JP5339670B2 - Resin composition and injection molded body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an injection molding having flame retardancy and heat resistance. <P>SOLUTION: The injection molding is prepared from a resin composition prepared by mixing a lactic acid-based resin (A) and a flame retardant (B) effective to plasticize the lactic acid-based resin (A) with a thermoplastic resin (C) having a &Delta;Hm of 0-30 J/g, wherein the flame retardant (B) accounts for 1-20 mass% of the total of the lactic acid-based resin (A), the flame retardant (B), and the thermoplastic resin (C), and the thermoplastic resin (C) accounts for 10-40 mass% of the resin composition. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

The present invention relates to a resin composition containing a lactic acid resin and an injection-molded product, and particularly to a resin composition having flame retardancy and an injection-molded product.

  Plastics are now widely used in every field such as daily life and industry, and the annual production of plastics around the world has reached about 100 million tons. Most of the plastic produced is discarded after use, and this has been recognized as one of the causes of the global environment. Therefore, there is a demand for materials that do not adversely affect the global environment even when discarded.

  In addition, since petroleum, which is a raw material for ordinary plastics, is a depleting resource, the use of renewable resources is required. For example, plant-derived plastics can be obtained by using renewable non-depleting resources, so it is possible to conserve petroleum-depleting resources such as oil, and after use, they are biodegraded and return to nature. Recyclable.

  Among plant raw material plastics, lactic acid resins are lactic acid obtained by fermentation of starch, can be mass-produced by chemical engineering, and are excellent in transparency, rigidity, heat resistance and the like. Therefore, in particular, lactic acid-based resins are attracting attention in the field of injection molding of film packaging materials, home appliances, OA equipment, automobile parts and the like as alternative materials for polystyrene and ABS resins.

An injection molded body used for applications such as home appliances, OA equipment, and automobile parts is required to have heat resistance to prevent fire.
Since lactic acid-based resins are easily combustible materials like polystyrene and ABS resins, it is necessary to add a flame retardant. However, when a metal hydroxide is blended as a flame retardant, the lactic acid resin is decomposed during resin kneading due to alkali ions in the metal hydroxide, resulting in a decrease in molecular weight and a decrease in mechanical strength. Moreover, in order to mix | blend a metal hydroxide and to provide sufficient flame retardance, a large amount of metal hydroxides must be mix | blended and the fall of the further mechanical strength arises.

  In addition, JP2003-192925A, JP2003-192929A, JP2004-190025A, JP2004-190026A, JP2005-89546A, JP2005-162872A, Japanese Patent Application Laid-Open No. 2005-248032 discloses a method of imparting flame retardancy by blending a phosphorus compound, and Japanese Patent Application Laid-Open No. 2005-2448032 discloses a phosphorus compound and a metal in a lactic acid resin. Although a technique for imparting flame retardancy by blending with a hydroxide has been disclosed, it involves problems. In other words, phosphorus compounds are widely used as flame retardants for polyesters such as acrylonitrile / butadiene / styrene copolymers, polycarbonate, polyethylene terephthalate or polybutylene terephthalate, and are used for flame retarding of lactic acid resins which are polyesters. On the other hand, since phosphorus compounds also act as plasticizers, it is known to significantly reduce the heat resistance of these resins. In a lactic acid resin having lower heat resistance than polyethylene terephthalate and polybutylene terephthalate, a decrease in heat resistance due to the incorporation of a phosphorus compound is fatal. For this reason, it has been very difficult to use a molded body made of a lactic acid-based resin for home appliances, OA equipment, automobile parts and the like that are required to have both flame retardancy and heat resistance.

JP 2003-192925 A JP 2003-192929 A JP 2004-190025 A JP 2004-190026 JP JP 2005-89546 A JP 2005-162872 A JP 2005-2448032 A JP 2005-162871 A

  As described above, the conventional method of imparting flame retardancy by blending a phosphorus compound with a lactic acid resin can improve the flame retardancy, but the heat resistance has been impaired.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a resin composition and an injection-molded article imparted with flame retardancy without impairing the heat resistance of the lactic acid-based resin. It is to provide.

As a result of intensive studies in view of such a current situation, the present inventors have completed the present invention with high effects.
The injection-molded article of the present invention comprises a mixture of a lactic acid resin (A) and a flame retardant (B) having a plasticizing effect on the lactic acid resin (A), and ΔHm of 0 J / g or more, 30 J / g. An injection-molded article using a resin composition obtained by blending the following thermoplastic resin (C), the lactic acid resin (A), the flame retardant (B), and the thermoplastic resin (C) The proportion of the flame retardant (B) in the interior is 1% by mass or more and 20% by mass or less, and the proportion of the thermoplastic resin (C) in the resin composition is 10% by mass or more and 40% by mass or less. It is characterized by being.

  Here, the flame retardant (B) having a plasticizing effect on the lactic acid resin (A) may be a phosphazene compound or a phosphoric ester amide compound.

In the present invention, the relative crystallinity χc (A) of the lactic acid resin (A), the crystallization heat amount ΔHc (A) of the lactic acid resin (A), and the crystal melting of the lactic acid resin (A) The crystallization treatment is preferably performed in the range of 60 ° C. or higher and 130 ° C. or lower so that the heat quantity ΔHm (A) satisfies the following formula.

χc (A) = {ΔHm (A) −ΔHc (A)} / ΔHm (A) ≧ 0.90

  The resin composition of the present invention comprises a mixture of a lactic acid resin (A) and a flame retardant (B) having a plasticizing effect on the lactic acid resin (A), and ΔHm of 0 J / g or more, 30 J / g. A resin composition comprising the following thermoplastic resin (C), wherein the lactic acid resin (A), the flame retardant (B), and the flame retardant in the thermoplastic resin (C) ( The proportion of B) is 1% by mass or more and 20% by mass or less, and the proportion of the thermoplastic resin (C) in the resin composition is 10% by mass or more and 40% by mass or less. .

  Here, the flame retardant (B) having a plasticizing effect on the lactic acid resin (A) may be a phosphazene compound or a phosphoric ester amide compound.

  According to the present invention, a resin composition imparted with flame retardancy by blending a specific flame retardant and a specific thermoplastic resin with a lactic acid resin without impairing the heat resistance of the lactic acid resin. Can be provided. Moreover, the injection molding excellent in the flame retardance and durability can be provided using this resin composition.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be described below.
The resin composition of the present invention comprises a mixture of a lactic acid resin (A) and a flame retardant (B) having a plasticizing effect on the lactic acid resin (A), and ΔHm of 0 J / g or more, 30 J / g. It is a resin composition formed by blending the following thermoplastic resin (C). A thermoplastic resin having a ΔHm of 0 J / g or more and 30 J / g or less with respect to the mixture of the lactic acid resin (A) and the flame retardant (B) having a plasticizing effect on the lactic acid resin (A). By blending C), the flame retardant (B) can remain in the low crystallinity thermoplastic resin (C) without shifting to the high crystallinity lactic acid resin, so the heat resistance of the resulting molded product Flame retardancy can be imparted without lowering the properties.

(Flame retardant with plasticizing effect)
Examples of the flame retardant having a plasticizing effect used in the present invention include trimethyl phosphate, triethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, cresyl di 2,6-xylenyl phosphate, etc. Phosphoric acid ester compounds, condensed phosphorus such as 1,3-phenylenebis (2,6-dimethylphenyl) phosphate, tetraphenyl (m-phenylene) bisphosphate, bis (ditolyl) isopropylidene-di-p-phenylenephosphate Examples thereof include acid ester compounds, phosphoric ester amide compounds such as 4,4′-bis (diphenylphosphorylamidophenyl) methane, and phosphazene compounds such as phosphonitrile phenyl esters. Among these, it is preferable to use a phosphoric ester amide compound or a phosphazene compound from the viewpoint of flame retardancy and hydrolysis resistance. Specific examples of phosphoric ester amide compounds include SP-670 and SP-703 manufactured by Shikoku Kasei Kogyo Co., Ltd., and specific examples of phosphazene compounds include KEMIDANT 302S manufactured by Chemipro Kasei Co., Ltd. FP-100 manufactured by Fushimi Pharmaceutical Co., Ltd.

(A thermoplastic resin having a ΔHm of 0 J / g or more and 30 J / g or less)
Examples of the thermoplastic resin having a ΔHm of 0 J / g or more and 30 J / g or less used in the present invention include polyethylene terephthalate / glycol copolymer, polystyrene, polybutadiene, styrene / butadiene copolymer, acrylonitrile / styrene copolymer. Examples thereof include amorphous thermoplastic resins such as polymers, acrylonitrile / butadiene / styrene copolymers, vinyl chloride and polycarbonate, or low crystalline resins such as polybutylene succinate / adipate and polybutylene adipate / terephthalate. In the present invention, ΔHm is 0 J / g or more and 30 J / g or less, preferably 0 J / g or more and 20 J / g or less, particularly preferably 0 J / g. When ΔHm of the thermoplastic resin is 0 J / g, the flame retardant (B) can remain more stable in the thermoplastic resin (C). In addition, when ΔHm exceeds 30 J / g, the flame retardant (B) shifts to the lactic acid resin (A), so that the heat resistance of the molded body obtained by plasticizing the lactic acid resin (A) is significantly reduced. Will be.

(Lactic acid resin)
The (A) lactic acid-based resin used in the present invention is composed of poly (L-lactic acid) having a structural unit of L-lactic acid, poly (D-lactic acid) having a structural unit of D-lactic acid, a structural unit of L-lactic acid, and Poly (DL-lactic acid) which is D-lactic acid, or a mixture thereof. Here, the composition ratio of D-lactic acid (D-form) and L-lactic acid (L-form) in the lactic acid resin is preferably L-form: D-form = 99.9: 0.1 to 97: 3, and L-form. : D-form = 99.5: 0.5 to 98: 2 is more preferable. If the proportion of D-lactic acid is less than 0.1%, the productivity may decrease, and if it exceeds 3%, the heat resistance of the injection-molded product may be difficult to obtain and the application may be limited. is there.

  As a polymerization method for the lactic acid-based resin, known methods such as a condensation polymerization method and a ring-opening polymerization method can be employed. For example, in the condensation polymerization method, L-lactic acid or D-lactic acid, or a mixture thereof can be directly subjected to dehydration condensation polymerization to obtain a lactic acid resin having an arbitrary composition.

  In the ring-opening polymerization method, a lactic acid-based resin can be obtained from lactide, which is a cyclic dimer of lactic acid, by selecting an appropriate catalyst and using a polymerization regulator as necessary. Lactide includes L-lactide, which is a dimer of L-lactic acid, D-lactide, which is a dimer of D-lactic acid, and DL-lactide composed of L-lactic acid and D-lactic acid. Accordingly, by mixing and polymerizing, a lactic acid resin having an arbitrary composition and crystallinity can be obtained.

Further, if necessary, such as improving heat resistance, a small amount of copolymer component within a range that does not impair the essential properties of the lactic acid resin, for example, within a range containing 90% by mass or more of the lactic acid resin component. Can be added. As a small amount of the copolymer component, a non-aliphatic dicarboxylic acid such as terephthalic acid and / or a non-aliphatic diol such as an ethylene oxide adduct of bisphenol A can be used.
Furthermore, for the purpose of increasing the molecular weight, a small amount of a chain extender such as a diisocyanate compound, an epoxy compound, or an acid anhydride can be used.

Even if the lactic acid-based resin is a copolymer with other hydroxycarboxylic acid units such as lactic acid and / or α-hydroxycarboxylic acid other than lactic acid, it is a copolymer with an aliphatic diol and / or an aliphatic dicarboxylic acid. It may be a polymer.
As other hydroxycarboxylic acid units, optical isomers of lactic acid (D-lactic acid for L-lactic acid, L-lactic acid for D-lactic acid), glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid Bifunctional aliphatic hydroxy-carboxylic acids such as 2-hydroxy-n-butyric acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-methyllactic acid, 2-hydroxycaproic acid, etc. Examples include lactones such as caprolactone, butyrolactone, and valerolactone.

  Examples of the aliphatic diol copolymerized with the lactic acid resin include ethylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol and the like. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, suberic acid, sebacic acid, and dodecanedioic acid.

  The lactic acid resin used in the present invention preferably has a weight average molecular weight in the range of 50,000 to 400,000, more preferably 100,000 to 250,000. When the weight average molecular weight of the lactic acid-based resin is smaller than 50,000, practical physical properties such as mechanical properties and heat resistance are hardly expressed. When it is larger than 400,000, the melt viscosity is too high and the molding processability is poor. Sometimes.

  Representative examples of the lactic acid resin preferably used in the present invention include the “Lacia” series manufactured by Mitsui Chemicals, Inc., and the “Nature Works” series manufactured by Nature Works, etc. Can be mentioned.

  In the present invention, a lactic acid resin (A), a flame retardant (B) having a plasticizing effect on the lactic acid resin (A), and a thermoplastic resin having a ΔHm of 0 J / g or more and 30 J / g or less The blending amount with (C) is such that the proportion of the flame retardant (B) in the mixture of the lactic acid resin (A), the flame retardant (B), and the thermoplastic resin (C) is 1% by mass or more and 20% by mass. Or less, preferably 5% by mass or more and 18% by mass or less, and more preferably 8% by mass or more and 15% by mass or less. When the ratio of the flame retardant (B) in the mixture is less than 1% by mass, it may be difficult to impart flame retardancy to the lactic acid-based resin, and when it exceeds 20% by mass, A flame retardant may migrate to a lactic acid resin and impair heat resistance.

  Moreover, the ratio for which the thermoplastic resin (C) accounts in the said mixture is 10 to 40 mass%, and it is preferable that it is 15 to 30 mass%. When the ratio of the thermoplastic resin (C) in the mixture is less than 10% by mass, the flame retardant (B) shifts to the lactic acid resin (A). Since the solvent resistance is reduced, appearance defects of the injection-molded product, cracks due to the solvent, and the like occur during use.

  In the present invention, the glass transition temperature of the thermoplastic resin (C) is preferably higher than the glass transition temperature of the lactic acid resin (A). When the glass transition temperature of the thermoplastic resin (C) is higher than that of the lactic acid resin (A), the heat resistance improving effect of the lactic acid resin (A) may be manifested.

  A phosphazene compound or a phosphoric ester amide compound used as a flame retardant (B) having a plasticizing effect is suitable for flame retardancy of lactic acid resins and has excellent hydrolysis resistance. A molded body in which the flame retardancy does not decrease even when used for a period is obtained.

In the present invention, a carbodiimide compound is preferably further blended in order to further improve the heat resistance of the obtained molded body.
As a carbodiimide compound used for this invention, what has the basic structure shown to the following general formula is mentioned as a preferable thing.

-(N = C = N-R-) n-

However, in the formula, R represents an organic bond unit, and may be, for example, aliphatic, alicyclic or aromatic. n represents an integer of 1 or more, and is usually appropriately determined between 1 and 50. When n is 2 or more, two or more R may be the same or different.

  Specifically, for example, bis (dipropylphenyl) carbodiimide, poly (4,4′-diphenylmethanecarbodiimide), poly (p-phenylenecarbodiimide), poly (m-phenylenecarbodiimide), poly (tolylcarbodiimide), poly ( Examples of the carbodiimide compound include diisopropylphenylenecarbodiimide), poly (methyl-diisopropylphenylenecarbodiimide), poly (triisopropylphenylenecarbodiimide), and the like. These carbodiimide compounds may be used alone or in combination of two or more.

  Specific examples of the carbodiimide compound include “STABAXOL” series manufactured by Rhein Chemie, “Carbodilite” series manufactured by Nisshinbo Co., Ltd., and the like.

  The compounding amount of the carbodiimide compound is preferably 0.1 parts by mass or more and 10 parts by mass or less, and preferably 1 part by mass or more and 5 parts by mass with respect to 100 parts by mass of the resin composition for forming the injection molded body. More preferably, it is as follows. If the compounding amount of the carbodiimide compound is 0.1 parts by mass or more, an effect of improving durability is obtained, and if it is 10% by mass or less, softening due to the carbodiimide compound does not occur, or due to excessive molecular weight improvement. Since there is no increase in viscosity, there is no problem in moldability.

  The resin composition of the present invention is blended with additives such as a heat stabilizer, an antioxidant, a nucleating agent, a UV absorber, a light stabilizer, a pigment, and a dye within the range not impairing the effects of the present invention. Can do.

Next, a method for forming an injection molded body using the resin composition of the present invention will be described.
A lactic acid resin (A), a flame retardant (B) having a plasticizing effect on the lactic acid resin, a thermoplastic resin (C) having a ΔHm of 0 J / g or more and 30 J / g or less, and, if necessary, Each raw material such as a carbodiimide compound and other additives is put into the same injection molding machine, directly kneaded, and injection molded to form an injection molded body. Alternatively, a dry blended raw material is extruded into a strand shape using a twin screw extruder to produce pellets, and the pellets are again put into an injection molding machine and injection molded to form a molded body. . In addition, since lactic acid-type resin is easy to raise | generate a hydrolysis at the time of melt molding, it is preferable to dry beforehand or pass through a vacuum vent extrusion process.

  Regardless of which method is employed, it is necessary to consider a decrease in molecular weight due to decomposition of the raw material, but the latter is preferably selected in order to uniformly mix the raw materials. For example, after removing moisture by sufficiently drying lactic acid resin, flame retardant, thermoplastic resin, and, if necessary, carbodiimide compound and other additives, a twin screw extruder is used. Used to melt mix and extrude into strand shape to make pellets. Note that the melting point of the lactic acid resin changes depending on the composition ratio of the L-lactic acid structure and the D-lactic acid structure, the melting point of the resin composition changes depending on the mixing ratio of the lactic acid resin, the flame retardant, and the thermoplastic resin. In view of the above, it is preferable to appropriately select the melt extrusion temperature. In practice, a temperature range of 180 ° C. to 230 ° C. is usually selected.

  After the pellets produced by the above method are sufficiently dried to remove moisture, an injection molded article is formed using the method shown below.

  As the injection molding method, for example, an injection molding method such as an injection molding method, a gas assist molding method, or an injection compression molding method that is generally employed when molding a thermoplastic resin can be employed. Further, in accordance with other purposes, in-mold molding method, gas press molding method, two-color molding method, sandwich molding method, and the like can be adopted in addition to the above methods. However, the injection molding method is not limited to these.

  The injection molding apparatus used is a general injection molding machine, gas assist molding machine, injection compression molding machine, etc., molding molds and incidental equipment used in these molding machines, mold temperature control device, raw material drying device Etc. Molding conditions are preferably such that the molten resin temperature is in the range of 180 ° C. to 210 ° C. in order to avoid thermal decomposition of the resin in the injection cylinder.

The injection molded product of the present invention has a relative crystallinity χc (A) of the lactic acid resin (A), a crystallization heat amount ΔHc (A) of the lactic acid resin (A), and a crystal melting of the lactic acid resin (A). It is preferable that the amount of heat ΔHm (A) satisfies the following formula. That is, in the present invention, it is preferable that the lactic acid resin (A) of the molded body satisfies the following formula, and the injection molded body of the present invention is in the range of 60 ° C. or higher and 130 ° C. or lower so as to satisfy the relationship of the following formula. A crystallization treatment is preferably performed. When the crystallization treatment is performed in this manner, further heat resistance can be imparted while minimizing shrinkage and deformation of the molded body.

χc (A) = {ΔHm (A) −ΔHc (A)} / ΔHm (A) ≧ 0.90

  As a method for the crystallization treatment, it is effective to perform the crystallization treatment in the mold during molding and / or after taking out from the mold. From the viewpoint of productivity, when the crystallization speed of the resin forming the injection-molded body is low, it is preferable to perform crystallization after taking out from the mold, and when the crystallization speed is high, within the mold It is preferable to perform a crystallization treatment.

  When crystallization is performed in the mold, the molten resin is filled in the heated mold and then held in the mold for a predetermined time. In this case, the mold temperature is preferably 60 ° C. or higher and 130 ° C. or lower, and more preferably 90 ° C. or higher and 120 ° C. or lower. The crystallization treatment time is preferably set as appropriate depending on the composition of the resin composition, the heat treatment temperature, etc. For example, the crystallization treatment time is preferably 1 second or more and 300 seconds or less, preferably 10 seconds or more, 100 More preferably, it is less than a second. By performing the crystallization treatment at a temperature within the above range and the crystallization treatment time, the heat resistance of the obtained molded body can be further improved.

  Further, when the crystallization treatment is performed after taking out the molded body from the mold, the heat treatment temperature is preferably in the range of 60 ° C. or higher and 130 ° C. or lower, and in the range of 70 ° C. or higher and 100 ° C. or lower. More preferably it is. If the heat treatment temperature is less than 60 ° C., crystallization may not proceed in the molding step, and if it is higher than 130 ° C., deformation or shrinkage may occur when the molded body is cooled.

  The crystallization treatment time is preferably set as appropriate according to the composition of the resin composition, the heat treatment temperature, etc. For example, when the heat treatment temperature is 70 ° C., the crystallization treatment time is 15 minutes or more and 5 hours or less. It is preferably 1 hour or longer and 4 hours or shorter, more preferably 2 hours or longer and 3 hours or shorter. When the heat treatment temperature is 130 ° C., the crystallization treatment time is preferably 10 seconds or longer and 30 minutes or shorter, more preferably 1 minute or longer and 20 minutes or shorter, and more preferably 5 minutes or longer and 10 minutes or shorter. It is particularly preferred that

  As a crystallization treatment method, the mold temperature is raised in advance and crystallized in the mold, or after the injection molded body is taken out from the mold in an amorphous state, hot air, steam, hot water, Examples of the method include crystallization using an infrared heater, an IH heater, or the like. When the crystallization treatment is performed, the molded body may be fixed without being fixed. However, in order to prevent deformation of the molded body, it is preferable to fix the molded body with a mold, a resin mold or the like. In consideration of productivity, heat treatment may be performed in a packed state.

  Thus, since the molded object formed using the resin composition of the present invention has excellent flame retardancy and heat resistance, home appliances and automobile applications that require flame retardancy, heat resistance, etc. Can be widely used for.

  The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these examples, and various applications are possible without departing from the technical scope of the present invention. In addition, each Example and each comparative example evaluated by the method shown below.

(1) Flame retardance Using a test piece having a length of 135 mm, a width of 13 mm, and a thickness of 3 mm, a combustion test was performed at n = 5 based on the safety standard UL94 vertical combustion test procedure of Underwriters Laboratories. Judgment was made based on the criteria of the UL94 vertical combustion test (UL94V), and those conforming to the V-2, V-1, and V-0 standards were accepted.

(2) Heat resistance (deflection temperature under load)
Based on JIS K7191, the test piece of length 120mm x width 11mm x thickness 3mm was created, and the deflection temperature under load was measured using S-3M made by Toyo Seiki Co., Ltd. The measurement was performed under the condition of edgewise direction and a load of 1.82 MPa applied to the test piece. The deflection temperature under load was 55 ° C. or higher.

(3) Bleed-out A test piece having a length of 100 mm, a width of 100 mm and a thickness of 3 mm was injection-molded, and the obtained test piece was allowed to stand in an atmosphere of 80 ° C. and 80% RH for 150 hours. Thereafter, the bleedout of the flame retardant on the surface of the test piece was visually evaluated. The symbol “X” indicates that the flame retardant bleeds out and the surface is whitened, and the symbol “◯” indicates that no whitening is observed.

(4) Measuring method of ΔHc and ΔHm Based on Japanese Industrial Standard JIS K-7121, a sample of about 10 mg was cut out from an injection molded product and a resin pellet, and “DSC-7” manufactured by PerkinElmer was used. The temperature rise was measured from 30 ° C. to 200 ° C. at a rate of minutes, and the heat of crystallization (ΔHc) and the heat of crystal fusion (ΔHm) were read from the obtained thermogram.

Example 1
Using Nature Works 4032D (L-lactic acid / D-lactic acid = 98.6 / 1.4, weight average molecular weight 200,000) manufactured by Nature Works as a lactic acid resin, it is difficult to have a plasticizing effect on the lactic acid resin. SP-670 (phosphate ester amide compound) manufactured by Shikoku Kasei Kogyo Co., Ltd. is used as a flame retardant, and Ecoflex F (manufactured by BASF Japan Ltd.) is used as a thermoplastic resin having a ΔHm of 0 J / g to 30 J / g. Polybutylene adipate / terephthalate, ΔHm: 18 J / g) was used. After dry blending Nature Works 4032D, SP-670, and Ecoflex F at a mass ratio of 80: 5: 15, a 40 mmφ small co-directional twin screw extruder manufactured by Mitsubishi Heavy Industries, Ltd. was used. And compounded at 200 ° C. to form a pellet. Using the obtained pellets, an injection molding machine “IS50E” (screw diameter: 25 mm) manufactured by Toshiba Machine Co., Ltd., a test piece having a length of 135 mm, a width of 13 mm, and a thickness of 3 mm was obtained as a test piece for flame retardancy evaluation. A test piece having a length of 120 mm, a width of 11 mm, and a thickness of 3 mm is used as a test piece for evaluation of heat resistance. The test piece was obtained by injection molding. However, the main molding conditions are as shown below.

・ Temperature condition: Cylinder temperature (200 ℃) Mold temperature (40 ℃)
・ Injection conditions: Injection pressure (115 MPa) Holding pressure (55 MPa)
・ Weighing conditions: Screw rotation speed (65rpm) Back pressure (15MPa)

  The obtained injection molded article (test piece) was evaluated for flame retardancy, heat resistance and bleed out. The results are shown in Table 1.

(Example 2)
Nature Works 4032D: SP-670: Ecoflex F The blending ratio of the lactic acid resin (A), the flame retardant (B), and the thermoplastic resin (C) in the pellets used for forming the injection-molded body is expressed by mass ratio. = 75: 10: 15 An injection molded article (test piece) was produced in the same manner as in Example 1 except that the ratio was changed to be 75:10:15.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 1.

(Example 3)
Nature Works 4032D: SP-670: Ecoflex F The blending ratio of the lactic acid resin (A), the flame retardant (B), and the thermoplastic resin (C) in the pellets used for forming the injection-molded body is expressed by mass ratio. An injection molded article (test piece) was prepared in the same manner as in Example 1 except that the ratio was changed to 70:15:15.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 1.

Example 4
Nature Works 4032D: SP-670: Ecoflex F The blending ratio of the lactic acid resin (A), the flame retardant (B), and the thermoplastic resin (C) in the pellets used for forming the injection-molded body is expressed by mass ratio. = 65: 20: 15 An injection-molded article (test piece) was produced in the same manner as in Example 1 except that the ratio was changed to be 65:20:15.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 1.

(Example 5)
Using Nature Works 4032D manufactured by Nature Works as the lactic acid resin (A) and SP-670 manufactured by Shikoku Kasei Kogyo Co., Ltd. as the flame retardant (B), ΔHm is 0 J / g or more and 30 J / g or less. As a certain thermoplastic resin (C), Iupilon S3000 (polycarbonate, ΔHm: 0J / g) manufactured by Mitsubishi Engineering Plastics Co., Ltd. is used, and Nature Works 4032D, SP-670, and Iupilon S3000 are used in a mass ratio of 70:15. : An injection-molded article (test piece) was prepared in the same manner as in Example 1 except that the ratio was changed to 15.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 1.

(Example 6)
Change the thermoplastic resin (C) having ΔHm of 0 J / g or more and 30 J / g or less to Asaflex T-420 (styrene / butadiene copolymer, ΔHm: 0 J / g) manufactured by Asahi Kasei Co., Ltd., Nature Works An injection molded body (test piece) was prepared in the same manner as in Example 1 except that 4032D, SP-670, and Asaflex T-420 were changed to have a mass ratio of 70:15:15. went.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 1.

(Example 7)
The thermoplastic resin (C) having a ΔHm of 0 J / g or more and 30 J / g or less is changed to a copolyester 6673 (polyethylene terephthalate / glycol copolymer, ΔHm: 0 J / g) manufactured by Eastman Chemical Co., Ltd. An injection molded article (test piece) was prepared in the same manner as in Example 1 except that SP-670 and copester 6663 were changed to have a mass ratio of 70:15:15.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 1.

(Example 8)
The blend ratio of the lactic acid-based resin (A), the flame retardant (B), and the thermoplastic resin (C) in the pellets used for forming the injection-molded body, in terms of mass ratio, Nature Works 4032D: SP-670: Iupilon S3000 = An injection molded body (test piece) was produced in the same manner as in Example 5 except that the ratio was changed to 55:15:30.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 1.

(Comparative Example 1)
An injection-molded article was produced in the same manner as in Example 1 except that only the Nature Workd 4032D was used as the lactic acid resin (A) without using the flame retardant (B) and the thermoplastic resin (C).
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 2.

(Comparative Example 2)
Without using the thermoplastic resin (C), Nature Workd 4032D is used as the lactic acid resin (A), SP-670 is used as the flame retardant (B), and the Nature Workd 4032 and SP-670 are massed. An injection-molded article was produced in the same manner as in Example 1, except that the ratio was changed to 95: 5.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 2.

(Comparative Example 3)
Without using the thermoplastic resin (C), Nature Workd 4032D is used as the lactic acid resin (A), SP-670 is used as the flame retardant (B), and the Nature Workd 4032 and SP-670 are massed. An injection molded body was produced in the same manner as in Example 1 except that the ratio was changed to 90:10.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 2.

(Comparative Example 4)
Without using the thermoplastic resin (C), Nature Workd 4032D is used as the lactic acid resin (A), SP-670 is used as the flame retardant (B), and the Nature Workd 4032 and SP-670 are massed. An injection molded body was produced in the same manner as in Example 1 except that the ratio was changed to 85:15.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 2.

(Comparative Example 5)
GSPla AZ91T (polybutylene succinate, ΔHm: 50 J / g) manufactured by Mitsubishi Chemical Corporation was used instead of the thermoplastic resin (C), and Nature Workd 4032, SP-670, and GSPla AZ91T in a mass ratio of 70 : An injection-molded article was produced in the same manner as in Example 1 except that the ratio was changed to 15:15.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 2.

(Comparative Example 6)
Instead of the thermoplastic resin (C), NOVADURAN 5010R5 (polybutylene terephthalate, ΔHm: 54 J / g) manufactured by Mitsubishi Engineering Plastics Co., Ltd. was used. In the same manner as in Example 1 except that the ratio was changed to 70:15:15, an injection-molded article was produced.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 2.

(Comparative Example 7)
Biomax 6926 (polyethylene terephthalate succinate, ΔHm: 38 J / g) manufactured by DuPont was used instead of the thermoplastic resin (C), and Nature Workd 4032, SP-670, and Biomax 6926 were used in a mass ratio of 70:15. : An injection-molded article was produced in the same manner as in Example 1 except that the ratio was changed to 15.
About the obtained injection molded object (test piece), evaluation similar to Example 1 was performed. The results are shown in Table 2.

As is clear from Table 1, the resin compositions of Examples 1 to 10 have flame retardancy based on the UL94 vertical combustion test satisfying the criteria of V-2 or V-0. I found it excellent. In addition, it was found that the resin compositions of Examples 1 to 10 had a weighted deflection temperature of 55 ° C. or higher, excellent heat resistance, and no bleed out.
That is, the resin composition of the present invention can be imparted with flame retardancy without causing a decrease in heat resistance, and a molded article formed using this resin composition has heat resistance and flame retardancy. It was excellent in both sex.

  On the other hand, as is clear from Table 2, it was found that the resin composition of Comparative Example 1 had a flame retardance based on the UL94 vertical combustion test at a non-standard level and was inferior in flame retardancy. The resin compositions of Comparative Examples 2 to 4 in which a flame retardant is blended with a lactic acid resin have a deflection temperature under load of less than 55 ° C, although the flame retardant evaluation based on the UL94 vertical combustion test satisfies V-2. It was found that the injection molded body obtained from this resin composition was bleed out. It turned out that the resin composition of Comparative Examples 5-7 is inferior to heat resistance, and the molded object obtained has a bleed-out.

  In the same manner as in Examples 1 to 8, when the injection molded article was produced by changing the type of the flame retardant (B) to a phosphazene compound, excellent flame retardancy was imparted without causing a decrease in heat resistance. It was confirmed that it was possible.

  Moreover, when 100 parts by mass of the resin compositions of Examples 1 to 8 above were added to add 3 parts by mass of a carbodiimide compound to produce an injection molded article, all of the obtained injection molded articles had excellent resistance. It showed hydrolyzability.

  Moreover, the crystallization process was performed to the injection molded object formed using the resin composition of the said Examples 1-8, and the lactic acid-type resin satisfy | filled (chi) (A)> = 0.90. This injection-molded product exhibited further excellent heat resistance.

  The resin composition of the present invention can be widely used for applications requiring flame retardancy and / or heat resistance, and can be used, for example, for home appliances, automobile products, and the like. In addition, it can also be used as electrical and electronic equipment parts, daily necessities, food containers, and other general injection molded products.

Claims (2)

A mixture of a lactic acid resin (A) and a flame retardant (B) that has a plasticizing effect on the lactic acid resin (A), and a thermoplastic resin having a ΔHm of 0 J / g or more and 30 J / g or less (C ) and by blending the resin composition (where I injection molded der that case made with the exception) an organic filler derived from nature are blended, the flame retardant (B) is phosphazene a compound or a phosphoric acid ester amide-based compound, the thermoplastic resin (C) is a polybutylene succinate / adipate or polybutylene adipate / terephthalate, the lactic acid-based resin (a), the said flame retardant (B) and the the proportion of the flame retardant occupying in the thermoplastic resin (C) (B) is 1 wt% or more, 20 or less wt%, the thermoplastic resin (C) the percentage of the resin composition is 10% by weight that's all Injection molded body, characterized in that at most 40 mass%. Relative crystallinity χc (A) of the lactic acid resin (A), crystallization heat amount ΔHc (A) of the lactic acid resin (A), and heat of crystal fusion ΔHm (A) of the lactic acid resin (A) DOO or higher 60 ° C. so as to satisfy the following formula, an injection molded article according to claim 1, wherein in the range of 130 ° C. or less to crystallize treated.

χc (A) = {ΔHm (A) −ΔHc (A)} / ΔHm (A) ≧ 0.90