JP2008050444A - Resin composition, resin-molded article, and housing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition containing a biomass material, and having excellent impact-resistant strength and surface-impact strength; and to provide a resin molded article and a housing obtained by using the resin composition. <P>SOLUTION: The resin composition contains the biomass material and a DNA compound (deoxyribonucleic acid). The resin molded article and the housing comprise the resin composition. A resin component having a functional group such as a carboxy group and a derivative thereof, an amino group and isocyanate is preferable as the biomass material, and a polylactic acid is especially preferably used. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a resin composition, a resin molded body, and a housing.

  In recent years, plant-derived biomass materials have been actively developed from the viewpoints of environmental issues such as global warming, oil depletion, waste problems, and the concept of building a sustainable recycling society. For example, polylactic acid is attracting attention as a biomass material produced from cereals and the like without using any petroleum, and is used for applications such as agricultural sheets and household garbage bags.

  However, biomass materials such as polylactic acid generally have problems such as being hard and brittle and having low heat resistance, and therefore, application to uses other than those described above is extremely limited.

Therefore, studies are being made to improve impact strength and heat resistance in order to expand the application range of biomass materials. For example, Patent Document 1 below discloses a resin composition in which polylactic acid and an aromatic polycarbonate are combined and an impact strength modifier such as an elastic polymer is added.
JP-A-2005-48067

  However, as in the resin composition described in Patent Document 1, even if an aromatic polycarbonate or an impact strength modifier is used, the impact strength of the resulting resin molded product is not necessarily sufficient. There is room for improvement in terms of surface impact strength.

  The present invention has been made in view of such circumstances, and is a resin composition containing a biomass material, which is excellent in impact resistance strength and surface impact strength, and uses the resin composition. An object of the present invention is to provide a molded resin body and a casing.

  In order to solve the above problems, the present invention provides a resin composition comprising a biomass-derived resin component and a DNA (deoxyribonucleic acid) compound. Here, the DNA compound means a high molecular weight polynucleotide in which deoxyribonucleotides are units and are polymerized by a phosphate group (see, for example, Chemical Dictionary).

  According to the resin composition of the present invention, both the impact resistance strength and the surface impact strength can be sufficiently improved by using the biomass material and the DNA compound in combination. The resin composition of the present invention is also excellent in terms of elongation at break and heat resistance, and is useful in that the degree of biomass can be sufficiently increased.

  The reason why the impact resistance strength and the surface impact strength are improved by the resin composition of the present invention is not necessarily clear, but the present inventors infer as follows. That is, when molding is performed using the resin composition of the present invention, the hydroxyl group of the DNA compound reacts or coordinates with the functional group of the biomass material, and the uniaxial regular arrangement of the DNA compound is connected through the biomass material. As a result, it is considered that a pseudo IPN (Inter Penetrating Network, interpenetrating polymer network structure) is formed. And it is thought that impact resistance strength and surface impact strength of the obtained resin molding improve by formation of such pseudo IPN. In addition, in the case of the DNA compound alone, the present inventor has confirmed that the impact resistance strength is high but the surface impact strength is extremely low.

  As the biomass material contained in the resin composition of the present invention, an aliphatic polyester is suitable.

  Moreover, it is preferable that the weight average molecular weights of the DNA compound contained in the resin composition of this invention are 1000-1 million. In addition, the weight average molecular weight as used in the field of this invention means the weight average molecular weight of polystyrene conversion obtained by a gel permeation chromatography (GPC) measurement.

  The present invention also provides a resin molded product comprising a biomass material and a DNA compound.

  In addition, the present invention provides a resin molded body obtained by molding a resin composition containing a biomass material and a DNA compound.

  Since the resin molded body of the present invention contains a biomass material and a DNA compound or is obtained by molding a resin composition containing a biomass material and a DNA compound, the impact resistance strength and the surface impact strength. Furthermore, it is excellent in elongation at break, heat resistance and biomass.

  Thus, the resin molding of this invention which has the outstanding characteristic is used suitably as an office equipment part.

  Moreover, this invention provides the housing | casing characterized by using the resin molding of the said this invention for part or all.

  Since the housing of the present invention is configured to include the resin molded body of the present invention, it is excellent in impact resistance strength and surface impact strength, as well as elongation at break, heat resistance, and degree of biomass.

  As described above, according to the present invention, a resin composition containing a biomass material, which is excellent in impact resistance strength and surface impact strength, and a resin molded body and a casing using the resin composition Is provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

  The resin composition of the present invention contains a biomass material and a DNA compound. Although it does not restrict | limit especially as a biomass material, In order to enable reaction or coordination with the hydroxyl group of a DNA compound, the resin component which has functional groups, such as a carboxyl group and its derivative (s), an amino group, and isocyanate, is preferable. Among such resin components, aliphatic polyesters such as polylactic acid and polyhydroxybutyric acid are preferable, and polylactic acid is particularly preferable.

  When the biomass material is a biomass-derived resin component, the average molecular weight is not particularly limited, but the weight average molecular weight of the resin component is preferably 5,000 to 500,000, and more preferably 10,000 to 200,000. When the weight average molecular weight of the resin component is less than the lower limit, the mechanical strength is lowered, and the use tends to be remarkably limited. Moreover, when the weight average molecular weight of a resin component exceeds the said upper limit, there exists a tendency for a moldability to fall remarkably.

  The biomass material content in the resin composition of the present invention is preferably 20 to 90 mass%, particularly preferably 30 to 80 mass%, based on the total amount of the resin composition. When the content of the biomass material is less than 20% by mass, the degree of biomass tends to be low, and the environmental load reduction effect tends to be insufficient. Moreover, when content of biomass material exceeds 90 mass%, it exists in the tendency for impact strength to become inadequate.

  Moreover, it is preferable that the weight average molecular weight of the DNA compound contained in the resin composition of this invention is 1000-1 million, and 5000-500000 are more preferable. If the weight average molecular weight of the DNA compound exceeds 1,000,000, the melt viscosity becomes too high and molding tends to be difficult. Further, if the weight average molecular weight of the DNA compound is less than 1000, sufficient impact strength tends not to be obtained.

  The content of the DNA compound in the resin composition of the present invention is preferably 1 to 70% by mass and more preferably 3 to 50% by mass based on the total amount of the resin composition. When the content of the DNA compound is less than the lower limit value, the impact resistance strength and the surface impact strength tend to decrease. Further, if the content of the DNA compound exceeds the upper limit value, it becomes too hard and the embrittlement is emphasized, and the impact strength tends to decrease.

  The resin composition of the present invention may comprise a biomass material and a DNA compound, but if necessary, a flame retardant, a compatibilizing agent, a reinforcing agent, a steel material, a hydrolysis inhibitor, an antioxidant. Various additives such as a thickener may be contained.

  For example, examples of the flame retardant include bromine-based flame retardant, phosphorus-based flame retardant, silicone-based flame retardant, and inorganic particle-based flame retardant. Of these flame retardants, brominated flame retardants have an excellent flame retardant effect, but may generate toxic gases during combustion. Therefore, phosphorus flame retardants, silicone flame retardants, and inorganic particle flame retardants are preferred from the viewpoint of reducing environmental burden.

  Specific examples of the flame retardant preferably used in the present invention include phosphoric acid flame retardants such as phosphoric acid esters, condensed phosphoric acid esters, and phosphorus polymerized polyesters, silicone flame retardants such as silicone powder and silicone resin, water Examples thereof include inorganic particle flame retardants such as aluminum oxide and magnesium hydroxide.

  The content of the flame retardant is preferably 1 to 50% by mass and more preferably 2 to 30% by mass based on the total amount of the resin composition.

  In preparing the resin composition of the present invention, the biomass material, DNA compound, and additives such as flame retardant added as necessary may be mixed by a mechanical method such as kneading, or DNA. May be mixed with lipid and solubilized in organic solvent, and mixed with organic solvent solubilization, or by mixing biomass material in organic solvent and mixing DNA in water, and interfacial reaction, You may emulsify and mix.

  Among them, it is preferable to add an acetic acid metal salt compound by biaxial kneading and mix at a temperature of 150 to 250 ° C., because the surface impact strength of the obtained resin molded product becomes extremely high. In addition, it is thought that this surface impact strength improvement effect originates in formation of pseudo IPN by reaction or coordination of the hydroxyl group of a DNA compound and the functional group of biomass material more effectively.

  By molding the resin composition of the present invention having the above structure, the resin molded article of the present invention having excellent impact strength and surface impact strength, as well as elongation at break, heat resistance and biomass degree can be obtained. The office equipment molding method is not particularly limited, and for example, known molding methods such as injection molding, extrusion molding, blow molding, and hot press molding can be used.

  Alternatively, the resin composition of the present invention may be dissolved in a solvent and molded by a known method such as coating, casting or dip coating using the solution. Depending on the composition, the solvent in this case includes alcohols such as methanol and ethanol, ketones such as methyl ethyl ketone and acetone, esters such as ethyl acetate, aromatic compounds such as benzene, toluene and xylene, tetrahydrohydro Furan, dioxane, dimethylformamide and the like can be used.

  As described above, the resin molded product of the present invention is excellent in impact resistance strength and surface impact strength, and further in elongation at break, heat resistance, and biomass degree, and therefore is preferably used for applications such as office equipment, home appliances, and containers. it can. More specifically, they are housings for home appliances and office equipment, various parts, wrapping films, storage cases such as CD-ROMs and DVDs, tableware, food trays, beverage bottles, and chemical wrap materials. Among these, office equipment housings represented by housings such as printers, copiers and fax machines are required to have a high level of surface impact strength. By configuring, it is possible to realize the required performance.

  The casing of the present invention may be entirely composed of the resin molded body of the present invention, but if the portion where performance such as surface impact strength is required is composed of the resin molded body of the present invention, This part may be composed of a resin molded body other than the resin molded body of the present invention. Specifically, a front cover, a rear cover, a paper feed tray, a paper discharge tray, a platen, and the like in a casing of a printer, a copier, a fax machine, or the like are preferably made of the resin molded body of the present invention. On the other hand, the interior cover, the toner cartridge, and the like may be configured by either the resin molded body of the present invention or other resin molded bodies.

  FIG. 1 is an external perspective view of an image forming apparatus provided with a housing and office equipment parts according to an embodiment of the resin molded body of the present invention, as viewed from the front side. The image forming apparatus 100 in FIG. 1 includes front covers 120 a and 120 b on the front surface of the main body device 110. These front covers 120a and 120b can be opened and closed so that the user can access the inside of the apparatus. As a result, the user can replenish the toner when the toner is exhausted, replace the exhausted process cartridge, and remove the jammed paper when a jam occurs in the apparatus. FIG. 1 shows the apparatus with the front covers 120a and 120b opened.

  On the upper surface of the main body 110, an operation panel 130 on which various conditions relating to image formation such as a paper size and the number of copies are input by a user operation, and a copy glass 132 on which a document to be read is placed are provided. . Further, the main body device 110 includes an automatic document feeder 134 that can automatically convey a document on the copy glass 132. Further, main device 110 includes an image reading device that scans a document image placed on copy glass 132 and obtains image data representing the document image. Image data obtained by the image reading apparatus is sent to the image forming unit via the control unit. Note that the image reading device and the control unit are housed in a housing 150 that forms part of the main body device 110. The image forming unit is provided in the housing 150 as a detachable process cartridge 142. The process cartridge 142 can be attached and detached by turning the operation lever 144.

  A toner container 146 is attached to the casing 150 of the main body device 110, and toner can be replenished from the toner supply port 148. The toner stored in the toner storage unit 146 is supplied to the developing device.

  On the other hand, sheet storage cassettes 140a, 140b, and 140c are provided at the lower portion of the main unit 110. In addition, the main body apparatus 110 has a plurality of conveying rollers formed of a pair of rollers arranged in the apparatus, thereby forming a conveying path through which the sheets of the sheet storage cassette are conveyed to the upper image forming unit. ing. The paper in each paper storage cassette is taken out one by one by a paper take-out mechanism disposed near the end of the transport path and sent out to the transport path. Further, a manual paper tray 136 is provided on the side surface of the main body 110, and paper can be supplied from here.

  The paper on which the image is formed by the image forming unit is sequentially transferred between two fixing rolls that are supported by a casing 152 constituting a part of the main body device 110 and abut against each other. Paper is discharged to the outside. The main body device 110 is provided with a plurality of discharge trays 138 on the side opposite to the side on which the paper tray 136 is provided, and paper after image formation is discharged to these trays.

  In the image forming apparatus 100, the front covers 120a and 120b are subjected to many loads such as stress and impact during opening and closing, vibration during image formation, and heat generated in the image forming apparatus. Further, the process cartridge 142 receives a lot of loads such as attachment / detachment impact, vibration during image formation, and heat generated in the image forming apparatus. Further, the housing 150 and the housing 152 receive many loads such as vibration during image formation and heat generated in the image forming apparatus. Therefore, the resin molded body of the present invention is preferably used as the front covers 120a and 120b of the image forming apparatus 100, the exterior of the process cartridge 142, the casing 150, and the casing 152.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.

(Example 1)
50 parts by mass of polylactic acid (manufactured by Mitsui Chemicals, Lacia H100, weight average molecular weight 90000), 35 parts by mass of DNA compound (manufactured by Nichiro, weight average molecular weight 100000), 15 parts by mass of condensed phosphate ester (manufactured by Daihachi Chemical, PX-201) Part and 0.5 parts by mass of calcium acetate were put into a biaxial kneader (Toyo Seiki, Labo Plast Mill) and kneaded at 180 ° C. to obtain a resin composition.

  The obtained resin composition was injection molded at an injection temperature of 190 ° C. and a mold temperature of 70 ° C. using an injection molding machine (manufactured by Nissei Plastic Co., Ltd., EX50), and an ISO multipurpose dumbbell test piece, 150 mm × 150 mm, thickness 3 mm A flat molded article was obtained.

An ISO multipurpose dumbbell test piece was produced from a molded product obtained by injection molding under the same conditions as described above, and Charpy impact strength was measured using a digital impact strength measuring device (DG-C, manufactured by Toyo Seiki Co., Ltd.). Moreover, the surface impact strength was measured on the conditions of a contact area of 900 mm ² and a drop speed of 100 mm / min by using a surface impact strength measuring device (manufactured by Koei Machinery Co., Ltd., ME-1). The obtained results are shown in Table 1.

(Example 2)
A resin composition was prepared in the same manner as in Example 1 except that polylactic acid was changed to 90 parts by mass, the DNA compound was changed to 5 parts by mass, and the condensed phosphate ester was changed to 5 parts by mass, and calcium acetate was not used. . Next, an ISO multipurpose dumbbell test piece and a flat molded article were produced in the same manner as in Example 1 except that the obtained resin composition was used, and Charpy impact resistance strength and surface impact strength were measured. The obtained results are shown in Table 1.

(Example 3)
A resin composition was prepared in the same manner as in Example 1 except that polylactic acid was changed to 20 parts by mass, the DNA compound was changed to 70 parts by mass, and the condensed phosphate ester was changed to 10 parts by mass, and calcium acetate was not used. . Next, an ISO multipurpose dumbbell test piece and a flat molded article were produced in the same manner as in Example 1 except that the obtained resin composition was used, and Charpy impact resistance strength and surface impact strength were measured. The obtained results are shown in Table 1.

Example 4
A resin composition was prepared in the same manner as in Example 1 except that a DNA compound (manufactured by Nichiro, weight average molecular weight 1000000) was used instead of the DNA compound (manufactured by Nichiro, weight average molecular weight 100000). Next, an ISO multipurpose dumbbell test piece and a flat molded article were produced in the same manner as in Example 1 except that the obtained resin composition was used, and Charpy impact resistance strength and surface impact strength were measured. The obtained results are shown in Table 1.

(Example 5)
A resin composition was prepared in the same manner as in Example 1 except that a DNA compound (manufactured by Nichiro, weight average molecular weight 1000) was used instead of the DNA compound (manufactured by Nichiro, weight molecular weight 100000). Next, an ISO multipurpose dumbbell test piece and a flat molded article were produced in the same manner as in Example 1 except that the obtained resin composition was used, and Charpy impact resistance strength and surface impact strength were measured. The obtained results are shown in Table 1.

(Example 6)
A resin composition was prepared in the same manner as in Example 1 except that poly-3-hydroxybutyric acid was used instead of polylactic acid. Next, an ISO multipurpose dumbbell test piece and a flat molded article were produced in the same manner as in Example 1 except that the obtained resin composition was used, and Charpy impact resistance strength and surface impact strength were measured. The obtained results are shown in Table 1.

(Comparative Example 1)
30 parts by mass of polylactic acid (manufactured by Mitsui Chemicals, Lacia H100, weight average molecular weight 90000), 30 parts by mass of polycarbonate and 40 parts by mass of phosphoric acid ester (manufactured by Daihachi Chemical Co., Ltd., CR-741) , Laboplast Mill) and kneaded at 180 ° C. to obtain a resin composition. In Comparative Example 1, calcium acetate was not used. Next, an ISO multipurpose dumbbell test piece and a flat molded article were produced in the same manner as in Example 1 except that the obtained resin composition was used, and Charpy impact resistance strength and surface impact strength were measured. The obtained results are shown in Table 1.

(Comparative Example 2)
50 parts by mass of polylactic acid (manufactured by Mitsui Chemicals, Lacia H100, weight average molecular weight 90000), 30 parts by mass of nanoclay and 20 parts by mass of phosphate ester (manufactured by Daihachi Chemical Co., Ltd., CR-741) , Laboplast Mill) and kneaded at 180 ° C. to obtain a resin composition. In Comparative Example 1, calcium acetate was not used. Next, an ISO multipurpose dumbbell test piece and a flat molded article were produced in the same manner as in Example 1 except that the obtained resin composition was used, and Charpy impact resistance strength and surface impact strength were measured. The obtained results are shown in Table 1.

(Examples 7 to 12)
In Examples 7 to 12, each of the resin compositions of Examples 1 to 6 was injection molded at an injection temperature of 190 ° C. and a mold temperature of 70 ° C. using an injection molding machine (manufactured by Nissei Resin, EX50). A front cover (manufactured by Fuji Xerox, DocuCenter 500) was produced.

  Next, the surface impact strength of the obtained front cover was measured in the same manner as in Example 1. In addition, ISO multipurpose dumbbell test pieces and UL test pieces were cut out from the front cover, and Charpy impact strength measurement and flame resistance test (UL94-V combustion test) were performed. The obtained results are shown in Table 2. In addition, about a UL94-V combustion test, a vertical combustion test is implemented according to JIS Z2391, and when it passes, V-0, V-1, and V-2 are set in descending order of flame retardancy, and these flame retardant grades are reached. What did not do was made disqualified ("Not-V" in a table).

(Comparative Examples 3-4)
In Comparative Examples 3 to 4, a front cover of a color copying machine was produced in the same manner as in Examples 7 to 12 except that the resin compositions of Comparative Examples 1 and 2 were used, respectively, and Charpy impact resistance strength and surface impact were obtained. Strength measurements and flame retardant tests were performed. The obtained results are shown in Table 2.

It is an appearance perspective view showing an image forming device provided with a case and office equipment parts concerning one embodiment of a resin molding object of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Image forming apparatus, 110 ... Main body apparatus, 120a, 120b ... Front cover, 130 ... Operation panel, 132 ... Copy glass, 134 ... Automatic document feeder, 136 ... Paper tray, 140a-140c ... Paper storage cassette, 142 ... Process cartridge, 144... Operating lever, 146... Toner container, 148.

Claims (4)

  A resin composition comprising a biomass material and a DNA compound.   A resin molding comprising a biomass material and a DNA compound.   A resin molded article obtained by molding a resin composition containing a biomass material and a DNA compound. A housing characterized in that part or all of a resin molded body containing a biomass material and a DNA compound is used.

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