JP2010189472A - Eco-friendly thermoplastic resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an eco-friendly resin composition which has a high impact resistance improved effect, also has excellent flexibility and heat resistance, and has a low degree of dependence on petroleum products; and to provide a molded body. <P>SOLUTION: The eco-friendly thermoplastic resin composition containing a polylactic resin (A), a polyamide resin (B), and a core-shell type graft copolymer (C) is characterized in that a mass ratio (A/B) between the polylactic resin (A) and the polyamide resin (B) is from 10/90 to 40/60; a contents of the core-shell type graft copolymer (C) is 1-10 pts.mass based on 100 pts.mass of the total of the polylactic resin (A) and the polyamide resin (B); and the polyamide resin (B) is a polyamide 11 resin (B1) and/or a polyamide 1010 resin (B2). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an environmentally friendly thermoplastic resin composition having improved heat resistance while having excellent heat resistance, flexibility and moldability, and a molded body using the same.

In recent years, polylactic acid resins have attracted attention as plant-derived thermoplastic resins from the viewpoint of environmental conservation. Polylactic acid resins can be mass-produced, so they are low in cost and high in usefulness, and can be produced from raw materials such as corn and sweet potato as a raw material, thereby contributing to saving of depleted resources such as oil.
However, the polylactic acid resin not only has a low crystallization rate, but also has the disadvantage that the resulting molded article is inferior in mechanical strength, impact resistance and flexibility. In order to solve such problems, for example, in Patent Document 1, a polylactic acid resin is blended with another petroleum-based biodegradable resin that is superior in performance to a polylactic acid resin, It has been disclosed to improve impact resistance. However, this resin composition also has a long molding cycle and is insufficient in all aspects of impact resistance, flexibility and heat resistance. Further, Patent Document 2 discloses a polymer alloy with polyester, which is a petroleum-derived thermoplastic resin, but the amount of polylactic acid resin is small, and environmental considerations are sufficient. Absent.
It is also known to blend a rubber-like polymer such as an olefin copolymer with a polylactic acid resin in order to improve the impact resistance of the resin. For example, in Patent Document 3, a modified olefin compound is added. A method is disclosed, and Patent Document 4 discloses a method of adding a multilayer structure polymer. However, none of these methods has improved the impact resistance to withstand actual use.

On the other hand, polyamide 11 resin and polyamide 1010 resin have attracted attention as plant-derived thermoplastic resins other than polylactic acid resins. The polyamide 11 resin is produced from plant-derived raw materials in the same manner as the polylactic acid resin, and is preferable in consideration of the environment, and is excellent in flexibility and impact resistance. However, due to the high price, the applications used are limited. Similarly, the biomass-derived resin polyamide 1010 resin is less expensive than the polyamide 11 resin, and its significance is great. This polyamide 1010 resin also exhibits the same physical properties as the polyamide 11 resin, and has excellent flexibility and impact resistance.
However, for example, there is an example used in a member requiring such characteristics in Patent Document 5, etc., but polyamide 11 resin and polyamide 1010 resin are deformed at the time of mold release in injection molding because of low rigidity. Therefore, it has been difficult to produce an injection molded product using this resin.

JP 2002-309074 A Japanese Patent Laying-Open No. 2005-2000593 JP 9-316310 A JP 2006-160925 A JP 2006-283781 A

  An object of the present invention is to provide an environmentally friendly resin composition and a molded article which have a high impact resistance improving effect and at the same time have excellent flexibility and heat resistance and have a low dependence on petroleum products.

As a result of diligent investigation to solve the above-mentioned problems, the present inventor can solve the above-mentioned problems by combining a polylactic acid resin, a polyamide 11 resin and / or a polyamide 1010 resin, and a core-shell type graft copolymer. The headline and the present invention were completed.
That is, the gist of the present invention is as follows.
(1) The polylactic acid resin (A), the polyamide resin (B), and the core-shell type graft copolymer (C) are contained, and the mass ratio of the polylactic acid resin (A) to the polyamide resin (B) (A / B) is 10/90 to 40/60, and the content of the core-shell type graft copolymer (C) is 1 to 10 with respect to 100 parts by mass in total of the polylactic acid resin (A) and the polyamide resin (B). An environmentally friendly thermoplastic resin composition characterized by being a mass part and the polyamide resin (B) being a polyamide 11 resin (B1) and / or a polyamide 1010 resin (B2).
(2) The organic crystal nucleating agent (D) is further contained, and the content of the organic crystal nucleating agent (D) is 0.1 to 100 parts by mass in total of the polylactic acid resin (A) and the polyamide resin (B). The resin composition according to (1), which is 5 parts by mass.
(3) The resin composition as described in (1) or (2), wherein the core component constituting the core-shell type graft copolymer (C) is a silicone acrylic rubber.
(4) The resin composition according to any one of (1) to (3), wherein the polylactic acid resin (A) is a crosslinked polylactic acid resin.
(5) A molded product obtained by molding the resin composition according to any one of (1) to (4).

  According to the present invention, it is possible to provide an environmentally friendly thermoplastic resin composition that is excellent in heat resistance and flexibility and has a high impact resistance and a balance of properties with a plant-derived thermoplastic resin composition. it can. The use of plant-derived resin in the molded body has a low environmental impact and has a very high industrial utility value.

Hereinafter, the present invention will be described in detail.
The polylactic acid resin (A) used in the present invention contains polylactic acid as a main component. As polylactic acid, it is desirable to use poly (L-lactic acid), poly (D-lactic acid), and a mixture or copolymer thereof. From the viewpoint of biodegradability, it is preferable that poly (L-lactic acid) is the main component.
In addition, the main component is one or more resins selected from polyglycolic acid, polycaprolactone, polybutylene succinate, polyethylene succinate, polybutylene adipate terephthalate, polybutylene succinate terephthalate, etc. as accessory components. It may be mixed with polylactic acid resin and used as polylactic acid resin (A).

  Further, the melting point of polylactic acid mainly composed of poly (L-lactic acid) varies depending on the optical purity. However, in the present invention, the melting point is 160 ° C. or higher in consideration of the mechanical properties and heat resistance of the molded product. It is preferable that In the polylactic acid mainly composed of poly (L-lactic acid), in order to make the melting point 160 ° C. or higher, the ratio of the D-lactic acid component may be less than about 3 mol%.

  The melt flow rate of the polylactic acid resin (A) at 190 ° C. and a load of 21.2 N is usually 0.1 to 50 g / 10 minutes, preferably 0.2 to 20 g / 10 minutes, and optimally 0.5 to 10 g / 10. Minutes. When the melt flow rate exceeds 50 g / 10 min, the melt viscosity is too low, and the mechanical properties and heat resistance of the molded product are inferior. When the melt flow rate is less than 0.1 g / 10 min, the load during the molding process becomes too high, and the operability may be lowered.

  The polylactic acid resin (A) is produced by adding a known melt polymerization method or a solid phase polymerization method. As a method for adjusting the melt flow rate of the polylactic acid resin (A) to a predetermined range, when the melt flow rate is too large, a small amount of chain extender, for example, a diisocyanate compound, a bisoxazoline compound, an epoxy compound, The method of increasing the molecular weight of resin using an acid anhydride etc. is mentioned. Conversely, when the melt flow rate is too low, a method of mixing with a polylactic acid resin or a low molecular weight compound having a high melt flow rate can be used.

  In the present invention, a crosslinked polylactic acid resin in which a crosslinked structure is introduced into the polylactic acid resin may be used as the polylactic acid resin (A). The form of cross-linking is not particularly limited, and may be one in which polylactic acid resin molecules are directly cross-linked, indirectly cross-linked through a cross-linking aid, or mixed.

  As a method for introducing a crosslinked structure into a polylactic acid resin, known methods such as electron beam irradiation and the use of a polyfunctional compound such as a polyvalent isocyanate compound can be applied. However, radicals based on the use of peroxides in terms of crosslinking efficiency. Crosslinking is desirable.

  In the present invention, the polylactic acid resin (A) has two or more functional groups selected from a peroxide, a (meth) acrylic acid ester compound, and / or an alkoxy group, an acrylic group, a methacryl group, and a vinyl group. It is also possible to adopt a method of crosslinking with a silane compound.

In the present invention, the peroxide is blended for the purpose of promoting the reaction between the (meth) acrylic acid ester compound and / or the silane compound and the polylactic acid resin (A).
Specific examples of peroxides include benzoyl peroxide, bis (butylperoxy) trimethylcyclohexane, bis (butylperoxy) cyclododecane, butylbis (butylperoxy) valerate, dicumyl peroxide, butylperoxybenzoate, dibutyl Examples thereof include peroxide, bis (butylperoxy) diisopropylbenzene, dimethyldi (butylperoxy) hexane, dimethyldi (butylperoxy) hexyne, and butylperoxycumene.

  The amount of the peroxide added is preferably 0.02 to 20 parts by mass and more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the polylactic acid resin. If the addition amount is less than 0.02 parts by mass, the intended effect cannot be obtained, and if the addition amount exceeds 20 parts by mass, the operability during kneading may decrease.

In the present invention, the (meth) acrylic acid ester compound and / or the silane compound are blended for the purpose of promoting crystallization of the resin composition and improving heat resistance, as described above. .
As a specific compound of the (meth) acrylic acid ester compound, two or more in the molecule because the reactivity with the polylactic acid resin is high, the monomer hardly remains, the toxicity is low, and the resin is less colored. Or a compound having one or more (meth) acryl groups and one or more glycidyl groups or vinyl groups.
Specific examples of (meth) acrylic acid ester compounds include glycidyl methacrylate, glycidyl acrylate, glycerol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, allyloxy polyethylene glycol monoacrylate, allyloxy (poly) ethylene glycol monomethacrylate. , (Poly) ethylene glycol dimethacrylate, (poly) ethylene glycol diacrylate, (poly) propylene glycol dimethacrylate, (poly) propylene glycol diacrylate, (poly) tetramethylene glycol dimethacrylate, or these alkylene glycol moieties Copolymers of alkylenes of various lengths, butanediol methacrylate, butanediol active Rate, and the like.

  The compounding amount of the (meth) acrylic acid ester compound is preferably 0.01 to 5 parts by mass and more preferably 0.05 to 1 part by mass with respect to 100 parts by mass of the polylactic acid resin. If the addition amount is less than 0.01 parts by mass, the desired heat resistance cannot be obtained, but it can also be used in excess of 5 parts by mass within the range where the operability is not hindered.

The silane compound having two or more functional groups selected from an alkoxy group, an acrylic group, a methacryl group, and a vinyl group used in the present invention is represented by the formula (1).
In Formula (1), at least two of R1 to R4 represent a functional group selected from an alkoxy group, an acrylic group, a methacryl group, and a vinyl group, or a substituent having these functional groups. The rest represents other than an alkoxy group, an acrylic group, a methacryl group, and a vinyl group, and examples thereof include hydrogen, alkyl groups, and epoxy groups. Examples of the alkoxy group include a methoxy group and an ethoxy group. Examples of the substituent having an acrylic group include a 3-acryloxypropyl group. Examples of the substituent having a methacryl group include a 3-methacryloxypropyl group. Examples of the substituent having a vinyl group include a vinyl group and a p-styryl group. Examples of the alkyl group include a methyl group and an ethyl group. Examples of the substituent having an epoxy group include a 3-glycidoxypropyl group and a 2- (3,4-epoxycyclohexyl) group.
Specific examples and trade names of such silane compounds include tetramethoxysilane (GE Toshiba Silicone TSL8114, Shin-Etsu Chemical KBM-04), tetraethoxysilane (GE Toshiba Silicone TSL8124, Shin-Etsu Chemical). Industrial KBE-04), methyltrimethoxysilane (GE Toshiba Silicone TSL8113, Shin-Etsu Chemical KBM-13), methyltriethoxysilane (GE Toshiba Silicone TSL813, Shin-Etsu Chemical KBE-13) ), Dimethyldimethoxysilane (GE Toshiba Silicone TSL8112), dimethyldiethoxysilane (GE Toshiba Silicone TSL8122, Shin-Etsu Chemical KBE-22), methyldimethoxysilane (GE Toshiba Silicone TSL8117), methyldi Toxisilane (GE Toshiba Silicone TSL8127), phenyltrimethoxysilane (GE Toshiba Silicone TSL8173), phenyltriethoxysilane (GE Toshiba Silicone TSL8178, Shin-Etsu Chemical KBE-103), diphenyldimethoxysilane (GE) TSL8172 manufactured by Toshiba Silicone), diphenyldiethoxysilane (TSL8177 manufactured by GE Toshiba Silicone), hexyltrimethoxysilane (KBM-3063 manufactured by Shin-Etsu Chemical Co., Ltd.), decyltrimethoxysilane (KBM-3103C manufactured by Shin-Etsu Chemical Co., Ltd.), 3-Glycidoxypropyldimethoxymethylsilane (GE Toshiba Silicone TSL-8355), 3-Glycidoxypropyltrimethoxysilane (GE Toshiba Silicone TSL-8350, Shin-Etsu) KBM-403 from Gaku Kogyo Co., Ltd., dimethylvinylmethoxysilane (TSL8317 from GE Toshiba Silicone), methylvinyldimethoxysilane (TSL8315 from GE Toshiba Silicone), methylvinyldiethoxysilane (TSL8316 from GE Toshiba Silicone), dimethyl Vinylethoxysilane (GE Toshiba Silicone TSL8318), vinyltrimethoxysilane (Shin-Etsu Chemical KBM-1003), vinyltriethoxysilane (GE Toshiba Silicone TSL8311, Shin-Etsu Chemical KBE-1003), 2 -(3,4-epoxycyclohexyl) ethyltrimethoxysilane (KBE-303, Shin-Etsu Chemical Co., Ltd.), 3-glycidoxypropylmethyldiethoxysilane (KBE-402, Shin-Etsu Chemical Co., Ltd.), p-styryltri Methoxysilane (KBE-1403 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-methacryloxypropylmethyldimethoxysilane (TSL8375 manufactured by GE Toshiba Silicone, KBM-502 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-methacryloxypropyltrimethoxysilane (GE Toshiba) Silicone TSL8370, Shin-Etsu Chemical KBM-503), 3-methacryloxypropylmethyldiethoxysilane (Shin-Etsu Chemical KBE-502), 3-methacryloxypropyltriethoxysilane (Shin-Etsu Chemical KBE) -503), 3-acryloxypropyltrimethoxysilane (KBM-5103 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-acryloxypropylmethyldimethoxysilane (KBM-5102 manufactured by Shin-Etsu Chemical Co., Ltd.) and the like.

  Among these, a silane compound having one functional group selected from an acryl group, a methacryl group, and a vinyl group and having three alkoxy groups is preferable in terms of improving the crystallization speed. Specific examples and trade names of such silane compounds include vinyltrimethoxysilane (KBE-1003 manufactured by Shin-Etsu Chemical Co., Ltd.), vinyltriethoxysilane (GE Toshiba Silicone Co., Ltd. TSL8311, Shin-Etsu Chemical Co., Ltd. KBE- 1003), p-styryltrimethoxysilane (KBM-1403 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-methacryloxypropyltrimethoxysilane (TSL8370 manufactured by GE Toshiba Silicone, KBM-503 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-methacryloxy Examples thereof include propyltriethoxysilane (KBE-503 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-acryloxypropyltrimethoxysilane (KBM-5103 manufactured by Shin-Etsu Chemical Co., Ltd.), and the like.

  The compounding amount of the silane compound is preferably 0.01 to 5 parts by mass, more preferably 0.02 to 3 parts by mass, and 0.05 to 1 part by mass with respect to 100 parts by mass of the polylactic acid resin. More preferably, it is a part. It can also be used in excess of 5 parts by mass as long as the operability is not particularly hindered.

  The crosslinked polylactic acid resin is obtained by melt-kneading the polylactic acid resin (A), the peroxide, the (meth) acrylic acid ester compound and / or the silane compound, and the means for melt-kneading is particularly limited. However, there can be mentioned a method of melt-kneading using a single-screw or twin-screw extruder. In order to improve the kneading state, it is preferable to use a twin screw extruder. The kneading temperature is preferably in the range of (melting point of polylactic acid resin + 5 ° C.) to (melting point of polylactic acid resin + 100 ° C.), and the kneading time is preferably from 20 seconds to 30 minutes. When the temperature is lower than this range or for a short time, kneading or reaction becomes insufficient. On the other hand, when the temperature is high or for a long time, the resin may be decomposed or colored.

In the present invention, polyamide 11 resin (B1) and / or polyamide 1010 resin (B2) is used as the polyamide resin (B).
Polyamide 11 resin (B1) is obtained by polycondensation of 11-aminoundecanoic acid using ricinoleic acid in natural castor oil as a raw material, and its production method is not particularly limited, and is performed according to a known method. I can do it. Moreover, you may use additives, such as various catalysts and a heat stabilizer, in the case of manufacture. Examples of commercially available polyamide 11 resin (B1) include “Rilsan KNO” manufactured by Arkema.
Polyamide 1010 resin (B2) is a polycondensate of sebacic acid and decanediamine in natural castor oil, and its production method is not particularly limited, and can be carried out according to known methods. The mechanical properties of the resin alone are equivalent to the polyamide 11 resin. Examples of commercially available polyamide 1010 resin (B2) include “Zytel FE110004 NC010” manufactured by DuPont.
In the resin composition of the present invention, the mass ratio (A / B) of the polylactic acid resin (A) and the polyamide resin (B) needs to be 10/90 to 40/60. If the blending amount of the polyamide resin (B) is less than 60% by mass, the excellent properties may not be fully exhibited. If it exceeds 90% by mass, the cost of the polyamide resin (B) is high if the price is high. It is disadvantageous in terms.

  In the present invention, the core component constituting the core-shell type graft copolymer (C) is not particularly limited, but butadiene rubber, acrylic rubber, silicone rubber, and silicone acrylic rubber are preferable. System rubber is more preferable.

The core component butadiene rubber is a polymer composed of only 1,3-butadiene monomer units, or 1,3-butadiene monomer units and one or more vinyl monomers copolymerizable therewith. It is a polymer composed of body units. In addition, it is preferable that content of the 1 or more types of copolymerizable vinyl monomer unit is 50% by mass or less in the butadiene rubber polymer.
Here, vinyl monomers copolymerizable with 1,3-butadiene include aromatic vinyl compounds such as styrene and α-methylstyrene, alkyl methacrylates such as methyl methacrylate and ethyl methacrylate, ethyl acrylate, n -Alkyl acrylates such as butyl acrylate, unsaturated nitriles such as acrylonitrile and methacrylonitrile, vinyl ethers such as methyl vinyl ether and butyl vinyl ether, vinyl halides such as vinyl chloride and vinyl bromide, vinylidene chloride, vinylidene bromide, etc. Examples thereof include vinyl monomers having a glycidyl group such as vinylidene halide, glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, and ethylene glycol glycidyl ether.
In addition to the above, aromatic polyfunctional vinyl compounds such as divinylbenzene and divinyltoluene, polyhydric alcohols such as ethylene glycol dimethacrylate and 1,3-butanediol diacrylate, trimethacrylates, triacrylates, acrylics Crosslinkable monomers (crosslinking agents) such as carboxylic acid allyl esters such as allyl acid and allyl methacrylate, diallyl compounds such as diallyl phthalate and diallyl sebacate, and triallyl compounds such as triallyl triazine can be used. These can be used alone or in admixture of two or more.

The core component acrylic rubber contains 50 to 100% by mass of the main structural unit acrylic ester and 50 to 0% by mass of vinyl monomer copolymerizable therewith. The acrylic ester of the main structural unit in this acrylic rubber polymer is an acrylic alkyl ester having 2 to 8 carbon atoms in the alkyl group, such as ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, etc. It is done.
Examples of the remaining vinyl monomer used for the formation of the acrylic rubber polymer include aromatic vinyl such as styrene and α-methylstyrene, alkyl methacrylate such as methyl methacrylate and ethyl methacrylate, and acrylonitrile. , Unsaturated nitriles such as methacrylonitrile, vinyl ethers such as methyl vinyl ether and butyl vinyl ether, vinyl halides such as vinyl chloride and vinyl bromide, vinylidene halides such as vinylidene chloride and vinylidene bromide, glycidyl acrylate, glycidyl methacrylate, allyl Examples thereof include vinyl monomers having a glycidyl group such as glycidyl ether and ethylene glycol glycidyl ether.

  The silicone rubber of the core component is a rubber containing polyorganosiloxane which is a linear polymer having an organosiloxane bond unit of several thousand or more. The silicone acrylic rubber as the core component is a rubber containing polyorganosiloxane and alkyl (meth) acrylate rubber. The rubber may be produced by any method, but the emulsion polymerization method is optimal. The polyorganosiloxane is not particularly limited, but is preferably a polyorganosiloxane containing a vinyl polymerizable functional group. Examples of the dimethylsiloxane used in the production of the polyorganosiloxane include a dimethylsiloxane-based cyclic body having a 3-membered ring or more, and a 3- to 7-membered ring is preferable. Specific examples include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, and the like. These may be used alone or in combination of two or more.

  In the present invention, the shell component constituting the core-shell type graft copolymer (C) is not particularly limited, and is an unsaturated carboxylic acid alkyl ester unit, a glycidyl group-containing vinyl unit, an aliphatic vinyl unit, an aromatic Polymer containing vinyl group-based unit, vinyl cyanide-based unit, maleimide-based unit, unsaturated dicarboxylic acid-based unit, unsaturated dicarboxylic acid anhydride-based unit and / or other vinyl-based units, among others, A polymer containing an unsaturated carboxylic acid alkyl ester unit, a glycidyl group-containing vinyl unit and / or an unsaturated dicarboxylic acid anhydride unit is preferred, and a polymer containing an unsaturated carboxylic acid alkyl ester unit is more preferred. preferable.

  The unsaturated carboxylic acid alkyl ester unit constituting the polymer of the shell component is not particularly limited, but (meth) acrylic acid alkyl ester is preferably used. Specifically, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, (meth) acrylic N-hexyl acid, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, stearyl (meth) acrylate, octadecyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, ( Chloromethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2,3,4,5,6 (meth) acrylic acid -Pentahydroxyhexyl, 2,3,4,5-tetrahydroxypentyl (meth) acrylate, amino acrylate Examples include ethyl, propylaminoethyl acrylate, dimethylaminoethyl methacrylate, ethylaminopropyl methacrylate, phenylaminoethyl methacrylate, cyclohexylaminoethyl methacrylate, and the like, which are highly effective in improving dispersibility in resins. , Methyl (meth) acrylate and n-butyl (meth) acrylate are preferably used. These units can be used alone or in combination of two or more.

The glycidyl group-containing vinyl-based unit constituting the polymer of the shell component is not particularly limited, but is glycidyl (meth) acrylate, glycidyl itaconate, diglycidyl itaconate, allyl glycidyl ether, styrene-4-glycidyl ether. Or 4-glycidyl styrene etc. are mentioned and glycidyl (meth) acrylate is preferably used from a viewpoint that the effect of improving impact resistance is large. These units can be used alone or in combination of two or more.
Examples of the aliphatic vinyl unit include ethylene, propylene, and butadiene.
Examples of aromatic vinyl units include styrene, α-methylstyrene, 1-vinylnaphthalene, 4-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 4 -(Phenylbutyl) styrene or halogenated styrene is exemplified.
Examples of the vinyl cyanide unit include acrylonitrile, methacrylonitrile, ethacrylonitrile and the like.
As maleimide units, maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-isopropylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N- (p-bromophenyl) maleimide or N- And (chlorophenyl) maleimide.
Examples of unsaturated dicarboxylic acid units include maleic acid, maleic acid monoethyl ester, itaconic acid, and phthalic acid.
Other vinyl units include acrylamide, methacrylamide, N-methylacrylamide, butoxymethylacrylamide, N-propylmethacrylamide, N-vinyldiethylamine, N-acetylvinylamine, allylamine, methallylamine, N-methylallylamine, p -Aminostyrene, 2-isopropenyl-oxazoline, 2-vinyl-oxazoline, 2-acryloyl-oxazoline or 2-styryl-oxazoline. These units can be used alone or in combination of two or more.

  In the resin composition of the present invention, the amount of the core-shell type graft copolymer (C) is 1 to 10 parts by mass with respect to 100 parts by mass in total of the polylactic acid resin (A) and the polyamide resin (B). It is necessary and it is preferable that it is 5-10 mass parts. When the blending amount of the core-shell type graft copolymer (C) is less than 1 part by mass, the effect of the present invention is not exerted, and when it exceeds 10 parts by mass, the heat resistance tends to decrease, and the impact resistance Is saturated and no significant improvement is observed.

The resin composition of the present invention preferably contains an organic crystal nucleating agent (D). By containing the organic crystal nucleating agent (D), the crystallization speed of the polylactic acid resin (A) can be accelerated and the heat resistance of the resin composition can be improved.
Specific examples of the organic crystal nucleating agent (D) include sorbitol compounds, benzoic acid and metal salts thereof, phosphoric acid ester metal salts, and rosin compounds, as well as ethylene bisoleic acid amide and methylene bisacrylic acid amide as amide compounds. , Ethylenebisacrylic acid amide, hexamethylene bis-9, 10-dihydroxystearic acid bisamide, p-xylylene bis-9, 10 dihydroxystearic acid amide, decanedicarboxylic acid dibenzoyl hydrazide, hexanedicarboxylic acid dibenzoyl hydrazide, 1,4- Cyclohexanedicarboxylic acid dicyclohexylamide, 2,6-naphthalenedicarboxylic acid dianilide, N, N ′, N ″ -tricyclohexyltrimesic acid amide, trimesic acid tris (t-butylamide), 1,4-cyclohexane Carboxylic acid dianilide, 2,6-naphthalenedicarboxylic acid dicyclohexylamide, N, N'-dibenzoyl-1,4-diaminocyclohexane, N, N'-dicyclohexanecarbonyl-1,5-diaminonaphthalene, ethylenebis (12-hydroxy Stearic acid) amide, octanedicarboxylic acid dibenzoyl hydrazide, potassium dimethyl sulfoisophthalate, and / or sodium dimethyl sulfoisophthalate, etc. Among them, in order to significantly accelerate the crystallization of polylactic acid resin, Potassium dimethyl sulfoisophthalate and / or sodium dimethyl sulfoisophthalate, ethylenebis (12-hydroxystearic acid) amide, octanedicarboxylic acid dibenzoyl hydrazide, tricyclohexane Shirutorimeshin acid amides are preferred.
In addition, the method for mixing the organic crystal nucleating agent (D) with the resin composition of the present invention is not particularly limited.
The compounding amount of the organic crystal nucleating agent (D) is preferably 0.1 to 5 parts by mass with respect to 100 parts by mass in total of the polylactic acid resin (A) and the polyamide resin (B). More preferably, it is part by mass. When the compounding amount of the organic crystal nucleating agent (D) is less than 0.1 parts by mass, the compounding effect is poor, and when it exceeds 10 parts by mass, the effect as the crystal nucleating agent is saturated, which is economically disadvantageous. In addition, since the residue after biodegradation increases, it is not preferable in terms of environment.

As long as the characteristics of the resin composition of the present invention are not significantly impaired, pigments, heat stabilizers, antioxidants, weathering agents, plasticizers, lubricants, mold release agents, antistatic agents, fillers, crystal nucleating agents, etc. Can be added. Examples of heat stabilizers and antioxidants include hindered phenols, hindered amines, sulfur compounds, copper compounds, alkali metal halides, and the like. Inorganic fillers include talc, calcium carbonate, zinc carbonate, wollastonite, silica, alumina, magnesium oxide, calcium silicate, sodium aluminate, calcium aluminate, sodium aluminosilicate, magnesium silicate, glass balloon, carbon black, Examples thereof include zinc oxide, antimony trioxide, zeolite, hydrotalcite, metal fiber, metal whisker, ceramic whisker, potassium titanate, boron nitride, graphite, and carbon fiber. Examples of the organic filler include naturally occurring polymers such as starch, cellulose fine particles, wood flour, okara, fir shell, bran, and modified products thereof. Examples of the inorganic crystal core material include talc and kaolin.
In addition, the method of mixing these with the thermoplastic resin composition of this invention is not specifically limited.

  The resin composition of the present invention can be formed into various molded products by molding methods such as injection molding, blow molding, extrusion molding, inflation molding, and vacuum molding, pressure molding, and vacuum / pressure molding after sheet processing. In particular, an injection molding method is preferable, and in addition to a general injection molding method, gas injection molding, injection press molding, or the like can be employed. As an example of injection molding conditions suitable for the resin composition of the present invention, the cylinder temperature is not lower than the melting point or flow start temperature of polylactic acid, preferably 180 to 250 ° C., optimally 190 to 240 ° C., and The mold temperature is suitably not higher than the melting point of the resin composition (−20 ° C.). If the molding temperature is too low, the operability becomes unstable, such as defective filling in the molded product, and overload tends to occur. Conversely, if the molding temperature is too high, the resin composition decomposes and the resulting molded product Problems such as reduction in strength and coloring are likely to occur.

  The heat resistance of the resin composition of the present invention can be enhanced by promoting crystallization. As a method for this, for example, the crystallization can be promoted by devising the cooling conditions in the mold at the time of injection molding. In that case, the mold temperature is set to the polylactic acid (glass transition temperature). It is preferable to cool the glass transition temperature to not more than + 20 ° C.) and not more than (melting point−20 ° C.) for a predetermined time and then to the glass transition temperature or less. Further, as a method for promoting crystallization after molding, it is preferable to directly cool the glass transition temperature or lower and then heat-treat again at Tg or higher and (melting point −20 ° C.) or lower.

  Specific examples of the molded body include resin parts for electrical appliances such as various cases, agricultural materials such as containers and cultivation containers, resin parts for agricultural machinery, resin parts for fisheries operations such as floats and processed fishery products containers, dishes, Tableware and food containers such as cups and spoons, medical resin parts such as syringes and infusion containers, drain materials, fences, storage boxes, resin parts for housing, civil engineering, and building materials such as construction switchboards, cooler boxes, fan fans, and toys Such as resin parts for miscellaneous goods, automobile parts such as bumpers, instrument panels and door trims. Moreover, it can also be set as extrusion molded articles, such as a film, a sheet | seat, and a pipe, and a hollow molded article.

Next, the present invention will be described more specifically with reference to examples. The materials used and the evaluation method fees in the examples and comparative examples are as follows.
(A) Materials used (1) Polylactic acid resin (A)
-NatureWorks 6201D manufactured by Cargill Dow, MFR = 10 g / 10 min, melting point 168 ° C.
(2) Cross-linked polylactic acid resin (A ')
Using a twin-screw extruder (TEM-37BS manufactured by Toshiba Machine Co., Ltd.), 100 parts by mass of the polylactic acid resin (A) is supplied from the top feeder, and the peroxide di-t is used from the middle of the kneader using a pump. -0.2 parts by mass of butyl peroxide (Nippon Yushi Co., Ltd., Perbutyl D) and 0.1 parts by mass of (meth) acrylic acid ester compound ethylene glycol dimethacrylate (Nippon Yushi Co., Ltd., Bremer PDE-50) A solution dissolved in 1 part by mass of glycerin diacetomonocaprate (PL-019 manufactured by Riken Vitamin Co., Ltd.) was poured, and melt kneading extrusion was performed at a processing temperature of 190 ° C. Then, the discharged resin was cut into pellets to obtain a crosslinked polylactic acid resin (A ′). MFR = 1 g / 10 min.
(3) Cross-linked polylactic acid resin (A ″)
In place of (meth) acrylic acid ester compound ethylene glycol dimethacrylate, silane compound vinyltrimethoxysilane (KBM-1003 manufactured by Shin-Etsu Chemical Co., Ltd.) was used in the same manner as in (2) above, and crosslinked polylactic acid. Resin (A ″) was obtained. MFR = 0.5 g / 10 min.

(4) Polyamide 11 resin (B1)
・ Rilsan KNO made by Arkema
(5) Polyamide 1010 resin (B2)
・ Zytel FE110004 NC010 made by DuPont

(6) Core-shell type graft copolymer (C)
-Mitsubishi Rayon Co., Ltd. Metablene C-233A (core component: butadiene rubber, shell component: methyl methacrylate) (hereinafter referred to as C-233A)
-Mitsubishi Rayon Co., Ltd. Metablen S-2001 (core component: silicone / acrylic rubber, shell component: methyl methacrylate) (hereinafter referred to as S-2001)

(7) Graft copolymer, manufactured by NOF Corporation Modiper A4200 (main chain: polyolefin, side chain: vinyl polymer) (hereinafter referred to as A4200)
・ Tafmer MA8510 (modified ethylene / α-olefin copolymer) manufactured by Mitsui Chemicals (hereinafter referred to as MA8510)

(8) Organic crystal nucleating agent (D)
Tricyclohexyltrimesic acid amide: TF-1 manufactured by Shin Nippon Rika Co., Ltd.
(9) Petroleum-derived resin / polypropylene resin: Novatec BC03C manufactured by Nippon Polypro
ABS resin: Techno ABS 170 manufactured by Techno Polymer

(B) Evaluation Method (1) Bending Properties A test piece of 127 mm × 12.7 mm × 3.2 mm was produced and measured according to ASTM D790.
(2) Izod impact strength A test piece of 64 mm × 12.7 mm × 3.2 mm was prepared in accordance with ASTM-D-256, and a notch was provided to measure the Izod impact strength.
(3) Deflection temperature under load Based on ASTM D648, the heat distortion temperature was measured at a load of 0.45 MPa.
(4) Molding cycle The molding test of the ASTM dumbbell-shaped test piece was performed with an injection molding machine (Toshiba IS-80G). The mold was melted at a molding temperature of 190 ° C., and the molten resin was filled in a 100 ° C. mold. Molding cycle is good because the resin composition is injected into the mold (filling, holding pressure) and cooled, and then the molded body can be fixed to the mold or taken out without resistance, and there is no deformation due to the protruding pin. It was set as the time (seconds) until the mold could be released. The molding cycle is preferably 80 seconds or less, more preferably 60 seconds or less, the molding cycle having a molding cycle of 60 seconds or less ◎, the molding cycle exceeding 60 seconds to 80 seconds or less, and the molding cycle exceeding 80 seconds. X was evaluated based on a three-stage standard.
(5) Surface appearance The surface of the above-mentioned dumbbell-shaped test piece was visually observed and evaluated according to a two-stage criterion, with ○ indicating that there was no peeling and × indicating that peeling was noticeable.
(6) Plant-derived ratio The ratio of the plant-derived raw material in the resin composition was calculated. Evaluation was made according to a three-stage criterion, where the proportion of plant-derived raw materials was 90% or more, ◯, 50% or more, less than 90% Δ, and less than 50% ×.

Examples 1-10, Comparative Examples 1-8
Using a twin screw extruder (TEM-37BS manufactured by Toshiba Machine Co., Ltd.), polylactic acid resin and other raw materials were supplied from the top feeder with the formulation shown in Table 1, and melt kneading extrusion was performed at a processing temperature of 190 ° C. The discharged resin was cut into pellets to obtain a resin composition. Next, it was dried at 70 ° C. for 24 hours in a vacuum dryer.

As is apparent from Table 1, in Examples 1 to 10, resin compositions having excellent heat resistance, flexibility, impact resistance, and moldability, having a high plant-derived ratio and considering the environment were obtained.
In Comparative Example 1, since the blending amount of the core-shell type graft copolymer did not reach the specified amount, the impact resistance was inferior. In Comparative Example 2, since the blending amount of the core-shell type graft copolymer exceeded the specified amount, the heat resistance and the plant-derived ratio were reduced, and no significant improvement in impact resistance was observed. In Comparative Examples 3 and 4, since a graft copolymer having no core-shell structure was used instead of the core-shell type graft copolymer, impact resistance was inferior.
In Comparative Example 5, since the blending amount of the polylactic acid resin does not reach the specified amount, it is economically disadvantageous in terms of price. In Comparative Example 6, since the blending amount of the polylactic acid resin exceeded the specified amount, the impact resistance was lowered, resulting in inferior molding cycle and surface appearance.
In Comparative Example 7, since a petroleum-derived polypropylene resin was used instead of the plant-derived polyamide resin, the plant-derived ratio of the resin composition was lowered, and the impact resistance was also lowered. In Comparative Example 8, since the petroleum-derived ABS resin was used instead of the plant-derived polyamide resin, the plant-derived ratio was decreased and the heat resistance was also decreased.

Claims (5)

  A polylactic acid resin (A), a polyamide resin (B), and a core-shell type graft copolymer (C), and a mass ratio (A / B) of the polylactic acid resin (A) and the polyamide resin (B) Is 10/90 to 40/60, and the content of the core-shell type graft copolymer (C) is 1 to 10 parts by mass with respect to 100 parts by mass in total of the polylactic acid resin (A) and the polyamide resin (B). An environmentally friendly thermoplastic resin composition, wherein the polyamide resin (B) is a polyamide 11 resin (B1) and / or a polyamide 1010 resin (B2).   Furthermore, the organic crystal nucleating agent (D) is contained, and the content of the organic crystal nucleating agent (D) is 0.1 to 5 parts by mass with respect to 100 parts by mass in total of the polylactic acid resin (A) and the polyamide resin (B). The resin composition according to claim 1, wherein:   The resin composition according to claim 1 or 2, wherein the core component constituting the core-shell type graft copolymer (C) is a silicone acrylic rubber.   The resin composition according to any one of claims 1 to 3, wherein the polylactic acid resin (A) is a crosslinked polylactic acid resin.   The molded object formed by shape | molding the resin composition in any one of Claims 1-4.