JP2008222865A - Biomass resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biomass composition containing a raw material derived from vegetables, composed of an environmentally friendly and resource-saving raw material and having high toughness and dimensional stability. <P>SOLUTION: The biomass resin composition contains (A) 50-99 pts.mass of a polyhydroxybutyrate and/or a polyhydroxybutyrate copolymer and (B) 50-1 pts.mass of a crosslinked polyolefin elastomer containing polypropylene as a matrix and a crosslinked polyolefin copolymer as a disperse layer. Preferably, the crosslinked polyolefin elastomer B has a Shore A hardness of 45-75; and preferably, the composition is composed of (C) 99.5-90 pts.mass of the resin composition and (D) 0.5-10 pts.mass of an epoxy-modified polyolefin copolymer. The melting point of the polyhydroxybutyrate copolymer is preferably 150-180°C. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a biomass resin composition. More specifically, an object of the present invention is to provide an ecological resin composition comprising a plant-derived polyester and a polyolefin-based elastomer, having good moldability, high rigidity and toughness, and high dimensional accuracy.

Conventionally, since polyhydroxybutyrate resin has biodegradability, research has been conducted to use molded articles as daily necessities, and to biodegrade after use and return naturally. However, the productivity during molding was inferior, the strength of the molded product was low, and the impact resistance was low, and the practical range was limited. In addition, attempts have been made to improve moldability and impact resistance by polymer blending with polyethylene, polyurethane, natural rubber, etc., but mutual dispersibility is not good. The improvement was insufficient for the demand. (See Patent Documents 1 to 3)
For this reason, there has been a request for development of a plant-derived resin composition having high moldability and toughness in terms of resource saving.
JP-A-2005-232228 JP 2005-232229 A JP-A-2005-255722

  An object of the present invention is to provide a by-mass resin composition having good moldability, high dimensional accuracy, high toughness, good appearance, excellent merchantability, and low dependence on petroleum. More specifically, an object of the present invention is to provide a resin composition comprising a specific cross-linked polyolefin elastomer highly compatible with a microorganism-produced polyhydroxybutyrate, having a low production energy and excellent moldability and mechanical properties.

As a result of intensive studies to solve the above problems, the present inventors have finally completed the present invention. That is, the present invention relates to a cross-linked polyolefin elastomer having a dispersion layer of 50 to 99 parts by mass of polyhydroxybutyrate and / or polyhydroxybutyrate copolymer (A) and a polyolefin copolymer having crosslinks using polypropylene as a matrix. (B) It is a biomass resin composition characterized by containing 50-1 mass part.
The biomass resin composition according to claim 1, wherein the cross-linked polyolefin elastomer (B) preferably has a Shore A hardness of 45 to 75.
Furthermore, the biomass resin composition which makes it a preferable aspect to contain the biomass resin composition 99.5-90 mass parts of Claim 1, and 0.5-10 mass parts of epoxy-modified polyolefin copolymers (C). object.
It is a biomass resin composition in which the melting point of the polyhydroxybutyrate copolymer is preferably from 150 to 180 ° C.

  The biomass resin composition of the present invention having the above structure has good compatibility between the polyhydroxybutyrate and the cross-linked polyolefin elastomer, and the appearance of the molded product is good. Moreover, it has good mold release properties, excellent moldability, and high toughness. Also, the molding shrinkage is relatively small. This composition contains a plant-derived resin component, and can provide a resource-saving molded article.

Hereinafter, the present invention will be described in detail.
In order to satisfy the objective moldability, toughness and appearance of the present invention, a dispersed structure having an average particle size of the dispersed phase of 10 μm or less is important. For this purpose, polyhydroxybutyrate and / or hydroxybutyrate is used. The ratio of the rate copolymer (A) to the polyolefin-based elastomer (B) is preferably 99 to 60 parts by mass to 1 to 40 parts by mass, and particularly 99 to 70 parts by mass with 1 to 30 parts by mass of plant-derived resin components. Part by mass is particularly preferred.

The polyhydroxybutyrate and / or polyhydroxybutyrate copolymer (A) used in the present invention is preferably a resin having a melt flow rate at 190 ° C. and 21.2 N of 0.1 to 100 g / 10 min. In particular, 0.5 to 50 g / 10 min is preferable. If it is 0.1 g / 10 min or less, the fluidity at the time of molding is low, and a large molded product cannot be molded. Further, if it is 100 g / 10 min or more, the mechanical strength is low and brittle, which is not preferable for the present invention. As the polyhydroxybutyrate copolymer, those having a melting point of 150 to 180 ° C. are preferable for the present invention because the molding cycle at the time of injection molding is short and the heat resistance and rigidity are high. Therefore, the copolymerization ratio of the polyhydroxybutyrate copolymer is preferably less than 20 mol%, particularly preferably less than 10 mol%. If it is 20 mol% or more, the melting point drop of polyhydroxybutyrate is large, and the heat resistance of the molded product is lowered, and the crystallization speed is lowered to lower the productivity at the time of molding, which is not preferable.
Examples of the copolymer component include hydroxyvalerate, lactic acid, ε-caprolactone, ethylene adipate, butylene adipate, hexylene adipate, ethylene succinate, butylene succinate, glycolic acid, ethylene terephthalate, and butylene terephthalate. Of these, hydroxyvalerate, lactic acid, ε-caprolactone, ethylene succinate and butylene succinate are particularly preferred.

  The production method of the polyhydroxybutyrate resin used in the present invention is not limited, but a product produced by extracting a polyhydroxybutyrate produced by fermentation using a microorganism with a solvent has a high biodependency rate. The energy required for production is low, which is preferable for life cycle assessment.

  The polyolefin-based elastomer used in the biomass resin composition of the present invention is a cross-linked polyolefin-based elastomer having a polypropylene as a matrix and a cross-linked polyolefin copolymer as a dispersion layer, and kneading the polypropylene and the polyolefin copolymer. Manufactured by dynamic crosslinking. From the viewpoint of improving the toughness of the polyhydroxy resin, the Shore A hardness is preferably 45 to 75. In general, toughness and heat resistance and dimensional stability are contradictory properties, but the composition of the present invention unexpectedly retains the heat resistance and dimensional stability of the polyhydroxybutyrate-based resin, and thus polyhydroxybutyrate. It is possible to improve the breaking elongation and impact strength of the rate. This is considered to be an effect that the polyolefin having the crosslink has a special higher order structure. A Shore hardness A of 75 or more is not preferable because the molding shrinkage ratio increases and the dimensional accuracy decreases. On the other hand, when it is 45 or less, the improvement in toughness of the polyhydroxybutyrate resin is small, which is not preferable. This Shore hardness depends on the proportion of polypropylene and copolymerized polyolefin copolymer, the dispersed particle diameter, and the degree of crosslinking of the polyolefin copolymer. If the Shore hardness A is in the range of 45 to 75, the object of the present invention is Achieved.

Further, since the polyolefin copolymer has cross-linking at the polyolefin-based copolymer portion, a fine dispersion layer is formed in the polypropylene even if the fraction exceeds 50%. Since the matrix is made of crystalline polypropylene having a melting point of 165 ° C., it is considered that the matrix has a low coefficient of thermal expansion and good dimensional stability.
Examples of the component monomer of the polyolefin copolymer include ethylene, propylene, butylene, pentene, hexene, octene, and isobutylene. According to these monomers, it is preferable to include a small amount of a monomer having a conjugated or non-conjugated double bond such as butadiene, pentagen or divinylbenzene, or a monomer having a functional group such as maleic anhydride or glycidyl methacrylate.
A cross-linked structure is formed in the polyolefin copolymer by mixing a polyfunctional compound such as diamine or dicarboxylic acid that reacts with an organic peroxide or active hydrogen when kneaded with polypropylene. The dispersed particle diameter of the polyolefin copolymer in polypropylene is preferably 10 μm or less, particularly preferably 3 μm or less.

Further, in the present invention, an epoxy-modified polyolefin copolymer is 0.5 to 90 parts by mass with respect to 99.5 to 90 parts by mass of a biomass resin composition comprising a polyhydroxybutyrate-based resin, polypropylene, and a polyolefin copolymer. It is a preferred embodiment that 10 parts by mass is blended. When an epoxy-modified polyolefin copolymer is blended, it is preferable because toughness increases synergistically. The reason why the synergistic effect of toughness due to the epoxy-modified polyolefin is not yet elucidated, but it is considered that the epoxy-modified polyolefin copolymer acts as a compatibilizing agent or an interfacial adhesive. If the polyolefin copolymer is less than 0.5 part, the effect of improving toughness is insufficient, and if it exceeds 10 parts by mass, the melt viscosity becomes high and the fluidity during molding is unfavorable.
Examples of the epoxy-modified polyolefin include copolymerization of glycidyl methacrylate and allyl glycidyl ether with monomers such as ethylene, propylene, butylene, pentene, hexene, isobutylene, vinyl ester, acrylic acid ester, methacrylic acid ester, and vinyl acetate. The polyolefin copolymer is modified by graft bonding by acting an organic peroxide and a compound containing an unsaturated bond and an epoxy group such as glycidyl methacrylate or allyl glycidyl ether. The epoxy group-containing monomer is preferably 1 to 20 parts by mass with respect to the polyolefin copolymer. If it is less than 1 part by mass, the effect is small, and if it exceeds 20 parts by mass, a gel is generated during molding, which is not preferable.

The production method for obtaining the biomass resin composition of the present invention is not particularly limited, but in order to enhance the effects of the present invention, polyhydroxybutyrate and / or polyhydroxy copolymer (A) and cross-linked polyolefin elastomer (B ) Is preferably melt-kneaded at 150 to 250 ° C.
From the viewpoint of improving the dimensional stability and toughness which are the objects of the present invention, the dispersed particle size of the dispersed phase is preferably 0.1 to 10 μm in terms of average particle size. When the thickness is 0.1 μm or less, the effect of improving toughness is small and not preferable. On the other hand, if it is 10 μm or more, the appearance and toughness of the molded product are lowered, which is not preferable.
Pellet and / or powdery polyhydroxybutyrate and / or polyhydroxybutyrate copolymer and cross-linked polyolefin alastomer are premixed and fed to an extruder, kneader or injection molding machine and melted under shear It can be produced by a method of kneading or by melting one of them in advance, adding another pellet or powder to this and melting and dispersing while kneading.

  The cross-linked polyolefin elastomer used in the present invention has an insoluble fraction of 30% by mass or more when frozen and pulverized into a powder of 100 mesh pass and immersed in n-hexane or cyclohexane at 23 ° C. for 10 hours. Is preferred.

  In the biomass composition used in the present invention, various modifying resins, stabilizers, colorants, fluidity improvers, mold release materials, crystal nucleating agents, and fibrous reinforcing materials are blended. These can be mixed before and after polymerization, but can be produced by kneading using a single screw extruder, a twin screw extruder, a kneader or the like. A composition containing the compounding agent at a higher concentration can be melt-kneaded in advance and mixed as a master batch at the time of molding.

  The use of the biomass composition of the present invention is not particularly limited. The biomass composition of the present invention is ecologically superior in that almost no residue is generated when incinerated after use, and the increase in carbon dioxide concentration in the atmosphere can be suppressed because a raw material derived from biomass components is used. The ecologically superior biomass composition of the present invention is used in industrial applications such as automobiles, electrical / electronic devices, OA equipment parts, and household equipment parts that require heat resistance and strength rigidity.

Hereinafter, although an example demonstrates, it is not limited to these. The physical properties in the specification were measured by the following methods.
(1) Charpy impact value A 10 mm x 4 mm x 80 mm notched test piece obtained from an ISO294-compliant mold conditioned for 48 hours at 23 ° C and 50% RH, a universal impact tester (60 kg- cm hammers) and tested according to ISO 179.
(2) Tensile Strength / Tensile Breaking Elongation ISO 294 compliant test pieces conditioned at 23 ° C. and 50% RH for 48 hours were tested in accordance with ISO 178 using Shimadzu Autograph AG-IS. The tensile strength, tensile modulus and tensile breaking elongation were measured.
(3) Mold shrinkage rate After drying at 100 ° C. for 3 hours with a hot air dryer, put it into the hopper of IS100 injection molding machine manufactured by Toshiba Machine Co., Ltd., and melt knead at the time of plasticization with a cylinder at 185 ° C. A test piece was molded by injection molding using a multi-mold die of a multi-purpose test piece according to ISO294-1 with a mold temperature of 50 ° C. as a standard. A multipurpose test was obtained with an injection time of 12 seconds and a cooling time of 12 seconds. The obtained multipurpose test was conditioned at 23 ° C. and 50% RH for 24 hours, and then the molded product was placed on a regular board, the length of the test piece was measured using a caliper, and the mold dimensions From the difference, the molding shrinkage was determined by the equation (1).
Mold shrinkage (%) = (Mold dimension-Molded product dimension) x 100 / Mold dimension (1)

(Examples 1-7, Comparative Examples 1-3)
The materials used in Examples and Comparative Examples and their abbreviations shown in the table are as follows.
<Polyhydroxybutyrate and / or polyhydroxybutyrate copolymer (A)>
PHB1: Enmat E200 [polyhydroxybutyrate, Tianan, melting point 174 ° C., melt flow rate (180 ° C./21.2 N) 30 g / 10 min],
PHB2: Enmat E100 [polyhydroxybutyrate copolymer, Tianan, melting point 170 ° C., melt flow rate (190 ° C./21.2 N) 24 g / 10 min].
<Crosslinked polyolefin elastomer (B)>
SL1: Sarlink 4155, manufactured by DSM, completely cross-linked type, Shore hardness 56
SL2: Sarlink 4165, manufactured by DSM, completely cross-linked type, Shore hardness 65
SL3: Sirlink 3150, manufactured by DSM, viaduct type, Shore hardness 57
SL4: Sirlink 4190, manufactured by DSM, completely crosslinked type, Shore hardness 88
<Epoxy-modified polyolefin (C)>
E2: Bond Fast 2C (manufactured by Sumitomo Chemical), ethylene-glycidyl methacrylate copolymer (glycidyl methacrylate 6 mass%)
E5: Bondfast 2B (manufactured by Sumitomo Chemical), ethylene-vinyl acetate-glycidyl methacrylate copolymer (glycidyl methacrylate 12 mass%, vinyl acetate 5 mass%),

  The above materials were preliminarily mixed in the dry ratios shown in Tables 1 and 2 and dried in a hot air dryer at 100 ° C. for 3 hours, and then in that state, a hopper of an IS injection molding machine manufactured by Toshiba Machine Co., Ltd. And melt-kneading at the time of plasticization with a cylinder whose temperature is adjusted to 170-180-180-180 ° C., and using a multi-mold die of a multi-purpose test piece conforming to ISO 294 at a mold temperature of 55 ° C. Thus, a test piece for evaluating mechanical properties was obtained with an injection time of 12 seconds and a cooling time of 12 seconds.

The obtained test piece was adjusted at 23 ° C. and 50% RH for 48 hours, and the tensile strength, tensile fracture elongation, and Charpy impact value were evaluated. The results are shown in Tables 1 and 2.
As is clear from Tables 1 and 2, the biomass composition comprising polyhydroxybutyrate and / or a polyhydroxybutyrate copolymer and a crosslinked polyolefin elastomer has high impact resistance and elongation. In addition, the molding shrinkage is small, and particularly the composition having a larger amount of the cross-linked polyolefin copolymer than the polyhydroxybutyrate is small in molding shrinkage and excellent in dimensional stability.

The biomass composition comprising polyhydroxybutyrate and a cross-linked polyolefin copolymer having high toughness and dimensional accuracy according to the present invention is a large-scale daily necessities and electrical appliances that require biodegradability and toughness that could not be designed individually. Used for product cases and housings. The resin composition of the present invention contains plant-derived raw materials, and is used as a molded product that is friendly to the earth in terms of reducing carbon dioxide and saving resources.

Claims (4)

  50 to 99 parts by mass of polyhydroxybutyrate and / or polyhydroxybutyrate copolymer (A), and cross-linked polyolefin elastomer (B) 50 to 50 using a polyolefin copolymer having cross-linking using polypropylene as a matrix as a dispersion layer A biomass resin composition comprising 1 part by mass.   The biomass resin composition according to claim 1, wherein the crosslinked polyolefin elastomer (B) has a Shore A hardness of 45 to 75.   A biomass resin composition comprising 99.5 to 90 parts by mass of the biomass resin composition according to claim 1 and 0.5 to 10 parts by mass of an epoxy-modified polyolefin copolymer (C). The biomass resin composition according to claims 1 to 3, wherein the polyhydroxybutyrate copolymer has a melting point of 150 to 180 ° C.