JP2008280517A - Method of manufacturing non-halogen flame-retardant thermoplastic composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a non-halogen flame-retardant thermoplastic composition having no quality fluctuation, and capable of manufacturing continuously. <P>SOLUTION: When the non-halogen flame-retardant thermoplastic composition composed of a constituent (A) and a constituent (B) constituted by a rubber or a resin, and a constituent (C) constituted by a metal hydroxide where the constituent (A) is silane-crosslinked is manufactured using an extruder, a process of graft-copolymerizing a silane compound to the constituent (A), and a process of thereafter dynamically silane-crosslinking the graft-copolymerized constituent (A) are carried out continuously in the extruder. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention comprises a non-halogen flame retardant comprising a silane-crosslinked rubber or resin, a non-crosslinked rubber or resin, and a metal hydroxide and having high mechanical strength, heat resistance, oil resistance, flame retardancy, and recyclability. More particularly, the present invention relates to a method for producing a non-halogen flame retardant thermoplastic composition capable of continuously producing a non-halogen flame retardant thermoplastic composition without quality variations.

  The activities for environmental conservation are increasing worldwide, and toxic gases are not generated during combustion, environmental pollution during disposal is low, and materials that can be recycled are rapidly spreading.

  A typical material is a composition in which a thermoplastic polymer is mixed with a non-halogen flame retardant such as a metal hydroxide. In order to enhance the mechanical strength, heat resistance, oil resistance, etc. of these materials, it is effective to introduce cross-linking. However, if the cross-linking range extends to the entire polymer, fluidity is lost and material recycling is difficult. It becomes.

  As a material for solving this difficulty, there is a dynamically crosslinked thermoplastic composition having thermoplasticity even after the introduction of crosslinking. That is, this dynamically crosslinked thermoplastic composition can maintain fluidity by a structure in which a crosslinked polymer phase (island phase) is dispersed in a continuous phase (sea phase) of a thermoplastic polymer.

  The present inventor has newly proposed silane crosslinking as a crosslinking method for such a dynamically crosslinked thermoplastic composition. According to the present invention, any kind and combination of rubber and resin can be used to prepare a dynamically crosslinked thermoplastic composition by previously graft-copolymerizing a silane compound to rubber or resin.

Japanese Laid-Open Patent Publication No. 1-254751 JP-A-2-19639 Japanese Patent Laid-Open No. 6-136066 JP-A-11-158233 JP-A-11-181102 JP-A-6-15716 JP-A-9-208620 JP 2007-70602 A

  However, since this dynamically cross-linked non-halogen flame retardant thermoplastic composition is a novel material that has not been developed so far, it is necessary to establish a production method with high reproducibility and excellent mass productivity. It is.

  Accordingly, an object of the present invention is to provide a method for producing a non-halogen flame retardant thermoplastic composition that can be continuously produced without quality variations.

  In order to achieve the above object, the invention of claim 1 comprises a component (A) and a component (B) made of rubber or resin, and a component (C) made of a metal hydroxide, wherein the component (A) is a silane. When a crosslinked non-halogen flame retardant thermoplastic composition is produced using an extruder, a step of graft copolymerizing the silane compound with the component (A), and after the step, the graft copolymerization is performed. The step of dynamically crosslinking the component (A) with the silane is continuously carried out inside the extruder, which is a method for producing a non-halogen flame retardant thermoplastic composition.

  The invention of claim 2 comprises a component (A) and a component (B) made of rubber or resin, and a component (C) made of a metal hydroxide, and the component (A) is a non-halogen difficult silane crosslinked. When the flammable thermoplastic composition is produced using an apparatus in which two extruders are configured in tandem, the component (A) and the silane compound are sequentially added to the first extruder, and the component (A). After the silane compound is graft copolymerized, the graft copolymer is continuously fed to a second extruder consisting of a twin screw extruder, and the graft copolymerized component (A) is dynamically added to the silane. It is a manufacturing method of the non-halogen flame-retardant thermoplastic composition of Claim 1 made to bridge | crosslink.

  According to a third aspect of the present invention, the first extruder is a single screw extruder or a twin screw extruder, the second extruder is a twin screw extruder, and is provided upstream of the first extruder. After charging the component (A) from the hopper, the solution of the silane compound and the organic peroxide is injected downstream of the first extruder, and the component (A) is graft copolymerized with the silane compound. Then, the graft copolymer is continuously supplied to the second extruder and the component (B), the component (C) and the silanol condensation catalyst are added at once from the same supply port, or The non-halogen flame-retardant thermoplastic resin composition according to claim 2, wherein the addition order of the silanol condensation catalyst is added from the different supply ports lastly, and the graft copolymerized component (A) is dynamically silane-crosslinked. Is the method.

  According to a fourth aspect of the present invention, the first extruder and the second extruder are twin-screw extruders, and the component (A) is introduced from a hopper provided on the upstream side of the first extruder. Then, a solution of the silane compound and the organic peroxide is injected on the downstream side of the first extruder, the component (A) is graft copolymerized with the silane compound, and then the above component (B ) To prepare a blend of component (A) and component (B) in which silane is graft-copolymerized, and then this blend is continuously fed to the second extruder and the same The component (C) and the silanol condensation catalyst are added at once from the supply port, or the component (C) and the silanol condensation catalyst are added in this order from different supply ports, and the graft copolymerized component (A) is added. The non-halo of claim 2, wherein the silane is dynamically crosslinked. A method for producing a down flame retardant thermoplastic composition.

  The invention of claim 5 comprises a component (A) and a component (B) made of rubber or resin, and a component (C) made of a metal hydroxide. When the flammable thermoplastic composition is produced using a single twin-screw extruder, the component (A) is obtained by graft-copolymerizing the silane compound to the component (A) on the upstream side and graft-copolymerizing on the downstream side. Is a method for producing a non-halogen flame retardant thermoplastic composition characterized by dynamically crosslinking silane.

  Invention of Claim 6 injects the solution of a silane compound and an organic peroxide from the supply port provided in the downstream after injecting ingredient (A) from the hopper provided in the upstream of the twin screw extruder, After graft copolymerization of the silane compound with the component (A), the component (B), the component (C) and the silanol condensation catalyst are then added at once from the same supply port, or the silanol condensation catalyst is added from a different supply port. 6. The method for producing a non-halogen flame-retardant thermoplastic resin composition according to claim 5, wherein the component (A) added last in the order of addition and dynamically graft-copolymerized is silane-crosslinked.

  According to the present invention, it is possible to continuously produce a non-halogen flame retardant thermoplastic composition having high mechanical strength, heat resistance, oil resistance, flame resistance, and recyclability without quality variations. is there.

  A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

  In order to achieve the above-described object, the present inventors have studied a manufacturing method.

  In producing a non-halogen flame retardant thermoplastic composition, a step of graft copolymerizing a silane compound with the component (A) selected from rubber or resin and a step of dynamically crosslinking the component (A) are necessary. It becomes. When these two steps are performed in separate and independent apparatuses, the rubber or resin in which the silane compound is graft-copolymerized is allowed to stand for a certain period of time. There is a concern about the problem that scorch (early vulcanization) occurs in the rubber or resin due to the progress of the crosslinking reaction, and it is disadvantageous in terms of production cost because it cannot be produced continuously. Therefore, the material (non-halogen flame retardant thermoplastic composition) is produced by performing two steps in one apparatus by one kneading or by combining two apparatuses and continuously performing two steps. desirable.

  When two steps are performed by one kneading in one apparatus, it is generally considered to use a batch kneader such as a kneader or a Banbury mixer, or a twin screw extruder as the apparatus.

  However, when a batch kneader is used, in the process of graft copolymerizing a silane compound with rubber or resin, if the temperature is raised to a temperature at which the organic peroxide is decomposed and free radicals are generated, the sealing property is not sufficient. There is a problem that the silane compound volatilizes. As a result, problems such as insufficient grafting of the silane compound and inability to obtain reproducibility arise.

  Thus, as a result of investigations by the present inventors, it was found that an apparatus suitable for producing the material is optimally a combination of two extruders or a single twin-screw extruder.

  When two extruders are combined, the two extruders are combined in tandem, and when manufacturing, the first extruder is graft copolymerized with a silane compound on rubber or resin (component (A)). , By continuously dynamically silane-crosslinking the rubber or resin in a second extruder (biaxial extruder), a silane-crosslinked rubber or resin (component (A)), an uncrosslinked rubber or A non-halogen flame retardant thermoplastic composition comprising a resin (component (B)) and a metal hydroxide (component (C)) can be continuously produced without quality variations.

  "Tandem" as used herein refers to an arrangement in which two extruders are connected in series, an outlet of one extruder and an inlet of the other extruder are connected in an L shape, Also included are those in which the outlet of one extruder and the side surface of the other extruder are connected and arranged in a T shape.

  When one twin-screw extruder is used, it is composed of components (A) and (B) selected from rubber or resin, component (C) selected from metal hydroxides, and component (A) is silane-crosslinked. In the production of the composition, the component (A) is graft-copolymerized with the component (A) on the upstream side of the twin-screw extruder, and the component (A) is dynamically silane-crosslinked on the downstream side. Halogen flame retardant thermoplastic compositions can be continuously produced without quality variations.

  A component (A) composed of a silane-crosslinked rubber or resin specified by the method for producing a non-halogen flame-retardant thermoplastic composition according to a preferred embodiment of the present invention, and a component (B) composed of a non-crosslinked rubber or resin ) Can be selected from the following:

  As rubber, ethylene-propylene-diene copolymer, ethylene-propylene copolymer, ethylene-butene-1-diene copolymer, ethylene-octene-1-diene copolymer, acrylonitrile butadiene rubber, acrylic rubber, styrene Styrene-diene copolymer represented by butadiene rubber and styrene isoprene rubber, or styrene-diene-styrene copolymer represented by styrene-butadiene-styrene rubber and styrene-isoprene-styrene rubber, or hydrogenated thereof. Styrenic rubber obtained from the above can be used.

  As the resin, known resins can be used, such as polypropylene, high density polyethylene, linear low density polyethylene, low density polyethylene, ultra low density polyethylene, ethylene-butene-1 copolymer, ethylene-hexene-1 copolymer. Polymer, ethylene-octene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polybutene, poly-4-methyl-pentene-1, ethylene-butene-hexene terpolymer, Examples thereof include an ethylene-methyl methacrylate copolymer, an ethylene-methyl acrylate copolymer, and an ethylene-glycidyl methacrylate copolymer. Two or more of these may be blended and used.

  In the present invention, the mixing ratio of the component (A) and the component (B) selected from rubber or resin is arbitrary, and can be freely set depending on the required physical properties.

  The silane compound is required to have both a group capable of reacting with a polymer and an alkoxy group that forms a crosslink by silanol condensation. Specifically, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β -Methoxyethoxy) silane and other vinylsilane compounds, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) γ-aminopropyltrimethoxysilane, β- (aminoethyl) γ- Aminosilane compounds such as aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycid Xypropylmethyldiethoxysila Epoxy silane compounds such as ethylene, acrylic silane compounds such as γ-methacryloxypropyltrimethoxysilane, polysulfides such as bis (3- (triethoxysilyl) propyl) disulfide, bis (3- (triethoxysilyl) propyl) tetrasulfide Examples include mercaptosilane compounds such as silane compounds, 3-mercaptopropyltrimethoxysilane, and 3-mercaptopropyltriethoxysilane.

  Examples of the organic peroxide include dicumyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5-di- (t-butylperoxy) hexane, 2, Dialkyl peroxides such as 5-dimethyl-2,5-di- (t-butylperoxy) hexyne-3, 1,3-bis (t-butylperoxyisopropyl) benzene, and diacyl peroxides such as dimethylbenzoyl peroxide Peroxyketals such as oxides, n-butyl-4,4-bis (t-butylperoxy) valerate, 1,1-bis (t-butylperoxy) cyclohexane can be used and are not particularly limited.

  The addition amount of the silane compound and organic peroxide is not particularly specified, and is appropriately determined in light of the physical properties of the obtained material (target non-halogen flame-retardant thermoplastic composition). .

  The component (C) comprising a metal hydroxide used in the present embodiment imparts flame retardancy to the composition, and examples thereof include magnesium hydroxide, aluminum hydroxide, calcium hydroxide, and the like. Magnesium hydroxide having the highest effect is preferred. The metal hydroxide is desirably surface-treated from the viewpoint of dispersibility.

  As the surface treatment agent used for this surface treatment, a silane coupling agent, a titanate coupling agent, a fatty acid or a fatty acid metal salt, etc. can be used, and in particular, the adhesion between the resin and the metal hydroxide is enhanced. A coupling agent is desirable.

  Examples of silane coupling agents that can be used include vinyl silane compounds such as vinyl trimethoxy silane, vinyl triethoxy silane, vinyl tris (β-methoxy ethoxy) silane, γ-aminopropyl trimethoxy silane, γ-aminopropyl triethoxy silane, N Aminosilane compounds such as β- (aminoethyl) γ-aminopropyltrimethoxysilane, β- (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, β- (3, 4-epoxycyclohexyl) epoxysilane compounds such as ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and acrylic silanes such as γ-methacryloxypropyltrimethoxysilane Compounds, polysulfide silane compounds such as bis (3- (triethoxysilyl) propyl) disulfide, bis (3- (triethoxysilyl) propyl) tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane And mercaptosilane compounds.

  The amount of the component (C) made of the metal hydroxide is arbitrary, and can be freely set according to the flame retardancy required for the composition.

  Further, the silanol condensation catalyst that can be used in the present embodiment is dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dioctate, dioctyltin dilaurate, stannous acetate, stannous caprylate, zinc caprylate, naphthenic acid. There are lead, cobalt naphthenate, and the like, and the addition amount is set to 0.001 to 0.1 parts by weight per 100 parts by weight of the rubber depending on the kind of the catalyst.

  As a method for adding the silanol condensation catalyst, there is a method of using a master batch in which a silanol condensation catalyst is mixed in advance with a resin, in addition to the method of adding it as it is.

  In addition to the above, process oil, processing aid, flame retardant aid, crosslinking agent, crosslinking aid, antioxidant, lubricant, inorganic filler, compatibilizer, stabilizer, carbon black, colorant, etc. It is also possible to add other additives.

  As the manufacturing apparatus used in the manufacturing method according to the present embodiment, a combination of two extruders in tandem or a single twin-screw extruder may be used. A single screw extruder 1 shown in FIG. 1 or a twin screw extruder 11 shown in FIG. 2 can be used as the first extruder of this manufacturing apparatus, and the second extruder shown in FIGS. 1 and 2 can be used as the second extruder. A screw extruder 4 can be used.

  Any screw diameter and L / D of these extruders can be used. General screws such as a full flight screw, a double flight screw, and a subflight screw can be used as the screw of the single screw extruder. The twin-screw extruder that can be used in this embodiment has two screw rotation directions that are the same direction, different directions, or two screws that are completely or partially engaged, or not engaged. Although the thing etc. are arbitrary, the screw rotation direction is the same direction among them, and the thing which two screws engage completely or partially especially is preferable. As the screw of the twin screw extruder, a segment type screw can be used, and the configuration of the kneading part can be freely set.

  There are weight-type and volume-type feeders such as a loss-in-weight type for feeding materials into the extruder, and they can be used freely according to the material shape, input amount, required accuracy, etc. Moreover, a general-purpose liquid addition apparatus can be used for liquid injection.

  Next, the manufacturing method of this embodiment will be described.

  As shown in FIG. 1, in the case of using a single screw extruder 1 (or a twin screw extruder) in the first stage, a non-halogen flame retardant thermoplastic composition is produced by the following procedure.

  First, a component (A) made of rubber or resin is introduced from the hopper 2, and then a solution in which an organic peroxide is dissolved in a silane compound is injected from a downstream liquid injection port 3 (liquid addition device). Further, the temperature on the downstream side of the single screw extruder 1 is raised to a temperature at which the organic peroxide is decomposed and free radicals are generated, and kneading is performed so that the silane compound is graft copolymerized with the component (A). . The optimum temperature at this time can be determined from the relationship between the temperature and half-life of the organic peroxide, the residence time, and the like, and is not particularly defined. The graft copolymer produced here is continuously fed to a second extruder (a twin screw extruder 4) combined in tandem as it is.

  Thereafter, on the downstream side of the twin-screw extruder 4, the component (B) composed of uncrosslinked rubber or resin, the component (C) composed of metal hydroxide, and the silanol condensation catalyst are simultaneously charged from the first supply port 5. Alternatively, it is introduced from different supply ports 5 to 7. For example, the component (B) made of uncrosslinked rubber or resin and the component (C) made of metal hydroxide are simultaneously charged from the first supply port 5 and finally the second supply port 6 (or the third supply). A silanol condensation catalyst is charged through the mouth 7). In addition, when charging from different supply ports 5 to 7, a component (B) made of uncrosslinked rubber or resin is charged from the first supply port 5, and then a component made of metal hydroxide from the second supply port 6. (C) is charged, and finally a silanol condensation catalyst is charged from the third supply port 7. In either case, the silanol condensation catalyst is added last. As the silanol condensation catalyst, a stock solution or a master batch can be used.

  Thereafter, the component (A) is dynamically subjected to a silane crosslinking reaction in the twin-screw extruder 4 to produce a non-halogen flame retardant thermoplastic composition. The temperature of the twin screw extruder 4 at this time is not particularly specified, but is preferably 160 ° C. or higher in consideration of silane crosslinking reactivity.

  Here, as a modification of FIG. 1, as shown in FIG. 2, a twin screw extruder 11 may be used for the first extruder. In this case, a non-halogen flame retardant thermoplastic composition can be produced by the following procedure.

  First, the component (A) is introduced from the hopper 2, and then a solution in which an organic peroxide is dissolved in a silane compound is injected from the downstream liquid injection port 3. Further, the temperature on the downstream side of the twin-screw extruder 11 is raised and kneading is performed, whereby the silane compound is graft copolymerized with the component (A). The optimum temperature at this time can be determined as described above. Finally, the component (B) made of rubber or resin that has not been cross-linked is introduced into the graft copolymer from the first supply port 5 to produce a blend of the graft copolymer and component (B). This blend is continuously fed to a second extruder (two-screw extruder 4) combined in tandem as it is.

  Thereafter, on the downstream side of the twin screw extruder 4, the component (C) made of metal hydroxide and the silanol condensation catalyst are simultaneously charged from the second supply port 6, or the component (C) and silanol condensation are made from different supply ports 6 and 7. Put the catalyst in order. Thereafter, the component (A) is dynamically subjected to a silane crosslinking reaction in the twin-screw extruder 4 to produce a non-halogen flame retardant thermoplastic composition. The extruder temperature at this time is as described above.

  In addition, as shown in FIG. 3, when using an apparatus in which the outlet of one extruder and the side surface of the other extruder are connected in a T shape as a tandem type, a non-halogen is used in the following procedure. A flame retardant thermoplastic composition is prepared.

  When the first extruder is the single-screw extruder 1 or the twin-screw extruder 11 and the second extruder is the twin-screw extruder 4, the hopper 2 provided first on the upstream side of the first extruder. After the above component (A) is added, a solution of the silane compound and the organic peroxide is injected from the liquid injection port 3 on the downstream side of the first extruder, and the silane compound is graft copolymerized with the component (A). . On the other hand, in the second extruder, the component (B), the component (C), and the silanol condensation catalyst are added at once from the same first supply port 5 from the upstream side, and then the first extrusion is performed downstream. The graft copolymer produced by the machine is continuously supplied, or the above component (B) and the above component (C) are added at once from the same supply port 5 from the upstream side, and then the first on the downstream side. The graft copolymer produced by the extruder is continuously supplied, and finally a silanol condensation catalyst is added at the second supply port 6 to dynamically silane-crosslink the graft copolymerized component (A). . Alternatively, the component (B) may be supplied from the upstream side from the supply port 5, and the component (C) and the silanol condensation catalyst may be added from the supply port 6.

  When the first extruder is a twin screw extruder, the component (A) is charged from the hopper 2 provided on the upstream side of the first extruder, and then a solution of the silane compound and the organic peroxide. Is injected into the liquid injection port 3 on the downstream side of the first extruder, the silane compound is graft copolymerized with the component (A), and the component (B) is supplied from a supply port (not shown) provided on the downstream side. ) And the blend of the graft copolymer and component (B) may be continuously fed to the second extruder.

Next, the case where one twin-screw extruder 10 is used will be described with reference to FIG. 4. Any screw diameter and L / D of the twin-screw extruder 10 which is a production apparatus in the present invention can be used. However, since it is necessary to perform two reactions, a reaction of graft copolymerizing a silane compound with rubber or resin and a reaction of dynamically crosslinking the rubber or resin, L / D is determined from the viewpoint of residence time (reaction time) and the like. It is preferable that it is 40 or more. Further, regarding the screw rotation method, the two screws may be rotated in the same direction, in different directions, or in which the two screws are completely or partially engaged or not engaged. Of these, those in which the screw rotation direction is the same and the two screws are completely or partially engaged are preferable. As the screw, a segment type screw can be used, and the configuration of the kneading part and the like can be set freely.

  There are weight-type and volume-type feeders such as a loss-in-weight type for supplying materials to the extruder, and they can be used freely according to the material shape, input amount, required accuracy, etc. Moreover, a general-purpose liquid addition apparatus can be used for supplying the liquid.

  The material is prepared by the following procedure. First, a component (A) selected from rubber or resin is introduced from the hopper 2, and then a solution obtained by dissolving an organic peroxide in a silane compound is injected from the liquid injection port 3 using a liquid addition device on the downstream side. Further, on the downstream side, the silane compound is graft copolymerized with the component (A) by raising the extruder temperature to a temperature at which the organic peroxide decomposes and generates free radicals. The optimum temperature at this time can be determined from the relationship between the temperature and half-life of the organic peroxide and the residence time, and is not particularly defined. Further, on the downstream side, the component (B) selected from rubber or resin, the component (C) selected from metal hydroxide, and a silanol condensation catalyst are charged simultaneously or through different supply ports 5, 6, and 7. As the silanol condensation catalyst, a stock solution or a master batch can be used. In addition, when charging from different supply ports 5, 6, and 7, after charging the component (B), the component (C) is charged downstream, and finally the silanol condensation catalyst is supplied, and the component (B) There is a method in which the component (C) is added simultaneously and finally a silanol condensation catalyst is supplied. In either case, the silanol condensation catalyst is added last. Thereafter, a silane crosslinking reaction is caused in the twin screw extruder 10. The extruder temperature at this time is not particularly defined, but is preferably 160 ° C. or higher in consideration of reactivity.

  Other timings of additives such as process oils, processing aids, flame retardant aids, crosslinking agents, crosslinking aids, antioxidants, lubricants, inorganic fillers, compatibilizers, stabilizers, carbon black, and colorants You can add it.

  As described above, according to the manufacturing method according to the embodiment shown in FIGS. 1, 2, and 3, after the silane compound is graft-copolymerized to the component (A) by the first extruder, this copolymer is used. Since the polymer is continuously supplied to the second extruder and the component (A) is dynamically silane-crosslinked, there is no possibility that the rubber or resin (component (A)) is scorched. Moreover, according to the method of FIG. 3, since all reaction is completed within one extruder, there is no possibility of scorching. As a result, since there is no quality variation, a non-halogen flame retardant thermoplastic composition having high reproducibility and excellent mass productivity can be obtained at a low manufacturing cost. Since the existing general-purpose products can be used for these extruders used for manufacturing, it is not necessary to design and manufacture a new apparatus.

  Since this non-halogen flame retardant thermoplastic composition is a composition in which a non-halogen flame retardant such as a metal hydroxide is mixed with a thermoplastic polymer, the flame retardant is high, and crosslinking is introduced. Therefore, mechanical strength, heat resistance, and oil resistance are also high. And since it is a dynamic bridge | crosslinking type thermoplastic composition which has thermoplasticity after bridge | crosslinking introduction | transduction, it also has recyclability.

  In addition, this non-halogen flame retardant thermoplastic composition can be applied to electric wires and cables as insulators and sheaths, and in particular, covers for electric wires and cables such as power cords and cabtyre cables that require excellent flexibility. Suitable as a material.

  FIG. 5 shows the structure of the non-halogen flame retardant thermoplastic composition obtained by the production method of the present invention, and the component (A) while the phase of the component (B) is the base (sea). This phase becomes an island and becomes a composition having a dispersed structure. The size of the island portion of the phase of component (A) is produced within the range of 10 nm to 10 μm by the combination of component (A) and component (B).

  Examples of the present invention will be specifically described below.

  First, about the structure of the extruder to which the manufacturing method of the non-halogen flame-retardant thermoplastic composition of this invention is applied, Examples 1-5 use Examples 6-, using the apparatus shown in FIG. 1, FIG. 8 used the apparatus shown in FIG.

As the rubber or resin of component (A), ethylene-vinyl acetate copolymer (vinyl acetate content 42 wt% or 20 wt%) or ethylene-propylene copolymer (ethylene content 56 wt%) is used as component (B) rubber. Alternatively, as the resin, styrene-ethylenebutylene-styrene copolymer (styrene content 28 wt%), ethylene-vinyl acetate copolymer (vinyl acetate content 20 wt%) or low density polyethylene (density 0.912 g / cm ³ ). As the metal hydroxide of component (C), magnesium hydroxide (silane treatment, average particle size 1 μm) was used. In addition, a master batch prepared by mixing vinyltrimethoxysilane as a silane compound, dicumyl peroxide as an organic peroxide, and dibutyltin dilaurate as a silanol condensation catalyst in a low-density polyethylene in a proportion of 3 wt% and pelletizing it. Using. Table 1 shows the blending ratio of each component.

Examples 1-5, Comparative Examples 1-4;
The production apparatus uses two single-screw extruders (65 mm, L / D = 40) and two twin-screw extruders (58 mm, L / D = 60), each as shown in FIG. 1 and FIG. Used in combination. A 75-liter kneader was used as a batch kneader. Table 2 shows the apparatus configuration, blending, and raw material charging order of Examples 1 to 5 and Comparative Examples 1 to 4, respectively.

  In the apparatus combined with the tandem, the kneading temperature of the first extruder was 180 ° C., and the kneading temperature of the second extruder was 200 ° C. The screw rotation speed was 150 rpm for the first extruder and 300 rpm for the second extruder. Moreover, in order to evaluate reproducibility, it manufactured 5 times in each conditions.

  In the evaluation of the kneaded product, a strand (string shape) was taken in the case of extruder kneading, and a kneaded product was taken in a strand shape through a feeder ruder in the case of kneader kneading. Each evaluation (crosslinking degree, quality stability, appearance) was performed by the following methods.

  <Degree of cross-linking> In order to measure the degree of cross-linking of component (A), a sample was wrapped in a 40-mesh stainless wire mesh, extracted in hot xylene at 130 ° C for 24 hours, and then the wire mesh was vacuumed at 80 ° C for 4 hours. Dried. The residual insoluble polymer weight is regarded as the crosslinked component (A), and {(component (A) weight after extraction and drying) / (component (A) weight in initial sample)} × 100 is the gel fraction (%) It was. The gel fraction of 10 samples was measured per production, and the calculated average value was taken as the degree of crosslinking.

  <Quality stability> The stability of quality was evaluated by the variation in the degree of cross-linking during the five productions. Evaluation was based on the ratio of the maximum value and the minimum value of the gel fraction (average value).

  <Appearance> Appearances such as the smoothness of the strand surface and the dispersibility of the metal hydroxide were evaluated visually and by touch. Those with good appearance (smooth surface) were accepted, and those with at least uneven surfaces were rejected.

  Each evaluation result is shown in Table 3.

  In Examples 1 to 5, non-halogen flame retardant thermoplastic compositions having high reproducibility and good appearance were obtained.

  On the other hand, in Comparative Example 1, since the silanol condensation catalyst is initially charged in the second extruder in the second stage, before kneading the component (B) and the component (C) which is magnesium hydroxide. The component (A) was cross-linked, and the coarsened cross-linked product became uneven and made the strand surface uneven. Also, the dispersibility of magnesium hydroxide was poor.

  Comparative Example 2 uses a single-screw extruder in the second extruder in the second stage, and kneading was insufficient. Therefore, variation in the degree of crosslinking due to poor dispersion of the silanol condensation catalyst and aggregated magnesium hydroxide particles It was observed.

  Since Comparative Example 3 was produced collectively with a kneader, the silane compound volatilized at the stage of graft copolymerization of the silane compound with the component (A), and the variation in the degree of crosslinking was large.

  Since the comparative example 4 is produced with the manufacturing apparatus which combined the extruder and the kneader and cannot manufacture continuously, the component (A) by which the silane compound produced with the twin-screw extruder was graft-copolymerized is (A). I scorched. As a result, variation in the degree of crosslinking and poor appearance occurred.

Examples 6-8, Comparative Examples 5-7;
No. of the composition shown in Table 1. 2, no. 5, no. 6 is a raw material, and the manufacturing apparatus uses a single screw extruder (80 mm, L / D = 60) and a twin screw extruder (80 mm, L / D = 75) as an extruder, and 75 liters as a batch kneader. The kneader was used.

  Table 4 shows the apparatus configuration, blending, and raw material charging order in Examples 5 to 8 and Comparative Examples 5 to 7.

  In the case of an extruder, the kneading temperature was 200 ° C. and the screw rotation speed was 100 rpm. In the case of a kneader, the kneading temperature was 200 ° C. and the rotation speed was 30 rpm. Moreover, in order to evaluate reproducibility, it manufactured 5 times in each condition.

  For the evaluation of the kneaded product, a material taken up in a strand shape in the case of extruder kneading, and a material taken in a strand shape through a feeder ruder in the case of kneader kneading were used.

  Each evaluation is the same as Table 3.

  The evaluation results are shown in Table 5.

  From Table 5, in Examples 5-8, the material with a high reproducibility and a favorable external appearance is obtained. On the other hand, in Comparative Example 5, since the order of adding the silanol condensation catalyst is fast, crosslinking of the component (A) occurs before kneading the component (B) and the component (C), and the coarsened crosslinked product becomes a brim. The strand surface is uneven, and the dispersibility of magnesium hydroxide is poor. In Comparative Example 6, since the kneader is used for batch production, the silane compound is volatilized at the stage where the silane compound is graft copolymerized with the component (A), and the variation in the degree of crosslinking is large. In the comparative example 7, since it cannot manufacture continuously, the component (A) which carried out the graft copolymerization of the silane compound produced with the single screw extruder will scorch. As a result, variations in the degree of crosslinking and poor appearance occur.

It is a figure which shows one Embodiment of the apparatus which enforces the manufacturing method of the non-halogen flame-retardant thermoplastic composition of this invention. It is a modification of FIG. It is a modification of FIG.1 and FIG.2. It is a figure which shows other embodiment of the apparatus which enforces the manufacturing method of the non-halogen flame-retardant thermoplastic composition of this invention. It is a figure which shows the structure of the non-halogen flame-retardant thermoplastic composition obtained with the manufacturing method of this invention.

Explanation of symbols

1 Single screw extruder (first extruder)
4 Twin screw extruder (second extruder)
10 twin screw extruder 11 twin screw extruder (first extruder)

Claims (6)

  A non-halogen flame retardant thermoplastic composition comprising a component (A) and a component (B) composed of rubber or resin, and a component (C) composed of a metal hydroxide, wherein the component (A) is silane-crosslinked. A step of graft-copolymerizing the silane compound to the component (A) when manufacturing using an extruder, and a step of dynamically silane-crosslinking the graft-copolymerized component (A) after the step; Is continuously performed inside the extruder, and a method for producing a non-halogen flame-retardant thermoplastic composition.   A non-halogen flame retardant thermoplastic composition comprising a component (A) and a component (B) composed of rubber or resin, and a component (C) composed of a metal hydroxide, wherein the component (A) is silane-crosslinked. When manufacturing using an apparatus in which two extruders are configured in tandem, the component (A) and the silane compound are sequentially added to the first extruder, and the silane compound is graft-copolymerized to the component (A). The graft copolymer is continuously fed to a second extruder comprising a twin-screw extruder, and the graft copolymerized component (A) is dynamically silane-crosslinked. A method for producing a non-halogen flame retardant thermoplastic composition.   The first extruder is a single-screw extruder or a twin-screw extruder, the second extruder is a twin-screw extruder, and the above components (A) are supplied from a hopper provided on the upstream side of the first extruder. ), The solution of the silane compound and the organic peroxide is injected downstream of the first extruder, and the component (A) is graft copolymerized with the silane compound. While continuously supplying to the second extruder, the component (B), the component (C) and the silanol condensation catalyst are added at once from the same supply port, or the silanol condensation catalyst is supplied from different supply ports. The method for producing a non-halogen flame retardant thermoplastic resin composition according to claim 2, wherein the component (A) added in the final order is dynamically silane-crosslinked.   The first extruder and the second extruder are twin screw extruders, and after the component (A) is introduced from a hopper provided on the upstream side of the first extruder, the silane compound and the organic peroxide are introduced. The product solution is injected on the downstream side of the first extruder, the component (A) is graft copolymerized with the silane compound, and then the component (B) is further added to the graft copolymer. A blend of component (A) and component (B) is prepared, and the blend is continuously fed to the second extruder and the component (C) is fed from the same feed port. ) And the above silanol condensation catalyst at once, or the components (C) and the silanol condensation catalyst are added in this order from different supply ports, and the graft copolymerized component (A) is dynamically silane-crosslinked. Item 2. Non-halogen flame retardant thermoplasticity Method of manufacturing a formed product.   A non-halogen flame retardant thermoplastic composition comprising a component (A) and a component (B) composed of rubber or resin, and a component (C) composed of a metal hydroxide, wherein the component (A) is silane-crosslinked. When producing using one twin-screw extruder, the component (A) is graft copolymerized with the component (A) on the upstream side, and the graft copolymerized component (A) is dynamically silane-crosslinked on the downstream side. A method for producing a non-halogen flame retardant thermoplastic composition characterized by the above.   After charging the component (A) from the hopper provided on the upstream side of the twin screw extruder, the silane compound and the organic peroxide solution are injected from the supply port provided on the downstream side, and the silane compound is added to the component (A). Then, component (B), component (C) and silanol condensation catalyst are added at once from the same supply port, or the addition order of the silanol condensation catalyst is added last from different supply ports. The method for producing a non-halogen flame retardant thermoplastic resin composition according to claim 5, wherein the graft copolymerized component (A) is dynamically silane-crosslinked.

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