Resin composition and component

Abstract

To provide a novel resin composition with a high biomass ratio and high heat resistance.SOLUTION: A resin composition contains resin materials and paramylon nanofibers.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a resin composition and a part. [Background technology]

[0002] For example, Patent Documents 1 and 2 disclose resin compositions containing a polyester resin, glass fibers, a bromine-based flame retardant, and an antimony-based flame retardant assistant.

[0003] For example, Patent Document 3 describes a thermoplastic resin composition containing cellulose acetate and a plasticizer selected from the group consisting of rosin-based plasticizers, ester-based plasticizers, glycerin-based plasticizers such as glycerin fatty acid esters and polyglycerin fatty acid esters, polyester-based plasticizers, and sugar alcohol-based plasticizers, and the thermoplastic resin composition contains cellulose nanofibers (CNF).

[0004] For example, Patent Document 4 describes a polyamide resin composition containing a polyamide having a terminal amino group concentration and a terminal carboxyl group concentration that satisfy certain requirements, and (B) cellulose fibers having an average fiber diameter of 500 nm or less. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-105433 A [Patent Document 2] Republished Patent No. 2007 / 007663 [Patent Document 3] Patent Publication No. 2021-109942 [Patent Document 4] JP 2023-24787 A Summary of the Invention [Problem to be solved by the invention]

[0006] There is a push to strengthen the energy supply system by using biomass, an organic resource derived from living organisms that can replace fossil resources. Biomass is defined as a renewable organic resource derived from living organisms, excluding fossil resources.

[0007] In the parts described in Patent Documents 1 and 2, it is preferable to use biomass as the material from the viewpoint of utilizing carbon-neutral circulative resources. For example, carbon fiber (CF) can be an alternative to glass fiber, but it is expensive and is a material derived from fossil resources, so it does not meet the demand for alternatives to circulative resources.

[0008] Patent Documents 3 and 4 disclose the use of, for example, cellulose nanofibers (CNF), which are organic resources derived from living organisms, as a reinforcing material as an alternative to glass fibers.

[0009] However, for parts that require high heat resistance due to their applications, and for the molded articles that make up the parts, there is a problem in that no biological fiber material has been found that has sufficient heat resistance comparable to that of the resin material contained in the molded article.

[0010] One aspect of the present invention has been made in consideration of the above-mentioned problems, and aims to provide a novel resin composition having a high bio content and high heat resistance derived from paramylon nanofiber, and a part having a molded body containing the resin composition. [Means for solving the problem]

[0011] In order to solve the above problems, a resin composition according to one embodiment of the present invention contains a resin material and paramylon nanofiber.

[0012] The above-mentioned configuration makes it possible to provide a novel resin composition that has a high bio content and high heat resistance derived from the paramylon nanofiber.

[0013] A part according to one aspect of the present invention includes a molded article formed from the resin composition according to the above aspect.

[0014] The above configuration makes it possible to provide parts with a high bio content and high heat resistance derived from the paramylon nanofiber.

[0015] In addition, in the component according to one aspect of the present invention, in the above aspect, the resin material may be a polyester-based resin.

[0016] With the above-described configuration, a part having excellent formability in the thin-walled portion can be provided, and further, a part having high heat resistance can be provided.

[0017] In addition, in the part according to one aspect of the present invention, in any one of the above aspects, it is preferable that the resin material contains a halogen-based flame retardant and a flame retardant auxiliary.

[0018] The above-mentioned composition can impart high flame retardancy to parts having a high bio content and high heat resistance.

[0019] In addition, a part according to one aspect of the present invention may, in any of the above aspects, include an electrical contact, or the electrical contact and a coil, and the molded body may encapsulate the electrical contact and the coil, or may be in contact with the electrical contact or the coil.

[0020] With the above-mentioned configuration, it is possible to increase the bio content of the electrical contact or the part including the electrical contact and the coil, and also to impart high heat resistance to the part.

[0021] In addition, in the part according to one aspect of the present invention, in any one of the above aspects, the molded body may be at least one molded body selected from a base, a case, a card, a spool, and a housing.

[0022] By using a molded article having the above-mentioned configuration, it is possible to provide a part having a high bio content and high heat resistance.

[0023] In addition, in any of the above aspects, the component according to one aspect of the present invention may be a relay, a switch, a connector, or a sensor.

[0024] A part having the above-mentioned configuration has a high bio content and high heat resistance derived from the paramylon nanofiber. Effect of the Invention

[0025] According to one aspect of the present invention, it is possible to provide a novel resin composition having a high bio content and high heat resistance derived from paramylon nanofiber, and a part having a molded body containing the resin composition. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a diagram illustrating an outline of a relay 10 which is a component according to one embodiment. [Diagram 2] FIG. 2 is a diagram illustrating a cross section of a card 31, and explaining the thickness a1 of the minimum thickness part of a molded body constituting a part. [Diagram 3] FIG. 3 is a diagram for explaining the definitions of the width and length of a test piece for a thermal shrinkage test in accordance with JIS K7152-4 (ISO294-4) and the width and length of a mold cavity. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] §1 Examples of application <Resin composition> A resin composition according to one embodiment of the present invention comprises a resin material and paramylon nanofibers.

[0028] The resin composition contains paramylon nanofiber (PNF), i.e., nanofiber of β-1,3-glucan having a triple helix structure, as a reinforcing material, and thus has a high bio content (also called biomass ratio) and high heat resistance. Therefore, for example, a molded product provided in a component part or other part can be given a high bio content and high heat resistance.

[0029] Paramylon nanofibers, unlike cellulose fibers derived from wood, do not contain lignin. Therefore, the resin composition according to one embodiment of the present invention does not cause corrosion of metal components due to lignin. Therefore, one of the advantages is that it can be suitably used for parts equipped with metal components such as electrical contacts, as described below.

[0030] <Parts> A part according to one embodiment of the present invention includes a molded body formed from a resin composition containing a resin material and paramylon nanofibers.

[0031] A component according to an embodiment of the present invention may be an electronic component that forms part of an electric circuit, for example, an electronic component that has electrical contacts for turning an electric circuit on / off, switching an electric circuit, or connecting to an electric circuit, or an electronic component that senses physical changes such as light, temperature, and stress and converts them into an electric signal.

[0032] Further, the part according to one embodiment may be a part having electrical contacts or wiring for turning on / off the device, switching the device, or connecting to the device, or a part for sensing physical changes such as light, temperature, and stress. Here, examples of the device into which the part is incorporated include an on-board device mounted on a vehicle such as an automobile, an electrical product, a medical machine, and a precision machine. That is, the part according to one embodiment of the present invention is not limited to an electronic component used in an electric circuit, but may be a component incorporated in various devices, electrical products, medical machines, precision machines, etc., but is not limited to a component, and can be widely used for a part having a molded body of a resin composition.

[0033] A part according to an embodiment may preferably be a component part, and the component part may preferably be, for example, a relay, a switch, a connector, a sensor, etc., and an example of the component part may be a mechanical part or an electronic part. Thus, in this specification, unless otherwise specified, the term "part" includes the meaning of "component part", and the "component part" includes the meaning of either or both of "mechanical part" and "electronic part".

[0034] The molded body of the part may be a member that is heated intermittently or continuously by each member that is energized via an external circuit or an external device, and therefore may be a molded body that requires heat resistance.

[0035] The part includes a molded article of a resin composition containing paramylon nanofiber (PNF) as a reinforcing material, and thus the bio content (also called biomass ratio) of the part is increased while the part has high heat resistance. In addition, the part includes paramylon nanofiber, and thus the part has a molded article with low anisotropy of molding shrinkage.

[0036] Therefore, the part according to one embodiment has heat resistance that is not inferior to parts that use glass fiber as a reinforcing material and to resin compositions, and can be provided as a preferable part from the viewpoint of utilizing carbon-neutral recyclable resources.

[0037] §2 Configuration example Below, a relay, a switch, and a connector will be described as typical examples of electronic components according to an embodiment, but the present invention is not limited to electronic components.

[0038] [1] Relay Fig. 1 is a diagram illustrating an outline of a relay 10, which is an electronic component (part) according to one embodiment. The relay 10 includes a contact (electrical contact) 1, a base 2, a card 3, a case 4, a coil 5, a spool 6, and an iron piece 7. In Fig. 1, the base 2 and the card 3 are in contact with the contact 1, and the case 4 encloses the contact 1.

[0039] The contact 1 includes a fixed piece 1a and a movable piece 1b. The fixed piece 1a includes a fixed contact a and a fixed piece terminal 1c, and the movable piece 1b includes a movable contact b and a movable piece terminal 1d.

[0040] The fixed piece 1a and the movable piece 1b are fixed to the base 2 so as to face each other. The movable piece 1b is biased so that the movable contact b moves away from the fixed contact a. The fixed piece terminal 1c and the movable piece terminal 1d are both terminals connected to an external circuit of the relay 10.

[0041] When the card 3 moves toward the movable piece 1b, the movable piece 1b moves with the card 3, bringing the movable contact b into contact with the fixed contact a. This causes electricity to flow between the fixed piece terminal 1c and the movable piece terminal 1d. This electricity causes the contact 1 to heat up, which in turn heats the base 2, the card 3, and the case 4 through the fixed piece 1a and the movable piece 1b, and may even heat the spool 6. For this reason, the base 2, the card 3, the case 4, and the spool 6 are required to have high heat resistance.

[0042] The base 2 is a molded body for fixing each of the fixed piece 1a, movable piece 1b, coil 5, iron core 5a, and iron piece 7 in positions where an insulating distance can be ensured between them, and can be a molded body molded from a resin composition containing paramylon nanofiber.

[0043] The card 3 transmits the force applied from the iron piece 7 to the movable piece 1b. The card 3 is a molded body for moving the movable contact b of the movable piece 1b toward the fixed contact a of the fixed piece 1a while ensuring an insulating distance between the movable piece 1b and the coil 5, and may be a molded body molded from a resin composition containing paramylon nanofiber. When the coil 5 is energized, one end of the iron piece 7 is attracted toward the spool 6 by a magnetic force generated in the iron core 5a arranged inside the coil 5. As a result, the other end of the iron piece 7 moves, applying a force to the card 3.

[0044] The case 4 is a molded body for protecting the contact 1 from dust, ensuring the insulation distance between the contact 1 and the coil 5, and protecting the contact 1 and the coil 5, and may be a molded body molded from a resin composition containing paramylon nanofiber.

[0045] In the relay 10, the coil 5 includes an iron core 5a and a coil terminal 5b. In the relay 10, the iron core 5a acts as an electromagnet in a magnetic circuit due to the magnetic flux of the coil 5 generated when a current is passed through the coil terminal 5b. The coil 5 is also called a wire terminal, and may generate heat when a current is passed continuously. The base 2, the card 3, the case 4, and the spool 6 may also be heated by the heat.

[0046] The spool 6 is a molded body for ensuring an insulating distance between the coil 5 and the iron piece 7, and may be a molded body made of a resin composition containing paramylon nanofiber. The spool 6 may be a molded body for fixing the coil 5 to the base 2 while maintaining an insulating distance between the coil 5 and the iron piece 7.

[0047] When the current to the coil 5 is cut off by an external circuit, the iron piece 7 is urged by the hinge spring 7a to move away from the spool 6. At this time, the pressure of the iron piece 7 against the card 3 is released, and the movable contact b moves away from the fixed contact a. This cuts off the current to the contact 1.

[0048] Additionally, the relay according to an embodiment is not limited to the relay 10 illustrated in Fig. 1 and may include other metal components such as a yoke. Furthermore, the relay according to an embodiment may include a molded body molded from a resin composition containing paramylon nanofiber, in addition to the base, card, case, and spool.

[0049] The molded bodies such as the base, card, case, and spool of the relay may have irregularities such as irregularities for defining the arrangement of the above-mentioned contacts, coil, iron core, and iron piece, irregularities formed as guides for fitting the base and case together in a predetermined arrangement, and irregularities for guiding the movement of the card inside the case. The irregularities of the molded bodies may be irregularities such as ribs, and irregularities derived from the shape of the design given to the relay. These irregularities define the thinnest part and the thickness of each molded body. The irregularities of the molded bodies may also be provided as irregularities that define holes such as through holes through which electrical contacts and the like are inserted.

[0050] FIG. 2 is a diagram illustrating a cross section of a card 31, and explaining the definition of the thickness a1 of the minimum thickness part of a molded body constituting an electronic component.

[0051] 2, a card 31 has an iron piece (not shown) abutted against flat portion 31a and a movable contact (not shown) abutted against protruding portion 31b, and moves along the X direction shown in Fig. 2 in response to the movements of the iron piece and the movable contact. The X direction in Fig. 2 is also the thickness direction of card 31. The thickness direction may be the normal direction to a plane that serves as a reference for the molded body.

[0052] As shown in FIG. 2, the card 31 has projections and recesses with thicknesses a1, a2, and a3 formed along the thickness direction, and the thicknesses of these projections and recesses along the Y direction, i.e., the vertical width direction, are defined as thicknesses b1 and b2. In the card 31, the thicknesses increase in the order of a1, b1, a2, b2, and a3, with a1 being the thinnest and a3 being the thickest. Therefore, in the card 31, the thickness a1 of the thinnest part corresponds to the thickness of the minimum thickness part. Although not shown for convenience, if there is a part thinner than a1 in the Z direction, i.e., the horizontal width direction of the card 31 shown in FIG. 2, the part thinner than a1 will be the minimum thickness part.

[0053] When the molded article is not a card but is a molded article having multiple surfaces such as a case, a housing, etc., the part of the molded article that has the thinnest thickness among all the surfaces is defined as the minimum thickness part. The minimum thickness part is the part of the molded article that has the thinnest thickness not only in the thickness direction but also in the vertical and horizontal directions.

[0054] The thickness of the minimum thickness part of the molded body is less than 2.0 mm, preferably less than 0.8 mm, and more preferably 0.5 mm or less. The thickness of the minimum thickness part may be 0.3 mm or more. This provides each molded body of the relay 10 with heat resistance and mechanical strength derived from the paramylon nanofiber.

[0055] Furthermore, the thickness a3 of the molded body exemplified by card 31 is the thickness of the molded body other than the minimum thickness part, and may be designed to be thicker than the thickness a1. For example, the thickness a3 of the molded body other than the minimum thickness part may be 2.0 mm or more. Furthermore, the thickness a2 of the molded body exemplified by card 31 may be greater than or equal to the thickness a1 and less than or equal to the thickness a3.

[0056] Furthermore, the thicknesses b1 and b2 in the longitudinal direction of the molded body may be appropriately designed to be thicker than the thickness a1 of the minimum thickness part of the molded body. However, it should be understood that when the thickness of the parts of the molded body corresponding to the thicknesses b1 and b2 is the thinnest, the thicknesses b1 and b2 of the parts should be designed as the minimum thickness part.

[0057] Examples of relays that require high heat resistance include relays that are required to open / close or switch an external circuit under high current and / or high voltage conditions, and also include relays that are required to be miniaturized. More specifically, examples of relays according to an embodiment include power relays, micro relays, and surface mount relays.

[0058] [2] Switch The electronic component (component) according to the embodiment is not limited to the relay described above, and may be, for example, a switch.

[0059] A switch is an electronic component that constitutes part of an electric circuit and switches the electric circuit. The switch includes an actuator, a snap action mechanism, electric contacts, and a housing. The switch housing includes a snap action mechanism and a housing that protects the electric contacts while maintaining an insulating distance between them. In a switch, the housing is sometimes called a cover.

[0060] The switch transmits a force or action from outside the housing to a snap action mechanism disposed inside the housing via an actuator. Types of actuators that the switch is equipped with include push button types and lever types. The type of actuator may be selected as appropriate depending on the application of the switch.

[0061] The switch includes a conductive spring as a snap action mechanism, and a movable contact is provided at the end of the conductive spring. The electrical contact of the switch may be composed of two fixed contacts facing each other inside the housing, and a movable contact provided on the conductive spring between the two fixed contacts. The movable contact provided at the end of the snap action mechanism can be switched to contact one of the two fixed contacts by the action transmitted from the actuator. Here, the snap action mechanism and each of the two fixed contacts include an external terminal connected to the outside of the housing. The movable contact of the snap action mechanism contacts one of the two fixed contacts that contact the inside of the housing to pass electricity, and at this time, cuts off electricity to the other fixed contact. This allows the switch to switch an external electric circuit. The switch generates heat when the contacts pass electricity inside the housing. For this reason, the housing of the switch may be required to have high heat resistance. Therefore, in one embodiment of the switch, the housing may be molded from a resin composition containing paramylon nanofiber.

[0062] The molded body such as the housing of the switch has projections and recesses for regulating the arrangement of the actuator, snap action mechanism, and electrical contacts, as in the case of the relay. Here, the housing of the switch according to the embodiment only needs to be designed for the thickness of the minimum wall thickness, as in the case of the card 31 described above. Also, thicknesses other than the minimum wall thickness of the housing can be appropriately designed. The switch according to the embodiment can achieve miniaturization of the switch itself by designing the thickness of the minimum wall thickness of the housing. Furthermore, by including paramylon nanofiber as a reinforcing material, the switch according to the embodiment can achieve heat resistance derived from paramylon nanofiber that is comparable to that of a switch having a molded body containing glass fiber.

[0063] The housing of the switch according to the embodiment may be formed by combining a plurality of parts into one housing. The switch may also include a molded body molded from a resin composition containing paramylon nanofiber in addition to the housing.

[0064] Specific examples of the switch according to the embodiment include switches that are required to be switched under high current and / or high voltage conditions, and further include switches that are required to be miniaturized. More specific examples of the switch according to the embodiment include switches such as micro switches, ultra-miniature basic switches, and sealed ultra-miniature basic switches.

[0065] [3] Connector The electronic component (component) according to the embodiment is not limited to the relay and switch described above, and may be, for example, a connector.

[0066] A connector may be an electronic component that connects two electric circuits or connects an electric circuit to a power source. The connector includes contacts (also called pins or electrodes) for connecting to an electric circuit, and a housing for protecting and fixing the contacts. Here, the electric circuit may be a printed circuit board or a flexible board. In a connector, the contacts that connect the electric circuits generate heat when an electric signal or current flows through the contacts. Therefore, the housing of the connector is required to be heat resistant.

[0067] Therefore, in one embodiment of the connector, the housing may be molded from a resin composition containing paramylon nanofiber.

[0068] The connector may be in the form of a plug or jack to be attached to a cable, or a receptacle to be attached to an electric circuit such as a board. The connector may be a pin insert type or a socket insert type. The connector may be, for example, an audio / video connector, a communication connector, or a power connector.

[0069] The arrangement of contacts in a connector is determined according to standards. Therefore, the shape of the connector housing, i.e., the unevenness, is molded according to the arrangement of the contacts. Here, the housing of the connector according to one embodiment only needs to be designed for the thickness of the minimum wall thickness part, like the card 31 described above. Also, the thickness of the connector housing other than the minimum wall thickness part can be designed like the card 31. The connector according to one embodiment achieves miniaturization of the connector itself by designing the thickness of the minimum wall thickness part of the housing (molded body), while achieving high heat resistance derived from the paramylon nanofibers by the molded body formed from a resin composition containing paramylon nanofibers.

[0070] The housing of the connector according to one embodiment may be molded by combining a plurality of parts into one housing, or may include a molded article molded from a resin composition containing paramylon nanofiber in addition to the housing. For example, the connector according to one embodiment may include a fixing mechanism (lock lever) for fixing the connector to an electric circuit after connecting the contacts, and the fixing mechanism may be a molded article formed from a resin composition containing paramylon nanofiber.

[0071] The connector according to an embodiment may be, for example, a flexible flat cable (FFC) connector, a half-pitch connector, etc. Also, the connector may be, for example, a connector conforming to standards such as DIN and MIL.

[0072] In addition, the components according to one embodiment are not limited to the electronic components described above, but may be at least one of relays, switches, connectors, and sensors incorporated into on-board devices mounted on vehicles such as automobiles, electrical appliances, medical equipment, and precision machinery, etc.

[0073] [4] Resin composition (first embodiment) The resin composition according to one embodiment contains paramylon nanofiber and a resin material, and may contain other components. By containing paramylon nanofiber as a reinforcing material, the resin composition can impart heat resistance derived from the paramylon nanofiber to molded articles and further parts.

[0074] The deflection temperature under load of a resin composition containing paramylon nanofiber and a resin material is preferably 190° C. or higher, and more preferably 200° C. or higher. The deflection temperature under load may be evaluated by carrying out a deflection temperature under load test in accordance with JIS K7191A method (ISO75).

[0075] [4-1] Paramylon nanofiber (PNF) Paramylon is an aggregate of fibrous β-1,3-glucan produced in the body of Euglena (Japanese name: Midorimushi), and the aggregate forms flat particles. Paramylon nanofiber is obtained by purifying paramylon and has a randomly branched three-dimensional structure.

[0076] In the three-dimensional structure described above, the paramylon nanofiber has a triple helical structure formed by β-1,3-glucan containing glucose units bonded by β-1,3-glucosidic bonds as the main chain. That is, the paramylon nanofiber may contain nanofibers of β-1,3-glucan in which the main chain of glucose units has a triple helical structure. The paramylon nanofiber may partially contain β-1,6-glucosidic bonds and may have branched chains, but it is more preferable that the paramylon nanofiber is a β-1,3-glucan containing only β-1,3-glucosidic bonds. In addition, the paramylon nanofiber may be chemically modified, for example, by substituting the hydroxyl group bonded to the 6-position carbon of the β-1,3-glucan.

[0077] The three-dimensional structure of paramylon nanofiber is different from that of known glass fibers, which are aggregates of single fibers. The three-dimensional structure of paramylon nanofiber can prevent anisotropy from occurring in molded bodies compared to glass fibers. Anisotropy means a difference in a specific physical property caused by a difference in the directionality of a single molded body. Here, the specific physical property includes molding shrinkage rate. Also, unlike glass fibers, paramylon nanofiber has the advantage that it can be used as a reinforcing material while increasing the bio ratio. The bio ratio is evaluated based on the content of bio-derived raw materials contained in the molded body of the resin composition on a mass basis.

[0078] In relation to the bio-ratio of the resin composition, for example, cellulose nanofibers derived from wood may be used as a reinforcing material. It is known that cellulose nanofibers undergo thermal denaturation at around 200°C, which can make them heat-resistant up to 250°C. It is known that the heat resistance of cellulose nanofibers can be reduced by heating them at a temperature higher than 250°C (Seikei-KakouVol. 28, No.6, 2016, pp.232-235 (jst.go.jp)). It is believed that the low heat resistance of cellulose nanofibers is due to the inclusion of lignin. On the other hand, parts such as relays, switches, and connectors are continuously or intermittently subjected to heat on their molded bodies. For this reason, plastics with high heat resistance can be used as the resin material for the molded bodies of the parts, as described later. Therefore, the resin composition for molding the molded bodies of the parts is also required to have high heat resistance as a reinforcing material. The heat resistance required for the reinforcing material herein not only contributes to the heat resistance of the molded article itself, but is also required during the production of the molded article, more specifically, in the process from mixing the resin composition to molding.

[0079] Paramylon nanofiber does not contain lignin in the raw material. Therefore, paramylon nanofiber does not have a drop in melting point caused by lignin and has high heat resistance. The melting point, which can be an indicator of the heat resistance of paramylon nanofiber, is preferably 250°C or higher, more preferably 290°C or higher, and has higher heat resistance than cellulose nanofiber. In addition, paramylon nanofiber may have a melting point of 400°C or lower, although this should not be limited. As a result, parts containing paramylon nanofiber in a molded body can not only increase the bio content, but also achieve high heat resistance.

[0080] The paramylon nanofibers may have a persistence length in the range of 0.5 to 10 μm, a diameter in the range of 0.5 to 1000 nm, and an aspect ratio in the range of 500 to 10,000.

[0081] Paramylon nanofiber has a specific gravity of 1.5g / cm, similar to cellulose nanofiber. 3 It is about as light as the original, which also helps reduce the weight of parts.

[0082] The resin composition preferably contains 1 to 80% by mass of paramylon nanofiber as a reinforcing agent, with the total of the resin material and the paramylon nanofiber being 100% by mass. When the resin composition contains 1% or more by mass of paramylon nanofiber, with the total of the resin material and the paramylon nanofiber being 100% by mass, the mechanical strength derived from the resin composition can be increased even in small parts. Furthermore, when the resin composition contains 80% or less by mass of paramylon nanofiber, with the total of the resin material and the paramylon nanofiber being 100% by mass, the fluidity of the resin composition can be maintained when molding a molded product.

[0083] [4-2] Resin materials From the viewpoint of imparting high heat resistance to a molded body of the resin composition and further to a part, the resin material is preferably a resin material having a high glass transition temperature (Tg) which can be an index of heat resistance. From the viewpoint of imparting high heat resistance to the resin composition, the resin material may have a glass transition temperature (Tg) which can be an index of heat resistance of, for example, 90° C. or more, and is more preferably a resin material having a glass transition temperature (Tg) of 260° C. or more. Although not limited, it is preferable that the resin material has a glass transition temperature (Tg) of 400° C. or less. By containing a resin material having a glass transition temperature (Tg) of 90° C. or more, the resin composition can mold a molded body of the resin composition without impairing the high heat resistance derived from the paramylon nanofiber, and can be used for various parts such as an in-vehicle device. In addition, by containing a resin material having a glass transition temperature (Tg) of 260° C. or more, the resin composition can be used for a molded body provided in an electronic part such as an electric circuit, which requires high heat resistance. Examples of such resin materials include engineering plastics such as nylon 6, nylon 66, polyacetal, polycarbonate, modified polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, and PC-ABS (polymer alloy of polycarbonate-acrylonitrile butadiene styrene); general-purpose plastics such as polyvinyl chloride, polyethylene, polypropylene, polystyrene, ABS, and polymethyl methacrylate; thermoplastics such as phenolic resins, urea resins, melamine resins, epoxy resins, unsaturated polyesters, silicone resins, and polyurethanes; and super engineering plastics such as polysulfone, polyethersulfone, polyarylate, polyamideimide, polyetherimide, liquid crystal polymers, polytetrafluoroethylene, polychlorotrifluoroethylene, and polyvinylidene fluoride. Among these resin materials, from the viewpoints of ease of molding of the molded body, mechanical strength of the molded body, and manufacturing costs, the resin material is preferably a polyester-based resin as an engineering plastic such as polyethylene terephthalate or polybutylene terephthalate.

[0084] Polyester-based resins as engineering plastics are composed of a dicarboxylic acid component and a diol component. For example, the dicarboxylic acid may be an aromatic dicarboxylic acid such as terephthalic acid, isophthalic acid, or naphthalenedicarboxylic acid, or an aliphatic dicarboxylic acid such as adipic acid or sebacic acid, and the diol may be an aliphatic glycol such as ethylene glycol, 1,4-butanediol, or polyoxymethylene glycol.

[0085] Moreover, examples of resin materials include bioplastics, which include, for example, biomass plastics and biodegradable plastics. Biomass plastics are resins synthesized using biomass such as sugars and oils derived from sugarcane, corn, etc., as raw materials, and examples of such plastics include fully biomass-based plastics and partially biomass-based plastics.

[0086] The fully biomass-based plastics are resins made only from biomass, such as polylactic acid and polyglycolic acid, which may also be biodegradable resins. The partially biomass-based plastics are resins made from both biomass and fossil resources, such as polyester resins made from sugar alcohols such as ethylene glycol derived from biomass. Examples of such partially biomass-based plastics include polylactic acid copolymers, polyethylene terephthalate (PET), and polypropylene terephthalate (PPT).

[0087] Further, examples of biodegradable plastics include polyester resins such as polybutylene adipate / terephthalate (PBAT) and polybutylene succinate / terephthalate (PBST) in addition to polylactic acid and polyglycolic acid.

[0088] [4-3] Other Composition The resin composition may contain other reinforcing materials such as glass fiber, wollastonite, zonolite, sepiolite, mica, potassium titanate whiskers, layered silicates, and organically modified bentonite, as long as the effects of the present invention are not impaired.

[0089] The resin composition may contain, as other components, additives such as an antioxidant, a hydrolysis inhibitor, a lubricant, a dispersing / wetting agent, and a silane coupling agent.

[0090] [5] Resin composition (second embodiment) The resin composition according to the present invention is not limited to the above-mentioned embodiment (first embodiment). For example, the resin composition according to one embodiment (second embodiment) contains paramylon nanofiber, a resin material, a flame retardant, and a flame retardant auxiliary, and may contain other components.

[0091] The paramylon nanofibers and other components can be the same as those in the resin composition according to the first embodiment, and therefore a description thereof will be omitted.

[0092] The resin material may be the resin material described in the resin composition according to the first embodiment. As already described, the resin material may have a glass transition temperature (Tg) of, for example, 90° C. or higher, and is more preferably a resin material having a glass transition temperature (Tg) of 260° C. or higher. By including a resin material having a glass transition temperature of 260° C. or higher, flame retardancy can be imparted to the resin composition that may be exposed to a high-temperature environment due to heat generation, and further to parts such as electronic parts that include a molded body of the resin composition.

[0093] [5-1] Flame retardants The resin composition may include a flame retardant. Examples of the flame retardant include organic flame retardants and inorganic flame retardants. Examples of the organic flame retardant include halogen-based flame retardants and non-halogen-based flame retardants.

[0094] The halogen-based flame retardant burns together with the molded body of the resin composition when it is burned, and serves as a source of halogen for the flame retardant auxiliary. Examples of the halogen-based flame retardant include bromine-based flame retardants and chlorine-based flame retardants, and bromine-based flame retardants are preferred. Examples of the bromine-based flame retardant include high molecular weight flame retardants such as TBA epoxy oligomer, TBA polycarbonate oligomer, brominated polystyrene, and bis(tetrabromophthalimide)ethane. In this specification, TBA is an abbreviation for tetrabromobisphenol A. Examples of the bromine-based flame retardant include tetrabromobisphenol A, tetrabromobenzene, hexabromobenzene, tribromophenol, and hexabromocyclodecane. It is preferable to use a high molecular weight bromine-based flame retardant because it can prevent bleeding onto the surface of the molded body and does not fall under the category of prohibited substances. Examples of the chlorine-based flame retardant include chlorinated paraffin and perchloropentacyclodecane.

[0095] Examples of non-halogen flame retardants include phosphorus flame retardants and nitrogen flame retardants. Examples of phosphorus flame retardants include triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, tert-butylphenyl diphenyl phosphate, bis-(tert-butylphenyl)phenyl phosphate, tris-(tert-butylphenyl)phosphate, isopropylphenyl diphenyl phosphate, bis-(isopropylphenyl)diphenyl phosphate, tris-(isopropylphenyl)phosphate, resorcinol bis-diphenyl phosphate, resorcinol bis-dixylenyl phosphate, and bisphenol A bis-diphenyl phosphate. In addition, examples of the nitrogen-based flame retardant include nitrogen-based flame retardants such as melamine cyanurate, and other composite flame retardants include guanidine sulfamate, guanidine phosphate, guanylurea phosphate, melamine phosphate, and other composite flame retardants.

[0096] Examples of inorganic flame retardants include metal hydroxides and red phosphorus, and examples of metal hydroxides include aluminum hydroxide and magnesium hydroxide.

[0097] The content of the flame retardant contained in the molded body of the resin composition is not limited, but is preferably 5 to 50 parts by weight, more preferably 5 to 20 parts by weight, and more preferably 8 to 18 parts by weight, based on 100 parts by weight of the resin material. By using 5 parts by weight or more of the flame retardant for 100 parts by weight of the resin material, the flame retardancy of the molded body of the resin composition and further the parts can be improved. In addition, by using 50 parts by weight or less of the flame retardant for 100 parts by weight of the resin material, the fluidity of the resin composition during molding and the mechanical strength of the molded body molded from the resin composition can be improved. Therefore, for example, the parts can be suitably miniaturized.

[0098] [4-3] Flame retardant synergists The resin composition may contain a flame retardant auxiliary. Examples of the flame retardant auxiliary include inorganic oxides of metals, such as antimony-based flame retardant auxiliary and bismuth-based flame retardant auxiliary. Examples of the antimony-based flame retardant auxiliary include diantimony trioxide or diantimony pentoxide, and examples of the bismuth-based flame retardant auxiliary include dibismuth trioxide or dibismuth pentoxide. To explain an example of an antimony-based flame retardant auxiliary, an antimony halide is generated by the heat generated when the part is burned and the halogen derived from the halogen-based flame retardant, and the antimony halide is vaporized by the heat. The antimony halide is highly stable against heat, suppresses the increase in the active gas concentration in the vicinity of the resin molding material, and suppresses the supply of oxygen to the burning resin molding material. This provides flame retardancy to the resin molding material. Here, the active gas may refer to a combustible organic matter generated by the decomposition of the resin molding material by heat, that is, a decomposition gas.

[0099] The content of the flame retardant auxiliary contained in the molded product of the resin composition may be adjusted by the ratio with respect to the content of the halogen-based flame retardant described above. For example, the content of the halogen-based flame retardant: the content of the flame retardant auxiliary is preferably within the range of 8:1 to 1:1, and more preferably within the range of 4:1 to 2:1. The content of the halogen-based flame retardant: the content of the flame retardant auxiliary in the resin composition is within the range of 8:1 to 1:1, and by increasing the content of the flame retardant auxiliary, the flame retardancy of the halogen-based flame retardant can be fully exhibited. In addition, the content of the halogen-based flame retardant: the content of the bismuth-based flame retardant auxiliary in the resin composition is within the range of 8:1 to 1:1, and by decreasing the content of the flame retardant auxiliary, the moldability of the molded product containing the resin composition can be improved.

[0100] [6] Molding of molded bodies The resin composition may be prepared, for example, by preliminarily mixing the resin material, the bromine-based flame retardant, and the bismuth-based flame retardant auxiliary in a known mixer such as a Henshiel mixer, and then melt-kneading the mixture in a known melt-kneading device such as a twin-screw extruder, followed by pelletization.

[0101] The heating temperature and kneading time during melt-kneading may be appropriately designed depending on the glass transition temperature of the resin material contained in the resin composition and the melting point of the paramylon nanofiber. The paramylon nanofiber has a high melting point, and therefore melting of the paramylon nanofiber in the resin composition can be prevented during the process from melt-kneading with the resin material having a high glass transition temperature to molding. This prevents the high heat resistance derived from the paramylon nanofiber from being impaired during the part manufacturing process.

[0102] In addition, the molding method of the resin composition includes known methods such as injection molding, extrusion molding, and press molding, and may be appropriately designed depending on the type of resin composition and the size of the molded product to be manufactured. The molded product of the resin composition has anisotropy with low molding shrinkage rate due to the three-dimensional structure of the paramylon nanofiber. Therefore, it is possible to improve dimensional stability when designing the molded product of the part.

[0103] 〔summary〕 As described above, the resin composition according to aspect 1 of the present invention contains a resin material and paramylon nanofibers.

[0104] The above-mentioned configuration makes it possible to provide a novel resin composition that has a high bio content and high heat resistance derived from the paramylon nanofiber.

[0105] A part according to a second aspect of the present invention includes a molded article formed from the resin composition according to the first aspect.

[0106] The above configuration makes it possible to provide parts with a high bio content and high heat resistance derived from the paramylon nanofiber.

[0107] In addition, in the part according to aspect 3 of the present invention, in the above aspect 2, the resin material may be a polyester resin.

[0108] With the above-described configuration, a part having excellent formability in the thin-walled portion can be provided, and further, a part having high heat resistance can be provided.

[0109] In addition, in the part according to a fourth aspect of the present invention, in the above-mentioned second or third aspect, the resin material may contain a halogen-based flame retardant and a flame retardant auxiliary.

[0110] The above-mentioned composition can impart high flame retardancy to parts having a high bio content and high heat resistance.

[0111] Furthermore, the part according to aspect 5 of the present invention may be any of aspects 2 to 4 above, and may include an electrical contact or the electrical contact and a coil, and the molded body may encapsulate the electrical contact and the coil or may be in contact with the electrical contact or the coil.

[0112] With the above-mentioned configuration, it is possible to increase the bio content of the electrical contact or the part including the electrical contact and the coil, and also to impart high heat resistance to the part.

[0113] A sixth aspect of the present invention relates to a part according to any one of the second to fifth aspects, wherein the molded article is at least one molded article selected from a base, a case, a card, a spool, and a housing.

[0114] By using a molded article having the above-mentioned configuration, it is possible to provide a part having a high bio content and high heat resistance.

[0115] In addition, the part according to a seventh aspect of the present invention may be a relay, a switch, a connector, or a sensor in any of the second to sixth aspects.

[0116] A part having the above-mentioned configuration has a high bio content and high heat resistance derived from the paramylon nanofiber.

[0117] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. EXAMPLES

[0118] An embodiment of the present invention will now be described.

[0119] [1] Preparation of resin composition As Example 1 and Comparative Examples 1 to 3, resin composition resins for molding molded bodies of parts were prepared, and the physical properties of the molded bodies were evaluated.

[0120] [1-1] Example 1 20 to 80 parts by mass of paramylon nanofiber (PNF) was added to 100 parts by mass of polybutylene terephthalate (PBT) and melt-kneaded.

[0121] Pellets of a resin composition to be used for evaluating transparency are prepared under the same conditions as in Example 1, except that polybutylene terephthalate is replaced with polycarbonate.

[0122] [1-2] Comparative Example 1 Pellets of the resin composition of Comparative Example 1 and pellets of the resin composition used for transparency evaluation were prepared under the same conditions as in Example 1, except that the paramylon nanofiber (PNF) used in Example 1 was changed to glass fiber (GF). The bio-ratio of the resin composition of Comparative Example 1, calculated from the composition ratio, was 0%.

[0123] [1-3] Comparative Example 2 Pellets of the resin composition of Comparative Example 2 and pellets of the resin composition used for transparency evaluation are prepared under the same conditions as in Example 1, except that the paramylon nanofiber (PNF) used in Example 1 is changed to cellulose nanofiber.

[0124] [1-4] Comparative Example 3 Pellets of the resin composition of Comparative Example 3 and pellets of the resin composition used for transparency evaluation were prepared under the same conditions as in Example 1, except that the paramylon nanofiber (PNF) used in Example 1 was changed to paramylon fiber (PF).

[0125] [1-5] Molding conditions of test pieces Test pieces (molded bodies) for evaluating each physical property are prepared from each of the pellets of the resin compositions of Example 1 and Comparative Examples 1 to 3. The test pieces are molded by injection molding to prepare the test pieces to be used in the evaluation of each physical property described below.

[0126] Next, as a pretreatment for each test, each test piece prepared is first placed in a thermostatic chamber at 23±2° C. and 50±10% RH for 48 hours.

[0127] [2] Evaluation methods for each physical property A test piece of the resin composition contained in the molded article used for the part according to one embodiment is prepared, and the bio content, bending strength, deflection under load, anisotropy, and transparency are evaluated as follows. In addition, the melting point of the reinforcing material contained in the molded article is measured.

[0128] [2-1] Bio rate The bio-ratio was evaluated by the mass content of bio-derived raw materials contained in a molded body (test piece) of the resin composition, and the evaluation criteria are as shown below.

[0129] [2-2] Bending strength evaluation The bending strength test of each molded body is performed according to the test method of JIS K7171 (ISO178). The test piece for bending strength test is made by the molding method of JIS K7139 Type A1 (ISO20753). The test piece is injection molded as a dumbbell with the length x width x thickness (h) of the parallel part of 80 x 10 x h4 mm.

[0130] [2-3] Load deflection evaluation (heat resistance evaluation) To evaluate the heat resistance of each molded body, a load deflection test is performed in accordance with JIS K7191A method (ISO75). Test pieces for the load deflection test are cut from injection molded plates in accordance with JIS K7139 Type A1 (ISO20753) as dumbbells with the parallel part's length x width x thickness (h) of 80 x 10 x 4 mm. The load deflection test is performed under a load of 1.8 MPa. The load deflection is evaluated based on the following criteria. +: The deflection temperature under load is 190°C or higher. -: Heat deflection temperature is lower than 190°C.

[0131] [2-4] Anisotropy evaluation The anisotropy of the thermal shrinkage of each molded body is evaluated. The anisotropy is evaluated by the mold shrinkage rate (S Mp ) and mold shrinkage rate (S Mn The test specimen is a flat plate conforming to JIS K7152-3 (ISO294-3).

[0132] Figure 3 shows the width b of the mold cavity used for anisotropy evaluation. c and length l c , and the relationship between the width b1 and length l1 of the test piece and the flow direction X. The mold shrinkage rate (S Mp) and the mold shrinkage perpendicular to the flow direction (S Mn ) are calculated from the following two formulas. Mn ) and mold shrinkage rate (S MP ) is the ratio of the mold shrinkage rate (S Mn ) / Mold shrinkage rate (S Mp ) is calculated.

[0133]

number

[0134] [2-5] Transparency evaluation Transparency evaluation is performed using a haze meter in accordance with the method of ASTM D 1003:C light source. In the transparency evaluation, polycarbonate (PC) is used as the resin material, and test pieces of 50 x 50 x 2 mmt are prepared, and the total light transmittance (unit: %) of each test piece is evaluated. +: Total light transmittance is 85% or more. -: Total light transmittance is less than 85%.

[0135] [2-6] Melting point measurement To evaluate the heat resistance of each reinforcing material, the melting points of the paramylon nanofiber (PNF) and cellulose nanofiber (CNF) used in Example 1 are measured. The melting point measurement is performed by differential scanning calorimetry (DSC) in accordance with JIS K7121 (ISO3146). Differential scanning calorimetry is performed using tin as the standard substance, with the start temperature set to 20°C, the end temperature set to 300°C, and the temperature rise rate set to 10°C / min and the temperature fall rate set to 10°C / min.

[0136] [3] Evaluation The evaluation results of each physical property of Example 1 and Comparative Examples 1 to 3 are expected to be as follows.

[0137] [Table 1]

[0138] Example 1 has a high bio content derived from PNF. Example 1 is expected to have higher bending strength and higher heat resistance than Comparative Example 2 containing CNF, which is believed to be due to the fact that PNF does not contain lignin, unlike CNF. Example 1 is expected to have low anisotropy of molding shrinkage, which is believed to be due to the three-dimensional branched structure of PNF. Example 1 is also expected to have high transparency, that is, high total light transmittance. [Industrial Applicability]

[0139] As described above, the resin composition according to one embodiment has a high bio content and high heat resistance. Therefore, it can be widely used for parts including molded bodies of the resin composition, and preferably, it can be used for components such as on-board devices mounted on automobiles, various devices mounted on aircraft, ships, etc., electrical products, medical machines, precision machines, etc., such as relays, switches, connectors, and various sensors, and resin molded bodies included in the components, and electronic components such as relays such as microrelays, switches such as microswitches, and connectors, and resin molded bodies included in the electronic components. [Explanation of symbols]

[0140] 1 Contact (electrical contact) 2 Base (molded body) 3 Cards (molded bodies) 4 Case (molded body) 5 Coil 6 Spool (molded body) 10 Relay (parts) 31 Card (molded body)

Claims

1. A resin material; A resin composition comprising paramylon nanofiber.

2. A part comprising a molded article formed from the resin composition according to claim 1.

3. The component of claim 2 , wherein the resin material is a polyester-based resin.

4. The component according to claim 2 , wherein the resin composition comprises a halogen-based flame retardant and a flame retardant synergist.

5. The present invention provides a coil and an electrical contact, The component of claim 2 , wherein the molding encapsulates or contacts the electrical contacts and the coil.

6. The component of claim 2 , wherein the molded body is at least one molded body selected from a base, a case, a card, a spool, and a housing.

7. The component according to any one of claims 2 to 6, which is a relay, a switch, a connector, or a sensor.

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