JP2002348575A - Biodegradable flame-retardant, flame-retardant resin composition containing the same and molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biodegradable flame-retardant. SOLUTION: The biodegradable flame-retardant contains a low-molecular organic substance (a) having at least hydroxy group and carboxy group in the molecule.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biodegradable flame retardant which is flame-retardant, does not generate a halogen-based gas by combustion, and is biodegradable when discarded to reduce the burden on the environment. And a flame-retardant resin composition and a molded article obtained using the same.

[0002]

2. Description of the Related Art Conventionally, thermoplastic resins have been used in a wide range of fields because of their excellent moldability, lightness, durability, and electrical insulation. However, since it is an organic material unlike an inorganic material represented by a metal, it has a drawback that it is inherently flammable. Since flame retardancy is indispensable from the viewpoint of fire prevention, a flame retardant resin composition in which various flame retardants are mixed with a resin has been proposed and disclosed.

In order to impart flame retardancy to a resin, a method in which an organic halogen compound and antimony trioxide are blended, and a chemical and physical synergistic effect of the two are generally used.
However, the resin composition containing an organic halogen-based compound has been regarded as a problem due to the corrosiveness of halogen-based gas generated at the time of combustion, molding, or incineration of a molded article.

[0004] In order to solve such a problem, there is a method of adding a hydrated metal oxide. However, since the flame retardancy is insufficient, it is necessary to add a large amount of the metal oxide, and the use thereof has been limited. In addition, various flame retardants such as phosphate esters, red phosphorus, metal compounds, and nitrogen compounds have been used. Was concerned.

[0005]

In recent years, attention has been paid to phosphorus-based compounds such as phosphate esters as non-halogen-based flame retardants in consideration of prevention of corrosiveness due to gas during incineration.
It is being used for equipment and the like. However, since phosphate esters are not biodegradable, there is a concern about the burden on the environment at the time of product disposal, and there has been a problem that it cannot be said that the purpose of the flame retardant is environmentally friendly. Accordingly, an object of the present invention is to provide a flame retardant which has sufficient flame retardancy when a product is used, and which is biodegraded into water and carbon dioxide by microorganisms and the like when discarded in a landfill or the like to reduce the load on the natural environment. To provide.

[0006]

Means for Solving the Problems In order to solve the above problems, the present inventors have conducted intensive studies and as a result, have been able to specify for the first time a substance having both flame retardancy and biodegradability. That is, the first invention of the present invention is a biodegradable flame retardant comprising a low-molecular organic substance (a) having at least a hydroxyl group and a carboxyl group in a molecule.

In a second aspect, the invention provides a method for producing a low-molecular organic substance (a), which is selected from the group consisting of tartaric acid, citric acid, gluconic acid, lactic acid, malic acid and gallic acid, an ester derivative thereof, and a metal salt. The biodegradable flame retardant according to the first invention, which is at least one kind.

[0008] A third invention is the biodegradable flame retardant according to the second invention, wherein the low-molecular organic substance (a) is a salt of an alkali metal or an alkaline earth metal.

A fourth invention is the biodegradable flame retardant according to the third invention, wherein the organic low molecular weight substance (a) is a potassium salt.

A fifth invention is the biodegradable flame retardant according to the fourth invention, wherein the low-molecular organic substance (a) is potassium hydrogen tartrate or potassium tartrate.

A sixth invention is a flame-retardant resin composition comprising the biodegradable flame retardant according to any one of the first to fifth inventions and a resin.

A seventh invention provides the flame-retardant resin composition according to the sixth invention, wherein 0.1 to 100 parts by weight of a biodegradable flame retardant is added to 100 parts by weight of the resin. is there.

An eighth invention is a molded article obtained by using the flame-retardant resin composition according to the sixth or seventh invention.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The biodegradable flame retardant of the present invention means that the organic low-molecular substance (a) having at least a hydroxyl group and a carboxyl group in the molecule is contained as a main component, that is, 50% by weight or more. Although there is no limitation, those having a number average molecular weight of 2000 or less are preferable. Among them, for example, an acid selected from the group consisting of tartaric acid, citric acid, gluconic acid, lactic acid, malic acid, and gallic acid, or an ester derivative thereof, or a metal salt thereof is preferable in terms of good biodegradability. As the metal salt, an alkali metal or alkaline earth metal salt is preferable, and a potassium salt selected from the above group is more preferable. Potassium hydrogen tartrate and potassium tartrate are particularly preferred as those which sufficiently satisfy both the properties of biodegradability and flame retardancy.

Although the flame-retarding mechanism of the organic low-molecular substance (a) is not yet clear, it has a hydroxyl group and a carboxyl group in the molecule and thus has an endothermic effect by dehydration and a carbonization promoting effect by dehydration of the organic acid. It is presumed that flame retardancy increases. It is presumed that among the low-molecular organic substances (a), the alkali metal salt, especially the potassium salt, is effective for improving the flame retardancy by the radical scavenging action.

As an example of confirming the biodegradability, a petri dish containing a fixed amount of a flame retardant and soil is allowed to stand in a thermo-hygrostat at 35 ° C./80% RH for 3 weeks. There is a method in which the weight before and after the measurement is measured, and the decrease is regarded as the decrease in the flame retardant.

In order to improve the dispersibility in the resin and easily exhibit an excellent flame retardant effect, a biodegradable flame retardant is added to a higher fatty acid such as stearic acid or oleic acid or an alkali thereof to such an extent that the biodegradability is not impaired. Dry treatment or wet coupling treatment can be performed with a metal salt, a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, or a surface treatment agent such as an ester of a polyhydric alcohol and a fatty acid. For example, 100 parts by weight of the biodegradable flame retardant can be treated with 0.1 to 10 parts by weight of these surface treating agents.

For the purpose of improving the heat resistance or water resistance of the biodegradable flame retardant, a composite material flame retardant can be obtained by a so-called sol-gel method using silicon alkoxide. Examples of the silicon alkoxide include tetramethoxysilane, tetramethoxysilane, tetrapropoxysilane, other alkoxysilanes and derivatives thereof.

The resin used in the flame-retardant resin composition of the present invention is not particularly limited. For example, thermoplastic resins include polyolefin resins such as polyethylene resin and polypropylene resin, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate (MMA) copolymer, and ethylene-methacrylic acid copolymer. Polymer, ethylene-based copolymer such as ethylene-methyl acrylate copolymer, linear low-density polyethylene which is an ethylene-α-olefin copolymer synthesized with a conventional catalyst or a metallocene catalyst, polyacetal resin, P
A (polyamide) resin, polyester resin, polybutadiene resin, acrylic rubber, ethylene acrylic rubber, methacrylic resin, polystyrene resin, ABS resin and PC /
Aromatic alloy resin such as ABS resin, PA / ABS resin, PC (polycarbonate) resin, AAS resin, AS
Resin, styrene copolymer elastomer, polyurethane elastomer, polyester elastomer, ethylene-
Examples include polyolefin elastomers such as propylene copolymer elastomers, thermoplastic elastomers such as polyamide elastomers and styrene-based elastomers. These thermoplastic resins can be used alone or in combination of two or more. Examples of the thermosetting resin include an epoxy resin, a melamine resin, a phenol resin, a urea resin, an unsaturated polyester resin, a polyimide resin, a silicone resin, and a polyurethane resin. These can be used alone or in combination of two or more.

The flame-retardant resin composition of the present invention comprises a resin 100
It is preferable to mix 0.1 to 100 parts by weight of the biodegradable flame retardant with respect to parts by weight, and more preferably 0.2 to 90 parts by weight. When the amount is outside the above range, the flame retardancy becomes insufficient when the amount is small, and the mechanical properties as a flame retardant resin composition or a molded article may be deteriorated when the amount is large.

The flame-retardant resin composition of the present invention may contain, if necessary, various additives other than the above-mentioned components, such as antioxidants, nucleating agents, ultraviolet absorbers, various dyes and pigments for coloring, In addition to a cross-linking agent, a cross-linking auxiliary, a foaming agent, an adsorbent represented by silica and zeolite, a viscosity adjuster, a lubricant, and the like, a flame retardant auxiliary such as various metal salts can be contained.

The flame-retardant resin composition of the present invention is produced by melt-kneading the above components using a two-roll mill, a Banbury mixer, a kneader, a twin-screw kneader or the like.

Representative examples of the flame-retardant resin composition of the present invention include compounds and masterbatches.
In the case of a compound, the composition is as it is, and in the case of a master batch, a desired flame retardant concentration is obtained by appropriately diluting with a thermoplastic resin at the time of molding, and an extruder, a calender molding machine, a T-die molding machine, an injection molding machine or the like is used. To form a molded product.

Examples of the molded article of the present invention include various extruded articles such as exterior or interior parts of home appliances or OA equipment, electric wires, high-voltage electric wires, tubes and tapes used in the field of electronic equipment and automobiles, and injection molding. Examples include, but are not limited to, molded articles, automotive interior materials and paints, building material films, sheets or paints, electrical components, and the like. Further, these molded products can be subjected to secondary processing such as electron beam crosslinking or chemical crosslinking for the purpose of improving heat resistance and maintaining shape.

[0025]

EXAMPLES The present invention will be described below in detail with reference to examples, but the scope of the present invention is not limited to the examples unless it exceeds the gist. Examples 1 to 5, Comparative Examples 1 to 4 A1: JSR ABS350 (manufactured by Nippon Synthetic Rubber) A2: Ethylene-vinyl acetate copolymer Evaflex P2505 (manufactured by Mitsui / Dupont Polychemical) B1: Special grade reagent (+)-tartaric acid Potassium hydrogen (manufactured by Kishida Chemical) B2: Special grade reagent Potassium gluconate (manufactured by Kishida Chemical) B3 (Comparative Example 1): Condensed phosphate ester ADK STAB PFR (manufactured by Asahi Denka) B4 (Comparative Example 2): Ammonium polyphosphate Exolite AP422 ( (Made by Clariant Japan) The above components were mixed in the blending amounts (parts by weight) shown in Table 1, and 1
The mixture was melted and kneaded with two rolls set at 40 ° C. for 5 minutes to obtain a resin composition. Further, a plate-like molded product was prepared by hot pressing at 200 ° C.

As an evaluation of the flame retardancy of the plate-like molded product, J
The oxygen index was measured according to IS K7201. A (flame index 25 or more), B (oxygen index 2)
1 or more), C (less than oxygen index 21), and B or more was accepted.

The biodegradability of the resin composition was evaluated as follows. The soil used was collected from a hardwood forest in Saitama Prefecture. Put 45g of soil in a Petri dish and put 10g on it
g of flame retardant and 45 g of soil. The whole weight was measured, and after standing still in a thermo-hygrostat at 35 ° C./80% RH for 3 weeks, the weight was measured again. The amount of weight loss is defined as the amount of flame retardant reduction. If a weight reduction of 50% or more is obtained, it is judged to be biodegradable, and the result is judged as pass (５０). did. Table 1 shows the above evaluation results.

[0028]

[Table 1]

The flame retardancy of Examples 1 to 5 was acceptable at Ranks A and B, and the biodegradability was good. Therefore, it was confirmed that the flame retardant had a low environmental load. In contrast,
In the comparative example, a product satisfying both flame retardancy and biodegradability was not obtained.

[0030]

As described above, the biodegradable flame retardant of the present invention comprises an organic low-molecular substance (a) having at least a hydroxyl group and a carboxyl group.
As a main component, the flame-retardant resin composition and the molded product obtained using the same have sufficient flame retardancy when the product is used, and then when the product is disposed of by landfill treatment or the like. The biodegradable flame retardant component is easily biodegraded. Therefore, it is possible to reduce the burden on the environment at the time of disposal, which has been concerned about the conventional flame retardant.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F071 AA12 AA12X AA15 AA20 AA20X AA22 AA22X AA28X AA34X AA40 AA41 AA42 AA43 AA49 AA50 AA52 AA53 AA54 AA60 AA67 AA77 AC09 AE07 4H028 BB07 BB07 BB07 BC BC061 BG041 BL011 BN121 BN151 CB001 CC041 CC161 CC181 CD001 CF001 CF211 CG001 CK021 CL001 CM041 CP031 EF036 EF096 EG026 EG036 FD136

Claims (8)

[Claims] 1. A biodegradable flame retardant comprising a low-molecular organic substance (a) having at least a hydroxyl group and a carboxyl group in a molecule. 2. The low-molecular organic substance (a) is at least one selected from the group consisting of tartaric acid, citric acid, gluconic acid, lactic acid, malic acid and gallic acid, an ester derivative thereof, and a metal salt. The biodegradable flame retardant according to claim 1, characterized in that: 3. The biodegradable flame retardant according to claim 2, wherein the organic low molecular weight substance (a) is a salt of an alkali metal or an alkaline earth metal. 4. The biodegradable flame retardant according to claim 3, wherein the low-molecular organic substance (a) is a potassium salt. 5. The biodegradable flame retardant according to claim 4, wherein the organic low molecular weight substance (a) is potassium hydrogen tartrate or potassium tartrate. 6. A flame-retardant resin composition comprising the biodegradable flame retardant according to claim 1 and a resin. 7. The flame-retardant resin composition according to claim 6, wherein 0.1 to 100 parts by weight of a biodegradable flame retardant is added to 100 parts by weight of the resin. 8. A molded article obtained by using the flame-retardant resin composition according to claim 6 or 7.