JP2009298939A - Flame-retardant resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-halogen-based flame-retardant resin composition completely free from antimony, phosphorus and phosphorus compounds and giving molded products excellent in surface appearance and mechanical characteristics. <P>SOLUTION: The flame-retardant resin composition comprises (a) a thermoplastic resin or a thermosetting resin, (b) polyimide particles and (c) a metal hydrate, as essential components, wherein the polyimide particles to be used is obtained by wet-grinding polyimide films or sheets as raw materials by a millstone type grinder to the extent that parallel planes derived from the polyimide film or sheet disappear. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a flame retardant resin composition, and more particularly to a non-halogen flame retardant resin composition containing no antimony, phosphorus, or phosphorus compound.

  Conventional flame retardant materials are widely used in combination with halogen compounds and antimony compounds. However, in recent years, halogen-based flame retardants have been considered to have a problem of impact on the environment, and the use of halogen-based flame retardants has been banned or restricted due to regulations in Europe. It is out.

  Phosphorus-containing compounds are mainly studied as non-halogen flame retardants, and phosphorus flame retardants such as red phosphorus and phosphate esters are used, but red phosphorus points out the generation of phosphine gas when used. In the case of phosphate esters, bleeding out during molding is a problem.

  Therefore, for the purpose of preventing secondary disasters such as smoke generation, toxicity, and corrosion during combustion, a non-halogen flame retardant resin composition using magnesium hydroxide has been proposed as disclosed in Patent Document 1, for example. ing.

  Further, in Patent Document 2, the present inventors have already blended a flame retardant composition composed of a mixture of polyimide particles and metal hydrate with a resin, so that flame retardancy by UL94 test is V0, ISO5660. It has been reported that a resin composition having a CO concentration of 0.01 g / kg or less in the total combustion gas by a compliant corn calorimeter can be obtained.

  However, the resin composition containing the flame retardant composition described in Patent Document 2 may have poor surface appearance characteristics of the molded product, and may not be sufficient in terms of tensile strength and tensile elongation. Has a problem.

  Poor surface appearance characteristics of a molded product may cause variations in electrical characteristics and a decrease in commercial value. In addition, when the tensile strength and tensile elongation of the resin composition are insufficient, the flexibility and workability are insufficient, so that the handleability and durability of the electric wire and cable are reduced when used as an insulator for electric wires and cables. It will make it worse.

However, if the polyimide resin is simply dry pulverized, coarse particles of 1000 μm or more remain, and on the other hand, there is a possibility that the characteristics of the polyimide may be impaired by pulverizing for a long time. In order to shorten the pulverization time of the polyimide, there is a method of cooling the polyimide film with liquid nitrogen or carbon dioxide and pulverizing it at -40 ° C. or lower. However, in this method, the pulverized product has a uniform spherical shape. Therefore, in order to improve the appearance characteristics of the resin molded product, the particle size of the pulverized product needs to be 10 μm or less. For this reason, fine grinding is required, and the pulverized product becomes bulky, which causes problems in terms of workability during pulverization and blending.
Japanese Patent Laid-Open No. 01-141929 JP 2007-297564 A

  The present invention has been made in view of the above circumstances, and is a non-halogen flame-retardant resin composition that does not contain antimony, phosphorus, or a phosphorus compound at all. An object of the present invention is to provide a non-halogen flame-retardant resin composition from which an excellent molded product can be obtained.

  In order to achieve the above object, as a result of intensive studies, the present inventors have used a polyimide film or sheet as a raw material, and adopted a means for wet pulverization with a stone mill type pulverizer conventionally used mainly for pulverizing foods. . This eliminates the need for special pre-treatment on the polyimide film or sheet, and makes the rounded polyimide particles industrially advantageous in a high yield in a short time with the optimum particle size suitable for the compounding agent for resin. Succeeded in getting. And in the flame retardant resin composition, by using it, it was found that the non-halogen resin composition excellent in the surface appearance characteristics and tensile strength and tensile elongation characteristics of the molded article, which was a problem, was obtained. The present invention has been completed.

  That is, the present invention provides (a) a thermoplastic resin or a thermosetting resin, (b) a polyimide particle, and (c) a flame retardant resin composition containing a metal hydrate as an essential component. A flame retardant resin composition characterized by using polyimide particles from which a parallel plane derived from a polyimide film or sheet has been obtained by using a film or sheet as a raw material and wet pulverizing it using a stone mill. provide.

In the flame-retardant resin composition of the present invention, the component (b) preferably has a median diameter of 10 to 200 μm, a maximum particle diameter of 1000 μm or less, and one peak in the particle size distribution. Thereby, it becomes excellent in the dispersibility to resin.
Moreover, in the flame-retardant resin composition of this invention, the total amount of (b) component and (c) component is 50-200 mass parts with respect to 100 mass parts of (a) component, and (b) The ratio of the component / (c) component is preferably 4/96 to 40/60 (mass ratio). Thereby, the flame-retardant resin composition which is excellent in the surface appearance characteristic of a molded article, and flexibility and mechanical characteristics can be obtained.

In the flame-retardant resin composition of the present invention, the polyimide particles used are not bulky and rounded, so that the dispersibility in the resin is good and the workability at the time of blending is excellent. Since it has excellent appearance characteristics and mechanical characteristics, it has good flexibility and workability when used for electric wires and cables.
The flame retardant resin composition of the present invention is a non-halogen flame retardant resin composition containing no phosphorus. Electrical parts such as electric wires and cables using the flame-retardant resin composition of the present invention have no concern about the elution of phosphoric acid due to moisture in the use environment, and the environmental load such as elution of phosphoric acid during use and disposal This is a true environmental non-halogen flame retardant.

  Hereinafter, the present invention will be described in detail.

  Examples of the thermoplastic resin of component (a) in the present invention include polyolefin resins such as polyethylene resins, polypropylene resins, and polybutylene resins; methacrylic resins such as polymethyl methacrylate resins; polystyrene resins, ABS resins, AS resins, and the like. Polystyrene resins: Polyesters such as polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, polytrimethylene terephthalate resin, polyethylene naphthalate (PEN) resin, poly 1,4-cyclohexyldimethylene terephthalate (PCT) resin Resins: Polycaproamide (Nylon 6) resin, Polyhexamethylene adipamide (Nylon 66) resin, Polyhexamethylene sebacamide (Nylon 610) resin, Polyhexamethylene dodecamide (Na Ron 612) resin, polydodecanamide (nylon 12) resin, polyhexamethylene terephthalamide (nylon 6T) resin, polyhexanemethylene isophthalamide (nylon 6I) resin, polycaproamide / polyhexamethylene terephthalamide copolymer (nylon) 6 / 6T) nylon, polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (nylon 66 / 6T) resin, polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (nylon 66 / 6I) resin, etc. Polyamide resins selected from resins and nylon copolymer resins; polyvinyl chloride resins; polyoxymethylene (POM) resins; polycarbonate (PC) resins; polyphenylene sulfide (PPS) resins; Renether (PPE) resin; Polyetherimide (PEI) resin; Polysulfone (PSF) resin; Polyethersulfone (PES) resin; Polyketone resin; Polyethernitrile (PEN) resin; Polyetherketone (PEK) resin; Etherketone (PEEK) resin; Polyetherketoneketone (PEKK) resin; Polyimide (PI) resin; Polyamideimide (PAI) resin; Fluororesin; Or a modified resin obtained by modifying these resins, or between these resins Examples include mixtures with other resins.

  Examples of the thermosetting resin (a) include phenol resin, epoxy resin, epoxy acrylate resin, polyester resin (for example, unsaturated polyester resin), polyurethane resin, diallyl phthalate resin, silicon resin, vinyl ester resin, and melamine. Resin, polyimide resin, polybismaleimide triazine resin (BT resin), cyanate resin (for example, cyanate ester resin), copolymer resins thereof, modified resins obtained by modifying these resins, or between these resins or other resins And the like.

  The polyimide particle of component (b) in the present invention is obtained by using a polyimide film or sheet as a raw material, adding it to a stone mill, adding water, and wet grinding while grinding with a stone mill. . The amount of water to be added is suitably determined according to the desired particle size. The pulverization may be performed at room temperature. Further, it is not necessary to pre-treat the polyimide film or sheet in advance such as high-temperature heat treatment or low-temperature cooling treatment. The pulverization time is not particularly limited, but is usually pulverized for 10 to 60 minutes according to the desired particle size. Depending on the ability of the machine used for pulverization and the thickness or size of the polyimide film or sheet to be pulverized, the pulverization can be performed in one stage or divided into a plurality of stages.

  Although the thickness of the polyimide film or sheet used as a raw material is not particularly limited, those having a thickness of about 10 μm to 300 μm are usually used. Since the polyimide resin film or sheet does not have a thickness, the parallel surface derived from the film or sheet disappears when the film or sheet is ground by a stone mortar type wet pulverizing means, and at least the thickness is smaller than the thickness. This makes it possible to obtain fine particles stably. In addition, since the particles pulverized by a stone mill are ground, the product particles are rounder than other pulverization methods, and the width of the particle size distribution is narrow and sharp. Has a peak. Such polyimide particles are also excellent in dispersibility in the resin during compounding.

  In the case of pulverization using a stone mill, it is preferable from the viewpoint of pulverization efficiency that the polyimide film or sheet is finely cut to obtain a small piece of about 2 to 5 mm square and then pulverized. By adopting such a method, polyimide particles having a small particle diameter can be obtained in a short time, so that the characteristics of the polyimide can be prevented from being impaired.

  As the polyimide film or sheet, a scrap film or sheet generated at the production site of the polyimide film or sheet, or a commercially available polyimide resin film or sheet can be used. For example, “Kapton H” manufactured by Toray DuPont Co., Ltd. (Product name), “Kapton EN”, “Kapton TN”, “Kapton TJ”, etc. can be used. Not only the above-mentioned film or sheet, but also two or more kinds of polyimide films or sheets having different compositions and thicknesses can be used as raw materials at the same time.

  Here, the polyimide resin is a resin produced by a method of condensation polymerization of aromatic tetracarboxylic dianhydride and diamine, etc., and has excellent heat resistance, chemical resistance, and electrical insulation. Either a thermosetting polyimide resin or a thermoplastic polyimide resin may be used, but a thermoplastic polyimide resin capable of forming a stable carbonized layer is preferable.

  The polyimide particles of component (b) obtained by the above method have a median diameter of 10 to 200 μm, more preferably 20 to 150 μm, and most preferably 30 μm to 100 μm. When trying to obtain polyimide particles having a median diameter of less than 10 μm, it is necessary to set the pulverization conditions strictly. By such setting, structural destruction of the polyimide may occur, and characteristics such as heat resistance inherent in the resin may be impaired. is there. On the other hand, when the median diameter exceeds 200 μm, mechanical properties such as tensile properties of the resin composition are deteriorated.

  The maximum particle size of the polyimide particles is 1000 μm or less. If the maximum particle size of the polyimide particles exceeds 1000 μm, the surface appearance characteristics of the molded product are remarkably impaired. Therefore, the maximum particle size is more preferably 800 μm or less, and most preferably 500 μm or less. . The maximum particle size of the polyimide particles is the maximum particle size of a pulverized product obtained by adopting a conventional pulverizing means using a stone mortar wet pulverizer, and the pulverized product is subjected to classification means such as classification or filtration. It is not what you did.

  In the present invention, the median diameter can be obtained by a laser diffraction scattering method using a wet method, and the maximum particle size can be obtained as a cumulative value by the method.

  Examples of the metal hydrate of component (c) in the present invention include magnesium hydroxide, aluminum hydroxide, calcium hydroxide and the like. These metal hydrates can be used in the form of particles, flakes, or fibers, but in terms of improving the mechanical properties such as tensile properties of the molded product, the powder has an average particle size of 20 μm or less. It is preferable to use a granular material. Among metal hydrates, magnesium hydroxide or aluminum hydroxide is preferable, and aluminum hydroxide is particularly preferable. A metal hydrate may be used independently and may be used in combination of 2 or more types as appropriate.

  In the flame-retardant resin composition of the present invention, the polyimide particles as the component (b) have a function of forming a carbonized layer on the surface of the molded product and suppressing the spread of fire and smoke during an initial fire. The metal hydrate of component (c) has the effect of imparting flame retardancy and tracking resistance. Therefore, it is essential to blend the component (a) with the component (b) and the component (c), and when either is blended alone, the flame retardancy imparting effect is insufficient.

  In the flame-retardant resin composition of the present invention, the proportions of the component (a), the component (b) and the component (c) are as follows: ) Component and (c) component are preferably 50 to 200 parts by mass in total, more preferably 60 to 150 parts by mass. When the total amount of the component (b) and the component (c) is small with respect to the component (a), the flame retardancy and tensile properties of the resin composition are insufficient. The surface appearance characteristics of the product become poor. The ratio of component (b) / component (c) is preferably 4/96 to 40/60 (mass ratio), more preferably 4/96 to 20/80 (mass ratio), and particularly preferably 5/95. ~ 20/80 (mass ratio). When the ratio of the component (b) is too low, the flame retardancy is inferior, and in particular, the amount of CO generated during combustion tends to increase. On the other hand, when the ratio of the component (b) is too high, the tracking resistance tends to decrease. For this reason, it is difficult to obtain a resin composition having a good balance between combustion resistance and tracking resistance outside the above range.

  In the flame-retardant resin composition of the present invention, a plasticizer, a pigment, and a component other than the above components (a), (b) and (c), as long as the object of the present invention is not impaired. Fillers, foaming agents, crystal nucleating agents, lubricants, processing aids, antistatic agents, antioxidants, ultraviolet absorbers, heat stabilizers, surfactants, and the like can be blended. Further, unless the object of the present invention is impaired, reinforcing fibers such as aramid fiber, glass fiber, carbon fiber, ceramic fiber, and fluorine fiber, and fillers such as silica, talc, clay, alumina, mica, vermiculite may be blended. good.

  As a general method when preparing the flame retardant resin composition of the present invention as a molding material, the polyimide particles of the component (b) and the metal hydrate of the component (c) prepared by the above method, Prepare a flame retardant composition by dry blending, blend the flame retardant composition into the resin of component (a), mix this thoroughly with a mixer, etc., and then perform a melt mixing process with a hot roll or kneader. Then, it is cooled and solidified, and pulverized to an appropriate size to obtain a molding material. Alternatively, the polyimide particles of component (b) and the metal hydrate of component (c) prepared by the above method are separately blended into the resin of component (a) and used as a molding material by the same method as described above. You can also.

  The molding material thus obtained is subjected to various moldings such as injection molding, extrusion molding, hollow molding, film molding, press molding, pultrusion and the like, and further subjected to secondary processing as necessary to form various molded products, electric wires, A cable or the like can be obtained.

  The flame-retardant resin composition of the present invention can be used for all applications where high flame retardancy and electrical characteristics are required, but is preferably used for an electrical insulating material or the like. For example, insulating materials such as electric wires and cables, connectors, plugs, arms, sockets, caps, rotors, motor components, transformers, resistors, and other electrical / electronic components.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely using an Example, this invention is not limited only to a following example. In addition, each physical-property value in a following example and a comparative example is measured as follows. “Part” means “part by mass”.

[Flame retardance]
In accordance with the vertical combustion test specified in UL94 of the US UL standard, the test piece (bar sample) having a thickness of 1/32 inch was used.

[Surface appearance characteristics of molded products]
The surface of the molded product was visually observed, and the case where the molded product had smoothness was evaluated as “◯”, and the case where the molded product did not have smoothness was evaluated as “X”.

[Tensile strength, tensile elongation at break]
Conforms to ASTM D-1708.

[Particle size of polyimide particles]
The median diameter on a volume basis was calculated by measuring with a microtrack particle size distribution measuring apparatus MT3300EX (Nikkiso Co., Ltd.).

(Production Example 1)
After cutting a polyimide film having a thickness of 50 to 100 μm to obtain a square piece of about 2 mm, 21.70 kg of this square piece was put into a stone mill type grinder (Masako Sangyo Co., Ltd. supermass colloider), with a clearance of 40 μm, The mixture was pulverized for 23 minutes under the conditions of a rotational speed of 1200 rpm and a water addition amount of 2.5 L / min. The pulverized particles were taken out and water was removed by drying. As a result, polyimide particles in which the parallel plane derived from the polyimide filament disappeared were obtained.

(Comparative Production Example 1)
A polyimide film having a thickness of 50 to 100 μm was cut to obtain a square piece of about 2 mm, and the obtained square piece was put into a dry jet mill and pulverized.

(Comparative Production Example 2)
A polyimide film having a thickness of 50 to 100 μm was cut to obtain about 2 mm square pieces, and the obtained square pieces were put into a hammer mill and pulverized.

  Table 1 shows the median diameter, maximum particle diameter, and particle size distribution of the polyimide particles obtained in Production Example 1 and Comparative Production Examples 1 and 2.

  The particle size distribution of the polyimide particles obtained in Production Example 1 is shown in FIG. As shown in FIG. 1, the polyimide particles obtained in Production Example 1 had a sharp particle size distribution and had one peak. On the other hand, polyimide particles having a median diameter of 200 μm or less were not obtained by dry pulverization.

(Example 1)
6 parts of the polyimide particles obtained in Production Example 1 and 94 parts of aluminum hydroxide (Al (OH) ₃ : 99.5% by mass, Na ₂ O: 0.25% by mass) having an average particle diameter of 10 μm are placed in a Henschel mixer. And dry blended at 600 rpm for 1 minute. 50 parts of the blend and 50 parts of a linear low density polyethylene resin (LLDPE) (trade name NEOZEX2540R prime polymer) are produced at a cylinder temperature of 280 ° C. and a screw rotation speed of 220 rpm using a twin screw extruder made by Toshiba Machine with a screw diameter of 45 mmφ. The mixture was melt-kneaded to form a strand-like gut, cooled with a cooling bath, and granulated with a cutter to obtain pellets.

  The obtained pellets were molded at a barrel temperature of 280 ° C. using an injection molding machine IS100 manufactured by Toshiba Machine to obtain a molded product.

(Comparative Example 1)
6 parts of the polyimide particles obtained in Comparative Production Example 1 and 94 parts of aluminum hydroxide (Al (OH) ₃ : 99.5% by mass, Na ₂ O: 0.25% by mass) having an average particle size of 10 μm were added to a Henschel mixer. For 1 minute at 600 rpm. Except for using 50 parts of the blended product, pellets were obtained in the same manner as in Example 1, and then the obtained pellets were injection molded to obtain a molded product.

(Comparative Example 2)
6 parts of the polyimide particles obtained in Comparative Production Example 2 and 94 parts of aluminum hydroxide (Al (OH) ₃ : 99.5% by mass, Na ₂ O: 0.25% by mass) having an average particle size of 10 μm were added to a Henschel mixer. For 1 minute at 600 rpm. Except for using 50 parts of the blended product, pellets were obtained in the same manner as in Example 1, and then the obtained pellets were injection molded to obtain a molded product.

(Comparative Examples 3-4)
Except for using aluminum hydroxide or polyimide particles individually, pellets were obtained in the same manner as in Example Product 1 and then the obtained pellets were injection molded to obtain a molded product.

  The molded products produced in Examples and Comparative Examples were evaluated by the above methods. The evaluation results are shown in Table 2.

  From the results of Table 2, the resin composition containing the polyimide particles obtained by wet grinding using a stone mill type grinder has excellent surface appearance characteristics of the molded product and excellent tensile elongation and tensile strength of the molded product. It was.

  On the other hand, the resin composition containing the polyimide particles obtained by dry pulverization has poor surface appearance characteristics of the molded product and inferior tensile properties of the molded product.

  When only aluminum hydroxide particles were blended, the surface appearance characteristics of the molded product were inferior and the tensile characteristics were also poor. When only polyimide particles were blended, although the molding was completed, the surface appearance characteristics of the molded product were inferior.

  The flame retardant resin composition of the present invention is a non-halogen flame retardant, and can impart flame retardancy, flexibility and processability to products. Expansion to electrical applications around voltage is greatly expected.

It is a graph which shows the particle size distribution of the polyimide particle used in Example 1 of this invention.

Claims (3)

  In the flame retardant resin composition having (a) a thermoplastic resin or a thermosetting resin, (b) a polyimide particle, and (c) a metal hydrate as an essential component, a polyimide film or a sheet is used as a raw material as the polyimide particle. A flame retardant resin composition comprising polyimide particles obtained by wet pulverization using a stone mortar pulverizer and having disappeared parallel surfaces derived from a polyimide film or sheet.   The flame retardant resin composition according to claim 1, wherein the polyimide particles have a median diameter of 10 to 200 μm, a maximum particle diameter of 1000 μm or less, and one peak in the particle size distribution.   The total amount of the component (b) and the component (c) is 50 to 200 parts by mass with respect to 100 parts by mass of the component (a), and the ratio of the component (b) / (c) is 4/96 to 40. It is / 60 (mass ratio), The flame-retardant resin composition of Claim 1 or 2 characterized by the above-mentioned.