JPH0525266B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a flame-retardant resin composition, and in particular, a flame-retardant resin composition containing modified red phosphorus coated with an electroless plating film to a combustible synthetic resin such as a thermoplastic resin or a thermosetting resin. The present invention relates to a flame-retardant resin composition. [Prior Art] Conventionally, the uses of various synthetic resin molded products have become more and more diverse and expanded, but at the same time, flame retardant requirements for the molded products have become increasingly strict. It is well known that red phosphorus is used as a typical additive in making synthetic resins flame retardant. However, since red phosphorus generates phosphine with an unpleasant odor when hydrolyzed, there is a problem in blending it as it is into a resin. Therefore, many proposals have been made regarding stabilized red phosphorus obtained by modifying red phosphorus. For example, modified red phosphorus coated with a thermosetting resin (Japanese Unexamined Patent Publication No. 105996/1982), modified red phosphorus coated with a thermosetting resin after converting the surface of red phosphorus into a metal phosphide (Japanese Unexamined Patent Publication No. 52-10599), -125489) or modified red phosphorus coated with a triple layer of aluminum hydroxide, other metal hydroxides, etc. and an inorganic or organic coating agent (Japanese Patent Application Laid-open No. 10462/1982). Representatively known. [Problems to be Solved by the Invention] As mentioned above, many proposals have been made for stabilizing red phosphorus through modification, but all of them have advantages and disadvantages, and still have some important problems. In particular, red phosphorus is easily hydrolyzed in the presence of moisture and is accompanied by the generation of phosphine gas, which is odorous and toxic even in a very small amount, so it is extremely difficult to completely suppress the generation of this gas. In particular, thermoplastic resins require processing temperatures of over 200℃, sometimes exceeding 300℃ due to demands such as improved workability.
Conventional modified red phosphorus cannot be put to practical use because the above-mentioned phosphine gas is insufficiently suppressed. The present invention has been achieved through extensive research and exploration of various stabilization methods in order to substantially completely suppress the generation of phosphine gas accompanying the decomposition of red phosphorus.
When electroless plating was applied to red phosphorus particles, it was surprisingly found that a stable red phosphorus powder was obtained, and it was found that it was flame retardant not only for thermosetting resins but also for thermoplastic resins. The present invention was completed based on the finding that it can be used effectively without sacrificing any of the properties. [Means for Solving the Problem] and [Operation] That is, the gist of the present invention is to blend modified red phosphorus in which the surface of red phosphorus particles of combustible synthetic resin is coated with an electroless plating film. The present invention relates to a flame-retardant resin composition characterized by comprising: The present invention will be explained in detail below. The flammable synthetic resin that can be used in the present invention is a flammable synthetic resin that is required to be flame retardant when used, and may be either a thermosetting resin or a thermoplastic resin. Further, the combustible synthetic resin can be used, for example, as various molding materials, paints, adhesives, etc., and the manner is not particularly limited. Examples of the thermosetting resin include phenolic resin, urea resin, melamine resin, unsaturated polyester resin, epoxy resin, silicone resin, phthalate diacrylic resin, and polyurethane resin. Examples of thermoplastic resins include polyethylene, polyα-olefins such as polypropylene, copolymers containing at least α-olefins with other monomers, polystyrene, methacrylic resins, styrene-acrylonitrile copolymers (AS
resin), acrylonitrile-butadiene-styrene resin (ABS resin), polyvinyl chloride, fluororesin, polyamide, polyimide, polycarbonate, polyacetal, thermoplastic polyester, cellulose acetate (cellulose resin), polystylphone thermoplastic polyimide, polyphenylene oxide , polybutylene ionomer resin, etc. Next, the modified red phosphorus that can be effectively blended into the flammable synthetic resin as a flame retardant refers to stabilized red phosphorus in which the surface of red phosphorus particles is coated with an electroless plating film. is not particularly limited as long as it is a metal that can form an electroless plating film, but a metal plating film selected from Fe, Ni, Co, Cu, Zn, Mn, or an alloy thereof is particularly practical. Among them, especially Ni
and its alloys are preferred. The modified red phosphorus in the present invention can be produced by a conventional known electroless plating method.
Among these electroless plating methods, in particular, electroless plating liquid is gradually added to an aqueous suspension of red phosphorus to form a plating film on the surface of red phosphorus particles. Preferably, modified red phosphorus is used. In addition, when using sodium hypophosphite or alkali borohydride as a reducing agent in the electroless plating method, depending on the conditions, some phosphorus or boron may constitute the film composition. ,
Of course, such a film is also acceptable in the present invention. Furthermore, in the case of a film that is easily oxidized, such as a film of Fe or its alloy, the surface of the film may be oxidized over time to form an oxide film, but in the present invention, red phosphorus particles are initially added to the plating layer. As long as it forms a film, it is included in the modified red phosphorus, regardless of its change over time. The reason for this is that even if there is some change in the surface, there is no problem in stabilizing red phosphorus, and in fact, if it is necessary to avoid the conductive properties of the metal film, the oxide film may be intentionally removed from the metal surface. This is because it may be necessary and preferable to form it on a coating film. The amount of the plating film coated varies depending on the use of the modified red phosphorus, the type of metal, etc., but in most cases it is desirable to be in the range of 0.5 to 50% by weight based on the total weight. The reason for this is that if the content is less than 0.5% by weight, the suppression of phosphine gas is incomplete, and if it exceeds 50% by weight, it is inappropriate from a practical standpoint. In particular, in the present invention, when the modified red phosphorus is used as a flame retardant for various flammable synthetic resins, the modified red phosphorus is preferably 0.5 to 50 parts by weight of P per 100 parts by weight of the flammable synthetic resin. 0.5
A range of 15 parts by weight is preferred, while a range of 5 to 50 parts by weight is preferred for use as a flame retardant electrically conductive material. The modified red phosphorus in the present invention can be easily identified by microscopic observation as compared to the original red phosphorus because the metallic luster is uniformly formed on the particle surface. The modified red phosphorus used in the present invention is a stabilized red phosphorus that almost completely suppresses the generation of phosphine gas, and although the details of the reason for this are unknown, it is probably because red phosphorus itself is a highly reducing base material. It seems that the plating film is formed more firmly than electroless plating of other base materials. Furthermore, the modified red phosphorus in the present invention can be used in combination with other inorganic or organic flame retardants. Examples of inorganic flame retardants include hydroxides of magnesium, aluminum, zirconium, etc., antimony oxide, etc., and organic flame retardants include various phosphate esters, phosphite esters, organic tin compounds, etc. You can choose. In addition, in the present invention, the flame-retardant resin composition may contain other resin additives that may be normally blended as necessary depending on the purpose of use, such as plasticizers, lubricants, stabilizers, fillers, colorants, and antioxidants. Alternatively, an ultraviolet inhibitor or the like may be appropriately added. [Examples] Hereinafter, the present invention will be explained in more detail by showing examples. Examples 1 to 13 (1) Preparation of modified red phosphorus Γ Samples 1 to 5 100 g of red phosphorus powder with a particle size of 44 μm or less and an average particle size of 24 μm was added to 0.1 g/palladium chloride diluted hydrochloric acid solution 1, and was heated for about 5 minutes. After stirring, the mixture was filtered, repulped, filtered, and catalyzed. The red phosphorus powder that has been catalyzed in this way is added to an aqueous solution 1 of various complexing agents shown in Table 1, thoroughly dispersed, and the liquid temperature is heated to 80°C to form an aqueous suspension. Prepared. Next, the electroless plating solution shown in Table 2 was added to a
Divided into liquid and b liquid, 41 ml of each was individually and simultaneously added to the above aqueous suspension while stirring at a rate of 5 ml/min, and plating was performed under each condition. In all experiments, after adding the entire plating solution, stirring was continued while maintaining the temperature at 80°C until hydrogen generation stopped. Then filtration, repulp washing,
After that, it was dried. When the obtained red phosphorus plating powder was observed under a microscope, it was found that the surfaces of the red phosphorus particles were completely coated with a uniform film with metallic luster. Further, as a result of measuring a thin film X-ray diffraction image of the film using a thin film X-ray diffraction measuring device, it was confirmed that all the precipitates were nickel metal.

【table】

[Table] Γ Samples 6 to 11 100 g of red phosphorus powder with a particle size of 44 μm or less and an average particle size of 24 μm was mixed with 2 g of aminopropyltriethoxysilane and 0.1 g of palladium chloride.
Pour into mixed solution 1 consisting of about 15 g/
After stirring for a minute to ensure good dispersion, the mixture was filtered and dried to completely remove water, followed by catalytic treatment. 10% of the red phosphorus powder pretreated in this way
g/sodium tartrate aqueous solution 1, subjected to a dispersion treatment so that substantially no agglomerate was present, and heated to 75° C. to prepare an aqueous suspension with a pH of 7.0. Next, the electroless plating solution shown in Table 3,
According to Table 4, the drugs in which solutions a, b, and c were prepared were first added individually and simultaneously at a dropping rate of 5 ml/min, and then added to solution a.
The solution was added to the above-mentioned suspension under stirring at the same dropping speed starting 30 seconds before the end of the dropwise addition. (Including cases where no C liquid is added) After adding the entire amount, wait 75 minutes until hydrogen generation stops.
Stirring was continued while maintaining the temperature. Then,
After filtration, repulp washing, and filtration, it was dried. When all of the Example products were observed under a microscope, it was found that the red phosphorus particles had a uniform metal coating on the entire surface.

【table】

[Table] Γ Sample No. 12 100 g of red phosphorus powder with a particle size of 44 μm or less and an average particle size of 24 μm was added to 0.1 g of palladium chloride diluted hydrochloric acid solution 1, and after stirring for about 5 minutes,
Filtration, repulping, filtration and catalytic treatment were performed. The red phosphorus powder catalyzed in this way was added to an aqueous solution 1 containing 20 g of sodium tartrate, thoroughly stirred and dispersed, and the liquid temperature was heated to 80°C to prepare an aqueous suspension with a pH of 7.0. . Next, 196g of copper sulfate/aqueous solution (liquid A)
105 ml of a mixed aqueous solution (liquid B) having a concentration of 105 ml, 208 g of sodium hypophosphite/and 118 g of sodium hydroxide were individually and simultaneously added to the aqueous suspension with stirring at a rate of 5 ml/min. After adding the entire amount, wait 80 minutes until hydrogen generation stops.
Stirring was continued while maintaining the temperature. Then, it was filtered, repulped, washed, and dried. When the obtained powder was observed under a microscope, it was confirmed that the entire surface of the red phosphorus particles was coated with a uniform copper film. Γ Sample No. 13 100 g of red phosphorus powder with a particle size of 44 μm or less and an average particle size of 24 μm was mixed with 2 g of aminopropyltriethoxysilane and 0.1 g of palladium chloride.
After stirring for about 15 minutes to ensure good dispersion, the mixture was filtered and dried to completely remove water, followed by catalytic treatment. 10 g of red phosphorus powder pretreated in this way was added to an aqueous solution 1 containing 30 g of sodium tartrate, thoroughly dispersed, and heated to 85°C to prepare an aqueous suspension with a pH of 5.0. did. Next, 249 g/ferrous sulfate aqueous solution (a
41 ml of a mixed aqueous solution (liquid B) with a concentration of 237 g/sodium hypophosphite and 134 g/sodium hydroxide were individually and simultaneously dropped into the above aqueous suspension under stirring at a rate of 5 ml/min. Added. After adding the entire amount, wait 85 minutes until hydrogen generation stops.
Stirring was continued while maintaining the temperature. Then, it was filtered, repulped, washed, and dried. When the obtained powder was observed under a microscope, it was found that the surface of the red phosphorus particles was entirely covered with a uniform metal film, and furthermore, the particles had a film that appeared to be iron oxide partially thereon. (2) Preparation of resin composition A mixture of the following composition was placed in a mold (12.7mm x 12.7mm x
127 mm) and heated at 100°C for 6 hours to harden to prepare an epoxy resin molded article. No odor of phosphine occurred during the preparation of this test piece, and it could not be detected even when measured using a detection tube (Gastech detection tube: detection limit: 0.04 ppm, manufactured by Kitazawa Sangyo Co., Ltd.). Epoxy resin (Epicote 828; Yuka Ciel Epoxy Co., Ltd. product) 10 parts by weight Anhydrous curing agent (hardener; Ciba Geigy Japan)
Co., Ltd. product) 8 Aluminum hydroxide (Higilite H32-;
Showa Light Metal Co., Ltd. product) 10 〃 Sample As red phosphorus 1 〃 (3) Measuring method and results 1 Measurement of amount of metal coating Collect a certain amount of metal-coated red phosphorus from each sample, and use nitric acid to form a metal coating. was dissolved, and the metal ions in the solution were analyzed by chelate titration to determine the amount of each metal coated. The results are shown in Table 5. 2 Measurement of specific resistance of metal-coated red phosphorus powder The resistance value of the metal-coated red phosphorus powder of each sample was
Measured by terminal method. The results are shown in Table 5. 3 Measurement of the amount of phosphine generated from metal-coated red phosphorus powder In a constant temperature and humidity chamber at a temperature of 30℃ and a relative humidity of 83%.
0.5 g of the sample stored for 48 hours is taken and heated in _N2 gas (150°C, 3 hours). The amount of PH ₃ generated was measured using a gas chromatograph and converted into the amount of PH ₃ (μg) generated per 1 g of sample. The results are shown in Table 5. 4 Flame resistance test The resin composition passed JIS K-6911 flame resistance test A.
It was measured by the method. The results are shown in the fifth section. In addition, a resin composition that does not contain red phosphorus (blank)
was "flammable".

【table】

[Table] Comparative Example 1 In the resin composition of Example 1, thermosetting resin coated red phosphorus (commercial product A, itself has a phosphine generation amount of 5 ppm) and alumina coated red phosphorus (commercial product B, itself) An epoxy resin molded body was prepared in the same manner as in Example 1, except that the amount of phosphine generated was 3 to 7 ppm), and the flame resistance test of the molded body was conducted. As a result, all of them had a phosphine odor, and as a result of the measurement, 0.3 to 1.5 ppm of phosphine was detected. Examples 14-22 Metal hydroxide modified red phosphorus (sample Nos. 1, 6, 7, 10, 13) for 100 parts by weight of unsaturated polyester
A resin composition containing a predetermined amount of (shown in Table 6)
1 part by weight of a curing catalyst of 55% by weight of methyl ethyl ketone peroxide per 100 parts by weight and an appropriate amount of cobalt naphthenate were mixed uniformly, poured into a mold (12.7 mm x 12.7 mm x 12.7 mm), and heated at 100°C.
A polyester resin molded article was prepared by heating and curing for a period of time. No odor of phosphine occurred during the preparation of this test piece, and the detection tube (Gastech detection tube: detection limit
0.04ppm (manufactured by Kitazawa Sangyo Co., Ltd.) could not be detected. Further, the obtained test piece was subjected to a heat resistance test using the measuring method shown in Example 1 above. The results are shown in Table 6.

[Table] Example 23 1,4-polybutadiene polyol (molecular weight
2800) Modified red phosphorus (sample No. 1) per 100 parts by weight
10 parts by weight, 50 parts by weight of zirconium hydroxide, N,N
-bis(2-hydroxypropyl)-aniline 15
15 parts by weight of modified liquid 4,4'-diphenylmethane diisocyanate (NCO equivalent: 145) was mixed with 100 parts by weight of a homogeneous mixture of parts by weight and 20 parts by weight of process oil, and the mixture was cured by heating at 65°C for 14 hours. A test piece (10 mm x 10 mm x 100 mm) was created. In this preparation, no phosphine odor was produced and was not detected even in the measurement with a detection tube. Next, the heat resistance of this test piece was evaluated according to Example 1 above.
When measured using the method shown in , it showed good flame retardancy. Examples 24-32 Various thermoplastic resin compositions having the formulations shown in Table 7 were prepared, heated at 180-270°C and kneaded with two rolls for 10 minutes, and then test pieces (12.7 mm x 3 mm x 12.7 mm) were prepared. We created it and tested its flame resistance. No odor of phosphine occurred during the preparation of this test piece, and the detection tube (Gastech detection tube: detection limit
0.04ppm (manufactured by Kitazawa Sangyo Co., Ltd.) could not be detected. Further, a heat resistance test was conducted on the obtained test piece. The results are shown in Table 7.

[Table] Comparative Example 2 Same method as in Example 28 except that the thermosetting resin coated red phosphorus (commercial product A) and alumina coated red phosphorus (commercial product B) were used as samples for the polystyrene in Example 28. A polystyrene resin molded body was prepared, and a flame resistance test was conducted on the molded body. As a result, all of them had a phosphine odor, and as a result of the measurement, 1 to 5 ppm of phosphine was detected. [Effects of the Invention] As explained above, in the modified red phosphorus of the present invention, the surface of the red phosphorus particles is coated with an electroless plating film, and the red phosphorus particles are shielded from the outside, so that they cannot be used in the presence of moisture. The hydrolysis reaction is suppressed, and the generation of toxic and foul-smelling phosphine gas is completely prevented. This modified red phosphorus can exert its inherent flame retardant effect on combustible resins without sacrificing anything, so the flame retardancy of various synthetic resins blended with it is as good as before. It is something that In particular, it is of great industrial significance that thermoplastic resins, which require high processing temperatures, can be made flame retardant without causing any problems in the working environment. Furthermore, when a large amount of modified red phosphorus with a high plating coverage is blended into a resin, a characteristic resin composition having flame retardant and electrically conductive properties can be obtained, and its use can be expected.

Claims (1)

[Scope of Claims] 1. A flame-retardant resin composition comprising a combustible synthetic resin and modified red phosphorus whose particle surfaces are coated with an electroless plating film. 2. The flame-retardant resin composition according to claim 1, wherein the flammable synthetic resin is a thermoplastic resin. 3. The flame-retardant resin composition according to claim 1, wherein the flammable synthetic resin is a thermosetting resin. 4 Electroless plating film is Ni, Cu, Co, Fe, Zn
The flame-retardant resin composition according to claim 1, which is a metal plating film selected from Mn, Mn, or an alloy thereof. 5. The flame-retardant resin composition according to claim 1, wherein the modified red phosphorus is blended in an amount of 0.5 to 50 parts by weight as P based on 100 parts by weight of the flammable synthetic resin.