JP2000319532A - Flame retardant composite resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition capable of giving remarkably little adverse effects to the natural environment when discarded and expressing flame retardancy and biodegradability by bringing the composition to obtain a compatibilized material of a biodegradable organic high polymer with a silicon oxide as main ingredients. SOLUTION: This flame retardant composite resin composition is obtained by bringing the composition to contain a compatibilized material of (A) a biodegradable organic high molecular compound with (B) a silicon oxide as main ingredients. As the ingredient A, a polysaccharide (e.g. a cellulose derivative), an aliphatic polyester (e.g. a polylactic acid), a polyamino acid (e.g. a polyaspartic acid), a polyvinyl alcohol, a polyalkylene glycol (e.g. polyethylene glycol) or a copolymer containing thereof are cited. The ingredient B becomes a compatibilized material with the ingredient A by being mixed in a form of a silicon alkoxide (e.g. tetramethoxy silane) with the ingredient A in a medium and hydrolyzed by a sol-gel method to give the objective composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flame-retardant,
Also, the present invention relates to a flame-retardant composite resin composition that can reduce the adverse effect on the environment by biodegradation when disposed in a natural environment.

[0002]

2. Description of the Related Art In recent years, various synthetic resin materials have been developed or provided, and their use in various industrial fields has been increasing year by year. As a result, the amount of synthetic resin waste also increases, and the treatment method has become a major social problem.
Incineration of the discarded resin as it is may generate harmful gas or cause damage to the incinerator due to large combustion heat, resulting in a heavy load on the environment.

Conventionally known treatment methods for reducing the burden on the environment of waste resin include, for example, incineration of waste resin having a low molecular weight by thermal decomposition or chemical decomposition,
There is a way to landfill. However, incineration involves the emission of carbon dioxide, which causes global warming. It can be. When the resin is landfilled, most of the resins currently in practical use remain as they are without being decomposed for a long time. Additives and the like contained in the resin buried during this period flow out, which is one of the causes of soil contamination.

In order to solve such a problem, biodegradable resins have recently been developed and are being put to practical use. The biodegradable resin is
Degraded biochemically by microorganisms into carbon dioxide and water, etc., and even when disposed of in the natural environment, easily decomposes to lower molecular weight and changes to compounds that are harmless to the environment. It is to reduce. Examples of the organic polymer compound constituting such a biodegradable resin include cellulose, those obtained by chemically modifying natural polymers such as starch, and polylactic acid, polyhydroxybutyric acid, and aliphatic polyesters such as polyhydroxyvaleric acid. It has been known.

[0005]

The above-mentioned conventional biodegradable resins ensure the safety of the natural environment. However, these resins are not sufficient in terms of flame retardancy, which has recently been required as one of the safety factors when actually using the resins. A common means of improving the flame retardancy is to add a flame retardant such as a halogen-based or phosphorus-based resin to a resin, but these flame retardants have a negative effect on the natural environment when the resin is disposed of. It is concerned and goes against the original purpose of biodegradable resin development, which does not adversely affect the environment. Accordingly, an object of the present invention is to provide a flame-retardant and biodegradable resin material which has very little adverse effect on the natural environment at the time of disposal.

[0006]

The above object is achieved by the present invention described below. That is, the present invention provides a flame-retardant composition comprising, as a main component, a solution of a biodegradable organic polymer compound (hereinafter abbreviated as “biodegradable organic polymer compound”) and silicon oxide. Provided are a composite resin composition and a method for producing the same.

The present invention has been made based on the following findings. That is, in recent years, a composite material in which an organic polymer compound and an inorganic oxide are compatible has a high film-forming property (Japanese Patent Laid-Open No. 6-32213).
6) and gas barrier properties (JP-A-7-118543), and the mechanical strength of some biodegradable resins can be ensured (JP-A-7-145239). Gazette). In particular, when the inorganic oxide is a silicon oxide, since the chemical composition is the same as that of the sand, the problem remains even if the composite material remains in the natural environment as a residue after being completely decomposed. Less convenient.

[0008] Here, the present inventors have found that when a non-combustible substance called silicon oxide is compatible with a biodegradable organic polymer compound at a molecular level, the biodegradable organic polymer compound is burned. We focused on showing difficult properties. Then, they came to the idea that by combining various biodegradable organic polymer compounds with silicon oxide, it is possible to obtain a flame-retardant resin having extremely little adverse effect on the environment. However, the flame retardancy described here means that the effect of slowing down the expansion of the burning portion and the effect of preventing the likelihood of burning are exhibited.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the constituent components and the production method of the flame-retardant composite resin composition of the present invention will be described.
The biodegradable organic polymer compound used in the present invention is not particularly limited as long as it is generally treated as a biodegradable resin. Specific examples include polysaccharides, aliphatic polyesters, polyamino acids, polyvinyl alcohol, polyalkylene glycols, and the like, or copolymers containing at least one of them.

Examples of the polysaccharide include cellulose, starch, chitosan, and derivatives thereof, and copolymers containing at least one of them. As the aliphatic polyester, for example,
Polylactic acid such as poly-L-lactic acid (PLLA), random copolymer of L-lactic acid and D-lactic acid, polycaprolactone such as poly-ε-caprolactone (PCL), polyhydroxybutyric acid, polyhydroxyvaleric acid, polyethylene Succinate (PES), polybutylene succinate (PB
S), polybutylene adipate, polybutylene succinate-adipate copolymer, β-hydroxybutyric acid (H
B) random copolymer of 3-hydroxyvaleric acid (HV), any of polymalic acid or the like, or a copolymer containing at least one of them, and alternate copolymerization of a saccharide compound and an aliphatic dicarboxylic acid Coalescence and the like.

The polyamino acids include, for example, polyaspartic acid, polylysine, gluten, gelatin, a hydrolyzed polypeptide obtained by hydrolyzing a naturally-derived polypeptide, and derivatives thereof, or at least one of them. And the like. Examples of the polyalkylene glycol include any of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like, or a copolymer containing at least one.

Further, even if the organic polymer compound is biodegradable at a low molecular weight but low at a high molecular weight,
As long as sufficient biodegradability is ensured by copolymerization such as graft copolymerization with the biodegradable organic polymer compound exemplified above, this can be used. Those usable by such copolymerization include polyethylene, polypropylene, polyacrylic acid derivatives, polyurethane and the like.

[0013] The molecular weight of the biodegradable organic polymer compound used in the present invention is not particularly limited. When producing a composition, the molecular weight must be in a range that is soluble in an organic solvent.

The silicon oxide used in the present invention is usually
The biodegradable organic polymer compound is mixed with the biodegradable organic polymer compound in a medium in the form of a silicon alkoxide, and is hydrolyzed by a so-called sol-gel method to become a compatible solution with the biodegradable organic polymer compound. This gives a resin composition. Examples of the silicon alkoxide include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, methyltrimethoxysilane, methyltriethoxysilane, other alkoxysilanes and derivatives thereof.

Examples of a medium for mixing the silicon alkoxide with the biodegradable organic polymer include ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ethers such as tetrahydrofuran; alcohols such as methanol, ethanol and isopropyl alcohol; Esters such as ethyl acetate and butyl acetate; amides such as dimethylformamide and dimethylacetamide; acetonitrile; halogenated hydrocarbons such as carbon tetrachloride, chloroform and methylene chloride; aromatic hydrocarbons such as toluene and xylene; No.

In the hydrolysis of silicon alkoxide by the sol-gel method, the amount of water necessary for hydrolysis of silicon alkoxide or more is added to a solvent obtained by mixing the biodegradable organic polymer compound and silicon alkoxide as described above, Stirring may be performed at an appropriate temperature for an appropriate time. After completion of the reaction, the mixture may be formed into a desired shape by casting or the like without removing the solvent, or the solid may be removed by removing the solvent, and the solid may be formed by an appropriate molding method.

In the above hydrolysis, it is preferable to use a catalyst. Preferred examples of the catalyst include acids such as hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid. These acids are preferably about 0.001 to 1.0N, more preferably about 0.005 to 0.1N aqueous solution,
What is necessary is just to add to the solution which melt | dissolved the said silicon alkoxide. The water in the added aqueous solution can be used as water for hydrolysis.

Also, a molded body of a biodegradable organic polymer compound alone is prepared by an appropriate method, the silicon alkoxide is hydrolyzed with a catalyst and water, and the molded body is immersed in a solvent containing the same. It is also possible to complex the biodegradable organic polymer compound with silicon oxide. This method is particularly effective when the biodegradable organic polymer compound is not soluble in an organic solvent.

The composition ratio of the biodegradable organic polymer compound and silicon oxide in the flame-retardant composite resin composition of the present invention is preferably such that the ratio of silicon oxide is less than 50% by weight, preferably 10%. More preferably, it is ４０40%. When the proportion of the silicon oxide is 50% or more, the flame-retardant composite resin composition may be inferior in flexibility and homogeneity.

As described above, the biodegradable organic polymer compound and the silicon oxide form a covalent bond (-
The composition is compounded by C—O—Si—) or hydrogen bond (—OH... OＯC—), and the flame-retardant composite resin composition of the present invention is obtained. Further, the flame-retardant composite resin composition of the present invention is a pigment, a filler, within a range that does not adversely affect the natural environment.
A plasticizer, a stabilizer and the like may be added.

When the molded article of the flame-retardant composite resin composition of the present invention is left in an environment where microorganisms are active, such as in soil or water, the biodegradable organic polymer constituting the flame-retardant composite resin composition The compound undergoes biochemical decomposition to change into carbon dioxide and water, and the remaining silicon oxide component becomes a part of the soil as sand, so that it does not affect the environment.
Further, the flame-retardant composite resin composition of the present invention exhibits flame retardancy, biodegradability, mechanical strength, gas barrier properties, etc., which are unique to silicon oxide composites. Can be used for

[0022]

The present invention will be described more specifically below with reference to examples and comparative examples. Example 1 80 g of tetramethoxysilane and acetylcellulose (degree of substitution: 39.8%, molecular weight: 30,000, manufactured by Aldrich) 1
Was dissolved in 500 ml of tetrahydrofuran.
25 ml of 01N hydrochloric acid was gradually added, and the mixture was further stirred at room temperature for 3 hours. This solution was cast on a Teflon plate and dried to obtain a film-shaped flame-retardant composite resin composition of the present invention.

Example 2 100 g of soluble starch (manufactured by Wako Pure Chemical Industries) was added to 500 ml of hot water.
, And cast and dried on a Teflon (registered trademark) plate to obtain a film-like member. Separately, 180 g of methyltriethoxysilane and 54 ml of 0.005N hydrochloric acid were dissolved in 300 ml of ethanol and stirred for 4 hours. The film-like member was immersed in this solution for 20 minutes, taken out and air-dried, and further heated at 100 ° C. for 1 hour to obtain a flame-retardant composite resin composition of the present invention.

Examples 3 to 9 In the same manner as in Example 1, each of 100 g of each of the biodegradable organic polymer compounds shown in Table 1 was combined with silicon oxide to obtain a film-shaped flame-retardant composite resin of the present invention. A composition was obtained. However,
As the solvent, Example 3 used dimethylformamide, Examples 5 and 7 used a mixed solvent of chloroform / isopropyl alcohol (9: 1), and the others used tetrahydrofuran.

Example 10 Cellobiose (100 g) was suspended in dimethylformamide (2 L), pyridine (80 ml) was added, and the mixture was heated to 70 ° C. in a nitrogen atmosphere. Here, sebacic chloride 80
A solution obtained by diluting the resultant solution into 800 ml of dimethylformamide was added thereto, followed by stirring for 2 hours. The solvent was distilled off, washed three times with water and dried (yield 110 g, weight average molecular weight 5,000).
0). 100 g of this polymer compound is added to 500 parts of methanol.
dissolved in 50 ml of tetraethoxysilane and 0.0 g of tetraethoxysilane.
25N hydrochloric acid (25 ml) was added and the mixture was stirred at room temperature for 2 hours. This solution was cast on a Teflon plate and dried to obtain a film-shaped flame-retardant composite resin composition of the present invention.

"Evaluation" The flame-retardant composite resin compositions of the present invention prepared in Examples 1 to 10 were evaluated for flame retardancy and biodegradability. For the evaluation of flame retardancy, U
It was evaluated by the L94HB horizontal flammability test. In addition, no flammability due to melting and dropping of the burning portion was observed in any of the resin compositions. About evaluation of biodegradability, Examples 1-1
0 resin composition is molded into a 5 cm × 2 cm film,
The film was buried in soil collected from a paddy field in Kanagawa Prefecture for 2 months, taken out, and it was confirmed and evaluated whether or not the film had partially disappeared, ruptured, or changed such as cloudiness.
Table 1 shows the results. ○ in the table indicates that good results were obtained.

[0027]

[Table 1]

[0028]

According to the present invention, it is safe when used,
Further, it is possible to provide a resin material exhibiting flame retardancy and biodegradability that has very little adverse effect on the natural environment at the time of disposal.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C08L 71/02 C08L 77/04 77/04 89/00 89/00 C08K 5/54 A

Claims (8)

[Claims] 1. A flame-retardant composite resin composition comprising, as a main component, a solution of a biodegradable organic polymer compound and silicon oxide. 2. The organic polymer compound according to claim 1, wherein the organic polymer compound is any one of polysaccharides, aliphatic polyesters, polyamino acids, polyvinyl alcohols, and polyalkylene glycols, or a copolymer containing at least one of them. Flame-retardant composite resin composition. 3. The flame-retardant composite resin composition according to claim 2, wherein the polysaccharide is a cellulose derivative, a starch derivative, a chitosan derivative, or a copolymer containing at least one of the derivatives. 4. The method according to claim 1, wherein the aliphatic polyester is any one of polylactic acid, polycaprolactone, polyhydroxybutyric acid, polyhydroxyvaleric acid, polyethylene succinate, polybutylene succinate, polybutylene adipate, and polymalic acid. The flame-retardant composite resin composition according to claim 2, which is a copolymer containing at least one of the following. 5. The flame-retardant composite resin composition according to claim 2, wherein the aliphatic polyester is an alternating copolymer of a saccharide compound and an aliphatic dicarboxylic acid. 6. The polyamino acid is polyaspartic acid,
Gluten derivative, gelatin derivative itself,
The flame-retardant composite resin composition according to claim 2, which is a copolymer containing at least one of them. 7. The flame-retardant composite resin composition according to claim 2, wherein the polyalkylene glycol is a copolymer containing at least one of polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. 8. A method for producing a flame-retardant composite resin composition, comprising reacting a biodegradable organic polymer compound with a silicon alkoxide to form a composite thereof.