JP2005133027A - Composition for forming flame-retardant polyurethane resin of cutting-workability, and flame-retardant resin molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyurethane resin molded article which gives the smooth cut-surface after the cutting thereof and which is excellent in the flame retardancy. <P>SOLUTION: The composition for forming a flame-retardant polyurethane resin of cutting-workability, which comprises an active hydrogen compound (A) and an organic polyisocyanate (B), is characterized by containing 2-20 % by mass of an inorganic acid melamine salt (C), and 0.8-40 % by mass in total of talc (D) and zeolite (E), with a ratio of (D) to the sum total of (D) and (E) being 10-90 % by mass; and the polyurethane resin molded article is obtained therefrom. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a flame-retardant polyurethane resin-forming composition for cutting, and a flame-retardant resin molded product obtained by curing and molding the composition. More specifically, the present invention relates to a resin molded product suitable for manufacturing models and building materials.

Conventionally, as a flame-retardant resin molded product, a resin molded product in which a synthetic resin such as a urethane resin is added with a composition composed of an expanding agent system including a foaming agent, a carbonizing agent, and a dehydrating agent and zeolite (patent document) 1) etc.
Japanese Patent Laid-Open No. 7-62142

  However, the flame retardant urethane resin described in Patent Document 1 has a problem that the surface after cutting is rough, and the coated surface does not become clean due to poor smoothness of the cut surface when coated on a molded product after cutting. Have.

The inventors of the present invention have arrived at the present invention as a result of intensive studies to obtain a polyurethane resin molded product having a smooth cut surface after cutting the molded product and excellent in flame retardancy.
That is, the present invention relates to a polyurethane resin-forming composition comprising an active hydrogen compound (A) and an organic polyisocyanate (B), wherein the inorganic acid melamine salt (C) is contained in an amount of 2 to 20% by mass, talc (D) and zeolite (E ) In a total of 0.8 to 40% by mass, and the ratio of (D) is 10 to 90% by mass with respect to the total of (D) and (E) A polyurethane resin-forming composition; a flame-retardant polyurethane resin molded product obtained by curing and molding the above composition; and a model or building material obtained by cutting the molded product.

  The polyurethane resin molded product of the present invention has an effect that the cut surface after cutting of the molded product is smooth and sufficient flame retardancy is obtained, and is useful as a model or building material obtained by cutting.

The active hydrogen compound (A) used in the present invention is a compound having 2 to 10 or more active hydrogen-containing groups. Examples of the active hydrogen-containing group include one or more groups selected from a hydroxyl group, a mercapto group, a primary and secondary amino group, a carboxyl group, and the like. In these, a hydroxyl group and a mercapto group, especially a hydroxyl group are preferable.
Specific examples include polyether polyols, polyester polyols, polybutadiene polyols, polyacrylic polyols, and polymer polyols obtained by polymerizing ethylenically unsaturated monomers in these polyols.

  Examples of the polyether polyol include low molecular active hydrogen-containing compounds having a molecular weight of 400 or less, such as the following (i) to (iv), alkylene oxide having 2 to 8 carbon atoms, such as ethylene oxide (hereinafter abbreviated as EO), propylene oxide. (Hereinafter abbreviated as PO), 1,2-butylene oxide (hereinafter abbreviated as BO), 2,3-BO, 1,4-BO, 2,4-BO, and styrene oxide are added alone, or 2 of these The polyol which added the seed | species or more at random or block shape is mentioned.

Examples of low molecular active hydrogen-containing compounds:
(I) Low molecular polyol (1) Dihydric alcohol having 2 to 20 carbon atoms (fats such as ethylene glycol, propylene glycol, 1,3- and 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, etc. Diols; cycloaliphatic diols such as cyclohexanediol and cyclohexanedimethanol)
(2) Trivalent alcohol having 3 to 20 carbon atoms (aliphatic triols such as glycerin, trimethylolpropane, trimethylolethane and hexanetriol; trialkanolamines such as triethanolamine; alicyclic triols such as cyclohexanetriol)
(3) 4 to 10 or more polyhydric alcohols having 5 to 20 carbon atoms (intramolecular of aliphatic polyols such as pentaerythritol, sorbitol, mannitol, sorbitan, diglycerin, dipentaerythritol and the like or aliphatic triol) Or intermolecular dehydrates; sugars such as sucrose, glucose, mannose, lactose, and methylglucoside and their derivatives).
(Ii) Polyvalent (2 to 10 or more) phenols Monocyclic phenols such as hydroquinone, resorcin, catechol, pyrogallol, phloroglucin; bisphenols such as bisphenol A, bisphenol B, bisphenol F, bisphenol S; Formaldehyde condensate (novolak), etc.

(Iii) Amines (1) Mono- and dialkanolamines having 2 to 20 carbon atoms (such as monoethanolamine, diethanolamine, and isopropanolamine)
(2) C2-C6 alkylenediamine (ethylenediamine, propylenediamine, hexamethylenediamine, etc.);
(3) Polyalkylene polyamine having 4 to 20 carbon atoms (dialkylene triamine to hexaalkylene heptamine having 2 to 6 carbon atoms in an alkylene group such as diethylenetriamine and triethylenetetramine)
(4) C6-C20 aromatic polyamine (phenylenediamine, tolylenediamine, xylylenediamine, diethyltoluenediamine, methylenedianiline, diphenyletherdiamine, etc.)
(5) C4-C20 alicyclic polyamine (isophoronediamine, cyclohexylenediamine, cyclohexylmethanediamine, etc.)
(6) C4-C20 heterocyclic amine (such as piperazine and aminoethylpiperazine)

(Iv) Polycarboxylic acid (1) Aliphatic polycarboxylic acid having 4 to 18 carbon atoms (such as succinic acid, adipic acid, sebacic acid, glutaric acid, and azelaic acid);
(2) C8-18 aromatic polycarboxylic acid (terephthalic acid, isophthalic acid, trimellitic acid, pyromellitic acid, etc.)

  As the polyester polyol, a condensed polyester polyol obtained by reacting the low molecular polyol with the polycarboxylic acid or an ester-forming derivative thereof [an acid anhydride and a lower alkyl (carbon number 1 to 4) ester, etc.]; ε- Examples include polyester polyols obtained by ring-opening polymerization of lactones having 6 to 10 carbon atoms such as caprolactone; polycarbonate diols obtained by addition polymerization of diols such as 1,6-hexanediol and ethylene carbonate.

  As the polybutadiene polyol, a (co) polymer [(butadiene / vinyl monomer (polymerization molar ratio) = 0.1 to 1) of a butadiene having a terminal hydroxyl group and other vinyl monomers such as styrene and acrylonitrile and the like. Examples of such hydrogenated products.

  Polyacryl polyols include vinyl monomers having a C2-C4 hydroxyalkyl group such as hydroxyethyl (meth) acrylate and other vinyl monomers [alkyl (meth) such as methyl (meth) acrylate and butyl (meth) acrylate). And acrylate; aromatic vinyl monomer such as styrene] and the like [hydroxyalkyl (meth) acrylate / vinyl monomer (polymerization molar ratio) = 0.05 to 0.5].

  Furthermore, as a polymer polyol obtained by polymerizing an ethylenically unsaturated monomer in these polyols, acrylonitrile is present in the presence of a radical polymerization initiator in at least one of the above exemplified polyols (preferably polyether polyols). And those obtained by polymerizing and stably dispersing a vinyl monomer such as styrene.

  As radical polymerization initiators, 2,2-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-methylbutyronitrile), 1 , 1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis (2,4,4-trimethylpentane), dimethyl 2,2′-azobis (2-methylpropionate), 2,2 Azo compounds such as' -azobis [2- (hydroxymethyl) propionitrile], 1,1'-azobis (1-acetoxy-1-phenylethane); dibenzoyl peroxide, dicumyl peroxide, bis (4- t-butyrocyclohexyl) organic peroxides such as peroxycarbonate, benzoyl peroxide, lauroyl peroxide, persuccinic acid; Sulfates, such as inorganic peroxides such as perborate can be used.

  Preferred as the active hydrogen compound (A) in the present invention is a polyether polyol, more preferably, a low molecular polyol as a low molecular active hydrogen-containing compound, a polyhydric phenol, or a PO adduct of an amine, and It is a co-adduct of EO and PO.

  Specific preferred examples of the above (A) include glycerin, trimethylolpropane, pentaerythritol, sorbitol, sucrose, bisphenol A, or a triethanolamine PO adduct.

In the present invention, as (A), together with the above-mentioned high molecular weight active hydrogen compound, a low molecular polyol itself [for example, (i) of the low molecular weight active hydrogen-containing compound having a molecular weight of 400 or less] is used in combination. [Preferably 0 to 30% in (A)].
In the above and below, “%” means “% by mass” unless otherwise specified.

  The hydroxyl value of (A) is preferably 200 to 1000. The lower limit is more preferably 250, and the upper limit is more preferably 600. When the hydroxy value is 250 or more, sufficient heat resistance and strength of a polyurethane resin molded product can be obtained, and when it is 1000 or less, scorch due to heat generation during molding does not occur.

Examples of the organic polyisocyanate (B) in the polyurethane resin-forming composition of the present invention include 2-8 or higher aromatic polyisocyanates, aliphatic polyisocyanates, alicyclic polyisocyanates, araliphatic polyisocyanates, And modified polyisocyanates thereof.
Aromatic polyisocyanates include 1,3- and / or 1,4-phenylene diisocyanate, 2,4- and / or 2,6-tolylene diisocyanate (TDI), crude TDI, 2,4'- and / or Fragrance of 6 to 20 carbon atoms (excluding carbon in the isocyanate group, the same shall apply hereinafter) such as 4,4′-diphenylmethane diisocyanate (MDI), polymethylene polyphenyl isocyanate (crude MDI), naphthylene-1,5-diisocyanate Group polyisocyanates.

  Aliphatic polyisocyanates include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexane diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethylcaproate, bis C2-C18 aliphatic polyisocyanates such as (2-isocyanatoethyl) fumarate and bis (2-isocyanatoethyl) carbonate.

  Examples of alicyclic polyisocyanates include isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis (2-isocyanatoethyl) 4-cyclohexene-1, C4-C15 alicyclic polyisocyanate, such as 2-dicarboxylate, is mentioned.

Examples of the araliphatic polyisocyanate include araliphatic polyisocyanates having 8 to 15 carbon atoms such as xylylene diisocyanate (XDI) and α, α, α ′, α′-tetramethylxylylene diisocyanate (TMXDI).
Examples of the modified products of these polyisocyanates include modified products containing urethane groups, carbodiimide groups, uretdione groups, uretoimine groups, urea groups, burette groups, isocyanurate groups, and the like.
Of these, preferred are aromatic polyisocyanates, and more preferred is crude MDI.

The inorganic acid melamine salt (C) used in the present invention is in a powder form, and its median diameter is preferably 0.5 to 100 μm, more preferably 1 to 50 μm. When the median diameter is 0.5 μm or more, the viscosity becomes moldable by the mechanical floss method, and when it is 100 μm or less, the surface after cutting is not rough.
Examples of the inorganic acid forming (C) include orthophosphoric acid, pyrophosphoric acid, polyphosphoric acid, cyanuric acid, boric acid, and sulfuric acid, and an acid containing a phosphorus atom is preferable. Specific examples of (C) include monomelamine orthophosphate, dimelamine orthophosphate, melamine pyrophosphate, melamine polyphosphate, melamine cyanurate, melamine borate, and melamine sulfate. Among these, a melamine salt of an acid containing a phosphorus atom is preferable, and melamine pyrophosphate and melamine polyphosphate are more preferable. (C) can be used alone or in combination.
The content of (C) in the polyurethane resin-forming composition of the present invention is usually 2 to 20%, the lower limit is preferably 3%, and the upper limit is preferably 15%. If it is less than 2%, sufficient flame retardancy cannot be obtained, and if it exceeds 20%, the strength of the molded product is insufficient.

  The median diameter of talc (D) used in the present invention is preferably 1 to 50 μm, more preferably 2 to 30 μm. When the median diameter is 1 μm or more, it becomes a viscosity that can be molded by the mechanical floss method, and when it is 50 μm or less, the surface after cutting is not roughened.

  The median diameter of the zeolite (E) used in the present invention is preferably 1 to 50 μm, more preferably 2 to 30 μm. When the median diameter is 1 μm or more, the viscosity can be formed by the mechanical floss method. When the median diameter is 50 μm or less, the surface after cutting is not rough. Examples of (E) include 3A, 4A, 5A, and 13X. Preferably, 3A and 3A are used in combination with other substances [3A in the total of (E) is 10 to 100%].

  The total content of (D) and (E) in the polyurethane resin-forming composition of the present invention is usually 0.8 to 40%. The lower limit is preferably 1% and the upper limit is preferably 30%. If it is less than 0.8%, sufficient flame retardancy cannot be obtained, and if it exceeds 40%, it becomes difficult to cut the molded product. Moreover, the ratio of (D) with respect to the sum total of (D) and (E) is usually 10 to 90%. The lower limit is preferably 12%, more preferably 15%, and the upper limit is preferably 85%, more preferably 80%. When the ratio of (D) is less than 10%, the surface after cutting may be rough, and when it exceeds 90%, sufficient flame retardancy cannot be obtained.

In the composition of the present invention, a catalyst usually used for polyurethane formation can be used, if necessary.
Examples of the catalyst include tertiary amines such as triethylamine, triethylenediamine, bis (dimethylaminoethyl) ether, N-methylmorpholine, dimethylaminomethylphenol, N-methyl-N-dimethylaminoethylpiperazine, pyridine, and the like. Acid block compounds; Sodium acetate, lead octylate, zinc octylate, cobalt naphthenate, stannous octoate, dibutyltin dilaurate, and other metal salts; metal complexes of acetylacetone, such as diacetylacetone zinc and triacetylacetone iron; sodium Alkali metal or alkaline earth metal alkoxide or phenoxide such as methoxide, sodium phenoxide; quaternary ammonium salt such as tetraethylhydroxylammonium; imidazo Le, imidazoles such as 2-ethyl-4-methylimidazole; tetraphenyl tin, tributyl antimony oxide, tin such as stannous octoate, organometallic compounds containing metals such as antimony; and the like.
These catalysts can be used alone or in combination.
The amount of the catalyst in the composition is preferably 5% or less, more preferably 0.001 to 4%, based on the total mass of (A) and (B).

Other additives that may be contained in the composition of the present invention include fillers, lubricants, foam stabilizers, hollow microspheres, colorants, anti-aging agents, plasticizers, bactericides, antioxidants, antifoams Agents, reaction retarders and the like.
Examples of the filler include carbon black, calcium carbonate, anhydrous silicic acid, hydrous silicic acid, and clay.
Examples of the lubricant include calcium stearate, zinc stearate, ethylenediamine distearyl amide and the like.
Examples of the foam stabilizer include silicone foam stabilizers (such as polysiloxane-polyoxyalkylene copolymers).
As the hollow microsphere, for example, a hollow microsphere made of a thermoplastic resin (polyvinylidene chloride, polymethyl methacrylate, polyacrylonitrile, etc.), a thermosetting resin (phenol resin, epoxy resin, urea resin, etc.); glass, alumina, And hollow microspheres made of inorganic materials such as shirasu and carbon.
Examples of colorants include anthraquinone, indigoid, and azo dyes; inorganic pigments such as titanium oxide, bengara, yellow lead, cadmium sulfide, and ultramarine; organic pigments such as azo, phthalocyanine, quinacridone, and dioxazine; Etc.
Anti-aging agents include amines such as N-phenyl-α-naphthylamine, N-phenyl-β-naphthylamine, N-phenyl-N′-isopropyl-p-phenylenediamine; 2,2,4-trimethyl-1,2 -Amine ketones such as dihydroquinoline polymers; 2,6-di-tert-butyl-4-methylphenol, 4,4'-thiobis (3-methyl-6-tert-butylphenol), 4,4'-butylidenebis (3 -Hindered phenols such as -methyl-6-t-butylphenol); dithiocarbamates such as nickel dibutyldithiocarbamate; and the like.
Examples of the plasticizer include phthalic acid esters and adipic acid esters, and examples of the antifoaming agent include dimethylsiloxane copolymer.

  The content of these additives in the composition is preferably 30% or less, more preferably 2 to 25% for the filler. The lubricant is preferably 20% or less, more preferably 0.2 to 15%. The foam stabilizer is preferably 3% or less, more preferably 0.1 to 2%. The hollow microsphere is preferably 25% or less, more preferably 0.2 to 20%. The colorant, anti-aging agent, plasticizer, disinfectant, anti-oxidant, antifoaming agent, and reaction retarder are each preferably 3% or less, more preferably 0.1 to 2%. The total addition amount of these additives is preferably 30% or less, more preferably 0.1 to 25%.

The flame-retardant polyurethane resin-forming composition for cutting according to the present invention is usually formed by mixing two components of an active hydrogen compound (A) and an organic polyisocyanate (B). (A) and (B) in the formed composition are reacted and cured and molded to obtain the flame-retardant polyurethane resin molded product of the present invention. (C), (D), and (E) may be added to either the component consisting of (A) or the component consisting of (B), or may be added to both. However, (C) is preferably blended with the component comprising (A).
The ratio of (A) and (B) in producing a molded product can be variously changed, but the isocyanate index [(NCO group / active hydrogen atom-containing group equivalent ratio) × 100] is a point of resin strength. Therefore, it is preferably 80 to 140, more preferably 85 to 120.
This production can be performed by a known method such as a one-shot method, a semi-prepolymer method, or a prepolymer method. Further, a foamed or non-foamed flame-retardant polyurethane resin molded product can be produced by reacting in a closed mold using a low-pressure or high-pressure molding apparatus.

The molded product obtained from the polyurethane resin-forming composition of the present invention has a density of 0.05 g / cm ^{3 to} 1.35 g / cm ³ , and a synthetic foam reduced in weight only with a resin foam or hollow microspheres. Or a non-foamed molded product having a density of 1.35 g / cm ³ or more, but in order to improve the machinability by reducing the density, it is a resin foam or a syntactic foam. It is preferable.

  Among the molded products, as a method for producing a foam, fluorocarbon, hydrogen can be used during and / or before mixing of an active hydrogen component composed of active hydrogen compound (A) and an organic polyisocyanate component composed of organic polyisocyanate (B). Inert gas while mixing the above components with volatile blowing agents such as atom-containing halogenated hydrocarbons (alternative chlorofluorocarbons), low boiling point hydrocarbons, and water that is a source of carbon dioxide The mechanical floss foaming method etc. which blow in is mentioned.

  The mechanical floss foaming method is a method for foaming while the rotor of a mechanical floss foaming machine consisting of a cylindrical stator with many teeth on the inner surface and a rotor with many teeth inside the stator is rotating. This is a method in which an inert gas (air, nitrogen, etc.) is continuously and simultaneously injected into the foaming machine to continuously take out the foamed liquid from the outlet of the foaming machine.

  Since an inlet for liquid or inert gas is provided as necessary, two or more kinds of liquid and inert gas can be mixed. Further, even if the liquid is curable, it does not matter as long as it is cured after leaving the foaming machine.

The liquid taken out is cast on a mold (open mold or sealed mold) whose temperature is adjusted in advance to room temperature to 120 ° C. or on a belt conveyor partitioned on both sides so as not to spill.
Metals (aluminum, stainless steel, etc.) and plastics (polypropylene, polycarbonate, etc.) are usually used as the material for the mold and belt conveyor.

The mechanical floss foaming method is more preferable in that the bubble diameter after foaming is fine and the density distribution in the resulting cured product is uniform.
The amount of the inert gas by the mechanical froth foaming method is preferably 10 to 70%, more preferably 15 to 65% with respect to the volume of the molded product (the sum of the volume of the inert gas and the volume of the polyurethane resin molded product). It is. When it is 10% or more, machinability is improved, and when it is 70% or less, fine and uniformly dispersed bubbles are easily obtained. Such a molded product can be obtained by using the above-mentioned amount of the inert gas with respect to the sum of the volume of the inert gas and the total volume of the resin-forming composition at the time of mechanical floss foaming.

The polyurethane resin molded product obtained in the present invention is subjected to cutting. The term “cutting” in the present invention is used to mean not only when cutting and grinding are performed simultaneously, but also when performing grinding after cutting.
For example, to obtain a model by cutting, a computer-controlled machine tool called an NC machine, which is usually cut (machined) by an NC milling machine or machining center, or sawed, sawed, planed, etc., is used. Then, it is cut (manually processed), and finally the finished surface is smoothed with sandpaper to become a model.
Cutting tools used in machining are ball end mills and flat end mills, and generally used are materials called high speed steel and carbide.

  In addition, the molded product of the present invention is cut using a band saw board, a circular saw board, a running saw, a radial saw, a lip saw, a cross-cut saw, a saw, etc., and finally the finished surface is a planer board, a sander, a molder, It is smoothed with sandpaper, etc., and if necessary, the surface is resin-coated to become a building material. For the resin coating, a solvent or water-based emulsion (polyurethane, epoxy resin, acrylic resin, etc.) coating agent can be used. As the coating agent, if necessary, a pigment colored with a pigment or dye can be used.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. In addition, below, a part represents a mass part.

The composition and symbols of the raw materials used in the examples and comparative examples are as follows.
Polyol (1): Polyether polyol polyol having a hydroxy value of 400 with PO added to glycerin (2): Polyether polyol having a hydroxy value of 280 having PO added to bisphenol A Organic polyisocyanate: Polymethylene polyphenyl isocyanate "Millionate MR-200" [manufactured by Nippon Polyurethane Industry Co., Ltd.]
Inorganic acid melamine salt (1): Melamine polyphosphate “MPP-B” with a median diameter of 14 μm [manufactured by Sanwa Chemical Co., Ltd.]
Inorganic acid melamine salt (2): Melamine pyrophosphate “MPP-1” with median diameter of 6 μm [manufactured by Juken Enterprise Co., Ltd.]
Talc: talc with a median diameter of 4 μm “Soapstone A” [manufactured by Nistron, Ltd.]
Zeolite: Zeolite (3A) “PURMOL 3” [manufactured by CU Chemie Ueticon AG]
Foam stabilizer: Silicone foam stabilizer “SZ-1932” [manufactured by Nippon Unicar Co., Ltd.]
Catalyst: Di-n-butyltin dilaurate “Stan BL” [manufactured by Sansha Co., Ltd.]
Hollow microsphere: Acrylic microballoon “Matsumoto Microsphere MFL-80GCA” having a median diameter of 20 μm and a density of 0.24 g / cm ³ [manufactured by Matsumoto Yushi Seiyaku Co., Ltd.]

The performance evaluation test of the molded product was performed according to the following method.
(1) Average surface roughness After cutting the surface of the molded product with an NC machine (cutting blade: flat end mill 20 mmφ high speed 4 blades, rotation speed 3000 rpm, feed rate 500 mm / min, cutting depth 0.2 mm), average cutting surface The surface roughness was measured with a non-contact type three-dimensional shape measuring machine “LM-3D system” manufactured by Keyence. A value obtained by numerically processing the measured value according to JIS B0601 (2001 version) was defined as an average surface roughness.
(2) Flame retardance Based on the US standard UL94, a vertical combustion test was performed using test pieces having a thickness of 1/16 inch (1.6 mm) and 1/32 inch (0.8 mm). All specimens extinguish the fire within 10 seconds after removing the flame, and V-0 is the one where the drop does not ignite cotton, the fire extinguishes within 30 seconds, and the drop is the cotton. Those that did not ignite were V-1, and those other than this evaluation standard were designated as non-flame retardant.

Examples 1-4
Among the compositions shown in Table 1 (parts blended), <active hydrogen component> of polyol to hollow microsphere is charged into a planetary mixer, stirred at 130 rpm for 10 minutes, and then stirred and degassed at 30 mmHg or less for 5 minutes. A liquid mixture of <active hydrogen component> was obtained. Similarly, a mixed liquid of <organic polyisocyanate component> of talc to hollow microspheres was obtained.
Next, the mixture of the active hydrogen component and the mixture of the organic polyisocyanate component are put into a planetary mixer, and mixed for 5 minutes at 130 rpm at 130 rpm, poured into a 50 mm × 50 mm × 200 mm mold, Heat curing at 80 ° C. for 2 hours. This was left to cool at room temperature for 8 hours and demolded to obtain a polyurethane resin molded product.
Table 1 shows the evaluation results of the molded product.

Example 5
The active hydrogen component and the organic polyisocyanate component were obtained in the same manner as in Examples 1 to 4 with the compositions shown in Table 1 (parts blended in parts).
Next, while rotating the rotor of the mechanical floss machine [MF-350 type mechanical floss foaming device [manufactured by Toho Machine Industry Co., Ltd.]] at 300 rpm, the total amount of the active hydrogen component and the organic polyisocyanate component is 10 to 20 L / min. Then, dry air was continuously supplied to the mixing head inlet at the rate shown in Table 1.
Then, the uniformly dispersed mixed solution continuously discharged from the outlet portion was poured into a 50 mm × 50 mm × 200 mm mold and heat-cured at 80 ° C. for 2 hours. This was left to cool at room temperature for 8 hours and demolded to obtain a polyurethane resin molded product.
Table 1 shows the evaluation results of the molded product.

Comparative Examples 1-4
The active hydrogen component, the organic polyisocyanate component, and a molded product thereof were obtained in the same manner as in Examples 1 to 4 with the composition shown in Table 1 (mixing amount in parts).
Table 1 shows the evaluation results of the molded product.

Comparative Example 5
In the same manner as in Example 5, active hydrogen components, organic polyisocyanate components, and molded products thereof were obtained with the compositions shown in Table 1 (parts included).
Table 1 shows the evaluation results of the molded product.

  The flame-retardant polyurethane resin molded product obtained from the flame-retardant polyurethane resin-forming composition of the present invention can be suitably used as a model or building material obtained by cutting.

Claims (5)

In the polyurethane resin-forming composition comprising the active hydrogen compound (A) and the organic polyisocyanate (B), the inorganic acid melamine salt (C) is 2 to 20% by mass, the talc (D) and the zeolite (E) are 0 in total. A flame-retardant polyurethane resin-forming composition for cutting, which is contained in an amount of 8 to 40% by mass and the ratio of (D) is 10 to 90% by mass with respect to the total of (D) and (E) Stuff. The composition according to claim 1, wherein the inorganic acid melamine salt (C) is at least one selected from monomelamine orthophosphate, dimelamine orthophosphate, melamine pyrophosphate, melamine polyphosphate, melamine cyanurate, melamine borate and melamine sulfate. Stuff. A flame-retardant polyurethane resin molded product obtained by curing and molding the composition according to claim 1. The molded product according to claim 3, wherein microbubbles occupying a total volume of 10 to 70% with respect to the molded product volume are uniformly dispersed in the molded product by a mechanical floss method. A model or building material obtained by cutting the molded product according to claim 3 or 4.