JPH0913037A - Capsuled flame retardant composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water-insol. granular flame retardant which exhibits an excellent flame retardant at a low loading without detriment to base material by capsuling a water-sol. component contg. a flame retardant with a coating agent. SOLUTION: A water-insol. granular flame retardant is obtd. by capsuling a water-sol. component contg. a flame retardant with a coating agent. Examples of the flame retardant are an inorg. acid, an ammonium salt, a guanidine salt, and a metal salt; pref. examples are sulfamic acid, sulfuric acid, boric acid, ammonium sulfamate, ammonium sulfate, and ammonium phosphate. The coating agent is pref. based on a polyamide resin, a methacrylic resin, a styrene- methacrylic resin, a styrene resin, or an acrylic resin. Thus, a water-insol. granular flame retardant is obtd. by coating a composition imparting retardancy with a coating agent by a chemical or physicochemical method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-insoluble particulate flame retardant encapsulated by a coating agent and a moisture resistant flame retardant base material containing the same.

[0002]

2. Description of the Related Art Today, cellulosic materials and synthetic resin materials are used for various purposes, but when used in interiors for construction, etc. It is important for fire prevention. In recent years, the required level of flame retardancy is increasing, and a base material with higher flame retardancy is required. However, flame retardancy of these materials imparts heat resistance and flame resistance, and at the same time, does not adversely affect other physical properties, that is, increase in hygroscopicity, decrease in strength, discoloration, etc. do not occur. There was a limited number of flame retardants that were necessary and met the conditions.

For example, as flame retardants for cellulosic materials such as wood, papers, wood boards, etc., Japanese Patent Publication Nos. 25,448, 56,42584, 58,29,344, etc. include guanidine sulfamic acid, dicyandiamide, dicyandiamide. A combination of the above-mentioned methylol compounds and the like is disclosed.

However, although these flame retardants have a relatively small decrease in strength and discoloration of the cellulose base material, it is necessary to maintain about 20% of the weight of the base material in order to impart sufficient flame retardancy. However, at this holding amount, not only the strength of the base material is deteriorated and the discoloration becomes remarkable, but also there is a disadvantage that it becomes sticky due to moisture absorption. In addition, depending on the application, stronger flame retardancy is required.
%, It was difficult to use for high flame retardancy.

Therefore, in JP-A-58-109577 and JP-A-6-172615, attempts have been made to increase the flame retardancy with a small amount of the flame retardant by using a combination of a highly flame-retardant ammonium sulfate and a modifier. . However, although these water-soluble flame-retardant materials impart excellent flame retardancy to the cellulosic base material, improvement of paper strength reduction and heat resistance reduction is insufficient,
Since it was particularly susceptible to humidity, it became sticky after processing and white powder was produced. In addition, its use has been limited because of problems such as irritation to the skin during work. Further, in the so-called internal addition method in which a flame retardant material is added to the material at the time of papermaking to make it a flame retardant material, it was practically difficult to keep the necessary amount of the water soluble flame retardant on the substrate.

On the other hand, JP-A-55-118988 discloses that
Disclosed are fine-particle flame retardants obtained by microencapsulating a chlorine-based flame retardant, a bromine-based flame retardant, and a phosphoric acid-based flame retardant with a resin for various plastics for building materials and interiors. These flame-retardant fine particles are not only insufficient in flame-retardant performance for cellulosic substrate applications, for example, when used for paper,
Particles of about several hundreds of μm were mixed in to cause “bugs” on touch, and the generation of halogen gas during combustion could not be suppressed. Even if the water-soluble flame retardant described above is produced by this method, the flame retardant is not incorporated into the particles because the flame retardant substance is not encapsulated in the water, and thus the produced particles have flame retardance. I didn't have it.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art, and it has excellent flame retardancy in a small amount without adversely affecting the substrate. It is intended to provide a particulate flame retardant.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted extensive research in order to solve the above-mentioned problems, and a water-insoluble particulate flame retardant in which a water-soluble component containing a substance imparting flame retardancy is encapsulated by a coating agent. Was completed.

Hereinafter, the present invention will be described in detail. In the present invention, the substance imparting flame retardancy is not particularly limited, but for example, inorganic acids such as phosphoric acid, condensed phosphoric acid, sulfamic acid, sulfuric acid, boric acid, such as ammonium phosphate, ammonium polyphosphate, ammonium sulfamate. Ammonium salts such as ammonium sulfate, ammonium borate, ammonium silicate, ammonium bromide and ammonium chloride, for example, guanidine sulfamate, guanidine methylolsulfamate, guanidine sulfate, 2-guanidine phosphate, 1-guanidine phosphate, methylol guanidine phosphate, guanidine phosphate ester, Phosphate ester dimethylolguanidine, guanidine hydrobromide, guanidine tetrabromphthalate, guanidine hydrochloride, guanidine methylol hydrochloride, guanidine borate, guanidine tetraborate, etc. Guanidine salts such as borax, water glass, stannate soda, metal salts such as tungsten sodium and the like.

As the above-mentioned substance imparting flame retardancy, since a harmful halide is not generated during combustion, a halogen-free inorganic acid, a halogen-free ammonium salt,
Halogen-free guanidine salts and halogen-free metal salts are preferable, and sulfamic acid, sulfuric acid, boric acid, phosphoric acid and ammonium sulfamate, ammonium sulfate, ammonium phosphate, etc., which show more remarkable flame retardancy in a small amount, are further preferable. preferable. When using the above-mentioned substance imparting flame retardancy, one kind or two or more kinds can be used at the same time.

In the present invention, the term "water-soluble" means that it is slightly soluble in water. Such components have disadvantages such as reduced moisture resistance and discoloration / deterioration of the substrate due to leaching of the component due to moisture absorption, making it difficult to use in large amounts on the substrate. It is extremely difficult to hold a large amount of it.

The above-mentioned component imparting flame retardancy is a chemical method,
For example, it can be produced by coating with a coating agent by an interfacial polymerization method, an in situ polymerization method or the like or a physicochemical method such as a coacervation method, an in-liquid drying method, a melt dispersion cooling method and the like. The coating may be carried out by a mechanical method, for example, an air suspension coating method, a spray drying method, a high-speed air current impact method, etc., but in order to reliably form particles, an interfacial polymerization method,
The in situ polymerization method is preferred.

The component of the resin constituting the above coating agent is not particularly limited, and examples thereof include polystyrene resin, polymethacrylic resin, polystyrene-methacrylic resin, polyolefin resin, polyamide resin, Thermoplastic resin such as polycarbonate resin, polyether resin, polysulfone resin, polyester resin, epoxy resin, butadiene resin, or thermosetting resin such as melamine resin, urea resin, urethane resin, urea resin, epoxy resin Resins, and further, copolymers, block polymers, graft copolymers, polymer blends and the like of these can be used, but in the case of coating by the interfacial polymerization method, a polyamide resin, a methacrylic resin, styrene Preference is given to methacrylic resin, styrene resin, acrylic resin Used properly.

In the case of coating by any method, if the polymer itself is water-soluble, it is necessary to make it water-insoluble by means such as crosslinking. A known technique can be used as a means for insolubilizing the water-soluble polymer, and a melamine compound, an isocyanate compound, an epoxy compound, a polyvalent metal salt, and the like are allowed to coexist to form a crosslinked structure according to the crosslinking conditions of each crosslinking agent. You can

The resin constituting the above coating agent can be appropriately selected according to the base material to which the water-insoluble particulate flame retardant to be produced is added. The compounding ratio of the substance that imparts flame retardancy to the resin that constitutes the coating agent is 10% by weight or more, preferably 40% by weight or more for the substance that imparts flame retardancy, and 90% by weight for the component that constitutes the coating agent. % Or less, preferably 60% by weight or less.

The water-insoluble particulate flame retardant of the present invention can have various average particle sizes, if desired.
From the viewpoint of flame retardancy and touch, it is preferably 0.05 to
The thickness is 60 μm, more preferably 0.1 to 30 μm, still more preferably 0.3 to 15 μm. If it is less than 0.05 μm, a coating film having sufficient strength cannot be obtained, and if it exceeds 60 μm, it cannot be uniformly dispersed in a substrate such as cellulose, so that it feels rough and has poor flame retardancy. .

The water-insoluble particulate flame retardant of the present invention may be, for example, a surfactant, a rust preventive, and a pH adjuster, in addition to the above-described water-soluble flame retardant-imparting substance having the main components and the coating agent. , Other additives such as moisture absorption inhibitors can be included. The amount of these additives used may be any amount that does not adversely affect the flame retardancy and other desirable properties of the water-insoluble particulate flame retardant.

The water-insoluble particulate flame retardant of the present invention can be obtained in powder form by recovering the dispersion, centrifuging and drying. Further, this powder can be used by redispersing it in water or another dispersion medium.

In the present invention, the water-insoluble particulate flame retardant may be blended with or applied to a cellulose base material such as papers and cloths and various synthetic resins to obtain the above-mentioned moisture resistant flame retardant base material. it can. Examples of the papers include wallpaper, fusuma paper, shoji paper, cone paper and the like. These are so-called “so-called“ paper-dried, paper-coated, or sprayed with the water-insoluble particulate flame retardant emulsion after papermaking as in the conventional case. The above flame-retardant base material can be made by the "external addition method", but when the paper is made, the above water-insoluble particulate flame retardant is added together with a filler, an internally added sizing agent, etc. Law "
Therefore, it is possible to rationalize the processing process by one-step processing. At this time, the substance imparting flame retardancy is preferably sulfamic acid, sulfuric acid, phosphoric acid and ammonium salts thereof, and the particle diameter of the water-insoluble particulate flame retardant is 0.3 to 15 μm.
m are particularly preferred.

In the case of the external addition method, it is preferable to hold about 3 to 50 parts by weight, preferably 5 to 40 parts by weight of the water-insoluble particulate flame retardant in 100 parts of the paper when using the internal addition method. In this case, it is preferable to use 5 to 50 parts by weight, preferably 10 to 40 parts by weight in terms of flame retardancy-providing component.

Examples of cloths include curtains, felts, blackout curtains, carpets, construction sheets, clothes, non-woven fabrics, filters, felts, and the like, which are the same as the conventional ones, with the above water-insoluble particulate flame retardant and binder. The above-mentioned flame-retardant base material can be prepared by dispersing other fiber processing aids in an aqueous medium, if necessary, and then using a means such as dipping, coating or spraying. At this time, the substance imparting flame retardancy is preferably sulfamic acid, sulfuric acid, phosphoric acid and ammonium salts thereof, and the water-insoluble particulate flame retardant having an average particle diameter of 0.3 to 3 μm is particularly preferable. When used, the water-insoluble particulate flame retardant is used in an amount of about 3 to 50 parts by weight, preferably 5 to 40 parts by weight, based on 100 parts of the cloth.
Good to use.

The above-mentioned base material can be suitably used as a JIS flame-retardant secondary material, especially paper such as wallpaper, fusuma paper, shoji paper or the like, or cloth such as non-woven fabric, felt or curtain.

[0023]

EXAMPLES The water-insoluble particulate flame retardant and the moisture-resistant flame-retardant base material of the present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

* Test Method 1 (External Addition Method) Flame retardant particles were adjusted to a dispersion having a solid content concentration of about 10% to prepare a flame retardant treatment liquid, and the treatment liquid had a basis weight of 60 to 6
A 5 g / m 2 paper was impregnated by a size press method so that the drawing ratio was 100%, and dried with a drum type dryer whose humidity was adjusted to 105 ° C. to obtain a flame-retardant processed paper. The flame-retardant evaluation of (1) was performed on this flame-retardant processed paper. Flame retardant
If it does not fall within the range of 6.3 cm to 6.5 cm, the solid content concentration is increased / decreased in units of about 1%, the flame-retardant processed paper is adjusted again by the above-mentioned operation, and the flame-retardant evaluation is repeated to make it difficult. The flame-retardant processed paper having a flammability of 6.3 cm to 6.6 cm was evaluated for performance by the methods (2) to (5).

* Test method 2 (internal addition method) 100 parts of absolutely dried NBKP was disaggregated and dispersed in water, and 25 parts of a flame retardant was added thereto to prepare a slurry, and a highly polymerized acrylic water-soluble resin as a coagulant. (“Phirex RC104” manufactured by Meisei Chemical Industry Co., Ltd.) was added to each of the above-mentioned slurries by 0.2%, and then paper was made with a normal square hand-making machine. This was dried with a drum type dryer whose humidity was adjusted to 105 ° C. to obtain a flame-retardant processed paper. The flame-retardant evaluation of (1) was performed on this flame-retardant processed paper. Flame retardant
Approximately 1% if it does not fall within the range of 6.3 cm to 6.5 cm
Repeatedly increasing and decreasing the slurry concentration in units and adjusting the flame-retardant processed paper again by the above operation, and performing flame retardancy evaluation,
The flame-retardant processed paper having a flame retardancy of 6.3 cm to 6.6 cm was evaluated for performance by the following methods (2) to (5). When the flame retardancy did not increase even if the slurry concentration was increased, it was evaluated as "combustion".

* Physical property measurement method (1) Flame retardance A sample was burned to measure the carbonization length according to JIS A 1322 "Test method for flame retardancy of thin building materials" (45 ° Meckel burner method). (2) Tear strength After heat-treating the sample in an oven at 200 ° C for 3 minutes, immediately according to JIS8116 "Paper tear strength test method",
It was measured by an Elmendorf tear strength tester. (3) Anti-coloring property The samples were heated in an oven at 200 ° C for 5 minutes to compare the degree of coloring. 5: Light yellow 4: Light yellow 3: Yellow 2: Light brown 1: Brown (4) Hygroscopicity The sample was left to stand at 40 ° C and 95% humidity for 24 hours, and then JIS
The water content was measured in accordance with P.8127 "Method for testing water content of paper and paperboard". (5) Surface condition The surface condition of the flame-retardant processed paper was evaluated by touching the surface.

Example 1 1.6 Hexamethylenediamine 11.6 parts by weight, sodium hydroxide 8.0 parts by weight, sodium lauryl sulfate 1.
0 parts by weight and 100.0 parts by weight of ammonium sulfamate dissolved in 100 parts by weight of water were dissolved in chloroform.
A solution in which 7.5 parts by weight of sorbitan monooleate was dissolved in 42.5 parts by weight of a mixed solution of cyclohexane (1: 4) was gradually added dropwise with stirring to prepare a w / o type emulsion.
The average particle size of the droplets at this time was about 5 μm. A solution prepared by dissolving 18.3 parts by weight of adipic acid chloride in 100 parts by weight of chloroform was gradually added dropwise to this emulsion with vigorous stirring to form a polyamide bond at the interface between the droplet and the solvent. I got a burning agent. The average particle size of the obtained microcapsules was 8 μm. The results of the test using this microcapsule are shown in Table-1 and Table-2.

Comparative Example 1 Ammonium sulfamate crystal (manufactured by Wako Pure Chemical Industries, Ltd.)
Was pulverized with a ball mill to an average particle size of about 10 μm, and the test results are shown in Table-1 and Table-2.

Example 2 Water-insoluble particulate flame retardant particles were produced by the same method as in Example 1 except that guanidine sulfamate was used instead of ammonium sulfamate in Example 1, and the average particle size of the microcapsules was It was 9 μm.
The results of the test using this microcapsule are shown in Table-1,
It is shown in Table-2.

Comparative Example 2 Guanidine sulfamate crystals (manufactured by Wako Pure Chemical Industries, Ltd.) were crushed with a ball mill to an average particle size of about 10 μm, and the test results are shown in Tables 1 and 2.

Example 3 Water-insoluble particulate flame retardant particles were prepared in the same manner as in Example 1 except that ammonium sulfate was used instead of ammonium sulfamate. The average particle size of the microcapsules was 8 μm. there were. The results of the test using this microcapsule are shown in Table-1 and Table-2.

Comparative Example 3 Ammonium sulfate crystals (manufactured by Wako Pure Chemical Industries, Ltd.) were crushed with a ball mill to an average particle size of about 10 μm, and the test results are shown in the table.
1, shown in Table-2.

Example 4 2 parts by weight of sorbitan monooleate was dissolved in 100 parts by weight of 50% by weight ammonium sulfamate aqueous solution, and 10% by weight of adipic acid chloride / chloroform solution 50 was added thereto.
The weight part was gradually added dropwise with stirring to prepare a w / o type emulsion. To this, 2 parts by weight of polyoxyethylene sorbitan monooleate was added, and 50 parts by weight of a 10% by weight 1.6 hexamethylenediamine aqueous solution was gradually added dropwise with stirring w /
An o / w type three-layer emulsion was obtained. To this three-layer emulsion, 50 parts by weight of a 10 wt% sodium hydroxide aqueous solution was added dropwise to initiate an amidation reaction to obtain microcapsules containing a sulfamic acid aqueous solution. The obtained microcapsules were dried in a hot air dryer at 60 ° C. to obtain the desired water-insoluble particulate flame retardant. The average particle size of the obtained microcapsules was 5 μm. The results of the test using this microcapsule are shown in Table-1 and Table-2.

Example 5 1.5 parts by weight of 1% by weight polyethylene glycol aqueous solution,
0.046% by weight 1.6 hexamethylenediamine aqueous solution 1.5 parts by weight, 0.047% by weight ammonium phosphate aqueous solution 1.5 parts by weight Sorbitan monooleate 1.5 parts by weight, n-hexane 10 with stirring in a mixed aqueous solution. .8 parts by weight,
A mixed solution of 2.7 parts by weight of chloroform was added dropwise to obtain a w / o type emulsion. Further, a chloroform / n-hexane (1: 4) solution of adipic acid dichloride adjusted to have a solid content of 4% was gradually added dropwise to this emulsion with stirring to obtain microcapsules having a particle diameter of 8 μm. The results of the test using this microcapsule are shown in Table-1 and Table-2.

Example 6 A solution prepared by dissolving 80 parts by weight of sulfamic acid in 320 parts by weight of water was charged into a 2 l separable flask and nitrogen was blown thereinto to replace air. This was heated to 80 ° C., a mixed monomer of 40 parts by weight of diethylaminoethyl methacrylate and 40 parts by weight of styrene was added all at once, and the mixture was kept at 80 ° C. for 60 minutes to suspend it. Thereafter, an 8 wt% ammonium persulfate aqueous solution was added to start the polymerization reaction. After 5 minutes, an aqueous 8 wt% ammonium persulfate solution was added dropwise over 60 minutes. After the completion of the addition, the mixture was aged for 120 minutes at 80 ° C. to obtain an emulsion containing sulfamic acid in the particles. The obtained emulsion had a particle size of 0.5 μm, a solid content of 33%, and a viscosity of 50 cPs. The results of the test using this microcapsule are shown in Table-1 and Table-2.

Reference Example 1 30 parts by weight of methyl methacrylate, 30 parts by weight of butyl acrylate and 40 parts by weight of acrylic acid were charged into a separable flask equipped with a reflux condenser, and the monomer concentration was 40% by weight.
Was added so that To this solution, 0.5 part by weight of azobisisobutyronitrile as a polymerization initiator was added, heated to a temperature above the boiling point of methanol, and after 30 minutes, 1 part by weight dissolved in a monomer solution of the same composition was added dropwise over 2 hours. After completion of the dropping, the methanol solution was dropped over 1 hour and aged for 1 hour to complete the polymerization reaction. The resulting polymer solution had a solid content of 25% and a viscosity of 3,000 cP. The results of the test using this microcapsule are shown in Table-1 and Table-2.

Example 7 To 100 parts by weight of a solution prepared by adjusting the solid content of the polymer of Reference Example 1 to 5% by weight with methanol, 5 parts by weight of guanidine sulfamate microcrystal (purified by recrystallization method) was added and an ultrasonic disperser was used. And dispersed. N-hexane 10 was added to this dispersion.
0 parts by weight of the polymer was gradually added dropwise under vigorous stirring to precipitate the polymer around the guanidine sulfamate crystals to obtain water-soluble microcapsules. To further crosslink the polymer, 10 parts by weight of a 5% by weight aluminum chloride solution in methanol was added, and stirring was continued at room temperature for 1 hour. The obtained microcapsules were filtered, washed with methanol and dried under reduced pressure to obtain the desired water-insoluble particulate flame retardant. The average particle size of the obtained microcapsules was 8 μm. The results of the test using this microcapsule are shown in Table-1 and Table-2.

Example 8 A separable flask equipped with a reflux condenser was charged with 100 parts by weight of n-heptane and 40 parts by weight of ammonium sulfate crystals and heated to 80 ° C. on a warm bath to start reflux.
Here, 2.4 parts by weight of ethyl acrylate, 7.6 parts by weight of methyl methacrylate, 1.0 part by weight of 1.6-hexanediol dimethacrylate, and a polymerization initiator of tertiary butyl peroxy (2-ethylhexanoate) 0 .0
5 parts by weight of 50 parts by weight of n-heptane was added dropwise over 30 minutes, and the mixture was aged for 5 hours while maintaining the reflux state to precipitate a polymer on the surface of ammonium sulfate microcrystals, which was cooled, filtered under reduced pressure and dried under reduced pressure. A target water-insoluble particulate flame retardant was obtained. The particle size of the obtained microcapsules was 8 μm. The results of the test using this microcapsule are shown in Table-1 and Table-2.

Example 9 Reference Example 1 in which 10 parts by weight of fine crystals of ammonium sulfamate purified by the recrystallization method were adjusted to a solid content of 5% by weight.
Was ultrasonically dispersed in 100 parts by weight of the polymer, and 1 part by weight of a cross-linking agent glycerol polyglycidyl ether was added thereto to obtain a water-insoluble particulate flame retardant having an average particle diameter of 20 μm by using a spray dryer. The results of the test using this microcapsule are shown in Table-1 and Table-2.

Comparative Example 4 Microcapsules having a particle size of 20 μm were obtained in the same manner as in Example 9 except that the crosslinking agent was not used.

[0041]

[Table-1]

[0042]

[Table-2]

[Table 1]

[Table 2]

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Claims (5)

[Claims] 1. A water-insoluble particulate flame retardant in which a water-soluble component containing a substance imparting flame retardancy is encapsulated by a coating agent. 2. The water-insoluble substance according to claim 1, wherein the substance imparting flame retardancy is one or more substances selected from the group consisting of inorganic acids, ammonium salts, guanidine salts and metal salts. Particulate flame retardant. 3. The substance imparting flame retardancy is one or more substances selected from sulfamic acid, sulfuric acid, boric acid, phosphoric acid and ammonium salts thereof.
The water-insoluble particulate flame retardant described. 4. The water-insoluble particulate flame retardant according to any one of claims 1 to 3, wherein the coating material is a polyamide resin, an acrylic resin or a polystyrene resin. 5. A moisture-resistant flame-retardant substrate containing the water-insoluble particulate flame retardant according to any one of claims 1 to 4.