JP5560576B2 - Resin composition and resin molded product - Google Patents

Description

  The present invention relates to a resin composition and a resin molded product.

  As a resin composition containing a biodegradable resin, and a molded product using the resin composition, a fiber composite material obtained by mixing a binder fiber made of a degradable resin and a natural fiber is used. A composite material of a biodegradable resin fiber and a natural fiber, which is coated with a hydrolysis inhibitor, preferably carbodiimide, and has effectively improved hydrolysis resistance, has been proposed (for example, see Patent Document 1). In addition, a composite composition containing a biodegradable organic polymer compound, plant fibers, and a biodegradable organic polymer compound hydrolysis inhibitor, and a molded article using the same are proposed. (For example, refer to Patent Document 2).

  Furthermore, a polylactic acid resin composition having excellent mechanical strength and heat resistance and excellent moldability and hue of a molded product has been proposed (see, for example, Patent Document 3).

JP 2004-232153 A JP 2006-63187 A JP 2008-150599 A

  This invention makes it a subject to provide the resin composition which improved the flame retardance, maintaining mechanical strength.

The above problems have been solved by the following means.
That is, the invention according to claim 1
(A) a biodegradable resin, (B) a natural fiber, (C) a hydrolysis inhibitor, and (D) an antioxidant,
Content of said (A) biodegradable resin is 65.25 mass% or more and 76.55 mass% or less,
The content of the (B) natural fiber is 20% by mass or more and 30% by mass or less,
The content of the (C) hydrolysis inhibitor is 2% by mass or more and 4% by mass or less,
The (D) antioxidant contains a hindered phenol antioxidant and a phosphorus antioxidant, and the content of the (D) antioxidant is 0.45 mass% or more and 1.5 mass% or less. It is a resin composition characterized by being.

The invention according to claim 2
The biodegradable resin (A) is at least one selected from polylactic acid, a copolymer of 3-hydroxybutyric acid and 3-hydroxyvaleric acid, and polybutylene succinate. 1. The resin composition according to 1.

The invention according to claim 3
The resin composition according to claim 1 or 2, wherein the (C) hydrolysis inhibitor is at least one selected from a carbodiimide compound and an isocyanate compound.

The invention according to claim 4
The resin composition according to any one of claims 1 to 3 , wherein the natural fiber (B) is at least one selected from kenaf, ramie, and bamboo.

The invention according to claim 5
(A) a biodegradable resin, (B) a natural fiber, (C) a hydrolysis inhibitor, and (D) an antioxidant,
Content of said (A) biodegradable resin is 65.25 mass% or more and 76.55 mass% or less,
The content of the (B) natural fiber is 20% by mass or more and 30% by mass or less,
The content of the (C) hydrolysis inhibitor is 2% by mass or more and 4% by mass or less,
The (D) antioxidant contains a hindered phenol antioxidant and a phosphorus antioxidant, and the content of the (D) antioxidant is 0.45 mass% or more and 1.5 mass% or less. It is a resin molded product characterized by being.

According to the invention which concerns on Claim 1, 2, 3 and 4 , compared with the case where it does not have this structure, the resin composition which improved the flame retardance is maintained, maintaining mechanical strength.
According to the invention which concerns on Claim 5 , compared with the case where it does not have this structure, the resin molded product which improved the flame retardance is provided, maintaining mechanical strength.

<Resin composition>
The resin composition according to this embodiment contains (A) a biodegradable resin, (B) natural fiber, (C) a hydrolysis inhibitor, and (D) an antioxidant.
Conventionally, in order to make a resin material flame-retardant, it has been necessary to mix a halogen-based, phosphorus-based, inorganic metal-based flame retardant, etc., but in this case, the mechanical properties are lowered. In particular, biodegradable resins have a low decomposition temperature and a high demand for flame retardancy. The proposals in Patent Documents 1 to 3 are intended to improve mechanical properties, but there is room for improvement in flame retardancy (especially when used for office equipment parts).
However, in the resin composition according to the present embodiment , the content of (A) the biodegradable resin is 65.25% by mass or more and 76.55% by mass or less, and (B) the content of natural fiber is 20% by mass or more and 30%. Mass% or less, (C) hydrolysis inhibitor content is 2 mass% or more and 4 mass% or less, (D) antioxidant contains hindered phenol antioxidant and phosphorus antioxidant, and antioxidant the content of the agent is applied not more than 1.5 mass% to 0.45 mass%.

  The resin composition according to the present embodiment contains (A) a biodegradable resin, (B) a natural fiber, (C) a hydrolysis inhibitor, and (D) an antioxidant, A resin composition having improved flame retardancy while maintaining mechanical strength is provided. This is because (D) an antioxidant is contained, and even when the resin composition according to this embodiment burns, the decomposition rate is suppressed by capturing radicals generated by thermal decomposition, and (C) hydrolysis By containing an inhibitor, the decomposed resin recombines, suppresses the generation of flammable gas due to decomposition, and (B) contains natural fiber, thereby forming high char and absorbing heat, resulting in mechanical strength. While maintaining the above, flame retardancy was improved. (B) When natural fiber burns, it has a function of efficiently generating soot (char), preventing diffusion of the generated combustible gas, and further insulating it, thereby contributing to improvement of flame retardancy.

Hereinafter, the configuration of the resin composition according to the present embodiment will be described.
(A) Biodegradable resin (A) The biodegradable resin may be any resin having biodegradability, such as polylactic acid, polyhydroxybutyrate, polycaprolactone, polybutylene succinate, poly (butylene succinate). Acrylate / adipate), poly (butylene succinate / carbonate), polyethylene succinate, polyvinyl alcohol, cellulose acetate, starch-modified resin, cellulose-modified resin, and the like, and at least polylactic acid, 3-hydroxybutyric acid and 3-hydroxyyoshi One selected from a copolymer with herbic acid and polybutylene succinate is preferred, and among them, polylactic acid that is easily available and excellent in moldability is more preferred.

  (A) The biodegradable resin is a matrix resin of the resin composition according to the present embodiment, and the content in the resin composition is preferably 60% by mass or more and 90% by mass or less, and 65% by mass or more and 85%. More preferably, it is 70 mass% or less, and more preferably 70 mass% or less. When the content of the (A) biodegradable resin is less than 60% by mass, the workability during kneading and molding deteriorates, and the generation of soot at the time of combustion may increase and flame retardancy may be reduced. If it exceeds 90% by mass, the mechanical properties may decrease and the flame retardancy may also deteriorate.

  (B) Natural fibers are not limited as long as they are naturally derived (plant derived, etc.) fibers, and include hemp (flax, ramie, manila hemp, sisal hemp, kenaf, jute), bamboo, cotton, pulp, etc. Among these, ramie, kenaf, and bamboo are preferable because they have high mechanical properties such as tensile strength.

  The content of the (B) natural fiber in the resin composition is preferably 10% by mass to 40% by mass, more preferably 15% by mass to 35% by mass, and more preferably 20% by mass to 30% by mass. % Or less is more preferable. When the content of the (B) natural fiber is less than 10% by mass, mechanical properties such as deflection temperature under load and bending characteristics may be lowered, and flame retardancy may be deteriorated. While workability at the time of kneading and molding deteriorates, soot generation at the time of combustion may be too fast and flame retardancy may be reduced.

  (C) A hydrolysis inhibitor will not be limited if it is a material which reacts with the terminal which has a carboxyl terminal or a hydroxyl group, A carbodiimide compound and an isocyanate compound are mentioned preferably. Examples of the carbodiimide compound include 2,2,6,6-tetraisopropyldiphenylcarbodiimide, dicyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, dioctylcarbodiimide, diisobutylcarbodiimide and the like.

  Examples of the isocyanate compound include aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and mixtures thereof.

  The content of the (C) hydrolysis inhibitor in the resin composition is preferably 0.5% by mass or more and 5% by mass or less, more preferably 1% by mass or more and 4% by mass or less, and 2% by mass. % To 3% by mass is more preferable. When the content of the (C) hydrolysis inhibitor is less than 0.5% by mass, the durability deteriorates and the flame retardancy during combustion may be further reduced. The physical properties and flame retardancy may be reduced.

  As the (D) antioxidant, a hindered phenol antioxidant, a phosphorus antioxidant, a sulfur antioxidant alone, or a hindered phenol antioxidant and a phosphorus antioxidant or a sulfur antioxidant. An hindered phenolic antioxidant and a phosphorus antioxidant are preferable, and it is more preferable to use a mixture of a plurality of these. Moreover, as said (D) antioxidant, a high molecular weight type is preferable and a molecular weight is 500 or more and 2000 or less.

  The content of the (D) antioxidant in the resin composition is preferably 0.01% by mass or more and 5% by mass or less, more preferably 0.05% by mass or more and 3% by mass or less. More preferably, the content is 1% by mass or more and 1% by mass or less. If the content of the antioxidant (D) is less than 0.01% by mass, it may cause a decrease in mechanical properties due to deterioration of the material during processing and a decrease in flame retardancy during combustion. If it exceeds 50%, the flame retardancy during combustion may be reduced.

You may mix | blend the stabilizer etc. which are normally mix | blended with the resin composition which concerns on this embodiment. These are not particularly limited, for example, crosslinking agents, crosslinking accelerators, crosslinking accelerators, activators, crosslinking inhibitors, anti-aging agents, antioxidants, ozone degradation inhibitors, ultraviolet rays Absorber, light stabilizer, tackifier, plasticizer, softener, reinforcing agent, reinforcing agent, foaming agent, foaming aid, stabilizer, lubricant, mold release agent, antistatic agent, modifier, colorant, cup Ring agent, preservative, antifungal agent, modifier, adhesive, flavoring agent, polymerization catalyst, polymerization initiator, polymerization inhibitor, polymerization inhibitor, polymerization regulator, crystal nucleating agent, compatibilizing agent, dispersant And antifoaming agents.
These may be used alone or in combination of two or more.

The resin composition according to the present embodiment includes the (A) biodegradable resin, (B) natural fiber, (C) hydrolysis inhibitor, (D) antioxidant, and stabilizer as necessary. Etc. are mixed and kneaded with a kneader.
Although it does not restrict | limit especially as said kneading machine, (B) natural fiber, (C) hydrolysis inhibitor, and (D) oxidation prevention by repeating a shear stress and position exchange using 3 rolls or 2 rolls. From the viewpoint of obtaining high dispersibility, a method of dispersing the agent and a method of dispersing by a collision force or shearing force of the disperser wall surface using a kneader, a Banbury mixer, an intermix, a single screw extruder, or a twin screw extruder are preferable. Used.

<Resin molded product>
The resin molded product according to this embodiment is characterized by containing (A) a biodegradable resin, (B) natural fiber, (C) a hydrolysis inhibitor, and (D) an antioxidant.
The resin molded product according to the present embodiment can be obtained by molding the resin composition according to the present embodiment described above with a molding machine.

  As a molding machine for molding the resin molded product according to the present embodiment, one or more moldings selected from a press molding machine, an injection molding machine, a molding machine, a blow molding machine, an extrusion molding machine, and a spinning molding machine Machine is used. Therefore, molding may be performed by one of these, or molding may be performed by one molding machine and then performed by another molding machine. In the present embodiment, it is preferable to use an injection molding machine from the viewpoint of obtaining a molded product that exhibits the effect of improving flame retardancy while maintaining biodegradability and mechanical strength.

  Molding conditions (cylinder temperature, mold temperature, etc.) when molding a resin molded product according to the present embodiment using an injection molding machine may be the general conditions of (A) biodegradable resin which is a matrix resin. Absent.

  The shape of the molded resin molded product according to the present embodiment is not particularly limited, such as a sheet shape, a rod shape, or a thread shape, and the size is not limited.

  The resin molded product according to the present embodiment is used for, for example, a packaging material and a building material as a sheet-shaped molded product, and as a structural molded product for OA equipment parts such as a casing of a copying machine and a printer, an internal part, and the like. May be.

Hereinafter, the present embodiment will be specifically described with reference to examples. However, this embodiment is not limited to the following examples.
<Examples 1 to 7, Comparative Examples 1 to 7>
A compound having a composition shown in Table 1 (unit: parts by mass) is kneaded with a biaxial kneader (Toyo Seiki, Labo Plast Mill) at the cylinder temperature shown in Table 1, and then pelletized (Toyo Seiki, PETE-C). The resin composition pellets were obtained by cutting with a mold.
The obtained pellets were molded into ISO multipurpose dumbbell test pieces and UL test pieces (thickness 2 mm) with an injection molding machine (NEX50, manufactured by Nissei Plastic Industry Co., Ltd.) at the cylinder temperature and mold temperature shown in Table 1. The following evaluation was implemented using the obtained test piece. The results are shown in Table 2.

In addition, the detail of the compound as described in the composition shown in Table 1 is as follows.
(A) Biodegradable resin / PLA-A
Polylactic acid, Terramac TE2000 (manufactured by Unitika)
・ PLA-B
Polylactic acid, Terramac TE7000 (manufactured by Unitika)
・ PHBV
Copolymer of 3-hydroxybutyric acid (HB) and 3-hydroxyvaleric acid (HV), Biopol (manufactured by Monsanto Japan)
・ PBS
Polybutylene succinate, GSPla (Mitsubishi Chemical Corporation)

(B) Natural fiber / kenaf (manufactured in-house)
・ Lamy (manufactured in-house)
・ Bamboo (manufactured in-house)

(C) Hydrolysis inhibitor, carbodilite carbodilite LA-1 (Nisshinbo Co., Ltd.)
・ Carbodiimide-modified diisocyanate millionate MTL (manufactured by Nippon Polyurethane Co., Ltd.)

(D) Antioxidants and phenolic A
Irganox 245 (Ciba Japan)
・ Phenolic B
irganox1010 (Ciba Japan)
・ Phosphorus irganox 168 (Ciba Japan)

(Evaluation)
[Flame retardance evaluation]
Using a UL test piece, a V test was performed in accordance with UL94 regulations. The results are shown in Table 2.

[Heat resistance evaluation]
Using an ISO multipurpose dumbbell test piece, the deflection temperature under load (DTUL) at 1.80 MPa load was measured with a DTUL measuring device (manufactured by Toyo Seiki Co., Ltd., HDT-3) according to ISO75. The results are shown in Table 2.

[Evaluation of flexural modulus]
Using ISO multi-purpose dumbbell test piece, in accordance with ISO 178, the ISO multi-purpose dumbbell test piece breaks or reaches a deflection of 10% or more with a bending property evaluation apparatus (manufactured by Shimadzu Corporation, precision universal testing machine Autograph AG-IS 5kN) Up to 2 mm / min. The load applied to the test piece during that time was measured. The results are shown in Table 2.

Claims (5)

(A) a biodegradable resin, (B) a natural fiber, (C) a hydrolysis inhibitor, and (D) an antioxidant,
Content of said (A) biodegradable resin is 65.25 mass% or more and 76.55 mass% or less,
The content of the (B) natural fiber is 20% by mass or more and 30% by mass or less,
The content of the (C) hydrolysis inhibitor is 2% by mass or more and 4% by mass or less,
The (D) antioxidant contains a hindered phenol antioxidant and a phosphorus antioxidant, and the content of the (D) antioxidant is 0.45 mass% or more and 1.5 mass% or less. A resin composition characterized by the above.   The biodegradable resin (A) is at least one selected from polylactic acid, a copolymer of 3-hydroxybutyric acid and 3-hydroxyvaleric acid, and polybutylene succinate. 2. The resin composition according to 1.   The resin composition according to claim 1 or 2, wherein the (C) hydrolysis inhibitor is at least one selected from a carbodiimide compound and an isocyanate compound. The resin composition according to any one of claims 1 to 3 , wherein the (B) natural fiber is at least one selected from kenaf, ramie, and bamboo. (A) a biodegradable resin, (B) a natural fiber, (C) a hydrolysis inhibitor, and (D) an antioxidant,
Content of said (A) biodegradable resin is 65.25 mass% or more and 76.55 mass% or less,
The content of the (B) natural fiber is 20% by mass or more and 30% by mass or less,
The content of the (C) hydrolysis inhibitor is 2% by mass or more and 4% by mass or less,
The (D) antioxidant contains a hindered phenol antioxidant and a phosphorus antioxidant, and the content of the (D) antioxidant is 0.45 mass% or more and 1.5 mass% or less. A resin molded product characterized by