JP2005344042A - Composition using vegetable resource as raw material and compounded with flame retardant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition which is prepared by imparting flame retardancy to a plastic resin using a plant friendly for global environments as a raw material and solves a problem that the plastic resin is expected as a resin friendly for the global environments to develop application technology in the next generation, but does not realize application to the external materials of household appliances and the like because of not having flame retardancy due to biodegradability, and to provide a method for realizing the composition without changing conventional production methods. <P>SOLUTION: Flame retardancy can be imparted by compounding a vegetable raw material resin with a flame retardant. The flame retardant is simultaneously together compounded with one or more other resins and a colorant, when the resins are kneaded. Thereby, a process accompanied by the compounding of a flame retardant is increased. The resin can be kneaded, when the resin is melted before molded. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a composition for adding flame retardancy to plastics made from plant resources.

In recent years, plastics that can be decomposed by bacterial action when buried in the soil have attracted attention. These resins, called biodegradable plastics, have the property of degrading in the presence of aerobic bacteria and degrading them into water (H ₂ O) and carbon dioxide (CO ₂ ), for agricultural use and disposable products Practical use for packaging materials, compostable garbage bags, etc. has been implemented.

Decomposition by soil bacteria can significantly reduce CO ₂ emissions compared to conventional incineration treatment, and it is not necessary to collect used plastic from the viewpoint of global warming prevention measures. The market is in the direction of expansion with support from users.

  Biodegradable plastics are largely composed of polylactic acid (hereinafter referred to as PLA), PBS (polybutyl succinate (a copolymer resin of 1,4 butanediol group and succinic acid group)), PET (polyethylene) due to its structural composition. It is divided into three (terephthalate) systems. Each feature is as shown in FIG.

  These biodegradable plastics have another major feature. The synthetic raw material does not use fossil resources such as petroleum, but has the possibility of industrial production using sugar produced by plants such as corn and sweet potato as raw materials. In this sense, these biodegradable plastics are also called bioplastics. Among them, PLA has been in the spotlight because mass production using corn as a raw material has been started, and there is a great demand for development of various applied technologies, not limited to biodegradation applications.

  However, to replace these bioplastics with existing materials, it is necessary to improve the properties. FIG. 8 shows a table of physical properties of polystyrene (PS) and acrylonitrile-butadiene-styrene resin (hereinafter referred to as ABS) as general plastics, and polylactic acid (PLA) and PBS as bioplastics. . “Bending elastic modulus” and “bending strength” indicate rigidity. The larger the value, the higher the rigidity. The “Izod impact strength” indicates the ease of damage to the impact. On the other hand, it is difficult to break. “Thermal deformation temperature” is a temperature at which heat starts to be deformed, and the higher the value, the higher the temperature can be used.

  From this figure, it can be seen that PLA is hard and brittle and PBS has soft properties. Thermally, PLA has poor heat resistance, and PBS has heat resistance higher than that of ABS.

  As a method for improving the characteristics of such bioplastic, a method of blending other components has been proposed. For example, it has been proposed to improve heat resistance by blending about 0.5-20 wt% of synthetic mica with PLA. At the same time, it has been proposed to add an additive (carbodiimide compound) that suppresses hydrolysis (biodegradation action) of the biodegradable resin (see Patent Document 1 below).

  According to the above method, it has been reported that PLA resin is hardly deformed by molding or machining by an injection method, and as a result, an exterior body of an electric product can be produced and deformation at high temperatures can be suppressed to a minimum.

  In addition, there is an example in which the possibility of application to a personal computer exterior body is reported by blending kenaf fiber with PLA (see Non-Patent Document 1 below). It has been reported that the heat resistance, which is a weak point of PLA resin, can be improved by adding an annealing process after molding of the PLA resin blended with kenaf fiber.

In this way, bioplastics are in a stage where application technology development for exterior bodies of home appliances is being promoted day and night by making full use of blending technology with other components.
JP 2002-173583 A Serizawa et al., “Development of Kenaf Fiber Reinforced Polylactic Acid” (Preliminary Proceedings of the 14th Annual Meeting of the Plastic Molding Society, Pages 161-162, 2003)

  However, the resin compositions described in the above-mentioned patent documents and non-patent documents are proposals focused on improving heat resistance, and can add flame retardance that is indispensable for application to exterior bodies of home appliances. Not. Therefore, it cannot be applied to an exterior body of an electrical appliance such as a television set having a high voltage portion inside. In recent years, electrical appliances place importance on safety, and there is a tendency to adopt flame retardant resins even in devices that do not have high-voltage elements inside. Even if a bioplastic that satisfies the requirements is completed, there are few situations where it can be used effectively.

  This invention is made | formed in view of the said problem, and it is providing the composition which adds a flame retardance to bioplastic, for example, the characteristic as an exterior body of an electrical appliance.

  As a method of adding flame retardancy to a resin, there is a method of adding a flame retardant. A variety of flame retardants have been developed, including halogen-based, phosphorus-based, inorganic-based, and silicon-based materials. The content and content ratio are optimized according to the application and applied to resins made from fossil resources. Yes. The present inventors have found that the effect of improving the flame retardancy of a plant raw material resin can be added by kneading the flame retardant into the plant raw material resin.

  TECHNICAL FIELD The present invention relates to a composition characterized in that a resin that uses plant resources as a main component is blended with a component that adds flame retardancy, and the resin that uses plant resources as a raw material is polylactic acid (PLA). It has a biodegradable group such as PBS.

  The present invention also relates to a composition in which a group synthesized from a plant is a lactic acid group, a 1,4-butanediol group or a succinic acid group.

  The present invention also relates to a component that adds flame retardancy, and relates to a composition characterized in that the flame retardant composition contains an appropriate amount of at least one of halogen, phosphorus, inorganic compound, silicon and the like. Is.

  The present invention relates to an inorganic flame retardant that is effective in a particularly small amount, and is made by impregnating porous silica with one or more of acetylacetonate iron, copper ethylenediaminetetraacetate, zinc oxide, and vanadium pentoxide. The present invention relates to a plastic resin composition containing a flame retardant.

  The present invention also relates to a plastic resin composition containing an organic peroxide as a flame retardant aid.

  Moreover, this invention is the compounding method. The blending method is characterized by blending at the time of kneading used for resin dissolution. Since the kneading process is an indispensable process at the time of plastic production or molding, an increase in the number of processes necessary for blending the flame retardant does not occur, and an increase in cost can be minimized.

  Moreover, this invention limits the shaping | molding method of the said composition. Since it is molded by injection or compression molding, it is not necessary to make a major change in the production facility, and it is possible to easily promote the transition from conventional plastic to bioplastic.

  According to the present invention, in a plant raw material resin friendly to the global environment, it is possible to add flame retardancy without increasing the production process, and as a result, it can be used as an exterior body for electrical appliances and the like. Value is great.

  In order to mold a resin as an exterior body of an electric appliance, a method of melting the resin and injection molding it into a mold having a predetermined shape, or a compression molding method of dissolving the resin and pressing a desired mold is common. .

  By dissolving the pellet-shaped resin, it becomes possible to form the resin into a desired shape. At this time, the resin can be colored in a desired color by kneading a colorant.

  As described above, a kneading step using a kneader is indispensable when the resin is used as an exterior body. Also, when blending other components for adjusting physical properties, a mixing blending method using a kneader is often used.

  Since the present invention proposes kneading a desired amount of the flame retardant at the time of kneading, no cost increase other than the flame retardant cost occurs.

  As the flame retardant to be kneaded, a wide variety of component systems can be considered in balance with the required flame retardancy and other physical properties. For example, halogen-based, phosphorus-based, inorganic compound-based, silicon-based, etc. can be mentioned, but there are cases where these are used in combination, and other component systems may be blended, but these are limited. Is not to be done.

  Examples of halogen flame retardants include tetrabromobisphenol A (TBBA), decabromodiphenyl ocside (DBDPO), hexabromocyclododecane (HBCD), octabromodiphenyl oxide (OBDPO), bistribromophenoxyethane (BTBPE), Tribromophenol (TBP), ethylenebistetrabromoflutalimide, TBA polycarbonate oligomer, brominated polystyrene, TBA epoxy oligomer, TBA epoxy polymer, TBA bisbromopropyl ether, ethylenebispentabromodiphenyl, polybromophenyl oxide, hexabromo Brominated flame retardants such as benzene and chlorinated flame retardants represented by chlorinated paraffin, perchlorocyclopentadecane, chlorendic acid, etc. And the like.

  Examples of the phosphorus-based flame retardant include TPP, triallyl phosphate, aromatic phosphate ester, 2 ethylhexyl diphenyl phosphate, triethyl phosphate, TCP, cresyl phenyl phosphate, resordiol bis (diphenyl) phosphate, tris (chloroethyl) phosphate. Fate, tris-β-chloropropyl phosphate, trisdichloropropyl phosphate, halogen-containing condensed phosphate, aromatic condensed phosphate, polyphosphate, red phosphorus and the like.

  In addition to these, for example, Mg (OH) 2, Al (OH) 3, Sb2O3, guanidinic acid, Sb2O5, zinc borate, molybdenum compound, zinc stannate, fluorobutanesulfonic acid potassium salt as super strong acid salt, fluoromethane Sulfonic acid potassium salt, fluoromethanesulfonic acid sodium salt, sulfuric acid-supported iron oxide, tungstic acid-supported iron, chromium oxide, copper chromium, copper oxide, iron oxide, lanthanum oxide, manganese oxide, molybdenum oxide, nickel oxide as dehydrogenation catalyst system , Nichrome oxide, copper-chromium catalyst, palladium oxide, tin pyrophosphate, tantalum oxide, titanium oxide, titanium pyrophosphate, tungsten oxide, zinc pyrophosphate, zirconium pyrophosphate, zinc oxide, acetylacetonatocobalt, acetylacena as metal complexes Copper, dimethylthiocar Min iron benzoyl acetonate iron, tris dibenzoyl meta isocyanatomethyl iron, smectite as clay-based, montmorillonite, APP / PER as intumescent systems, PPE, such as PC and the like as the resin system.

  Examples of other flame retardants include silicon flame retardants, odor-oxidized aromatic triazines, and composite flame retardants. In the present invention, in addition to conventionally known flame retardants, acetylacetonate iron, ethylenediaminetetraacetate copper, zinc oxide, vanadium pentoxide, acetylacetonate copper, copper EDTA, benzoyl acenate are particularly effective in small amounts. Using one with one or more organometallic complexes such as iron mixed or one or more impregnated with porous silica, flame retardancy was achieved by adding a small amount.

  Typical examples of the organic peroxide used as a flame retardant aid include ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, peroxyester, peroxydicarbonate, and dimethyl-diphenylbutane. But also their derivatives.

  The above-mentioned compound is generally used as the flame retardant to be kneaded, but any other substance that can add flame retardancy may be used, and is not limited thereto. In addition, the above flame retardants and flame retardant aids may be used alone or in combination with a plurality of flame retardants in order to meet the required flame retardant properties. The ratio is not limited.

  As described above, since the kneading step is an indispensable step when the resin is applied to the exterior body, kneading a desired flame retardant at the time of kneading does not substantially increase the work process.

  The kneading step is not particularly limited, and may be performed at the time of resin dissolution immediately before molding or may be pelletized again after kneading.

  An example of the blending sequence (order) of the composition of the present invention is shown as a flow diagram in FIG.

  In this example, 70 wt% of polylactic acid (PLA) synthesized from corn as a raw material and 30 wt% of polybutyl succinate (PBS) for the purpose of improving heat resistance were used to prepare a kneaded pellet. (Step 1).

  Then, 15 wt% of tetrabromobisphenol A (TBBA) as a flame retardant was added to the obtained pellets (85 wt%), and kneaded at 185 ° C. with a twin screw extruder (step 2), 125 × 13 × 3.2 mm. The test piece was injection molded (molding temperature 180 ° C., mold temperature 25 ° C.) (step 3).

  This test piece was subjected to a vertical combustion test with a flame height of 20 mm in accordance with UL94. The result is shown in FIG. From the figure, it was found that the sample was UL standard V0.

As another example, a test piece in which a resin compounded with 5% of Mg (OH) ₂ is molded into a plastic compounded with polylactic acid (PLA): kenaf fiber = 70: 30 is the same as in Example 1 The experiment was conducted. As a result, it was found that it has flame retardancy that complies with the V0 standard.

  Another example of the sequence (order) is shown as a flowchart in FIG.

  A kneaded pellet is prepared by using a biaxial kneader with 70 wt% of polylactic acid (PLA) synthesized from corn and 30 wt% of polybutyl succinate (PBS) for the purpose of improving heat resistance (step 1). .

Then, 10 wt% of the pellets (90 wt%) obtained by attaching acetylacetonate iron (Fe (acac) ₃ ) as a flame retardant to the SiO ₂ porous body was added to the obtained pellet (90 wt%) at 185 ° C. with a biaxial kneader. (Step 2), press-molded into a 125 × 13 × 3.2 mm test piece (molding temperature 180 ° C., 120 kg / cm ² ) (Step 3).

  This test piece was subjected to a vertical combustion test with a flame height of 20 mm in accordance with UL94. The results are shown in FIG. As a result, the sample was found to be UL standard V0.

  As a result, the non-halogen material enables flame retardancy.

  In addition, the content ratio of the flame retardant has an optimum value depending on the required degree of flame retardancy and the amount of other physical property change due to the inclusion of the flame retardant, but the blending ratio of about 5% to 40% generally gives good results. Often brings. When the flame retardant is 5% or less, it is difficult to obtain a remarkable effect of improving flame retardancy, and when it is 30% or more, the adverse effect of the flame retardant (such as poor moldability due to a decrease in fluidity) becomes remarkable. is there.

As another example, polylactic acid (PLA) 50 wt%, polybutyl succinate 22.5 wt%, TBBA 22.5 wt%, Mg (OH) 25 wt% are mixed into a twin screw extruder, 500 rpm, 195 ° C. Kneading was performed, and the melt was injection molded into a TV back cover mold. The molding temperature was 180 ° C., and the mold temperature was 80 ° C. in order to avoid elution of the flame retardant due to rapid cooling. After molding, the mold was cooled, the molded product was taken out at room temperature, and a resin having a back cover shape of a television receiver was prepared.
The physical properties of the molded product were compared with those of a television receiver back cover formed of “conventional PS (polystyrene) + flame retardant”, but no significant difference was found.
As another example, 70 wt% of polylactic acid (PLA) synthesized from corn as a raw material and 30 wt% of polybutyl succinate (PBS) for the purpose of improving heat resistance are mixed into a kneaded pellet using a biaxial kneader. create.

  Then, 10 wt% of the obtained pellets (90 wt%) with ethylenediaminetetraacetate as a flame retardant adhering to the SiO2 porous body were kneaded at 185 [deg.] C. with a biaxial kneader, and 125 * 13 * 3.2 mm The test piece was press-molded (molding temperature 180 ° C., 120 kg / cm 2).

  This test piece was subjected to a vertical combustion test with a flame height of 20 mm in accordance with UL94. The results are shown in FIG. As a result, the sample was found to be UL standard V0.

  In addition, the content ratio of the flame retardant has an optimum value depending on the required degree of flame retardancy and the amount of other physical property change due to the inclusion of the flame retardant, but the blending ratio of about 5% to 40% generally gives good results. Often brings. When the flame retardant is 5% or less, it is difficult to obtain a remarkable effect of improving flame retardancy. When the flame retardant is 40% or more, the adverse effect of the flame retardant (such as poor moldability due to decreased fluidity) becomes remarkable. is there.

  Another example of the sequence (order) is shown as a flowchart in FIG.

  Kneaded pellets were prepared using a polylactic acid 70 wt% synthesized from corn and polybutyl succinate 30 wt% for the purpose of improving heat resistance using a twin-screw kneader (step 1).

  7% by weight of pellets (90% by weight) obtained by adding acetylacetonate iron as a flame retardant to the SiO 2 porous material, and 5% by weight of t-butyltrimethylsyl peroxide (Nippon Yushi Fatty Perbutyl SM) as a flame retardant aid. Was kneaded at 185 ° C. with a twin-screw kneader (step 2) and press-molded into a 125 × 13 × 3.2 mm test piece (molding temperature 180 ° C., 120 kg / cm 2) (step 3).

  A vertical combustion test of a flame height of 20 mm in accordance with UL94, similar to (Example 3), was performed on this test piece. The result is shown in FIG. As a result, it became clear that it was UL standard V0.

  The total component ratio of the flame retardant and the flame retardant aid has an optimum value depending on the required degree of flame retardancy and the amount of other physical property change due to the inclusion of the flame retardant, but is generally 5% to 40%. In many cases, the blending ratio of gives a good result. When the total of the flame retardant and the flame retardant auxiliary is 5% or less, it is difficult to obtain a remarkable effect of improving flame retardancy, and when it is 40% or more, the adverse effect of the flame retardant (formability failure due to decrease in fluidity) ) Becomes prominent.

  As another example, polylactic acid (PLA) 50 wt% and polybutyl succinate (PBS) 22.5 wt%, TBBA 22.5 wt%, Mg (OH) 25 wt% are mixed into a twin screw extruder, Kneading was performed at 500 rpm and 195 ° C., and the melt was injection molded into a TV back cover mold. The molding temperature was 180 ° C., and the mold temperature was 80 ° C. in order to avoid elution of the flame retardant due to rapid cooling.

  After molding, the mold was cooled, the molded product was taken out at room temperature, and a resin having a TV back cover shape was produced. The physical properties of the molded product were compared with those of a conventional TV back cover formed of “PS (polystyrene) + flame retardant”, but no significant difference was confirmed.

  According to the plastic composition of the present invention, which is made from plant resources with added flame retardancy, it is friendly to the global environment, it is possible to add flame retardancy without increasing the production process to plant raw material resin, As a result, it can be used as an exterior body such as an electric appliance, and the industrial value is great.

The figure which describes the flow for creating the composition which is an example of this invention The figure which shows the characteristic of the same composition The figure which describes the flow for creating the composition which is another example of this invention The figure which shows the characteristic of the same composition The figure which describes the flow for creating the composition which is another example of this invention The figure which shows the characteristic of the same composition Diagram showing characteristics of bioplastics Diagram showing characteristics of general plastic and bioplastic

Claims (2)

A composition comprising a plant resource as a main ingredient and a flame retardant component as main ingredients, wherein the main ingredient from the plant resource is at least a lactic acid group and 1,4 butane Components that contain either a diol group or a succinic acid group and add flame retardancy are halogen compounds, phosphorus compounds, inorganic compounds, silicon compounds, acetylacetonate iron, copper ethylenediaminetetraacetate, zinc oxide, five A composition comprising one or more of vanadium oxide, acetyl acetonate copper, copper EDTA, and benzoyl acetonate iron, or a composition in which one or more is impregnated with porous silica. 2. The composition according to claim 1, further comprising an organic peroxide as a flame retardant aid.

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