reactant to obtain a molded body with excellent water resistance, mechanical strength, and heat resistance. Furthermore, in the second method, functional groups can be acquired by using a second reactant, starting from the first reactive group remaining in the intermediate, thus easily obtaining molded bodies with various functionalities.

[0385] (Method 3)

[0386] The hydroxyl-modified polymer in method 3 is a polymer with functional groups bonded to a hydroxyl-containing polymer. Hydroxyl-modified polymers can be obtained, for example, by reacting a hydroxyl-containing polymer with a reactant having functional groups.

[0387] Hydroxyl-containing polymers are any high molecular weight compounds containing hydroxyl groups, and their use is not particularly restricted. Specific examples of hydroxyl-containing polymers include, for instance, polysaccharides such as starch, glycogen, cellulose, chitin, agarose, hyaluronic acid, chondroitin sulfate, pectin and carrageenan, as well as synthetic polymers such as polyvinyl alcohol (PVA) and phenolic resins.

[0388] From the viewpoint of biodegradability, polysaccharides are preferred as hydroxyl-containing polymers. Furthermore, from the viewpoint of high solubility, in addition to biodegradability, starch is preferred as a hydroxyl-containing polymer.

[0389] The so-called functional group refers to a functional group that has properties (such as hydrophobicity and hydrophilicity) corresponding to the desired function (such as water resistance, hydrophilicity, oleophilicity, and oil resistance), and can be appropriately selected according to the desired function.

[0390] For example, when it is desired to improve water resistance, as functional groups, hydrophobic functional groups such as alkyl groups such as methyl, ethyl, n-propyl, isopropyl, aromatic groups such as phenyl and naphthyl, and acyl groups such as acetyl, propionyl, benzoyl, etc. can be used.

[0391] The reactant with functional groups is a compound that has functional groups and, more particularly, bonding functional groups capable of bonding with hydroxyl-containing polymers. The bonding functional groups only need to be able to bond with the hydroxyl-containing polymer via hydrogen bonds or covalent bonds, preferably functional groups capable of bonding with the hydroxyl-containing polymer via covalent bonds, and more preferably functional groups capable of bonding with the hydroxyl groups in the hydroxyl-containing polymer via covalent bonds.

[0392] Examples of reactants with functional groups include isocyanates (R-N=C=O: R is a functional group), acid anhydrides (R-C(=O)-O-C(=O)-R: R is a functional group), epoxides, aziridines, and alkyl halides. Since these reactants can covalently bond with the hydroxyl groups in hydroxyl-containing polymers, isocyanates and acetic anhydrides with functional groups are preferred. Furthermore, since any functional group can be introduced, isocyanates with functional groups are more preferred.

[0393] In the third method, for example, functional artificial fur can be obtained by using fibers containing hydroxyl-modified polymers as raw materials. Fibers containing hydroxyl-modified polymers can be produced, for example, by spinning a raw material mixed with hydroxyl-modified polymers using conventional methods. In the third method, for example, functional artificial fur can be obtained by using a mixture of ordinary fibers and hydroxyl-modified polymers as raw materials.

[0394] There are no particular restrictions on the content of hydroxyl-modified polymers in the raw materials, and it can be set appropriately according to the desired functionality. For example, based on the total amount of artificial fur, the content of hydroxyl-modified polymers can be 0.001–70% by mass, 0.01–65% by mass, or 0.1–60% by mass.

[0395] Hydroxyl-modified polymers are preferably hydrogen-bonded with fibers. This further enhances functionality. For example, hydrogen bonds can be formed between functional groups in the hydroxyl-modified polymer (e.g., hydroxyl groups, functional groups, or functional groups in bonded functional groups) and functional groups in the fiber (e.g., in the case of protein fibers, amino groups, carboxyl groups, etc.).

[0396] In the third method, the artificial fur may further comprise a hydroxyl-containing polymer. This hydroxyl-containing polymer is preferably the same type of polymer as the hydroxyl-containing polymer used as a raw material for the hydroxyl-modified polymer. When a hydroxyl-containing polymer is included, the content of the hydroxyl-containing polymer may be 50% by mass or more, 60% by mass or more, 70% by mass or more, or 80% by mass or more, relative to 100% by mass of the total amount of the hydroxyl-modified polymer and the hydroxyl-containing polymer. Furthermore, as an upper limit, it may be 90% by mass or less.

[0397] The artificial fur obtained by the second or third method described above may or may not contain modified silk core protein.

[0398] The artificial fur described in this embodiment may also contain other components besides fibers. Other components, in addition to the predetermined protein crosslinkers and hydroxyl-modified polymers mentioned above, include, for example, colorants, smoothing agents, antioxidants, UV absorbers, dyes, fillers, crosslinking agents, matting agents, leveling agents, etc.

[0399] In the artificial fur of this embodiment, when using fibers containing modified silk core protein, it may also have the same maximum moisture absorption heat generation, critical oxygen index (LOI) value, and thermal insulation performance index as the artificial fur of the first embodiment.

[0400] (Manufacturing method of artificial fur)

[0401] The artificial fur described in this embodiment can be manufactured, for example, using the aforementioned fibers (fibers containing artificial protein fibers) and by the same method described in the first embodiment.

[0402] <Example 4>

[0403] The artificial fur according to the fourth embodiment of the fourth invention contains fibers and a substance that imparts water resistance.

[0404] The fibers included in the artificial leather according to this embodiment (4th embodiment) may be synthetic fibers such as nylon, polyamide, polyester, polyacrylonitrile, polyolefin, polyvinyl alcohol, polyethylene terephthalate, polytetrafluoroethylene and acrylic resin, regenerated fibers such as cupro fiber, rayon and lyocell, natural fibers such as cotton, linen, silk, wool and cashmere, artificial fibers such as protein fibers, and composite fibers thereof.

[0405] The fiber preferably contains modified silk protein, more preferably modified spider silk protein. By including modified silk protein (preferably modified spider silk protein), the artificial fur can be endowed with functional properties such as heat insulation, moisture absorption and heat generation, and / or flame retardancy. The modified silk protein can be included in the artificial fur as a modified silk protein fiber (protein fiber) or a composite fiber of modified silk protein fiber and other fibers. The modified silk protein preferably included in the fiber providing the artificial fur according to this embodiment (fourth embodiment) can be the same modified silk protein used in the artificial fur according to the aforementioned embodiments 1 to 3.

[0406] For example, proteins can be dissolved in a soluble solvent to form a spinning solution, and then spun using known spinning methods such as wet spinning, dry spinning, wet-dry spinning, or melt spinning to obtain protein fibers. Examples of soluble protein solvents include dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), formic acid, and hexafluoroisopropanol (HFIP). Inorganic salts can be added to these solvents as solubilizing agents.

[0407] Protein fibers containing modified fibroin can also contain other proteins besides modified fibroin. There are no particular restrictions on the other proteins; any protein can be used.

[0408] (Substances that impart water resistance)

[0409] Water-repellent substances are materials that improve the water resistance of artificial fur. By including water-repellent substances in artificial fur, effects such as improving its water resistance and inhibiting shrinkage upon contact with water can be achieved, thereby further enhancing its water resistance. Artificial fur may contain one water-repellent substance alone or two or more.

[0410] Specific examples of materials imparting water resistance include fluoropolymers, organosilicon polymers, and hydroxyl-modified polymers with hydrophobic functional groups bonded to hydroxyl-containing polymers. In cases where artificial fur contains proteins, other specific examples of materials imparting water resistance include protein binders such as multifunctional reactants (first reactants) having two or more first reactive groups capable of reacting with proteins and forming bonds, and reactants having one or more first reactive groups capable of reacting with proteins and forming bonds, as well as functional groups.

[0411] As a fluoropolymer, any polymer containing fluorine is acceptable, without particular limitation. For example, a fluoropolymer can be a polymer obtained by polymerizing a fluorinated olefin. Examples of fluoropolymers include polytetrafluoroethylene (PTFE), polytrifluoroethylene (PTFE), polychlorotrifluoroethylene (CH3), polyvinylidene fluoride (PVDF), polyperfluoroalkyl vinyl ether (PVDE), polyperfluoropropylene (PTFE-PTFE copolymer), tetrafluoroethylene-ethylene copolymer, and polyvinylidene fluoride-ethylene copolymer. A fluoropolymer can also be a copolymer (including random copolymers, block copolymers, or alternating copolymers) obtained by polymerizing two or more monomers constituting the illustrated polymer.

[0412] As a silicone polymer, any polymer with a polysiloxane structure in its main chain is acceptable; there are no particular limitations. For example, a silicone polymer can be a homopolymer or copolymer (including random copolymers, block copolymers, or alternating copolymers) obtained by polymerizing one or more monomers with siloxane structural units. Alternatively, a silicone polymer can be a copolymer (including random copolymers, block copolymers, or alternating copolymers) obtained by polymerizing one or more monomers with siloxane structural units with one or more monomers without siloxane structural units.

[0413] Hydroxyl-modified polymers are polymers to which hydrophobic functional groups are bonded. Hydroxyl-modified polymers can be obtained, for example, by reacting a hydroxyl-containing polymer with a reactant having hydrophobic functional groups.

[0414] Hydroxyl-containing polymers are any high molecular weight compounds containing hydroxyl groups, and their use is not particularly restricted. Specific examples of hydroxyl-containing polymers include, for instance, polysaccharides such as starch, glycogen, cellulose, chitin, agarose, hyaluronic acid, chondroitin sulfate, pectin, and carrageenan, as well as synthetic polymers such as polyvinyl alcohol (PVA) and phenolic resins. From the viewpoint of biodegradability, polysaccharides are preferred as hydroxyl-containing polymers. Furthermore, in addition to biodegradability, starch is preferred as a hydroxyl-containing polymer from the viewpoint of high solubility.

[0415] A reactant with a hydrophobic functional group is a compound that has a hydrophobic functional group and, more importantly, a bonding functional group capable of bonding with a hydroxyl-containing polymer. The bonding functional group only needs to be able to bond with the hydroxyl-containing polymer via hydrogen bonds or covalent bonds, preferably a functional group capable of bonding with the hydroxyl-containing polymer via covalent bonds, and more preferably a functional group capable of bonding with the hydroxyl group in the hydroxyl-containing polymer via covalent bonds. Examples of hydrophobic functional groups include, for example, alkyl groups such as methyl, ethyl, n-propyl, and isopropyl, aromatic groups such as phenyl and naphthyl, and acyl groups such as acetyl, propionyl, and benzoyl. Examples of reactants with hydrophobic functional groups include, for example, isocyanates (R-N=C=O: R is a hydrophobic functional group), acid anhydrides (R-C(=O)-O-C(=O)-R: R is a hydrophobic functional group), epoxides, aziridines, and alkyl halides.

[0416] Based on the total amount of artificial fur, the content of the above-mentioned hydrophobic polymer in the artificial fur involved in this embodiment can be 0.001 to 70% by mass, 0.01 to 65% by mass, 0.1 to 60% by mass, 1 to 50% by mass, 1 to 40% by mass, 1 to 30% by mass, 1 to 20% by mass, 1 to 10% by mass, or 1 to 5% by mass.

[0417] As protein binders, examples include multifunctional reactants (first reactants) having two or more first reactive groups capable of reacting with proteins and forming bonds, and reactants (functional reactants) having one or more first reactive groups capable of reacting with proteins and forming bonds.

[0418] The first reactant has a first reactive group capable of reacting with a reactive functional group and forming a bond, the reactive functional group being selected from at least one of the group consisting of amide, hydroxyl, phenolic hydroxyl, amino, carboxyl, thiol, selenophenol, imidazole, indole, and guanidine groups contained in the protein.

[0419] As the first reactive group, for example, groups represented by the following formulas (A-1), (A-2), (A-3), (A-4), (A-5), or (A-6) can be listed. The wavy lines in each formula represent the bonding bonds of the groups.

[0420]

[0421] In equation (A-1), X 1 This represents an oxygen atom (O) or a sulfur atom (S). In formula (A-3), X 2 This represents the leaving group. In formula (A-4), X 3Oxygen (O) and sulfur (S) atoms are represented by -NR. 4 - indicates a group, or is represented by -C(R) 5 )2- represents the group. R 4 For example, it can be a hydrogen atom, alkyl, aryl, haloalkyl or haloaryl, arylsulfonyl, alkylsulfonyl, acyl, or carbamate group. 5 This indicates an electron-withdrawing group. In formula (A-5), X 4 Y represents an oxygen atom (O) or a sulfur atom (S). 1 Halogen atoms and hydroxyl groups are represented by -R. 6 The group to be represented is indicated by -OR 6 The group indicated, or represented by -OCOR 6 The group indicated by R. 6 For example, it can be alkyl, aryl, haloalkyl, or haloaryl. In formula (A-6), X 5 Y represents an oxygen atom (O) or a sulfur atom (S). 2 Representing oxygen atoms (O), sulfur atoms (S), or using NR 7 The group indicated by R. 7 For example, it can be alkylsulfonyl, arylsulfonyl, acyl, carbamate, alkyl, aryl, haloalkyl or haloaryl.

[0422] Functional reactants can be produced by reacting a first reactant with a second reactive group (one) that can react with the first reactive group to form a bond, and with a reactant having a functional group (the second reactant).

[0423] Examples of secondary reactive groups include hydroxyl, thiol, amino, and groups represented by formula (B-1).

[0424]

[0425] In equation (B-1), X 6 It represents an oxygen atom (O) or a sulfur atom (S).

[0426] As functional groups, examples include hydrocarbon groups such as alkyl, alkenyl, and alkynyl; groups with ring structures such as aryl and heterocyclic groups; reactive groups protected by protecting groups (hydroxyl, amino, thiol, etc.); carbonyl groups (-C(=O)-), groups with structures such as ether bonds (-O-), amide bonds (>NC(=O)-), urethane bonds (>NC(=O)O-), urea bonds (>N(C=O)N<), carbonate bonds (-OC(=O)O-); alkoxysilyl groups, sulfonyl groups (-S(=O)-), carboxyl groups (-C(=O)OH), sulfonic acid groups (-S(=O)2OH), and quaternary ammonium groups, etc.

[0427] Specific examples of the first reactant include, for example, hexamethylene diisocyanate (HDI). Specific examples of the second reactant include, for example, butanol (BuOH).

[0428] From the perspective of improving the waterproof performance of artificial fur and inhibiting shrinkage upon contact with water, the preferred materials for imparting water resistance are fluoropolymers and organosilicon polymers.

[0429] As a method for incorporating a water-resistant substance into artificial fur, examples include: a method of manufacturing artificial fur using fibers containing the water-resistant substance (e.g., fibers mixed with or bonded with the water-resistant substance) according to conventional methods (the method according to the first embodiment); a method of mixing artificial fur made from fibers without the water-resistant substance with the water-resistant substance (the method according to the second embodiment); and a method of combining artificial fur made from fibers without the water-resistant substance with the water-resistant substance (the method according to the third embodiment). In the method according to the second embodiment, the artificial fur and the water-resistant substance are not necessarily combined.

[0430] The method according to the third embodiment includes a step of combining a water-resistant material with artificial fur (a bonding step). The bonding step can be performed, for example, by contacting the water-resistant material with the artificial fur through methods such as coating or impregnation, followed by heating or plasma irradiation as needed, and then bonding the artificial fur with the water-resistant material. When the water-resistant material is a hydrophobic polymer, such as a silicone polymer or a fluoropolymer, the bonding step can be, for example, by irradiating the artificial fur with plasma while the water-resistant material or its precursor (monomer) is in contact with it, thus covalently bonding the artificial fur with the water-resistant material. When using a precursor (monomer) of the water-resistant material, plasma irradiation polymerizes the precursor (monomer) to form the water-resistant material (a hydrophobic polymer such as a silicone polymer or a fluoropolymer), thus obtaining artificial fur containing the water-resistant material. Furthermore, the method according to the third embodiment can be used not only for artificial fur but also for fleece fabrics before the shearing process.

[0431] The irradiated plasma can be appropriately set according to the type of artificial fur (the fibers used) and the material imparting water resistance (or its precursor). The flow rate of the discharge gas can, for example, be in the range of 0.1 L / min or higher and 10 L / min or lower. The plasma density of the generated plasma can, for example, be 1 × 10⁻⁶. 13 cm －3Above and 1×10 15 cm －3 Within the following range. The discharge gas can be, for example, rare gases such as helium, neon, and argon, oxygen, nitrogen, etc. Atmosphere can also be used as the discharge gas.

[0432] Plasma irradiation can be carried out using known plasma irradiation devices. For example, a plasma treatment device manufactured by Europlasma can be used as a plasma irradiation device.

[0433] (Artificial fur)

[0434] The artificial fur described in this embodiment may further contain other components besides fibers and substances that impart water resistance. Examples of such other components include, for instance, colorants, smoothing agents, antioxidants, UV absorbers, dyes, fillers, crosslinking agents, matting agents, leveling agents, etc.

[0435] In the artificial fur of this embodiment, when using fibers containing modified silk core protein, it may also have the same maximum moisture absorption heat generation, critical oxygen index (LOI) value, and thermal insulation performance index as the artificial fur of the first embodiment.

[0436] (Manufacturing method of artificial fur)

[0437] The artificial fur described in this embodiment can be manufactured, for example, using the aforementioned fibers (fibers containing artificial protein fibers) and by the same method described in the first embodiment.

[0438] (Uses of artificial fur)

[0439] The artificial fur described in this embodiment (Embodiments 1 to 4) can be applied to any of the uses of known artificial fur (artificial fur made of synthetic fibers, etc.) (e.g., accessories for clothing and backpacks, carpets, plush toys, etc.).

[0440] Example

[0441] The present invention will now be described in more detail based on experimental examples, etc. However, the present invention is not limited to the following experimental examples.

[0442] [Experimental Example 1: Modification of the Manufacturing of Silk Core Protein]

[0443] Modified spider silk filamentin with the amino acid sequence shown in SEQ ID NO. 18 (PRT399), modified spider silk filamentin with the amino acid sequence shown in SEQ ID NO. 12 (PRT380), modified spider silk filamentin with the amino acid sequence shown in SEQ ID NO. 13 (PRT410), modified filamentin with the amino acid sequence shown in SEQ ID NO. 37 (PRT918), modified filamentin with the amino acid sequence shown in SEQ ID NO. 40 (PRT966), and modified filamentin with the amino acid sequence shown in SEQ ID NO. 15 (PRT799) were designed. Nucleic acids encoding the designed modified filamentin were synthesized. These nucleic acids had an NdeI site appended to the 5' end and an EcoRI site appended downstream of the stop codon. The nucleic acid was cloned into the cloning vector (pUC118). Then, the nucleic acid was treated with restriction enzymes using NdeI and EcoRI, excised, and recombined into the protein expression vector pET-22b(+) to obtain the expression vector.

[0444] The obtained expression vector was used to transform *E. coli* BLR(DE3). The transformed *E. coli* were cultured in 2 mL of LB medium containing ampicillin for 15 hours. This culture was then added to 100 mL of seed culture medium containing ampicillin (Table 4) to adjust the OD... 600 The OD value reached 0.005. The culture medium temperature was maintained at 30°C, and flask incubation was continued until the OD value reached 0.005. 600 Seed culture medium is obtained when the concentration reaches 5 (approximately 15 hours).

[0445] [Table 4] Culture media for seed culture

[0446]

[0447] The seed culture solution was added to a fermenter containing 500 mL of production medium (Table 5) to allow OD to rise. 600 The concentration was reduced to 0.05. The culture medium temperature was maintained at 37°C, and the pH was kept constant at 6.9. Furthermore, the dissolved oxygen concentration in the culture medium was maintained at 20% of the dissolved oxygen saturation point.

[0448] [Table 5] Production Culture Media

[0449]

[0450] After the glucose in the production medium was completely consumed, feed solution (455 g / L glucose, 120 g / L yeast extract) was immediately added at a rate of 1 mL / min. The culture temperature was maintained at 37°C, and the pH was kept constant at 6.9. Furthermore, the dissolved oxygen concentration in the culture medium was maintained at 20% of the dissolved oxygen saturation point, and the culture was incubated for 20 hours. Then, 1 M isopropyl-β-thiogalactopyranoside (IPTG) was added to the culture medium to achieve a final concentration of 1 mM, and the induced modified filamentin was expressed. Twenty hours after the addition of IPTG, the culture medium was centrifuged, and the cells were recovered. SDS-PAGE was performed using cells prepared from the cultures before and after IPTG addition. The expression of the target modified filamentin was confirmed by the appearance of bands indicating the size of the target modified filamentin, which depended on the IPTG addition.

[0451] Two hours after IPTG addition, the recovered bacterial cells were washed with 20 mM Tris-HCl buffer (pH 7.4). The washed cells were then resuspended in 20 mM Tris-HCl buffer (pH 7.4) containing approximately 1 mM PMSF and homogenized using an autoclave (GEA Niro Soavi). The homogenized cells were centrifuged to obtain a precipitate. The precipitate was washed with 20 mM Tris-HCl buffer (pH 7.4) until high purity was achieved. The washed precipitate was then resuspended at a concentration of 100 mg / mL in 8 M guanidine buffer (8 M guanidine hydrochloride, 10 mM sodium dihydrogen phosphate, 20 mM NaCl, 1 mM Tris-HCl, pH 7.0) and stirred at 60°C for 30 minutes to dissolve. After dissolution, the cells were dialyzed with water using dialysis tubing (Sanko Pure Chemical Industries, Ltd. cellulose tubing 36 / 32). The white aggregated proteins obtained after dialysis were recovered by centrifugation, and the moisture was removed by freeze drying. The modified silk core proteins (PRT399, PRT380, PRT410, PRT918, PRT966 and PRT799) were obtained by recovering the freeze-dried powder.

[0452] PRT918 and PRT966 are hydrophobic modified filamentin with an average HI greater than 0. PRT410, PRT399, and PRT799 are hydrophilic modified filamentin with an average HI less than 0.

[0453] [Experimental Example 2: Manufacturing and Shrinkage Evaluation of Modified Silk Core Protein Fiber (1)]

[0454] Prepare a solution of dimethyl sulfoxide (DMSO) containing LiCl as a solvent to achieve a concentration of 4.0% by mass. Add lyophilized powder of modified fibroin (PRT399, PRT380, PRT410, or PRT799) to achieve a concentration of 18% by mass or 24% by mass, and dissolve using a shaker for 3 hours. Then, remove insoluble matter and air bubbles to obtain the modified fibroin solution.

[0455] The obtained modified silk core protein solution was used as the spinning solution (spinning dope), and was applied according to... Figure 6 The spinning apparatus 1000 shown is used for dry and wet spinning to produce spun and stretched modified spider silk core protein fibers. Figure 6 In the spinning apparatus 1000 shown, the spinning apparatus used also includes a second undrawn yarn manufacturing apparatus (second bath) between the undrawn yarn manufacturing apparatus 102 (first bath) and the wet-heat drawing apparatus 103 (third bath). The conditions for dry-wet spinning are as follows.

[0456] Extrusion nozzle diameter: 0.2mm

[0457] Coagulation bath temperature: 2~15℃

[0458] Total stretch ratio: 1 to 4 times

[0459] Drying temperature: 60℃

[0460] (Shrinkage assessment)

[0461] The shrinkage rate of the obtained modified silk core protein fibers (manufacturing examples 1-19) was evaluated. That is, for each modified silk core protein fiber (fiber after spinning and before contact with water), a shrinkage process was performed in which the fiber was brought into a wet state after contact with water (contact step) and then dried (drying step). The shrinkage rate of the modified silk core protein fiber in the wet state and the shrinkage rate of the modified silk core protein fiber after being brought into a wet state and then dried were calculated.

[0462] <Contact Steps>

[0463] Multiple experimental modified fibroin fibers, each 30 cm in length, were cut from the windings of each modified fibroin fiber. These fibers were bundled together to obtain a bundle of modified fibroin fibers with a fineness of 150 denier. A 0.8 g weight was attached to each bundle, and the bundle was immersed in water at the temperatures shown in Tables 6-9 for 10 minutes. The length of each bundle was then measured in water. To eliminate wrinkling, the measurement was performed with a 0.8 g weight attached to the bundle. Next, the shrinkage rate (shrinkage rate when wet) of the modified fibroin fibers in the wetted state was calculated using Formula V. In Formula V, L0 represents the length of the modified fibroin fiber bundle before immersion in water (30 cm), and Lw represents the length of the modified fibroin fiber bundle immersed in water and in a wetted state.

[0464] Shrinkage rate upon wetting (%) = {1 - (Lw / L0)} × 100... (Equation V)

[0465] <Drying Steps>

[0466] After the contact step, the modified fibroin fiber bundles were removed from the water. The removed bundles were then dried at room temperature for 2 hours with a 0.8g lead weight attached. After drying, the length of each bundle was measured. Next, after rehydration, the shrinkage rate (shrinkage during drying) of the dried modified fibroin fibers was calculated using Formula VI. In Formula VI, L0 represents the length of the modified fibroin fiber bundle before immersion in water (30cm), and Lwd represents the length of the modified fibroin fiber bundle after immersion in water and rehydration, followed by drying.

[0467] Shrinkage rate during drying (%) = (1 - (Lwd / L0)) × 100 (%) ... (Equation VI)

[0468] The results are shown in Tables 6-9. Additionally, in Tables 6-9, "total draw ratio" refers to the total draw ratio during the spinning process.

[0469] [Table 6]

[0470]

[0471] [Table 7]

[0472]

[0473] [Table 8]

[0474]

[0475] [Table 9]

[0476]

[0477] The modified silk core protein fiber exhibits high shrinkage rates both when wetted and when dried. However, the shrinkage rate of the modified silk core protein fiber, after undergoing the aforementioned shrinkage assessment (shrinkage process), is significantly reduced upon re-contact with water. It is believed that the shrinkage process mitigates residual stress caused by stretching during spinning.

[0478] [Experimental Example 3: Manufacturing and Shrinkage Evaluation of Modified Silk Core Protein Fiber (2)]

[0479] Modified fibroin (PRT799) was added to formic acid to achieve a concentration of 24% by mass, and the mixture was stirred at room temperature for 1 hour to dissolve. Then, insoluble matter and air bubbles were removed to obtain the modified fibroin solution.

[0480] The obtained modified silk core protein solution was used as the spinning solution (spinning dope), and by using according to Figure 6 The spinning apparatus 1000 shown is used for dry-wet spinning to obtain modified silk core protein fibers. The conditions for dry-wet spinning are as follows.

[0481] Temperature of the coagulated liquid (methanol): 5–10℃

[0482] Stretch ratio: 6x

[0483] Drying temperature: 80℃

[0484] The obtained modified silk core protein fibers were subjected to a heat relaxation and shrinkage treatment. The modified silk core protein fibers were brought into contact with a drying hot plate heated to a predetermined temperature while being passed over the drying hot plate. The feed speed was increased relative to the winding speed, and the modified silk core protein fibers were relaxed. The relaxed portion was shrunk by heating, resulting in a dry relaxation treatment. The relaxation ratio was calculated by dividing the feed speed by the winding speed. In this experiment, the relaxation ratio was adjusted so that the amount of relaxation in the modified silk core protein fibers caused by overfeeding reached the limit shrinkage ratio (maximum shrinkage rate) offset by the relaxation. The relaxation ratio was adjusted by adjusting at least one of the feed-side rollers and the winding-side rollers.

[0485] The water shrinkage assessment was performed in the following order. The heat-treated fiber (test piece) was cut into 300mm pieces and immersed in water at 40°C without load for 10 minutes. The length of the test piece (length when wetted) was then immediately measured, while it was dried at room temperature for 2 hours. The length of the test piece (length of the dried fiber) was then measured, and the water shrinkage rate was also measured. The water shrinkage rate was calculated using the following formula (1).

[0486] Shrinkage rate upon contact with water = (1 - fiber length after drying / fiber length before impregnation) × 100・・・(1)

[0487] (Experimental Example 3-1)

[0488] The relationship between heating temperature and relaxation ratio was confirmed. In this test example 3-1, the length before immersion was set to 300 mm in all tests 3-1-1 to 3-1-7, and tests were conducted by changing other conditions. Specifically, tests were conducted by changing the heating temperature, relaxation ratio, and dwell time. The measurement results of temperature conditions, relaxation conditions, and shrinkage rate are shown in Table 10. As shown in Table 10, the higher the heating temperature or the higher the relaxation ratio, the lower the shrinkage rate upon contact with water. As shown in the results of tests 3-1-3 to 3-1-5, a shrinkage rate of less than 4% upon contact with water was obtained by heating at 220°C or higher. In addition, fiber coloring was found in Example 5, where the heating temperature was 280°C. From the results of this test, it can be seen that the optimal heating temperature is 240°C.

[0489] [Table 10]

[0490]

[0491] (Experimental Example 3-2)

[0492] Next, the relationship between the relaxation ratio and the shrinkage rate upon contact with water was confirmed. In this test example 3-2, the length before immersion was set to 300 mm, the heating temperature to 240°C, and the dwell time to 1 minute (60 seconds) in all test examples 3-2-1 to 3-2-6, and the tests were conducted by changing other conditions. Specifically, the relaxation ratio (feed-out speed) was changed during the tests. The measurement results of the relaxation conditions and shrinkage rate are shown in Table 11. As shown in Table 11, the shrinkage rate upon contact with water decreases as the relaxation ratio increases. As shown in the results of test examples 3-2-3 to 3-2-5, a shrinkage rate upon contact with water of less than 16% was obtained by setting the relaxation ratio to 1.4 to 2.0 times.

[0493] [Table 11]

[0494]

[0495] (Experimental Example 3-3)

[0496] The relationship between various heating temperatures, heating times, relaxation ratios, and water shrinkage rates was confirmed. In this test example 3-3, the length before immersion was set to 300 mm in all tests 3-3-1 to 3-3-10, and tests were conducted by changing other conditions. Specifically, the heating temperature, heating time (dwell time), and relaxation ratio (feed speed / winding speed) were changed. The measurement results of temperature conditions, relaxation conditions, and shrinkage rates are shown in Table 12. In test example 3-3-10, the test piece was simply immersed in water and dried without relaxation or heating. As shown in the results of tests 3-3-4 to 3-3-9, a water shrinkage rate of less than 15% was obtained by setting the heating temperature above 200°C. A lower water shrinkage rate of less than 4% can be obtained by setting the heating temperature above 220°C. The dwell time required for shrinkage is 5 seconds, and even with an extended dwell time, the shrinkage rate hardly changes.

[0497] [Table 12]

[0498]

[0499] [Experimental Example 4] Shrinkage prevention treatment and evaluation of braided fabrics using modified silk core protein fibers.

[0500] [Manufacturing, Shrink-proofing and Evaluation of Knitted Fabrics] (Experimental Example 4-1)

[0501] Except that the total draw ratio in the spinning process was set to 4.55, the modified silk core protein fiber obtained in the same manner as in Experimental Example 2 was used to knit the fabric using circular knitting on a seamless knitting machine. Here, the count of the modified silk core protein fiber was 58.1 Nm, and the needle pitch of the seamless knitting machine was 18.

[0502] Mark squares with sides of 1 cm in each direction (warp, row, etc.) of the knitted fabric obtained above. Then, immerse the knitted fabric in water at 20°C for 10 minutes. Perform shrinkage prevention treatment by drying the knitted fabric after immersion in water.

[0503] <Measurement of Dimensional Change Rate>

[0504] The dimensional change rate (%) of the knitted fabric after shrink-proofing treatment in each direction (warp, column, etc.) is calculated according to the following formula. In the formula, L0f represents the side length recorded on the knitted fabric before contact with water, and Lwf represents the side length of the square recorded on the knitted fabric after shrink-proofing treatment. The results are shown in Table 13.

[0505] Formula: Dimensional change rate = {(Lwf / L0f)-1}×100(%)

[0506] <Measurement of the rate of increase in the number of loops>

[0507] For the knitted fabrics obtained above and the knitted fabrics after shrink-proofing treatment, the number of loops per 1 cm in each direction, including the warp and transverse directions, was counted, and the increase rate of the number of loops was calculated according to the following formula. In the formula, N0 represents the number of loops in the knitted fabric before contact with water, and Nw represents the number of loops in the knitted fabric after shrink-proofing treatment. The results are shown in Table 13.

[0508] Formula: Increase rate of number of loops = {(Nw / N0)-1}×100(%)

[0509] Measurement of Knitting Density Increase Rate

[0510] For the knitted fabrics obtained above and the knitted fabrics after shrink-proofing treatment, count every 1cm. 2 The number of loops was determined, and the increase rate of knitting density was calculated using the following formula. In the formula, M0 represents the knitting density of the fabric before contact with water, and Mw represents the knitting density of the fabric after anti-shrinkage treatment. The results are shown in Table 13.

[0511] Formula: Knitting density increase rate = {(Mw / M0)-1}×100%

[0512] Measurement of the rate of increase in fracture strength

[0513] For the knitted fabrics obtained above and the knitted fabrics after shrink-proofing treatment, the bursting strength was measured according to JIS L 1096 B method, and the increase rate of bursting strength was calculated according to the following formula. In the formula, R0 represents the bursting strength of the knitted fabric before contact with water, and Rw represents the bursting strength of the knitted fabric after shrink-proofing treatment. The results are shown in Table 13.

[0514] Formula: Increase rate of fracture strength = {(Rw / R0)-1}×100(%)

[0515] (Experimental Example 4-2)

[0516] Natural silk fibroin fiber (natural silk) was used instead of modified fibroin fiber to knit a fabric using a seamless knitting machine for transverse knitting. Here, the natural silk fibroin fiber was made by bundling two 29 Nm yarns together. Furthermore, the needle pitch of the seamless knitting machine was 18. The resulting fabric was subjected to shrink-proofing treatment in the same manner as in Experiment 4-1. The dimensional change rate, the increase in loop count, and the increase in knit density were calculated for both the resulting fabric and the fabric after shrink-proofing treatment. The results are shown in Table 13.

[0517] (Experimental Example 4-3)

[0518] Except for using polyethylene terephthalate (PET) fibers instead of modified silk core fibers, the knitted fabrics were obtained in the same manner as in Example 4-1. The obtained knitted fabrics were subjected to shrink-proofing treatment under the same conditions as in Example 4-1. The dimensional change rate, loop count increase rate, knit density increase rate, and bursting strength were calculated for both the obtained knitted fabrics and the knitted fabrics after shrink-proofing treatment. The results are shown in Table 13.

[0519] (Experimental Example 4-4)

[0520] Except for replacing the modified silk core protein fiber with polyethylene terephthalate (PET) fiber and changing the knitting method from circular knitting to plain knitting, the knitted fabric was obtained in the same manner as in Experimental Example 4-1. The obtained knitted fabric was subjected to shrink-proofing treatment under the same conditions as in Experimental Example 4-1. The dimensional change rate, loop count increase rate, knit density increase rate, and bursting strength were calculated for both the obtained knitted fabric and the knitted fabric after shrink-proofing treatment. The results are shown in Table 13.

[0521] [Table 13]

[0522]

[0523] [Manufacturing, Shrink-proofing, and Evaluation of Woven Fabrics]

[0524] Using twisted yarns composed of modified silk core fibers, plain weave was performed on a rapier loom (manufactured by Evergreen Automatic Sampling Loom: CCI) to weave four woven fabrics with different weave densities as shown in Table 14 (Examples 4-5 to 4-8). Here, the fineness of the twisted yarns composed of modified silk core fibers was 190d, and the twist count was 450T / m.

[0525] The four types of woven fabrics obtained above were immersed in water at 40°C for 10 minutes and then dried to perform shrinkage prevention treatment. The densities of the woven fabrics from Test Examples 4-5 to 4-8 were then investigated. The results are shown in Table 14 below. In the table, the weave density is expressed as the warp density multiplied by the weft density. For example, weave density [26×26] refers to a warp density of 26 (threads / in) and a weft density of 26 (threads / in).

[0526] Except for using twisted yarn made of polyamide fibers instead of twisted yarn made of modified silk core protein fibers, the other four types of woven fabrics with different densities shown in Table 14 (Examples 4-9 to 4-12) were woven in the same manner as the above-mentioned test examples. Here, the fineness of the twisted yarn made of polyamide fibers was 150d and the twist count was 150T / m.

[0527] For the woven fabrics of Test Examples 4-9 to 4-12, shrinkage prevention treatment was performed in the same manner as in the aforementioned test examples. Then, the density of the woven fabrics of Test Examples 4-9 to 4-12 was investigated. The results are shown in Table 14 below.

[0528] [Table 14]

[0529]

[0530] [Experimental Example 5: Manufacturing and Evaluation of Functionalized Protein Fibers]

[0531] (Experimental Example 5-1)

[0532] <Preparation of spinning solution (spinning solution)>

[0533] 200 mg of starch (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 11400 mg of solvent (dimethyl sulfoxide (DMSO) containing 4% by weight of LiCl), and then 400 mg of phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added. The mixture was stirred at 90°C for 4 hours to allow the reaction to occur. As a result, the hydroxyl groups of the starch react with the isocyanate groups of the phenyl isocyanate to obtain modified starch (hydroxyl-modified polymer) with phenyl groups (functional functional groups) bonded by urethane bonds. The modification rate (the proportion of hydroxyl groups converted to functional functional groups) of the modified starch, determined by the addition ratio, was 100%.

[0534] After cooling the reaction solution to room temperature, 300 mg of the modified silk protein (PRT799) powder obtained above was added to the reaction solution, and the mixture was stirred at 90°C for 12 hours to dissolve it, resulting in a transparent spinning solution. Based on the total content of modified starch and starch, the modified starch content in the spinning solution was 17% by mass.

[0535] <Manufacturing of Protein Fibers>

[0536] The prepared spinning solution was filtered at 60°C using a metal filter with a mesh size of 5 μm. It was then placed in a 30 mL stainless steel syringe and allowed to stand to remove bubbles. Nitrogen gas was then sprayed from a solid nozzle with a needle diameter of 0.2 mm into a 100% (w / w) methanol coagulation bath. The spraying temperature was 60°C, and the spraying pressure was 0.3 MPa. After coagulation, the obtained precursor fiber was wound at a speed of 3.00 m / min and allowed to air dry to obtain protein fibers (modified silk core protein fibers).

[0537] <Shrinkage test upon contact with water>

[0538] The obtained protein fibers were cut into lengths of approximately 10 cm, and the yarn length (cm) before immersion in water was measured. Next, the yarn was immersed in a water bath at 40°C for 1 minute. Then, the yarn was removed from the water bath and vacuum-dried at room temperature for 15 minutes, after which the length of the dried yarn was measured. The water shrinkage rate of the protein fibers was calculated using the following formula.

[0539] Shrinkage rate upon contact with water (%) = {(Length before impregnation / Length after impregnation and drying) - 1} × 100

[0540] (Experimental Example 5-2)

[0541] <Preparation of spinning solution (spinning solution)>

[0542] 253 mg of starch (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 7600 mg of solvent (dimethyl sulfoxide (DMSO) containing 4% by weight of LiCl), and then 147 mg of acetic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.) was added. The mixture was stirred at 90°C for 4 hours to allow the reaction to occur. As a result, the hydroxyl groups of the starch react with the acetic anhydride to obtain modified starch (a hydroxyl-modified polymer) bonded with acetyl groups (functional functional groups). The modification rate (the proportion of hydroxyl groups converted to functional functional groups) of the modified starch, determined by the addition ratio, was 100%.

[0543] After cooling the reaction solution to room temperature, 2000 mg of the modified silk protein (PRT799) powder obtained above was added to the reaction solution, and the mixture was stirred at 90°C for 12 hours to dissolve it, resulting in a transparent spinning solution. Based on the total content of modified starch and starch, the modified starch content in the spinning solution was 17% by mass.

[0544] <Manufacturing and Water Shrinkage Test of Protein Fibers>

[0545] Using the prepared spinning solution, protein fibers were manufactured and tested for shrinkage upon contact with water in the same order as in Example 5-1.

[0546] (Experimental Example 5-3)

[0547] <Preparation of spinning solution (spinning solution)>

[0548] 215 mg of starch (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 7600 mg of solvent (dimethyl sulfoxide (DMSO) containing 4% by weight of LiCl), and then 185 mg of acetic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.) was added. The mixture was stirred at 90°C for 4 hours to allow the reaction to occur. As a result, the hydroxyl groups of the starch react with the acetic anhydride to obtain modified starch (a hydroxyl-modified polymer) bonded with acetyl groups (functional functional groups). The modification rate (the proportion of hydroxyl groups converted to functional functional groups) of the modified starch, determined by the addition ratio, was 50%.

[0549] After cooling the reaction solution to room temperature, 2000 mg of the modified silk protein (PRT799) powder obtained above was added to the reaction solution, and the mixture was stirred at 90°C for 12 hours to dissolve it, resulting in a transparent spinning solution. Based on the total content of modified starch and starch, the modified starch content in the spinning solution was 17% by mass.

[0550] <Manufacturing and Water Shrinkage Test of Protein Fibers>

[0551] Using the prepared spinning solution, protein fibers were manufactured and tested for shrinkage upon contact with water in the same order as in Example 5-1.

[0552] (Experimental Example 5-4)

[0553] <Preparation of spinning solution (spinning solution)>

[0554] 128 mg of polyvinyl alcohol (PVA) (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 7600 mg of a solvent (dimethyl sulfoxide (DMSO) containing 4% by weight of LiCl), and then 272 mg of phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added. The mixture was stirred at 90°C for 4 hours to allow the reaction to occur. As a result, the hydroxyl groups of PVA react with the phenyl isocyanate to obtain modified PVA (hydroxyl-modified polymer) with phenyl groups (functional functional groups) bonded by urethane bonds. The modification rate (the proportion of hydroxyl groups converted to functional functional groups) of the modified PVA, determined by the addition ratio, was 100%.

[0555] After cooling the reaction solution to room temperature, 2000 mg of the modified silk core protein (PRT799) powder obtained above was added to the reaction solution, and the mixture was stirred at 90°C for 12 hours to dissolve it, resulting in a transparent spinning solution. Based on the modified PVA and the total PVA content, the modified PVA content in the spinning solution was 17% by mass.

[0556] <Manufacturing and Water Shrinkage Test of Protein Fibers>

[0557] Using the prepared spinning solution, protein fibers were manufactured and tested for shrinkage upon contact with water in the same order as in Example 5-1.

[0558] (Experimental Example 5-5)

[0559] <Preparation of spinning solution (spinning solution)>

[0560] 193 mg of polyvinyl alcohol (PVA) (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 7600 mg of a solvent (dimethyl sulfoxide (DMSO) containing 4% by weight of LiCl), and then 207 mg of phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added. The mixture was stirred at 90°C for 4 hours to allow the reaction to occur. As a result, the hydroxyl groups of PVA react with the phenyl isocyanate to obtain modified PVA (hydroxyl-modified polymer) with phenyl groups (functional functional groups) bonded by urethane bonds. The modification rate (the proportion of hydroxyl groups converted to functional functional groups) of the modified PVA, determined by the addition ratio, was 50%.

[0561] After cooling the reaction solution to room temperature, 2000 mg of the modified silk core protein (PRT799) powder obtained above was added to the reaction solution, and the mixture was stirred at 90°C for 12 hours to dissolve it, resulting in a transparent spinning solution. Based on the modified PVA and the total PVA content, the modified PVA content in the spinning solution was 17% by mass.

[0562] <Manufacturing and Water Shrinkage Test of Protein Fibers>

[0563] Using the prepared spinning solution, protein fibers were manufactured and tested for shrinkage upon contact with water in the same order as in Example 5-1.

[0564] (Experimental Examples 5-6)

[0565] <Preparation of spinning solution (spinning solution)>

[0566] The 1200 mg of modified silk core protein (PRT799) powder obtained above was added to a solvent (dimethyl sulfoxide (DMSO) containing 4% by weight of LiCl) and stirred at 90°C for 12 hours to dissolve it, resulting in a transparent spinning solution.

[0567] <Manufacturing and Water Shrinkage Test of Protein Fibers>

[0568] Using the prepared spinning solution, protein fibers were manufactured and tested for shrinkage upon contact with water in the same order as in Example 5-1.

[0569] (Experimental Examples 5-7)

[0570] <Preparation of spinning solution (spinning solution)>

[0571] The 3000 mg of modified silk core protein (PRT799) powder and 600 mg of starch (manufactured by Wako Pure Chemical Industries, Ltd.) obtained above were added to a solvent (dimethyl sulfoxide (DMSO) containing 4% by weight of LiCl), and stirred at 90°C for 12 hours to dissolve it, resulting in a transparent spinning solution.

[0572] <Manufacturing and Water Shrinkage Test of Protein Fibers>

[0573] Using the prepared spinning solution, protein fibers were manufactured and tested for shrinkage upon contact with water in the same order as in Example 5-1.

[0574] The results are as follows Figure 7 As shown in Table 15. Furthermore, in Table 15, Test Example 3-1 represents Test Example 5-1 above, Test Example 3-2 represents Test Example 5-2 above, Test Example 3-3 represents Test Example 5-3 above, Test Example 3-4 represents Test Example 5-4 above, Test Example 3-5 represents Test Example 5-5 above, Test Example 3-6 represents Test Example 5-6 above, and Test Example 3-7 represents Test Example 5-7 above.

[0575] [Table 15]

[0576]

[0577] (Content of hydroxyl-modified polymers / Total content of hydroxyl-modified polymers and hydroxyl-containing polymers) × 100

[0578] When protein fibers are manufactured using spinning solutions containing hydroxyl-modified polymers (modified starch or modified PVA) and proteins (modified fibroin) bonded with hydrophobic functional groups (phenyl or acetyl groups) as functional functional groups (Experiments 5-1 to 5-5 (Experiments 3-1 to 3-5 in Table 15)), compared to using spinning solutions containing only proteins (Experiments 5-6 (Experiments 3-6 in Table 15)) and using spinning solutions containing both proteins and unmodified hydroxyl-containing polymers (Experiment 5-7 (Experiments 3-7 in Table 15)), protein fibers with lower water shrinkage and water resistance can be obtained. Functional (water-resistant) fabrics can be obtained by weaving or knitting these protein fibers.

[0579] [Experimental Example 6: Manufacturing and Evaluation of Functionally Constructed Protein Fibers]

[0580] (Manufacturing Example 1)

[0581] Spider silk filamentin (PRT799) was added to dimethyl sulfoxide (DMSO) to achieve a concentration of 24% by mass, followed by the addition of LiCl as a dissolution promoter to achieve a concentration of 4.0% by mass. The spider silk filamentin was then dissolved using a shaker for 3 hours to obtain a DMSO solution. Foreign matter and air bubbles were removed from the obtained DMSO solution, which was then used as the spinning solution. The viscosity of the spinning solution at 90°C was 5000 cP (centipoise).

[0582] Using the spinning solution obtained as described above and a known wet-dry spinning apparatus, wet-dry spinning is performed to obtain monofilaments composed of spider silk fibroin. Furthermore, wet-dry spinning is performed under the following conditions.

[0583] Temperature of the coagulated liquid (methanol): 5–10℃

[0584] Stretch ratio: 6x

[0585] Drying temperature: 80℃

[0586] Using the modified spider silk filament protein fiber obtained as described above, a yarn was spun using a known method, and a 5cm square knitted fabric (knitted body) was woven using the yarn made of the modified spider silk filament protein fiber and a known knitting machine by transverse knitting. Furthermore, the yarn made of the modified spider silk filament protein fiber has a count of 58.1 Nm, and the knitting machine has a needle pitch of 18.

[0587] (Experimental Example 6-1)

[0588] The knitted fabric (5 cm square) obtained in Manufacturing Example 1 was immersed in 20 mL of hexamethylene diisocyanate (HDI). Next, the HDI-impregnated knitted fabric was sandwiched between aluminum foils and heated at 130°C for 30 minutes. After heating, the knitted fabric was removed, immersed in 20 mL of butanol (BuOH), and reacted at 100°C for 240 minutes. The reacted test sample was washed with THF to obtain a knitted fabric endowed with functionality (bonded with water-resistant substances (first and second reactants)).

[0589] (Experimental Example 6-2)

[0590] The woven fabric obtained in Manufacturing Example 1 was evaluated as the woven fabric in Test Example 6-2.

[0591] (Experimental Example 6-3)

[0592] The braid obtained in Manufacturing Example 1 was impregnated in 20 mL of hexamethylene diisocyanate (HDI, the first reactant). Next, the HDI-impregnated braid was sandwiched between aluminum foils and heated at 130°C for 30 minutes. Then, the braid was washed with THF to obtain the braid of Test Example 6-3, which only bonded to the first reactant.

[0593] For the woven fabrics of Test Examples 6-1 to 6-3, the water resistance (shrinkage properties) and texture were evaluated using the following test methods.

[0594] <Water Resistance (Shrinkage Performance) Assessment>

[0595] A 3cm square was drawn on the knitted fabric with a pencil as an evaluation sample. The evaluation sample was washed using the "Home Wash" mode of a Panasonic washing machine (Na-VG1100L). Next, it was spun in the same washing machine for 15 minutes and then allowed to air dry for 120 minutes. The longitudinal and transverse lengths of the square were measured before and after washing, and the longitudinal and transverse shrinkage rates were calculated. The same experiment was performed three times, and the average of the three results was used as the evaluation result. The results are shown in Table 16. In Table 16, Example 4-1 represents Example 6-1 above, Example 4-2 represents Example 6-2 above, and Example 4-3 represents Example 6-3 above.

[0596] <Texture Assessment>

[0597] The skin feel of the knitted fabric was evaluated using a three-tiered system. Based on the skin feel of the knitted fabric in Example 6-2 (B), fabrics with a superior skin feel were rated A, while those with a rough and poor skin feel were rated C. The results are shown in Table 16.

[0598] [Table 16]

[0599]

[0600] [Experimental Example 7: Manufacturing and Evaluation of Woven Fabrics Using Modified Silk Core Protein Fibers]

[0601] (1) Preparation of spinning solution (spinning solution)

[0602] DMSO containing dissolved lithium chloride was used as a solvent to achieve a concentration of 4% by mass, and the lyophilized powder of the modified silk core protein (PRT799) prepared above was added to the solvent to achieve a concentration of 24% by mass. After dissolving in an aluminum block heater at 90°C for 1 hour, insoluble matter and air bubbles were removed to prepare the spinning solution (spinning solution).

[0603] (2) Spinning: Fill the spinning solution into the storage tank and use a gear pump to spray it from a single-hole nozzle with a diameter of 0.1 or 0.2 mm into a 100% (w / w) methanol coagulation bath. Adjust the spray rate to 0.01–0.08 mL / min. After coagulation, wash and stretch the product in a 100% (w / w) methanol washing bath. After washing and stretching, dry the product using a hot dry plate and wind the resulting precursor fiber (modified silk core protein fiber).

[0604] (3) Manufacturing of woven fabrics

[0605] The modified silk core protein fibers obtained are used to produce various twisted yarns. The produced twisted yarns are then plain-woven to obtain woven fabric.

[0606] (4) Imparting water-resistant materials to woven fabrics

[0607] Fluorinated coating monomers were coated onto the obtained woven fabric, and plasma treatment was performed using a plasma treatment apparatus (manufactured by Europlasma). Through plasma treatment, a woven fabric covalently bonded with a fluoropolymer (a substance imparting water resistance) polymerized from the fluorinated coating monomers was obtained. Nanofics 110 (Example 7-2) and Nanofics 120 (Example 7-3) (both manufactured by Europlasma) were used as the fluorinated coating monomers.

[0608] (5) Waterproof performance evaluation

[0609] Water resistance performance tests (spray tests) were conducted on the woven fabrics of Test Examples 7-2 and 7-3 that underwent plasma treatment, and on the woven fabric of Test Example 7-1 that did not undergo plasma treatment. The water resistance performance tests (spray tests) were conducted in accordance with ISO 4920:2012. The evaluation was performed visually according to the following six levels (scores 0 to 5).

[0610] Score 5: The surface is not wetted and no water droplets are attached.

[0611] Score 4: The surface is not wetted, but water droplets are attached.

[0612] Score 3: The surface is slightly damp.

[0613] Score 2: Wetting and spreading, partially connected

[0614] Score 1: The part in contact with water is completely wetted.

[0615] Score 0: Shows the entire surface is wetted.

[0616] The results are shown in Table 17. The woven fabric of Test Example 7-1, which was not treated with plasma, scored 0. In contrast, the woven fabrics of Test Examples 7-2 and 7-3, which were treated with plasma, both scored 4, thus imparting water resistance (waterproofing). Furthermore, as described below, in Tables 17, 18, and 19, Test Example 2-1 represents Test Example 7-1, Test Example 2-2 represents Test Example 7-2, and Test Example 2-3 represents Test Example 7-3.

[0617] [Table 17]

[0618]

[0619] (6) Tactile assessment and shrinkage assessment

[0620] Square test pieces with sides of 5 cm were cut from the woven fabrics of Test Examples 7-1 to 7-3. On one surface of each test piece, the vertices (4 points) of a square with sides of 30 mm were marked with a pencil. Each test piece was immersed in water at 40°C for 10 minutes, followed by five repeated vacuum drying cycles at room temperature. Vacuum drying was performed using a vacuum constant temperature dryer (VOS-310C, manufactured by Tokyo Rikka Equipment Co., Ltd.) at a set pressure of -0.1 MPa for 30 minutes. Furthermore, at the end of each cycle, a sensory evaluation of the tactile feel was performed, and the distance between the four marked points was measured to assess the shrinkage rate.

[0621] The tactile sensation was determined according to the following criteria. The results are shown in Table 18. Compared with the woven fabric of Test Example 7-1, which was not treated with plasma, the woven fabrics of Test Example 7-2 and Test Example 7-3, after plasma treatment, showed suppressed deterioration of tactile sensation.

[0622] Rating 5: Just as good as the original fabric.

[0623] Rating 4: Good, but slightly worse than the original fabric.

[0624] Rating 3: Not bad, but a bit stiff.

[0625] Rating 2: Poor and stiff, but bendable.

[0626] Rating 1: Very poor, hard and inflexible.

[0627] [Table 18]

[0628]

[0629] The shrinkage rate is calculated using the following formula. Additionally, the "average length of each side" is the value obtained by dividing the sum of the lengths of the sides of the quadrilateral formed by the four marked points by 4.

[0630] Shrinkage rate (%) = (1 - (average length of each side (mm) / 30mm)) × 100

[0631] The results are shown in Table 19. Compared with the woven fabric of Test Example 7-1 without plasma treatment, the woven fabrics of Test Examples 2-2 and 7-3 after plasma treatment had a smaller shrinkage rate.

[0632] [Table 19]

[0633]

[0634] [Experimental Example 8: Manufacturing and Evaluation of Knitted Fabrics Using Modified Silk Core Protein Fibers]

[0635] (1) Preparation of spinning solution (spinning solution)

[0636] DMSO containing dissolved lithium chloride was used as a solvent to achieve a concentration of 4% by mass, and the lyophilized powder of the modified silk core protein (PRT918) prepared above was added to the solvent to achieve a concentration of 24% by mass. After dissolving in an aluminum block heater at 90°C for 1 hour, insoluble matter and air bubbles were removed to prepare the spinning solution (spinning solution).

[0637] (2) Spinning

[0638] The spinning solution is filled into a storage tank and sprayed into a 100% (w / w) methanol coagulation bath using a gear pump through a single-hole nozzle with a diameter of 0.1 or 0.2 mm. The spray rate is adjusted to 0.01–0.08 mL / min. After coagulation, the product is washed and stretched in a 100% (w / w) methanol washing bath. After washing and stretching, the product is dried using a hot dry plate and then wound into the resulting precursor fiber (modified silk core protein fiber).

[0639] (3) Evaluation of the manufacturing of knitted fabrics

[0640] The obtained modified silk protein fibers are cut to produce modified silk protein short fibers. After the produced modified silk protein short fibers are opened and spun using a known spinning device, yarn is obtained. The obtained yarn is then knitted using a WHOLEGARMENT flat knitting machine (MACH2XS, manufactured by Shima Seiki) to obtain knitted fabric.

[0641] (4) Imparting water-resistant materials to knitted fabrics

[0642] A fluorinated coating monomer was coated onto the obtained knitted fabric, and plasma treatment was performed using a plasma treatment apparatus (manufactured by Europlasma). Through plasma treatment, a knitted fabric covalently bonded with a fluorinated polymer (a substance imparting water resistance) polymerized from the fluorinated coating monomer was obtained (Example 3-2). Nanofics 120 (manufactured by Europlasma) was used as the fluorinated coating monomer.

[0643] (5) Waterproof performance evaluation

[0644] Using the same method as in Test Example 7, a water resistance test (spray test) was conducted on the knitted fabric of Test Example 8-2, which underwent plasma treatment, and the knitted fabric of Test Example 8-1, which did not undergo plasma treatment. The results are shown in Table 20. The knitted fabric of Test Example 8-1, which did not undergo plasma treatment, scored 0, while the knitted fabric of Test Example 8-2, which underwent plasma treatment, scored 5, thus exhibiting water resistance (waterproof performance). Furthermore, as described below, in Tables 20, 21, and 22, Test Example 3-1 refers to Test Example 8-1, and Test Example 3-2 refers to Test Example 8-2.

[0645] [Table 20]

[0646]

[0647] (6) Tactile assessment and shrinkage assessment

[0648] Square test pieces with sides of 5 cm were cut from the knitted fabrics of Test Examples 8-1 and 8-2. On one surface of each test piece, the vertices (4 points) of a square with sides of 30 mm were marked with a pencil. As a pretreatment, each test piece was immersed in water at 40°C for 10 minutes, followed by five repetitions of the vacuum drying process at room temperature. Vacuum drying was performed using a vacuum constant temperature dryer (VOS-310C, manufactured by Tokyo Rikka Equipment Co., Ltd.) at a set pressure of -0.1 MPa for 30 minutes.

[0649] Next, the pretreated test pieces were subjected to five cycles of washing, drying, immersion, and drying. In the washing cycle, a Panasonic washing machine (NA-VG1100L) and Lion detergent (Top Clear Liquid) were used to wash the test pieces for 5 minutes, followed by two rinses and a 1-minute spin-drying process. In the drying cycle, a vacuum constant-temperature dryer (VOS-310C, Tokyo Rikka K.K.) was used to dry the test pieces at room temperature for 30 minutes at a set pressure of -0.1 MPa. In the immersion cycle, the test pieces were immersed in water at 40°C for 10 minutes. At the end of each cycle, sensory evaluation of the tactile feel was performed using the same standards as in Test Example 7, and the distance between four marked points was measured to assess the shrinkage rate.

[0650] The sensory evaluation results of the tactile sensation are shown in Table 21. Additionally, "at the beginning" refers to the evaluation results after pretreatment and before the start of the cycle. Compared to the knitted fabric of Test Example 8-1 (Test Example 2-1 in Table 21), which did not undergo plasma treatment, the knitted fabric of Test Example 8-1 (Test Example 2-1 in Table 21) showed suppressed deterioration of tactile sensation after plasma treatment.

[0651] [Table 21]

[0652]

[0653] The results of the shrinkage assessment are shown in Table 22. The knitted fabric of Test Example 8-2 (Test Example 2-2 in Table 22) after plasma treatment had a smaller shrinkage rate compared with the knitted fabric of Test Example 8-1 (Test Example 2-1 in Table 22) without plasma treatment.

[0654] [Table 22]

[0655]

[0656] [Experimental Example 9: Manufacturing and Evaluation of Modified Silk Core Protein Fibers]

[0657] <Experimental Example 9-1>

[0658] (1) Preparation of spinning solution (spinning solution)

[0659] 200 mg of starch (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 11400 mg of solvent (dimethyl sulfoxide (DMSO) containing 4% by weight of LiCl), and then 400 mg of phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added. The mixture was stirred at 90°C for 4 hours to allow the reaction to occur. As a result, the hydroxyl groups of the starch react with the isocyanate groups of the phenyl isocyanate to obtain modified starch (hydroxyl-modified polymer) with phenyl groups (functional functional groups) bonded by urethane bonds. The modification rate (the proportion of hydroxyl groups converted to functional functional groups) of the modified starch, determined by the addition ratio, was 100%.

[0660] After cooling the reaction solution to room temperature, 300 mg of lyophilized modified fibroin (PRT799) powder was added to the reaction solution, and the mixture was stirred at 90°C for 12 hours to dissolve it, resulting in a transparent spinning solution. Based on the total content of modified starch and starch, the modified starch content in the spinning solution was 17% by mass.

[0661] (2) Manufacturing of fibers containing modified silk core protein and substances that impart water resistance

[0662] The prepared spinning solution was filtered at 60°C using a metal filter with a mesh size of 5 μm. It was then placed in a 30 mL stainless steel syringe and allowed to stand to remove bubbles. Nitrogen gas was then sprayed from a solid nozzle with a needle diameter of 0.2 mm into a 100% (w / w) methanol coagulation bath. The spraying temperature was 60°C, and the spraying pressure was 0.3 MPa. After coagulation, the obtained precursor fiber was wound at a speed of 3.00 m / min and allowed to air dry, yielding fibers containing modified core proteins and a water-resistant substance (modified starch).

[0663] (3) Shrinkage performance assessment

[0664] The obtained fibers were cut into lengths of approximately 10 cm, and the yarn length (cm) before immersion in water was measured. Next, the yarn was immersed in a water bath at 40°C for 1 minute. Then, the yarn was removed from the water bath and vacuum-dried at room temperature for 15 minutes, after which the length of the dried yarn was measured. The shrinkage rate of the fiber was calculated using the following formula. The results are shown in Table 23.

[0665] Shrinkage rate (%) = {(Length before impregnation / Length after impregnation and drying) - 1} × 100

[0666] In addition, in Table 23, Test Example 5-1 represents Test Example 9-1, and Test Example 5-2 represents Test Example 9-2 described later, Test Example 5-3 represents Test Example 9-3 described later, Test Example 5-4 represents Test Example 9-4 described later, Test Example 5-5 represents Test Example 9-5 described later, Test Example 5-6 represents Test Example 9-6 described later, and Test Example 5-7 represents Test Example 9-7 described later.

[0667] <Experimental Example 9-2>

[0668] (1) Preparation of spinning solution (spinning solution)

[0669] 253 mg of starch (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 7600 mg of solvent (dimethyl sulfoxide (DMSO) containing 4% by weight of LiCl), and then 147 mg of acetic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.) was added. The mixture was stirred at 90°C for 4 hours to allow the reaction to occur. As a result, the hydroxyl groups of the starch react with the acetic anhydride to obtain modified starch (a hydroxyl-modified polymer) bonded with acetyl groups (functional functional groups). The modification rate (the proportion of hydroxyl groups converted to functional functional groups) of the modified starch, determined by the addition ratio, was 100%.

[0670] After cooling the reaction solution to room temperature, 2000 mg of lyophilized modified fibroin (PRT799) powder was added to the reaction solution, and the mixture was stirred at 90°C for 12 hours to dissolve it, resulting in a transparent spinning solution. Based on the total content of modified starch and starch, the modified starch content in the spinning solution was 17% by mass.

[0671] (2) Manufacturing of fibers containing modified silk core protein and substances that impart water resistance

[0672] Using the prepared spinning solution, fibers containing modified silk core protein and water-resistant material (modified starch) were obtained in the same order as in Experimental Example 9-1.

[0673] (3) Shrinkage performance assessment

[0674] The shrinkage of the obtained fibers was evaluated in the same order as in Experiment 9-1. The results are shown in Table 23.

[0675] <Experimental Example 9-3>

[0676] (1) Preparation of spinning solution (spinning solution)

[0677] 215 mg of starch (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 7600 mg of solvent (dimethyl sulfoxide (DMSO) containing 4% by weight of LiCl), and then 185 mg of acetic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.) was added. The mixture was stirred at 90°C for 4 hours to allow the reaction to occur. As a result, the hydroxyl groups of the starch react with the acetic anhydride to obtain modified starch (a hydroxyl-modified polymer) bonded with acetyl groups (functional functional groups). The modification rate (the proportion of hydroxyl groups converted to functional functional groups) of the modified starch, determined by the addition ratio, was 50%.

[0678] After cooling the reaction solution to room temperature, 2000 mg of lyophilized modified fibroin (PRT799) powder was added to the reaction solution, and the mixture was stirred at 90°C for 12 hours to dissolve it, resulting in a transparent spinning solution. Based on the total content of modified starch and starch, the modified starch content in the spinning solution was 17% by mass.

[0679] (2) Manufacturing of fibers containing modified silk core protein and substances that impart water resistance

[0680] Using the prepared spinning solution, fibers containing modified silk core protein and water-resistant material (modified starch) were obtained in the same order as in Experimental Example 5-1.

[0681] (3) Shrinkage performance assessment

[0682] The shrinkage of the obtained fibers was evaluated in the same order as in Experiment 9-1. The results are shown in Table 23.

[0683] <Experimental Example 9-4>

[0684] (1) Preparation of spinning solution (spinning solution)

[0685] 128 mg of polyvinyl alcohol (PVA) (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 7600 mg of a solvent (dimethyl sulfoxide (DMSO) containing 4% by weight of LiCl), and then 272 mg of phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added. The mixture was stirred at 90°C for 4 hours to allow the reaction to occur. As a result, the hydroxyl groups of PVA react with the phenyl isocyanate to obtain modified PVA (hydroxyl-modified polymer) with phenyl groups (functional functional groups) bonded by urethane bonds. The modification rate (the proportion of hydroxyl groups converted to functional functional groups) of the modified PVA, determined by the addition ratio, was 100%.

[0686] After cooling the reaction solution to room temperature, 2000 mg of lyophilized modified silk protein (PRT799) powder was added to the reaction solution, and the mixture was stirred at 90°C for 12 hours to dissolve it, resulting in a transparent spinning solution. Based on the modified PVA and the total PVA content, the modified PVA content in the spinning solution was 17% by mass.

[0687] (2) Manufacturing of fibers containing modified silk core protein and substances that impart water resistance

[0688] Using the prepared spinning solution, fibers containing modified silk core protein and water-resistant material (modified PVA) were obtained in the same order as in Experimental Example 9-1.

[0689] (3) Shrinkage performance assessment

[0690] The shrinkage of the obtained fibers was evaluated in the same order as in Experiment 9-1. The results are shown in Table 23.

[0691] <Experimental Example 9-5>

[0692] (1) Preparation of spinning solution (spinning solution)

[0693] 193 mg of polyvinyl alcohol (PVA) (manufactured by Wako Pure Chemical Industries, Ltd.) was dissolved in 7600 mg of a solvent (dimethyl sulfoxide (DMSO) containing 4% by weight of LiCl), and then 207 mg of phenyl isocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added. The mixture was stirred at 90°C for 4 hours to allow the reaction to occur. As a result, the hydroxyl groups of PVA react with the phenyl isocyanate to obtain modified PVA (hydroxyl-modified polymer) with phenyl groups (functional functional groups) bonded by urethane bonds. The modification rate (the proportion of hydroxyl groups converted to functional functional groups) of the modified PVA, determined by the addition ratio, was 50%.

[0694] After cooling the reaction solution to room temperature, 2000 mg of lyophilized modified silk protein (PRT799) powder was added to the reaction solution, and the mixture was stirred at 90°C for 12 hours to dissolve it, resulting in a transparent spinning solution. Based on the modified PVA and the total PVA content, the modified PVA content in the spinning solution was 17% by mass.

[0695] (2) Manufacturing of fibers containing modified silk core protein and substances that impart water resistance

[0696] Using the prepared spinning solution, fibers containing modified silk core protein and water-resistant material (modified PVA) were obtained in the same order as in Experimental Example 9-1.

[0697] (3) Shrinkage performance assessment

[0698] The shrinkage of the obtained fibers was evaluated in the same order as in Experiment 9-1. The results are shown in Table 23.

[0699] <Experimental Example 9-6>

[0700] (1) Preparation of spinning solution (spinning solution)

[0701] 1200 mg of lyophilized modified silk core protein (PRT799) powder was added to a solvent (dimethyl sulfoxide (DMSO) containing 4% by weight of LiCl) and stirred at 90 °C for 12 hours to dissolve it, resulting in a transparent spinning solution (spinning solution).

[0702] (2) Fiber manufacturing

[0703] Using the prepared spinning solution, fibers were obtained in the same order as in Experimental Example 9-1.

[0704] (3) Shrinkage performance assessment

[0705] The shrinkage of the obtained fibers was evaluated in the same order as in Experiment 9-1. The results are shown in Table 23.

[0706] <Experimental Example 9-7>

[0707] (1) Preparation of spinning solution (spinning solution)

[0708] 3000 mg of lyophilized modified silk core protein (PRT799) powder and 600 mg of starch (manufactured by Wako Pure Chemical Industries, Ltd.) were added to a solvent (dimethyl sulfoxide (DMSO) containing 4% by weight of LiCl) and stirred at 90°C for 12 hours to dissolve it, resulting in a transparent spinning solution (spinning solution).

[0709] (2) Fiber manufacturing

[0710] Using the prepared spinning solution, fibers were obtained in the same order as in Experimental Example 9-1.

[0711] (3) Shrinkage performance assessment

[0712] The shrinkage of the obtained fibers was evaluated in the same order as in Experiment 9-1. The results are shown in Table 23.

[0713] [Table 23]

[0714]

[0715] Fibers containing modified silk core protein and water-resistant materials (hydroxyl polymers (modified starch or modified PVA)) have lower shrinkage rates compared to fibers without water-resistant materials.

[0716] [Experimental Example 10: Evaluation of the flame retardant properties of modified silk core protein fibers]

[0717] Prepare a solution of dimethyl sulfoxide (DMSO) containing LiCl to achieve a concentration of 4.0% by mass. Add lyophilized powder of modified silk core protein (PRT799) to achieve a concentration of 24% by mass, and dissolve using a shaker for 3 hours. Then, remove insoluble matter and air bubbles to obtain the modified silk core protein solution (spinning solution).

[0718] The prepared spinning solution was filtered at 90°C through a 5μm mesh metal filter, then placed in a 30mL stainless steel syringe to stand and degas. After degassing, it was sprayed from a solid nozzle with a 0.2mm diameter into a 100% (w / w) methanol coagulation bath at 90°C. After coagulation, the resulting yarn was wound up and allowed to air dry to obtain modified silk core protein fibers.

[0719] The modified silk core protein fiber (twisted filament) was used to manufacture an evaluation fabric by circular knitting on a circular knitting machine. The fabric had a denier of 180 and a stitch length of 18. 20g was cut from the resulting fabric as a test piece.

[0720] The flammability test was conducted according to the Test Method for Powdered or Low-Melting-Point Synthetic Resins (Fire Hazard No. 50, May 31, 1995) issued by the Hazardous Materials Regulation Division of the Japanese Fire and Disaster Management Agency. The test was conducted at a temperature of 22°C, a relative humidity of 45%, and an atmospheric pressure of 1021 hPa. The measurement results (oxygen concentration (%), flammability (%), and combustion conversion rate (%)) are shown in Table 24.

[0721] [Table 24]

[0722]

[0723] As a result of the flame retardant performance test, the critical oxygen index (LOI) value of the modified fibroin (PRT799) fiber was 27.2. Generally, an LOI value above 26 is considered to indicate flame retardant properties. Therefore, it can be concluded that the modified fibroin fiber exhibits excellent flame retardant performance.

[0724] [Experimental Example 11: Evaluation of the moisture absorption and heat generation properties of modified silk core protein fibers]

[0725] Prepare a solution of dimethyl sulfoxide (DMSO) containing LiCl as a solvent to achieve a concentration of 4.0% by mass. Add lyophilized powder of modified silk core protein to achieve a concentration of 24% by mass, and use a shaker to dissolve it for 3 hours. Then, remove insoluble matter and air bubbles to obtain the modified silk core protein solution (spinning solution).

[0726] The prepared spinning solution was filtered at 60°C through a 5μm mesh metal filter, then placed in a 30mL stainless steel syringe to stand and degas. After degassing, it was sprayed from a solid nozzle with a 0.2mm diameter nozzle into a 100% (w / w) methanol coagulation bath at 60°C. After coagulation, the resulting yarn was wound up and allowed to air dry to obtain modified silk core protein fibers.

[0727] For comparison, commercially available wool fibers, cotton fibers, Tencel fibers, rayon fibers, and polyester fibers will be prepared.

[0728] Evaluation fabrics were manufactured using various fibers and horizontal knitting on a flat knitting machine. Fabrics using modified silk core protein (PRT918) fiber had a yarn width of 1 / 30N (monofilament wool count) and a gauge of 18. Fabrics using modified silk core protein (PRT799) fiber had a yarn width of 1 / 30N (monofilament wool count) and a gauge of 16. The yarn width and gauge of fabrics using other fibers were adjusted to achieve approximately the same coverage as fabrics using PRT918 and PRT799 fibers. Specifically, as described below.

[0729] Wool thickness: 2 / 30N (double-ply yarn), gauge: 14

[0730] Cotton thickness: 2 / 34N (double-ply yarn), gauge: 14

[0731] Tencel thickness: 2 / 30N (double-ply yarn), needle pitch: 15

[0732] Rayon thickness: 1 / 38N (single yarn), needle pitch: 14

[0733] Polyester yarn thickness: 1 / 60N (single yarn), gauge: 14

[0734] Two pieces of knitted fabric, each 10cm x 10cm, were glued together and the four sides were sewn together to create a test piece (sample). The test piece was placed in a low-humidity environment (temperature 20±2℃, relative humidity 40±5%) for more than 4 hours, and then moved to a high-humidity environment (temperature 20±2℃, relative humidity 90±5%). Temperature measurements were taken for 30 minutes at 1-minute intervals using a temperature sensor installed in the center of the test piece.

[0735] Based on the measurement results, the maximum hygroscopic heat generation is calculated according to the following formula A.

[0736] Formula A: Maximum hygroscopic heat generation = {(the highest temperature of the sample after it has been placed in a low humidity environment until its temperature reaches equilibrium, and then moved to a high humidity environment) - (the temperature of the sample after it has been placed in a low humidity environment until its temperature reaches equilibrium, and then moved to a high humidity environment)} (°C) / sample weight (g)

[0737] Figure 8 This is an example graph showing the results of a moisture absorption and heat dissipation performance test. The horizontal axis of the graph represents the placement time (in minutes) in a high humidity environment, where 0 represents the time it takes for the sample to be transferred from a low humidity environment to a high humidity environment. The vertical axis of the graph represents the temperature (sample temperature) measured by a temperature sensor. Figure 8 In the graph shown, the point represented by M corresponds to the highest value of the sample temperature. The calculation results of the highest hygroscopic heat generation are shown in Table 25.

[0738] [Table 25]

[0739]

[0740] As shown in Table 25, it can be seen that the modified silk core protein fibers (PRT918 fiber and PRT799 fiber) have a higher maximum moisture absorption and heat generation capacity and excellent moisture absorption and heat generation performance compared with existing fibers.

[0741] [Experimental Example 12: Evaluation of the thermal insulation performance of modified silk core protein fiber]

[0742] Prepare a solution of dimethyl sulfoxide (DMSO) containing LiCl as a solvent to achieve a concentration of 4.0% by mass. Add lyophilized powder of modified silk core protein to achieve a concentration of 24% by mass, and use a shaker to dissolve it for 3 hours. Then, remove insoluble matter and air bubbles to obtain the modified silk core protein solution (spinning solution).

[0743] The prepared spinning solution was filtered at 60°C through a 5μm mesh metal filter, then placed in a 30mL stainless steel syringe to stand and degas. After degassing, it was sprayed from a solid nozzle with a 0.2mm diameter nozzle into a 100% (w / w) methanol coagulation bath at 60°C. After coagulation, the resulting yarn was wound up and allowed to air dry to obtain modified silk core protein fibers.

[0744] For comparison, commercially available wool fibers, silk fibers, cotton fibers, rayon fibers, and polyester fibers will be prepared.

[0745] Evaluation fabrics were manufactured using various fibers and horizontal knitting on a flat knitting machine. The fabric using modified silk core protein (PRT966) fiber had a yarn count of 30 Nm, a twist count of 1, a gauge length of 18 GG, and a basis weight of 90.1 g / m². 2 Knitted fabrics using modified silk core protein (PRT799) fibers have a yarn count of 30 Nm, a twist count of 1, a stitch length of 16 GG, and a weight per unit area of ​​111.0 g / m². 2 Adjust the thickness and stitch length of the knitted fabric using other fibers to achieve approximately the same coverage as the knitted fabric using PRT966 and PRT799 fibers. Specifically, as described below.

[0746] Wool count: 30 Nm, twist count: 2, needle pitch: 14 GG, area weight: 242.6 g / m² 2

[0747] Silk count: 60 Nm, twist count: 2, stitch length: 14 GG, weight per unit area: 225.2 g / m² 2

[0748] Cotton count: 34 Nm, twist count: 2, needle pitch: 14 GG, weight per unit area: 194.1 g / m² 2

[0749] Rayon count: 38 Nm, twist count: 1, needle pitch: 14 GG, area weight: 181.8 g / m² 2

[0750] Polyester count: 60 Nm, twist count: 1, needle pitch: 14 GG, area weight: 184.7 g / m² 2

[0751] Thermal insulation performance was evaluated using a KES-F7 Thermolab II testing machine manufactured by JAD Technology Co., Ltd., and using the dry contact method (assuming direct contact between skin and clothing in a dry state). A piece of knitted fabric cut to 20cm × 20cm was used as a test piece (sample). The test piece was placed on a hot plate set to a constant temperature (30°C), and the heat dissipated through the test piece was calculated (a) under the condition of a wind tunnel with a wind speed of 30cm / s. Without the test piece, the heat dissipated under the same conditions was calculated (b), and the thermal insulation rate (%) was calculated according to the following formula.

[0752] Thermal insulation rate (%) = (1 - a / b) × 100

[0753] Based on the measurement results, the thermal insulation performance index is calculated according to the following formula B.

[0754] Formula B: Thermal insulation performance index = Thermal insulation rate (%) / Unit area weight of the sample (g / m²) 2 )

[0755] The calculation results of the thermal insulation performance index are shown in Table 26. It can be assessed that the higher the thermal insulation performance index of a material, the better its thermal insulation performance.

[0756] [Table 26]

[0757]

[0758] As shown in Table 26, it can be seen that the modified silk core protein fibers (PRT966 fiber and PRT799 fiber) have a higher thermal insulation performance index and excellent thermal insulation performance compared with existing fibers.

[0759] [Experimental Example 13: Manufacturing of Artificial Fur]

[0760] Lyophilized powder of modified spider silk fibroin (PRT966) was added to formic acid to achieve a concentration of 30% by mass, and dissolved in a dissolving tank with stirring blades for 1.5 hours. Then, insoluble matter and air bubbles were removed to obtain a modified spider silk fibroin solution (spinning solution). Using the obtained modified spider silk fibroin solution as the spinning solution (spinning solution), modified spider silk fibroin fibers (filaments) were manufactured by wet-dry spinning using a known wet-dry spinning apparatus. Next, the obtained modified spider silk fibroin fibers were mechanically crimped using a known crimping apparatus and cut into lengths of 110–150 mm to obtain short fibers. The obtained short fibers were spun using conventional methods. Then, the obtained yarn was knitted using a pile knitting process to obtain a pile knitted fabric with pile protruding on one side. Then, the pile loops were cut and combed. Thus, an artificial fur composed of modified spider silk fibroin fibers was obtained. An image of the obtained artificial fur is shown below. Figure 9 and Figure 10 As shown.

Claims

1. An artificial fur comprising artificial protein fibers.

2. The artificial fur according to claim 1, wherein, The artificial protein fiber comprises modified silk core protein fiber, preferably modified spider silk core protein fiber.

3. An artificial fur comprising shrink-resistant protein fibers.

4. The artificial fur according to claim 3, wherein, The shrinkage rate of the protein fiber upon wetting, as defined by the following formula I, is 2% or more: [Formula I] Shrinkage rate during wetting = {1 - (length of protein fiber in wet state after contact with water / length of protein fiber after spinning and before contact with water)} × 100%.

5. The artificial fur according to claim 3 or 4, wherein, The shrinkage rate of the protein fiber during drying, as defined by Formula II below, is greater than 7%. [Formula II] Shrinkage during drying = {1 - (length of protein fiber in dry state / length of protein fiber after spinning and before contact with water)} × 100%.

6. The artificial fur according to any one of claims 3 to 5, wherein, The protein fiber comprises modified silk core protein fiber, preferably modified spider silk core protein fiber.

7. An artificial fur comprising protein fibers and a functional substance.

8. The artificial fur according to claim 7, wherein, The protein fiber comprises modified silk core protein fiber, preferably modified spider silk core protein fiber.

9. The artificial fur according to claim 7 or 8, wherein, The substance that imparts functionality is a protein cross-linker. The protein crosslinker comprises: a polypeptide backbone; a first residue, which is a residue of a first reactive agent having two or more first reactive groups capable of reacting with the protein and forming a bond; and a second residue, which is a residue of a second reactive agent having one second reactive group capable of reacting with the first reactive group and forming a bond. Wherein, at least one of the first residues is cross-linked with the polypeptide backbone, and At least one of the first residues is bonded to the polypeptide backbone at one end and to the second residue at the other end.

10. The artificial fur according to any one of claims 7 to 9, wherein, The artificial fur also includes a hydroxyl-modified polymer to which functional functional groups are bonded.

11. An artificial fur containing protein fibers and a substance that imparts water resistance.

12. The artificial fur according to claim 11, wherein, The protein fiber comprises modified silk core protein fiber, preferably modified spider silk core protein fiber, and is covalently bonded to the water-resistant material.

13. The artificial fur according to claim 11 or 12, wherein, The water-resistant material is selected from at least one of organosilicon polymers and fluoropolymers.

14. The artificial fur according to any one of claims 1 to 13, wherein, The critical oxygen index (LOI) value is above 26.

0.

15. The artificial fur according to any one of claims 1 to 14, wherein, The highest hygroscopic heat generation calculated using the following formula A is greater than 0.025°C / g, preferably greater than 0.031°C / g: Formula A: Maximum hygroscopic heat generation = {(the highest temperature of the sample after it has been placed in a low humidity environment until its temperature reaches equilibrium, and then moved to a high humidity environment) - (the temperature of the sample after it has been placed in a low humidity environment until its temperature reaches equilibrium, and then moved to a high humidity environment)} / sample weight In Formula A, the unit of temperature is °C, and the unit of sample weight is g. Low humidity environment refers to an environment with a temperature of 20 °C and a relative humidity of 40%, and high humidity environment refers to an environment with a temperature of 20 °C and a relative humidity of 90%.

16. The artificial fur according to any one of claims 1 to 15, wherein, The thermal insulation performance index calculated using the following formula B is greater than 0.18, preferably greater than 0.22: Formula B: Thermal insulation performance index = thermal insulation rate / weight per unit area of ​​the sample In Formula B, the unit of heat retention rate is %, and the unit of weight per unit area of ​​the sample is g / m². 2 The heat retention rate was measured using the dry contact method at a temperature of 30°C and a wind speed of 30 cm / s, and calculated using (1 - a / b) × 100, where a represents the heat released through the test piece and b represents the heat released without passing through the test piece.

17. A method for manufacturing artificial fur according to any one of claims 1 to 16.

18. A method for manufacturing artificial fur, comprising the following steps: Use fibers containing synthetic protein fibers to obtain a plush fabric with pile prominently set on one or both sides of the fabric. and The loops of the pile are cut to form cut pile.

19. The method according to claim 18, wherein, The artificial protein fiber is a shrink-resistant protein fiber.

20. The method of claim 18, further comprising shrink-proofing the fleece fabric.

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