JP4587677B2 - Long fiber reinforced polylactic acid resin composition and method for producing the same - Google Patents

Description

  The present invention relates to a long fiber reinforced polylactic acid resin composition for producing a molded article that is excellent in mechanical performance and heat resistance and decomposes in a natural environment after use, and a method for producing the same.

  In recent years, attention has been paid to biodegradable plastics that decompose in a natural environment as an environmental problem. Among the biodegradable plastics, polylactic acid resins can be produced at low cost with a resin that has been known for a long time, and it has been confirmed that they have been decomposed by microorganisms even in burial tests in the soil.

  However, since polylactic acid resins usually have a low crystallization rate, when a molded product is produced by injection molding, it takes a long time to cool and solidify, and the molded product is soft at a low temperature and has sufficient mechanical strength. The molded product which has is not obtained.

In order to solve the above problems, in Patent Document 1, poly-ε-caprolactone is mixed with L-lactic acid in an amount of 75% by weight or more with respect to the lactic acid resin, and the mixture contains 50% by mass or more of SiO _2. Mix and melt the crystalline inorganic powder. Next, by filling this into a mold of a molding machine set to 85 to 125 ° C. and molding while crystallizing, a molded product having excellent mechanical strength such as heat resistance and impact resistance can be obtained. Are listed.

  Patent Document 2 describes that the weak mechanical strength of biodegradable plastics is reinforced by mixing glass fibers using epoxy resin as a sizing agent to improve mechanical strength such as impact resistance. Is disclosed.

JP-A-8-193165 JP-A-11-79793

  However, the molded product obtained by Patent Document 1 still does not have sufficient mechanical strength and heat resistance (deflection temperature under load), and still has mechanical strength and high heat resistance. A molding material to obtain is desired.

  Further, Patent Document 2 discloses a so-called short fiber reinforced plastic that reinforces a biodegradable plastic using chopped strand glass fibers, which certainly improves the mechanical strength of the molded product. When adapting to, there is a big problem. In other words, when a sizing agent containing an epoxy resin, which is conventionally considered to give high strength, is used, in the production of a long fiber reinforced resin composition, the epoxy resin is melted in the resin bath in the impregnation die, and the opening comes from stickiness. Due to the resistance of the fibers at the time of contact with the fiber bar, a lot of fluffing occurs and the workability deteriorates so much that it is difficult to produce a long fiber reinforced resin composition.

  In view of the above problems, the present invention provides a polylactic acid resin molded product which is a biodegradable plastic having excellent mechanical strength and heat resistance (deflection temperature under load), and has manufacturing stability and molding operation. It aims at providing the long fiber reinforced polylactic acid-type resin composition which is excellent also in the property.

  The present inventor has intensively studied to solve the above-mentioned problems. As a result, the present inventors have found a long fiber reinforced polylactic acid resin composition, which is a biodegradable plastic, which can solve this problem, and have reached the present invention.

  That is, the present invention contains a specific amount of reinforcing fibers treated with a specific sizing agent and a specific amount of talc having a specific average particle diameter with respect to a polylactic acid resin, which is a biodegradable plastic. By developing a novel polylactic acid resin composition and manufacturing method thereof, long fiber reinforced polylactic acid having high mechanical strength such as impact resistance and excellent heat resistance (high deflection temperature under load) The present inventors have found that a resin molded product can be obtained and have reached the present invention.

That is, the present invention has the following features.
(1) A polylactic acid-based resin, a reinforcing fiber having a fiber length of substantially 2 mm or more, and talc having an average particle diameter of 0.1 to 3 μm are contained, and the reinforcing fiber is included in the composition in an amount of 5 to 70% by mass The talc is contained in the composition in an amount of 5 to 25 % by mass , and the polylactic acid resin is contained in the composition so that the total amount of the reinforced fiber and the talc is 100% by mass, and the reinforcing fiber. Is a fiber treated with a sizing agent containing a urethane resin and having an epoxy resin content of 20% by mass or less, a long fiber reinforced polylactic acid resin composition.
(2) The long fiber reinforced polylactic acid resin composition according to (1), wherein an epoxy resin is attached to the talc.
(3) The long fiber reinforced polylactic acid resin composition according to the above (1) or ( 2 ), wherein the epoxy resin is a phenol novolac type epoxy resin.
(4) The long fiber reinforced polylactic acid resin composition according to any one of (1) to (3), wherein the resin composition is in the form of a pellet having a length of 2 to 50 mm.
(5) Polylactic acid resin and talc having an average particle size of 0.1 to 3 μm are added to a continuous bundle of reinforcing fiber bundles containing urethane resin and treated with a sizing agent having an epoxy resin content of 20% by mass or less. Is impregnated with a melt containing 5.5 to 33 parts by mass of 100 parts by mass of a polylactic acid resin to obtain a composition containing 5 to 70% by mass of reinforcing fibers. A method for producing a lactic acid resin composition.
(6) While drawing the continuous product of the reinforcing fiber bundle through the crosshead, the melt supplied from the extruder to the crosshead is impregnated and drawn out into a linear product, and the linear product has a length of 2 to 50 mm. The manufacturing method of the long fiber reinforcement polylactic acid-type resin composition as described in said (5) cut | disconnected.
(7) The manufacturing method of the long fiber reinforced polylactic acid-type resin composition as described in said (5) or (6) in which the epoxy resin has adhered to the said talc.
(8) The long fiber reinforced polylactic acid-based resin composition according to any one of (5) to (7), wherein the epoxy resin is a phenol novolac epoxy resin.
(9) A molded article obtained by molding the long fiber reinforced polylactic acid resin composition according to (4) above, wherein the reinforcing fibers are contained in a weight average length of 1 mm or more.

  According to the present invention, a novel long-fiber reinforced polylactic acid resin composition is provided, and the polylactic acid resin composition is molded by injection molding or the like, whereby heat resistance (high deflection temperature) and impact resistance are provided. A biodegradable plastic molded product having excellent mechanical strength can be obtained.

  The polylactic acid resin used in the present invention is a lactic acid homopolymer resin, a lactic acid copolymer resin, a blend resin containing these lactic acid resins, or the like. Although it does not specifically limit as a lactic acid component which is a raw material of a lactic acid resin, L-lactide and D-lactide which are L-lactic acid, D-lactic acid, DL-lactic acid, or a mixture thereof, or a lactic acid cyclic dimer , Meso-lactide, or mixtures thereof can also be used.

  As the lactic acid, the constituent molar ratio (L / D) of the L-form and the D-form is not particularly limited, but in order to obtain a high melting point, the L-form in the total lactic acid is 80 mol% or more, preferably 90 mol%. It is preferable to include the above. Further, regarding lactide, it is preferable that L-form is contained in the total lactide in an amount of 80 mol% or more, preferably 90 mol or more. The weight average molecular weight of the polylactic acid resin is generally 50,000 to 500,000, preferably 100,000 to 250,000. If the weight average molecular weight is less than 50,000, physical properties necessary for practical use cannot be obtained. On the other hand, if the weight average molecular weight exceeds 500,000, the moldability tends to deteriorate.

  The lactic acid homopolymer resin used in the present invention is obtained by directly dehydrating condensation of L-lactic acid, D-lactic acid, DL-lactic acid or a mixture thereof, or L-lactide, D-lactide, meso-lactide, or a mixture thereof. Examples thereof include resins obtained by ring-opening polymerization. The lactic acid copolymer resin is a resin in which a lactic acid monomer or lactide and another component copolymerizable with the monomer are copolymerized. Examples of other components that can be copolymerized include dicarboxylic acids, polyhydric alcohols, hydroxycarboxylic acids, lactones, etc. having two or more ester bond-forming functional groups in the molecule, or various constituents thereof. Examples include polyester, various polyethers, and various polycarbonates.

  Examples of the dicarboxylic acid include succinic acid, adipic acid, phthalic acid, terephthalic acid and the like. Examples of the polyhydric alcohol include aliphatic polyhydric alcohols such as ethylene glycol and propylene glycol, aromatic polyhydric alcohols obtained by non-reacting ethylene oxide with bisphenol, and ether glycols such as diethylene glycol and triethylene glycol. .

  Examples of the hydroxycarboxylic acid include glycolic acid and hydroxybutylcarboxylic acid. Examples of the lactone include glycolide, ε-caprolactone glycolide, and ε-caprolactone.

  The various polyesters, various polyethers, and various polycarbonates can be used without particular limitation as long as they are conventionally used in the production of lactic acid copolymer resins.

  The lactic acid homopolymer or copolymer is produced by a conventionally known method. That is, direct dehydration condensation from a lactic acid monomer as described in JP-A-7-33861, JP-A-59-96123, Polymer Proceedings Proceedings Vol. 44, pages 3198-3199, or cyclic lactic acid It can be produced by ring-opening polymerization of a monomeric lactide.

  When performing direct dehydration condensation, any lactic acid of L-lactic acid, D-lactic acid, DL-lactic acid, or a mixture thereof may be used. Moreover, when performing ring-opening polymerization, you may use any lactide of L-lactide, D-lactide, DL-lactide, meso-lactide, or a mixture thereof.

Lactide synthesis, purification and polymerization operations are described, for example, in U.S. Pat. No. 4,057,537, published European Patent Application No. 261572, Polymer.
Bulletin, 14, 491-495 (1985), and Makromol Chem., 187, 1611-1628 (1986).

  The catalyst used for the polymerization reaction of the lactic acid monomer or lactide is not particularly limited, and a known catalyst for lactic acid polymerization can be used. For example, tin compounds such as tin lactate, tin tartrate, dicaprylate, dilaurate, dipalmitate, tin distearate, tin dioleate, tin α-naphthoate, tin β-naphthoate, tin octylate, Tin powder, tin oxide; zinc powder, zinc halide, zinc oxide, organic zinc compounds; titanium compounds such as tetrapropyl titanate; zirconium compounds such as zirconium isopropoxide; antimony compounds such as antimony trioxide; oxidation Examples thereof include bismuth compounds such as bismuth (III); aluminum compounds such as aluminum oxide and aluminum isopropoxide.

  In the present invention, the blend resin containing a lactic acid resin is a mixture obtained by mixing and melting a lactic acid homopolymer resin and / or a lactic acid copolymer resin, and preferably a polyester other than lactic acid. The blend of polyester can impart flexibility and impact resistance to the molded product. The proportion of the blend is usually about 10 to 100 parts by mass of polyester other than lactic acid with respect to 100 parts by mass of lactic acid homopolymer resin and / or lactic acid copolymer resin. The polyester is an aliphatic polyester, an aromatic polyester, or a mixture thereof, and an aliphatic polyester is particularly preferred because of its miscibility with lactic acid.

  In the present invention, the aliphatic polyester to be blended is a resin comprising an aliphatic carboxylic acid component and an aliphatic alcohol component, or an aliphatic hydroxycarboxylic acid resin obtained by ring-opening polymerization of a cyclic anhydride such as ε-caprolactone. Etc. The aliphatic polyester may be a copolymer or a mixture with other resins as long as it is a resin mainly containing the aliphatic monomer component.

  The aliphatic polyester used in the blend is preferably composed of an aliphatic dicarboxylic acid and an aliphatic diol. Examples of the aliphatic dicarboxylic acid include compounds such as succinic acid, adipic acid, suberic acid, sebacic acid, and dodecanoic acid, and anhydrides and derivatives thereof. On the other hand, as the aliphatic diol, glycol compounds such as ethylene glycol, butanediol, hexanediol, octanediol, cyclohexanedimethanol, and derivatives thereof are common. These aliphatic dicarboxylic acids and aliphatic diols are monomer compounds having an alkylene group, a cyclocyclic group or a cycloalkylene group having 2 to 10 carbon atoms. Aliphatic polyesters are produced by condensation polymerization of monomer compounds selected from these aliphatic dicarboxylic acids and aliphatic diols. Two or more kinds of carboxylic acid components or alcohol components may be used.

  The aliphatic polyester used in the blend is a trifunctional or higher polyfunctional carboxylic acid, alcohol or hydroxycarboxylic acid as a component of the aliphatic polyester for the purpose of providing a branch in the polymer to improve the melt viscosity. May be used. When these components are used in a large amount, the resulting polymer has a cross-linked structure and may not be thermoplastic, or even if it is thermoplastic, a microgel partially having a highly cross-linked structure may be produced. Therefore, these tri- or higher functional components are contained in such a small amount that they do not significantly affect the chemical and physical properties of the polymer. As the polyfunctional component, malic acid, tartaric acid, citric acid, trimellitic acid, pyromellitic acid, pentaerythritol, trimethylolpropane and the like can be used.

  Among the methods for producing aliphatic polyesters, the direct polymerization method is a method for obtaining a high molecular weight product while removing water contained in the compound by selecting the above compound or generated during the polymerization. The indirect polymerization method selects the above compounds and polymerizes them to an oligomer level, and then, for the purpose of increasing the molecular weight, a small amount of chain extender, for example, diisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, and diphenylmethane diisocyanate. This is a method of increasing the molecular weight using a compound. Alternatively, there is a method of obtaining aliphatic polyester carbonate using a carbonate compound.

  In the present invention, the talc contained in the lactic acid resin composition needs to be a powder having an average particle diameter of 0.1 to 3 μm. If the average particle size is less than 0.1 μm, aggregates are formed during kneading, resulting in poor dispersibility in the resin composition. If the value exceeds 3 μm, the dispersion state in the resin composition is not preferable. Not only is it non-homogeneous, but it is considered undesirable to damage glass fibers in the resin impregnation step. Especially, it is more preferable that the average particle diameter of talc is 0.5 to 1.5 μm. The average particle diameter of talc can be measured by a laser diffraction type particle size distribution measuring device and obtained from the average area diameter.

  In addition, talc is preferable because it improves the heat resistance of the molded product, but regarding mechanical strength, when talc is blended, the elastic modulus is improved, but the impact strength may be lowered. In the present invention, it has been found that by attaching an epoxy resin to talc, the mechanical strength such as impact strength of the molded product is improved and the heat resistance is further improved. This is considered that adhesion with a polylactic acid-type resin improves by making an epoxy resin adhere to talc.

  The epoxy resin is preferably attached in an amount of 0.1 to 5% by mass with respect to the total amount of talc including the epoxy resin. More preferably, it is 0.5-2 mass%. When the value is less than 0.1% by mass, the adhesion to the polylactic acid resin is lowered, and the impact strength and heat resistance are inferior, and when the value exceeds 5% by mass, an aggregate is formed at the time of adhesion. It is easy and the dispersibility at the time of kneading is inferior. The talc to which the epoxy is attached is preferably contained in an amount of 50% by mass or more in the total amount of talc to be used, and particularly preferably 100% by mass.

  Epoxy resins attached to talc are bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AD type epoxy resins, phenol novolak type or cresol novolak type epoxy resins, aliphatic epoxy resins, One or more of these hydrogenated types or ether-modified products and phenoxy resins can be selected and used. In particular, it is effective to use a novolac type epoxy resin in order to express the above effect highly.

  In the present invention, as the novolac type epoxy resin, it is preferable to use a phenol novolac type epoxy resin from the viewpoint of adhesion to the polylactic acid resin and heat resistance. The molecular weight and epoxy equivalent of the novolac type epoxy resin are not particularly limited, but the weight average molecular weight is preferably about 300 to 900, and the epoxy equivalent is preferably 172 to 182 and is also preferable from the viewpoint of handling.

  The epoxy resin is preferably used in a state of being dispersed in water by emulsification or water solubilization. The method for adhering the epoxy resin to talc is not particularly limited when adhering the above-mentioned epoxy dispersed in water, and after spraying the epoxy resin by spraying or the like, the method of evaporating and drying the moisture is used. be able to.

  The reinforcing fiber contained in the polylactic acid resin composition in the present invention is not particularly limited, and examples thereof include carbon fiber and glass fiber. Various conventionally known carbon fibers can be used as the carbon fiber, and specific examples include polyacrylonitrile-based, pitch-based, and rayon-based carbon fibers. The filament diameter of the carbon fiber is preferably 6 to 20 μm, and the number of bundles is preferably 1000 to 30000. In the case of glass fiber, the average diameter of the monofilament is preferably 6 to 23 μm, more preferably 10 to 20 μm. When the average diameter of the monofilament is less than 6 μm, the cost is increased in the glass fiber manufacturing process, and when the glass fiber reinforced resin pellet is finally used, the cost of the pellet becomes high. If it exceeds 23 μm, the mechanical properties of the resulting molded product are inferior, which is not preferable. Moreover, it is preferable that the number of focusing is 600 to 10,000. If the number of bundles is less than 600, the work rate is inferior when aligning glass fiber bundles, and if it exceeds 10,000, the impregnation property is reduced when glass fibers are used, so the mechanical strength of the molded product. Is not preferable.

  In the present invention, a sizing agent is preferably attached to the reinforcing fiber. In the present invention, the sizing agent contains a urethane resin, but the epoxy resin content is preferably 20% by mass or less. In the case of glass fiber, a silane coupling agent is used, and the silane coupling agent is preferably contained in the sizing agent in an amount of 5 to 50% by mass, more preferably 10 to 30% by mass in terms of solids. . If the value is less than 5%, the adhesiveness with the resin is lowered, resulting in a decrease in mechanical strength and heat resistance, which is not preferable. If the value exceeds 50%, further effects cannot be expected, and the cost is increased. It is not preferable. Further, the urethane resin is preferably contained in the sizing agent in an amount of 20% by mass or more, more preferably 50% by mass or more in terms of solid content. If the value is less than 20% by mass, not only the adhesion to the resin is lowered, resulting in a decrease in mechanical strength and heat resistance, but also productivity is increased by the pre-process of the impregnation die and generation of fuzz in the impregnation die. It is not preferable because of lowering and workability. When the content of the epoxy resin in the sizing agent exceeds 20% by mass, fluffing and yarn breakage occur in the pre-process of the impregnation die and in the impregnation die, resulting in poor productivity and workability. The content of the epoxy resin in the sizing agent is preferably 10% by mass or less, particularly preferably 5% by mass or less.

  In the present invention, the sizing agent is preferably added in an amount of 0.1 to 2% by mass as a solid content with respect to the total amount of reinforcing fibers to be treated. When the applied amount is less than 0.1% by mass, the fiber is not sufficiently converged and easily fuzzed, and the adhesion between the reinforcing fiber and the polylactic acid resin is inferior, and the applied amount exceeds 2% by mass. When the fiber bundle is impregnated with the polylactic acid resin, the fiber bundles are unsatisfactory and undesired due to the presence of unopened fiber bundles in the polylactic acid resin.

  As a sizing agent for reinforcing fibers of the present invention, a urethane resin and, if necessary, a silane coupling agent are added, and a sizing agent component used in ordinary reinforcing fibers such as saturated polyester resins and polylactic acid resins is used in combination. Can do.

  The silane coupling agent is not particularly limited as long as it has an amino group, but the amino group of the aminosilane is preferably a primary and / or secondary amino group, and more preferably γ-aminopropyltriethoxy. Silane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -N′-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-anilino Aminosilanes such as propyltrimethoxysilane are preferred. Aminosilane is preferable in terms of enhancing adhesiveness with the resin and excellent mechanical strength. Furthermore, it is more preferable to use γ-aminopropyltriethoxysilane because the color tone of the molded product is good.

  The polyurethane resin is not particularly limited as long as it is usually used as a sizing agent. For example, a conventionally known polyurethane resin derived from a polymer polyol, an organic diisocyanate, and, if necessary, a chain extender and / or a crosslinking agent. Things can be used. Urethane resin is dispersed in water as an emulsion, dispersion or the like and used as a sizing agent.

  Specific examples of the polymer polyol include, for example, polyester polyol (for example, polyethylene adipate diol, polybutylene adipate diol, polyethylene butylene adipate diol, polyneopentyl adipate diol, polyneopentyl terephthalate diol, polycaprolactone diol, polyvalerolactone diol, Polyhexamethylene carbonate diol); polyether polyol (polyethylene glycol, polypropylene glycol, polyoxyethyleneoxypropylene glycol, polyoxytetramethylene glycol, ethylene oxide and / or propylene oxide adducts of bisphenols) and the like. The number average molecular weight of the polymer polyol is usually 500 to 6,000, preferably 800 to 3,000.

  Specific examples of the organic diisocyanate include, for example, 2,4′- or 4,4′-diphenylmethane diisocyanate (MDI), 2,4- or 2,6-tolylene diisocyanate (TDI), 4,4′-dibenzyl diisocyanate. , 1.3- or 1,4-phenylene diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, etc .; aliphatic diisocyanates such as ethylene diisocyanate, hexamethylene diisocyanate (HDI), lysine diisocyanate; isophorone Examples thereof include alicyclic diisocyanates such as diisocyanate (IPDI) and 4,4′-dicyclohexylmethane diisocyanate; or a mixture of two or more thereof. Of these, MDI, TDI, HDI and IPDI are preferred.

  Examples of the chain extender and / or crosslinking agent used as necessary include active hydrogen-containing compounds having a number average molecular weight of less than 60 to 500, such as polyhydric alcohols (ethylene glycol, propylene glycol, 1,3-butylene glycol, 1 , 4-butanediol, 1,6-hexanediol, 3-methylpentanediol, diethylene glycol, neopentyl glycol, 1,4-bis (hydroxymethyl) cyclohexane, 1,4-bis (hydroxyethyl) benzene, 2,2 -Dihydric alcohols such as bis (4,4'-hydroxycyclohexyl) propane; Trihydric alcohols such as glycerin and trimethylolpropane; Pentaerythritol, diglycerin, α-methylglucoside, sorbitol, xylit, man Knit, Dipentaerythri -4- to 8-valent alcohols such as glucose, fructose, fructose, sucrose, etc., polyvalent phenols (polyphenols such as pyrogallol, catechol, hydroquinone; bisphenol) Bisphenols such as A, bisphenol F and bisphenol S), water, polyamines (aliphatic polyamines (ethylenediamine, hexamethylenediamine, diethylenetriamine, etc.)), alicyclic polyamines (isophoronediamine, 4,4'-dicyclohexylmethane) Diamines), aromatic polyamines (such as 4,4′-diaminodiphenylmethane), aromatic alicyclic polyamines (such as xylylenediamine), hydrazine or derivatives thereof, and the like.

  In the long fiber reinforced resin composition of the present invention, the reinforcing fiber is contained in an amount of 5 to 70% by mass, preferably 15 to 50% by mass. Talc is contained in the composition in an amount of 5 to 25% by mass, preferably 7.5 to 15% by mass. When the content of the reinforcing fiber in the composition is less than 5% by mass, the mechanical strength is inferior, and when it exceeds 70% by mass, the molding fluidity is inferior. Further, when the content of talc in the composition is less than 5% by mass, the mechanical strength and heat resistance are not sufficiently exhibited, and when it exceeds 25% by mass, the impact strength is remarkably lowered and the specific gravity is large. It is not preferable. Moreover, the fiber length of the reinforcing fiber contained in the composition of this invention needs to be 2 mm or more. When the fiber length is smaller than 2 mm, the mechanical strength of the molded product is inferior, and the pellet length is inevitably shortened, so that the pellet is easily cracked and bulky, and the conveying efficiency is inferior. Among these, the fiber length is preferably 6 mm or more. However, depending on the method of manufacturing the molded product, for example, in the case of injection molding, the fiber length is 50 mm or less, particularly 20 mm, for reasons of stable supply at the inlet of a hopper or the like when supplying materials. The following is preferred.

  Furthermore, the long fiber reinforced polylactic acid resin composition of the present invention can be used in combination with a small amount of one or more other thermoplastic resins within a range that does not significantly impair the purpose and effect thereof. In addition, in order to impart desired properties according to the purpose, known substances generally added to thermoplastic resins, for example, antioxidants, heat stabilizers, stabilizers such as ultraviolet absorbers, antistatic agents, flame retardants, Flame retardant aids, colorants such as dyes and pigments, lubricants, plasticizers, crystallization accelerators, crystal nucleating agents, and the like can be further blended.

  The long fiber reinforced polylactic acid resin composition of the present invention is a talc having a polylactic acid resin and an average particle size of 0.1 to 3 μm while drawing a continuous reinforcing fiber bundle treated with the sizing agent. It is preferable to manufacture by a so-called pultrusion method that impregnates a matrix resin containing. That is, in the present invention, a method of impregnating the matrix resin through the reinforcing fiber bundle in a bath containing the emulsion, suspension or solution of the matrix resin, a method of spraying the matrix resin powder onto the reinforcing fiber bundle, a tank containing the matrix resin powder A method in which a reinforcing fiber bundle is passed through a matrix resin powder and then the matrix resin is melted and impregnated in the fiber bundle, while passing through the reinforcing fiber bundle through the crosshead from an extruder or the like to the crosshead. A method of supplying a matrix resin and impregnating the fiber bundle can be used. In the present invention, it is particularly preferable to dissolve and impregnate by a method using a crosshead from the viewpoint of resin impregnation.

  In the above production method, the temperature of the molten matrix resin impregnated in the reinforcing fiber bundle is preferably 150 to 300 ° C, more preferably 200 to 280 ° C. In this way, a strand in which the reinforcing fiber bundle is impregnated with the molten matrix resin is obtained. The strand can be formed into an arbitrary shape such as a pellet by cutting the strand into an appropriate length. In the present invention, a pellet-shaped wire composition having a length of 2 to 50 mm is preferably used, particularly for application to injection molding, which is easy to mold. Further, in molding the resin composition of the present invention, when it is molded, it is preferable to form a molded product in which reinforcing fibers are preferably dispersed with a weight average fiber length of 1 mm or more. It can be set as the molded article holding intensity | strength.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, it should be understood that the present invention should not be construed as being limited to such examples.

In the following examples, the following were used as “polylactic acid resin”, “talc”, and “glass fiber”.
-Polylactic acid resin: Laissia H-100J manufactured by Mitsui Chemicals.
-Talc (A, B, C):
A: Talc with an average particle diameter of 1.0 μm (SG-2000 manufactured by Nippon Talc Co., Ltd.).
B: Talc with 1% by mass solid content of phenol novolac type epoxy resin obtained by applying an epoxy equivalent 180 phenol novolac type resin emulsion to SG-2000 and drying.
C: Talc with an average particle size of 5.0 μm (C-3 manufactured by Nippon Talc Co.).

The average particle size was measured with a laser diffraction particle size distribution analyzer SALD-2000J manufactured by Shimadzu Corporation and obtained from the average area diameter.

Glass fiber (A, B, C, D, E, F):
A: A sizing agent comprising 100 parts by mass of a urethane resin emulsion solid content, 15 parts by mass of a γ-aminopropyltriethoxysilane coupling agent, and 0.6 parts by mass of a cationic surfactant, and a glass having a filament diameter of 16 μm and a number of sizings of 3000. Glass fiber having a sizing agent adhesion amount of 0.4% by mass applied to the fiber and dried.
B: A sizing agent composed of 100 parts by mass of a phenol novolac type epoxy resin emulsion having an epoxy equivalent of 180, 15 parts by mass of a γ-aminopropyltriethoxysilane coupling agent, and 0.6 parts by mass of a surfactant, with a filament diameter of 16 μm and a sizing A glass fiber having a sizing agent adhesion amount of 0.4% by mass, applied to 3000 glass fibers and dried.
C: 50 mass parts of urethane resin emulsion solid content, 50 mass parts of phenol novolac-type epoxy resin emulsion solid content of epoxy equivalent 180, 15 mass parts of γ-aminopropyltriethoxysilane coupling agent, 0.6 mass of cationic surfactant A glass fiber having a sizing agent adhesion amount of 0.4% by mass, which is obtained by applying a sizing agent comprising a part to glass fibers having a filament diameter of 16 μm and a bundling number of 3000.
D: 80 parts by mass of urethane resin emulsion solids, 20 parts by mass of phenol novolac type epoxy resin emulsion having an epoxy equivalent of 180, 15 parts by mass of γ-aminopropyltriethoxysilane coupling agent, 0.6 parts by mass of cationic surfactant A glass fiber having a sizing agent adhesion amount of 0.4% by mass, which is obtained by applying a sizing agent comprising a part to glass fibers having a filament diameter of 16 μm and a bundling number of 3000.
E: 95 parts by mass of urethane resin emulsion solids, 5 parts by mass of phenol novolac-type epoxy resin emulsion having an epoxy equivalent of 180, 15 parts by mass of γ-aminopropyltriethoxysilane coupling agent, 0.6 mass of cationic surfactant A glass fiber having a sizing agent adhesion amount of 0.4% by mass, which is obtained by applying a sizing agent comprising a part to glass fibers having a filament diameter of 16 μm and a bundling number of 3000.
F: A sizing agent consisting of 100 parts by mass of a phenol novolac-type epoxy resin emulsion having an epoxy equivalent of 180, 15 parts by mass of a γ-aminopropyltriethoxysilane coupling agent, and 0.6 parts by mass of a surfactant, and having a filament diameter of 16 μm A glass fiber having a mass of 0.4% by weight and a cut length of 3 mm, applied to 2,000 glass fibers.

  In the composition shown in Table 1, polylactic acid resin and talc are dry blended, melted and kneaded in an extruder with a cylinder temperature of 200 to 280 ° C., and continuously from the middle of the extruder so as to have a predetermined glass fiber content. The glass fiber was supplied, impregnated with the kneaded resin, and then cut to obtain a glass fiber reinforced resin composition in a pellet form having a length of 6 mm.

In addition, when glass fiber D was used, it knead | mixed and pelletized using the twin-screw extruder whose temperature setting of a cylinder is 210 degreeC, and it was set as the resin composition of the comparative example.
The obtained pellet-shaped resin composition was dried at 80 ° C. for 5 hours, and then molded using an injection molding machine at a cylinder temperature of 210 ° C. and a mold temperature of 80 ° C. to obtain a test molded product piece.

The physical properties of the obtained molded product are shown in “Table 1”. The TS, FS, FM, IZOD, DTUL, and performance measurement methods shown in “Table 1” are as shown below.

TS: Definition and measurement method Tensile strength (ASTM D-638)

FS: Definition and measurement method Bending strength (ASTM D-790)

FM: Definition and measurement method Flexural modulus (ASTM D-790)

IZOD: Definition and measurement method Notched IZOD impact strength (ASTM D-256)

・ DTUL: Definition and measurement method Deflection temperature under load (Load 1.82 MPa) (ASTM D-648)

・ Method of measuring the amount of fluff generation in ROV

Measurement was carried out as follows by the method shown in FIG.
(Preparation)
a. An evaluation sample 1 (glass fiber wound body) is set at a designated position.
b. The glass fiber strand end yarn 2 is pulled out and passed through the pre-opening bar 3 and bar 4.
c. The strand is passed through the opening skewer in the opening BOX 5 and the end yarn is put on the take-up device 6.
d. A predetermined weight is placed on the upper bar of the spread BOX of the spread BOX, and a load is applied to the strand.
e. The take-up device is activated for a predetermined time.

(Fuzz amount measurement)
f. After taking a predetermined time, the fluff on the mesh in the opened BOX sucked by suction is collected, and the fluff weight is precisely weighed.
g. After changing the measurement load and starting the take-up device for a predetermined time, d to f are repeated.
h. When exchanging the sample, the strand of the previous sample is cut in front of the pre-opening bar, a sample to be newly evaluated is set at a designated position, and the end yarn is bound.
i. The binding end yarn portion is passed to the take-up device, and the procedures d to h are repeated after the inspection of the process.
・ Nozzle generation amount during nozzle long fiber pellet production Monofila fluff coming out from nozzle of impregnation die is evaluated by visual observation, ○ when there is little fluff generation from nozzle, △ when fluff is generated, nozzle clogging with fluff The production efficiency was extremely inferior and evaluated as x or difficult to manufacture.

表１から明らかなように、実施例はロービング（ＲＯＶ）での毛羽の発生が少なく、また長繊維強化樹脂組成物（ペレット）での毛羽の発生が少なく、作業性や生産性に優れる上に、機械的強度、耐熱性に優れる成形品が得られた。また、ガラス繊維にエポキシを付与した実施例５，６では、成形品の機械的強度に優れるが、ＲＯＶでの毛羽の発生が実施例１〜４に比べて多かった。これに対し、比較例は機械的強度及び耐熱性に劣り、更に比較例２，４はＲＯＶ毛羽が多く、比較例２〜４はペレット製造時に毛羽が発生し生産性に劣るものであった。

As is clear from Table 1, the examples show less fluffing in roving (ROV), less fluffing in the long fiber reinforced resin composition (pellet), and excellent workability and productivity. A molded product having excellent mechanical strength and heat resistance was obtained. In Examples 5 and 6 in which epoxy was added to the glass fiber, the mechanical strength of the molded product was excellent, but the occurrence of fluff in ROV was larger than in Examples 1 to 4. On the other hand, the comparative example was inferior in mechanical strength and heat resistance. Further, Comparative Examples 2 and 4 had many ROV fluff, and Comparative Examples 2 to 4 were inferior in productivity because fluff was generated during pellet production.

  The molded product of the long fiber reinforced polylactic acid resin composition of the present invention is excellent in heat resistance and has high mechanical strength, and therefore can be suitably used in various fields such as automobiles, home appliances and general industrial materials. And since this molded article has biodegradability, even when it is dumped as waste without being subjected to combustion treatment, it is decomposed into materials that are harmless to the environment in a relatively short period of time in the natural environment.

The outline of the method for measuring the amount of fluff generation in ROV used in the examples is shown. DESCRIPTION OF SYMBOLS 1: Sample for evaluation (Glass fiber wound body) 2: Glass fiber strand end yarn 3, 4: Pre-opening bar 5: Opening BOX 6: Pulling device

Claims (9)

Polylactic acid resin, reinforcing fibers having a fiber length of more than substantially 2 mm, and the average particle size is contained talc of 0.1 to 3 m, the reinforcing fibers 5-70% by weight in the composition, the talc 5 to 25 % by mass in the composition , the polylactic acid-based resin is contained in the composition so that the total amount of the reinforcing fiber and the talc is 100% by mass, and the reinforcing fiber is urethane. A long fiber reinforced polylactic acid resin composition comprising a resin and a fiber treated with a sizing agent having an epoxy resin content of 20% by mass or less.   The long fiber reinforced polylactic acid resin composition according to claim 1, wherein an epoxy resin is attached to the talc.   The long fiber reinforced polylactic acid resin composition according to claim 1 or 2, wherein the epoxy resin is a phenol novolac type epoxy resin.   The long fiber reinforced polylactic acid resin composition according to any one of claims 1 to 3, wherein the resin composition is in the form of a pellet having a length of 2 to 50 mm.   Polylactic acid-based resin and talc having an average particle size of 0.1 to 3 μm are added to a continuum of reinforcing fiber bundles containing urethane resin and epoxy resin content of 20% by mass or less. A long fiber reinforced polylactic acid resin obtained by impregnating a melt containing 5.5 to 33 parts by mass with respect to 100 parts by mass of a resin to obtain a composition containing 5 to 70% by mass of reinforcing fibers A method for producing the composition.   While drawing the continuous bundle of reinforcing fibers through a crosshead, the melt supplied from the extruder to the crosshead is impregnated and drawn into a linear product, and the linear product is cut to a length of 2 to 50 mm. Item 6. A process for producing a long fiber reinforced polylactic acid resin composition according to Item 5.   The manufacturing method of the long fiber reinforced polylactic acid-type resin composition of Claim 5 or 6 with which the epoxy resin has adhered to the said talc.   The said epoxy resin is a phenol novolak-type epoxy resin, The manufacturing method of the long fiber reinforced polylactic acid-type resin composition in any one of Claims 5-7.   A molded product obtained by molding the long fiber reinforced polylactic acid resin composition according to claim 4, wherein the reinforcing fibers are contained in a weight average length of 1 mm or more.

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