JPS62112639A - Flame retarder for synthetic resin - Google Patents

Abstract

PURPOSE:To provide the titled flame retarder which gives moldings having excellent flame retardance, resistance to water and impact and appearance, by coating a mixture of an inorg. ammonium salt and an antimony flame- retardant aid with a urethane resin so as to give a specified max. particle size. CONSTITUTION:100pts.wt. powder mixture (A) of 100pts.wt. inorg. ammonium salt (a) such as NH4Cl, NH4Br, (NH4)2SO4, etc. and 1-30pts.wt. antimony flame-retardant aid (b) (e.g., Sb2O3) is suspended and dispersed in an org. solvent contg. a surfactant (e.g., a polyoxyethylene alkylaryl ether) dissolved therein. An isocyanate (e.g., toluene diisocyanate) and a polyol (e.g., a polyester polyol) in such amounts as to give 3-30pts.wt. polyurethane resin component are then dissolved therein, and while stirring, the resulting suspension is cured by drying in a spray dryer to obtain the titled flame retarder having a max. particle size of 50mu or below, wherein the surface of the inorg. ammonium salt powder is coated with the urethane resin.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to flame retardants for synthetic resins.

More specifically, the present invention provides an inorganic ammonium salt flame retardant whose powder surface is coated with a urethane resin.

[Conventional technology]

The use of inorganic ammonium salts as flame retardants for flammable polymers is well known. However, this compound has strong self-aggregation properties and not only causes f-blocking during storage, but also
It is known that when kneaded with synthetic resins such as polyethylene, polybrepylene, polystyrene, etc., agglomeration may occur due to shear force during kneading. Furthermore, in the field of molded resins containing inorganic ammonium salts, water resistance becomes a problem due to the strong hygroscopicity of inorganic ammonium salts. That is, when a resin composition or a molded product obtained by processing the resin composition is brought into contact with an aqueous substance, the inorganic ammonium salt is eluted and the physical properties of the composition or the surface condition of the molded product change, causing problems in use.

In addition, when the composition is used under high humidity conditions, it may absorb moisture from the air, or the above-mentioned salts may be eluted by the moisture, causing practical problems such as precipitation of soil crystals on the resin surface. There is. These are the reasons that limit the use of inorganic ammonium salts in synthetic resins such as polyolefins and polystyrene.

As a method to improve these problems of inorganic ammonium salts, chlorinated paraffin (Japanese Patent Publication No. 47-56246, Japanese Patent Publication No. 51-7494), polysiloxane (Japanese Patent Publication No. 59-1989)
1746), urea-formaldehyde resin (Unexamined Japanese Patent Publication No. 1746)
-100544).

A method of coating the surface with a resin such as the following is already known. When ammonium bromide whose surface is coated with chlorinated paraffin is kneaded into a resin, it can significantly reduce the heat resistance (thermal discoloration) of the resin and cause bleeding, which can greatly impair the appearance of the molded product. In the case of ammonium sulfate that has not been surface-treated with curable polysiloxane, the water absorption rate of the compounded resin is considerably lower than that of an untreated product, but the water absorption rate is still about 1 to 2%, and there is a need to further improve the water resistance. Regarding the method of coating with urea-formaldehyde resin, there are various problems in applying it to inorganic ammonium salts, which are easily water-soluble compounds, in that the resin is water-soluble. Furthermore, amino resins also have the disadvantage of being susceptible to thermal discoloration. Furthermore, the present inventors previously modified ammonium chloride by coating it with unsaturated polyester (
However, in this case, the particle size is as large as 100 to 200 microns, and it is industrially difficult to obtain a coating of 50 microns or less, which is preferable as an additive flame retardant. It is conceivable to physically grind the powder of 100 to 200 microns, but in this case the capsules will be destroyed and the same drawbacks mentioned above will occur as when adding ammonium chloride alone.

[Problem that the invention seeks to solve]

In order to solve this problem, the inventors of the present invention have conducted extensive studies and found that the problem can be solved by applying urethane coating to an inorganic ammonium salt that has been treated with a surfactant, leading to the present invention.

The present invention relates to a surfactant and then an inorganic ammonium end yarn flame retardant treated with urethane. A resin containing this does not generate toxic gas when burned, suppresses black smoke generation, and is extremely economical. The purpose of this invention is to provide a flame retardant that is highly effective.

[Means for solving problems]

The present invention is a flame retardant for synthetic resins, which is a powder in which a mixture of an inorganic ammonium salt and an antimony-based flame retardant aid is coated with a urethane resin, and the coated powder has a maximum particle size of 50 microns or less. It is in. The present invention will be explained in detail below.

Inorganic ammonium salts in the present invention include phosphoric acid, sulfuric acid, boric acid, hydrobromic acid, hydrochloric acid, and sulfamino acid.

It is an ammonium salt of imidodisulfonic acid, and these are used alone or in a mixture of 2flJ1 or more.

When used as an additive to a resin, it must be stable at the molding temperature. Therefore, it is desirable that the decomposition temperature of the silver salt is 130°C or higher. Considering cost advantages, ammonium chloride, ammonium bromide and ammonium sulfate are particularly preferred. Isocyanates and polyols are not particularly limited as long as they have heat resistance of ℃ or higher. Typical isocyanates include toluene diisocyanate (TD Engineering) and methidi/diphenyl diisocyanate + MDI, while polyols include polyester polyols, polyether polyols, and the like.

Urethane coating can be performed satisfactorily by using a surfactant during coating. This is probably due to the improvement in the elasticity (adhesion) between the urethane resin and the inorganic surface of the inorganic ammonium salt and/or antimony-based inorganic flame retardant aid. The surfactant used must be heat resistant to 130°C or higher. z Not determined. If it has a heat resistance of 130° C. or lower, it will decompose or denature when blended into a resin, resulting in undesirable phenomena such as deterioration of resin processability or yellowing of the surface of molded products. In the present invention, nonionic surfactants such as polyoxyethylene alkyl ether and polyoxyethylene alkyl allyl ether are particularly preferred since they do not have any of the above problems.

The particle size of the coated powder in the present invention is at most 50 microns or less. If a powder with a maximum particle size exceeding 50 microns is kneaded into a resin for flame retardation, the impact resistance of the resulting resin product will be extremely deteriorated, which is not preferable. Moreover, the variation in flame retardancy becomes large, which is not preferable. Therefore, raw inorganic ammonium salts and antimony-based flame retardant aids having a maximum particle size of 45 microns or less are used. An inorganic ammonium salt having such a particle size can be obtained by a method similar to the method described in Japanese Patent Application No. 1985-92085, such as a jet stream pulverization method, a spray drying method of an aqueous ammonium chloride solution, or other special ball mill method. I can do it.

The flame retardant in the present invention is an aggregate of fine particles covered with a film of urethane a-fat, and the inside of the surface film of the fine particles is a mixed powder of an inorganic ammonium salt and an antimony-based flame retardant aid. Further, the mixed powder is a mixture of 1 to 30 parts by weight of an antimony-based flame retardant aid to 100 parts of an inorganic ammonium salt. The antimony-based flame retardant aid is mixed in advance with an inorganic ammonium salt and coated to further synergistically amplify the function of the flame retardant. If the antimony-based flame retardant aid is mixed in an amount of 1 part by weight or less with respect to 100 parts by weight of the inorganic ammonium salt, the synergistic effect is small, and there is no point in adding the flame retardant aid. Furthermore, when the antimony-based flame retardant adjuvant is mixed at a mixing ratio of 30 parts by weight or more, almost no synergistic effect is observed, and there is no point in increasing the amount of the expensive antimony-based flame retardant adjuvant.

The antimony-based flame retardant aid, which is a component of the present invention, is
It is an antimony-based compound represented by antimony trioxide, potassium antimonate, etc., and antimony trioxide is particularly preferred.

There are various methods for manufacturing the coated mixture of fine powder of inorganic ammonium salt and antimony-based flame retardant used in the present invention. Some examples of manufacturing methods are shown below, but the manufacturing method is limited to these. It is not something that will be done.

(A) Spray Drying Method A predetermined amount of a fine inorganic ammonium salt and a surfactant such as antimony trioxide are suspended and dispersed in an organic solvent. 6 to 301 parts per 100 parts of inorganic mixed powder in the organic solvent.
Incyanate and polyol are dissolved so that the amount of the urethane resin is equal to the amount of the urethane resin. Next, the suspension is dried and cured using a conventional spray drying apparatus while stirring to obtain the desired coating.

(B) In 5 in situ polymerization method Fine inorganic ammonium salt and antimony trioxide measured at a predetermined ratio are suspended in polyol in which a surfactant has been dissolved in advance, and the surfaces of the inorganic particles are sufficiently wetted. The suspension is subjected to solid-liquid separation by standing still or by centrifugation. The powder coated with polyol is added little by little to a large amount of stirred isocyanate.

The liquid temperature may be increased in order to accelerate the mixing rate. 1~
Continue stirring for 10 hours. The resulting fine particle precipitate is then separated, and the precipitate is washed with an organic solvent such as ethyl acetate. The obtained precipitated powder is dried at 30 to 100°C to obtain the desired coating. In this method, the size of the coating depends on the size of the internal inorganic powder and the stirring speed of the isocyanate.

In the above operations (A) and (B), the polyurethane obtained by polymerizing the polyol and isocyanate with respect to 100 parts by weight of the inorganic ammonium salt and antimony-based flame retardant aid is 3 to 50 parts by weight. part is preferred. The greater the amount of polyurethane, the more complete the coating will be, but this is not preferred because the flame retardancy will be poorer. In addition, it is a preferable method to not only perform each of the above operations (A) and (B) once, but also to perform the same operation several times on the obtained coating to complete the film formation. A combination with the operation is also possible.

The flame retardant of the present invention includes unsaturated polyester, Evoresin, total polyethylene, polypropylene, polystyrene,
Polyvinyl acetate, polyacrylate, nylon, polymethacrylate, polyacrylonitrile, polycarbonate, polyurethane, polyvinyl chloride, thermosoluble polyester, diene thread plastic, phenolic resin, and mixtures of two, three or more of these resins, and Extremely effective as a flame retardant for resins such as copolymers.

The flame retardant resin composition according to the present invention contains the above-mentioned resins, the flame retardant of the present invention, and, if necessary, a heat stabilizer.

It is obtained by blending antioxidants, pigments, lubricants, mold release agents, etc. The amount of the flame retardant of the present invention to be used in the resin varies depending on the type of resin and the degree of flame retardancy required, but is usually 5 to MC1i parts, preferably 10 to 50 parts by weight, per 100 parts of the resin. It is.

Although the use of large amounts of flame retardants is particularly desirable for improving the level of flame retardancy, it often impairs the physical properties of the resin.

The flame-retardant resin composition of the present invention is usually used as a molded article for electrical parts, furniture, building materials, parts for transportation materials, and other uses. In the case of compression molding, transfer molding,
Injection molding, laminated molding.

In the case of thermoplastic resins, extrusion molding, calendar molding, injection molding, etc. are used, and depending on the properties of the resin and the form of the molded product,
You can freely choose the molding method.

The thus obtained molded article shows no migration or embossment of the flame retardant of the present invention on its surface, and no yellowing due to thermal deterioration of the polyurethane coating material. In addition, even if the molded product is left standing in air with 90% humidity, not only does the precipitation phenomenon of inorganic ammonium salts on the surface of the molded product or the acetation phenomenon on the surface not occur, but the molded product does not appear when exposed to water at room temperature. Since the water absorption rate when immersed is very small at α1% or less, there is no problem with water resistance in practical use. According to an electron microscope observation of a cut surface of a molded article containing the flame retardant of the present invention, the dispersibility of the flame retardant is extremely good.

The impact strength of the molded article is excellent. It has extremely high flame retardancy and, unlike organic halogen flame retardants, generates almost no hydrogen halide gas during combustion, and also generates little smoke.

〔Example〕

Details will be shown below with examples, and parts in the examples and comparative examples indicate parts by weight. The various test methods carried out in the Examples and Comparative Examples are as follows.

- Surface condition after molding Immediately after molding, the presence or absence of yellowing due to thermal deterioration of the coating material (urethane) and surfactant, and the presence or absence of 7 leads of flame retardant after 48 hours were visually evaluated.

·water resistance This was evaluated using (A) and (B) below.

(A) After standing for 48 hours at 90% RH and 23° C. RT, the presence or absence of efflorescence or ashes was visually evaluated.

(B) Water absorption rate Measured as follows according to ASTM-D-570. Five specimens 2+ inches long, 10 inches wide, and 10 inches thick
Dry for 24 hours in an open oven at 0°C, leave to cool in a desiccator at 23°C for 3 hours, and then weigh (a) 6 test pieces? 23℃
After immersing the test piece in pure water for 168 hours, the water droplets on the test piece are wiped off with a dry cloth and immediately weighed (b). This test was performed on three test pieces to determine the water absorption rate.

Average values are shown in the table.

(a) - Oxygen index fL according to Flame Retardant J Engineering S K 7201-1972
o engineering) was determined individually.

・Impact resistance Measured according to J Engineering SK 7110-1977.

- The cut surface of the dispersible molded product was visually observed using an electron microscope, and the presence or absence of coarse aggregates was used to determine whether the dispersibility was good or bad.

Production Example 1 The surfactant Emulgen 810 (polyoxyethylene octylphenyl ether) α49 manufactured by Kao Sekiken ■ is dissolved in 150 ml of reagent grade methylene dichloride. Next, the average particle size is 10 microns (maximum particle size is 40 microns)
After powder-blending 40 g of ammonium chloride fine particles and antimony trioxide (Atox S: average particle size 1 to 2 microns) 49 manufactured by Nihon Seiko Co., Ltd., the mixture was dispersed in the methylene dichloride solution. While stirring the suspension, add 15 g of incyanate Furonate C-2030 + manufactured by Nippon Polyurethane Aji Co., Ltd.), then add 2.29 g of Niboran N-125 (manufactured by Nippon Polyurethane Co., Ltd.) as a polyol.
Add and dissolve. Incidentally, the amount of urethane obtained from the incyanate and polyester is 4.09. The thus obtained suspension was spray-dried in a uniform suspended state while stirring to obtain a urethane-coated ammonium chloride flame retardant powder. The spray dryer used was Pulvis Mini Spray manufactured by Yamato Scientific Co., Ltd. The equipment conditions were: inlet temperature 70°C;
Suction pressure gauge scale 5. Spray gas pressure 1 to 9/cITt
, the sample liquid feeding amount gauge scale was 5-0. The obtained fine powder was placed in an oven at 80°C for curing of the urethane.
It was left still for 5 hours. No agglomeration of powders was observed in the fine powder after curing, and Seishin Enterprise ■ WS
When the particle size was measured using a K laser micron sizer, the maximum particle size was 45 microns, and the average particle size was 12 microns.
It was a micron.

Production Example 2 Urethane encapsulated fine powder was obtained using the same recipe and method as Production Example 1, except that ammonium bromide with a maximum particle size of 53 microns and an average particle diameter of 12 microns was used instead of ammonium chloride in Production Example 1. Ta. The particle size was found to be 37 microns in maximum particle size and 15 microns in average particle size using the same method as in Production Example 1.

Production Example 3 Urethane-encapsulated ammonium chloride fine powder was obtained by following the same formulation procedure as Production Example 1 except that antimony trioxide was not used. The particle size distribution was the same as the powder of Production Example 1.

Example 1 The fine powder 309 obtained in Production Example 1 was kneaded with 100 mm of polypropylene (-7014, manufactured by Chichi Kagaku Co., Ltd.) using a roll. Roll kneading conditions are temperature 170°C, kneading time 1
It was 0 minutes. The obtained kneaded material was pressed to 150
A sheet of X 150 X 3 (, u) was produced.

Pressing conditions are: preheating = 200°C x 7 minutes, pressure = 20°0
°C x 6 minutes x 100kg/ctd, cooling: water temperature x 3 minutes x 1
0 (B9/crd.This C)k was used to conduct various tests shown in Table 1.

The results are shown in Table 1.

Example 2 The physical properties were measured using the same recipe 1 procedure as in Example 1 except that the fine powder obtained in Production Example 2 was used.

Example 3 Powder 209 of Production Example 1 was kneaded into polystyrene 1009 (Diaflex HT-91, manufactured by Mitsubishi Monsando Kasei Corporation). Kneading was performed at 200° C. for 15 minutes using a small kneader. 150×15 by pressing in the same manner as in Example 1.
0X3. It was molded into the shape of W. The measured physical property values are listed in Table 1.

Example 4 20g of the fine powder obtained in Production Example 1 was mixed with 1009 PBT (
It was blended into PBT1401) manufactured by Toshisha.

The blending method is to powder blend the two powders,
A test plate of 150×150×31+u) was prepared by an injection method using an extrusion unit of 30 Uφ. The measured physical property values are listed in Table 1.

Comparative Example 1 All examples were the same except that a tri-blended mixed powder of 27.09 fine powder of yam and 109 antimony trioxide (Atox 5) used in Production Example 1 was used instead of fine powder 309 of Example 1. Prescription similar to 1.

It was blended into polypropylene according to the procedure and tested. Bleeding, efflorescence, and acetic phenomena were observed on the surface of the test piece, and the dispersibility was completely poor.

Comparative Example 2 Mixed powder sag obtained by tri-blending the fine powder 279 obtained in Production Example 3 and 3 g of antimony trioxide (Atox S)
Example 1 except that the powder of Example 1 was replaced with
It was blended into polypropylene using the same recipe 9 procedure and its physical properties were measured. The flame retardance was particularly poor compared to Example 1.

Comparative Example 3 Unsaturated polyester resin 1259 (product name: Borac G
Ammonium chloride 4009 and antimony trioxide (manufactured by Nippon Seiko Co., Ltd., ATOX 5) ground to an average particle size of 10 μm in a mixed solution of -155AL, Nippon Shokubai Kagaku ■), hendiyl peroxide paste 12.59, and benzene 125
409 was added and dispersed using a kneader (manufactured by Moriyama Seisakusho), while benzene was removed under reduced pressure. The resulting paste-like mixture was spread thinly on a Teflon plate and placed in an oven at 150°C to cure for 30 minutes. The obtained film was pulverized to a particle size of 50 mesh or less using an ultracentrifugal pulverizer (manufactured by Mitamura Riken Kogyo ■). Except that this powder 309 was used instead of the fine powder of Example 1, it was blended with polypropylene in the same formulation 1 procedure as in Example 1, and the physical properties were measured. All physical properties were inferior to those of Example 1.2.

Comparative Example 4 Ammonium chloride 1 finely ground to under 50 microns
009 and antimony trioxide (Atox 5) 109 were placed in a Nigu with a heating device, and while stirring, 1,1,1-trichloroethane in which methylhydropolysiloxane 2.09 and dibutyltin dioctoate) [12] were dissolved in advance. Add the solution little by little and mix thoroughly. Next, the temperature is increased to remove the solvent. Powder temperature 150~1
The mixture was heated to 55° C. and stirred for 6 hours, followed by sufficient hardening reaction, and then cooled to room temperature to obtain a fine powder. This fine powder 30
The mixture was blended into polypropylene in the same manner as in Example 1 except that the powder was used in place of the fine powder in Example 1, and the physical properties were measured. Dispersibility compared to Example 1.2.

It had poor water resistance and low flame retardancy.

Comparative Example 5 A brominated organic flame retardant, decabromodiphenyl ether (manufactured by Toyo Genji Kogyo Co., Ltd., BR-100), 25 days of antimony trioxide (Atox S), and 5 days of antimony trioxide (Atox S) were used in place of the fine powder of Example 1. All other ingredients were blended into polypropylene according to the recipe 1 procedure of Example 1, and the physical properties were measured.

Compared to Example 2, bleeding was particularly observed and the surface condition was poor.

Claims (4)

[Claims] (1) A flame retardant for synthetic resins, which is a powder obtained by coating a mixture of an inorganic ammonium salt and an antimony-based flame retardant aid with a urethane resin, the coated powder having a maximum particle size of 50 microns or less. . (2) The flame retardant for synthetic resins according to claim 1, wherein the inorganic ammonium salt is ammonium chloride, ammonium bromide, or ammonium sulfate. (3) The flame retardant for synthetic resins according to claim 1, wherein the antimony-based flame retardant aid is antimony trioxide. (4) The flame retardant for synthetic resins according to claim 1, wherein the mixture is a mixture of 100 parts by weight of an inorganic ammonium salt and 1 to 30 parts by weight of an antimony-based retardant.