JP3994072B2 - Flame retardant polyurethane resin composition for cutting and molded article thereof - Google Patents

Description

【００４８】
ゼオライトを特定量併用した実施例１〜４のプレナリーミキサーで混合して得られた成形品も、実施例５、６のメカニカルフロス法で得られた成形品も、いずれも優れた難燃性を示すのは当然として、十分な熱変形温度を示し、メカニカルフロス法による成形品でさえも優れた衝撃強度を示す。
それに対して、特許文献１のリン系難燃剤を使用した比較例１の成形品は熱変形温度が著しく低く、衝撃強度もやや劣る。また、メラミンと水酸化アルミニウムのみの組み合わせの特許文献２の技術を適用した比較例２の成形品は、メラミンと水酸化アルミニウムの含有量を増やすことにより難燃性はクリアするが、衝撃強度が劣る。
なお、併用するゼオライトの添加量が少ない比較例３では、難燃性が不足し、他方、添加量が多過ぎる比較例４では、切削抵抗が大きく、切削加工性に問題がある。
【００４９】
【発明の効果】
以上説明したように、本発明の樹脂成型品は、熱変形温度の低下および衝撃強度の低下を起こさずに、十分な難燃性が得られるという効果があり、切削加工して得られる模型、樹脂型、または建材として有用である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a raw material composition of a flame retardant polyurethane resin for machining, and a flame retardant resin molded product obtained by curing and molding the raw material composition. More specifically, it is a molded article having cutting workability and flame retardancy suitable for producing models, resin molds, building materials and the like.
[0002]
[Prior art]
Conventionally, as a flame retardant polyurethane resin composition excellent in cutting workability and a flame retardant resin molded product, addition of a phosphorus-based flame retardant in a urethane resin (for example, Patent Document 1), or addition of melamine and aluminum hydroxide (For example, Patent Document 2).
[0003]
[Patent Document 1]
JP 10-147707 A
[Patent Document 2]
JP-A-7-292055
[0004]
[Problems to be solved by the invention]
However, in the former urethane resin composition, since the phosphorus-based flame retardant acts as a urethane plasticizer, there is a problem that the thermal deformation temperature of the resulting molded body is lowered and the molded product is deformed during cutting. Yes.
Further, the latter urethane resin composition has a problem that the impact strength of the molded product is lowered because of the large amount of melamine and aluminum hydroxide added.
[0005]
[Means for Solving the Problems]
The inventors of the present invention have reached the present invention as a result of earnestly studying to obtain a resin molded product excellent in cutting workability and flame retardancy, in which the thermal deformation temperature of the molded product does not decrease and the impact strength does not decrease. .
[0006]
That is, the present invention relates to the following (1) to (4).
(1) In the polyurethane resin comprising the active hydrogen compound (A) and the organic polyisocyanate (B), melamine is 8 to 20% by mass, aluminum hydroxide or magnesium hydroxide is 3 to 30% by mass, and zeolite is 0.8%. A flame retardant polyurethane resin composition for cutting, characterized by containing ~ 20% by mass
(2) Flame-retardant resin molded product obtained by curing and molding the composition of (1)
(3) The resin molded product according to (2), in which fine bubbles 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.
(4) Model obtained by cutting the molded product of (2) or (3)
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Examples of the active hydrogen compound (A) used in the present invention include polyether polyols, polyester polyols, polybutadiene polyols, polyacrylic polyols, and polymer polyols obtained by polymerizing ethylenically unsaturated monomers in these polyols. Can be mentioned.
[0008]
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.
[0009]
Examples of low molecular active hydrogen-containing compounds:
(I) Low molecular weight polyols
(1) C2-C20 dihydric alcohol (aliphatic diols such as ethylene glycol, propylene glycol, 1,3- and 1,4-butanediol, 1,6-hexanediol, neopentyl glycol; cyclohexanediol, Cycloaliphatic diols such as cyclohexanedimethanol, cycloalkylene glycol);
(2) Trivalent alcohols having 3 to 20 carbon atoms (glycerin, trimethylolpropane; aliphatic triols such as trimethylolethane and hexanetriol; trialkanolamines such as triethanolamine; alicyclic triols such as cyclohexanetriol);
(3) A tetrahydric or higher polyhydric alcohol having 5 to 20 carbon atoms (aliphatic polyols such as pentaerythritol, sorbitol, mannitol, sorbitan, diglycerin, dipentaerythritol; and intramolecular or intermolecular dehydrates thereof; Sugars, glucose, mannose, lactose, saccharides such as methyl glucoside and derivatives thereof).
(Ii) polyhydric phenols
Monocyclic phenols such as hydroquinone, resorcin, catechol, pyrogallol, and phloroglucin; bisphenols such as bisphenol A, bisphenol B, bisphenol F, and bisphenol S; condensates of phenol and formaldehyde (novolac).
[0010]
(Iii) Amines
(1) C2-C20 alkanolamines (monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, etc.)
(2) C2-C6 alkylenediamine (ethylenediamine, propylenediamine, hexamethylenediamine, etc.);
(3) Polyalkylene polyamines 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) Aromatic polyamines having 6 to 20 carbon atoms (phenylenediamine, tolylenediamine, xylylenediamine, diethyltoluenediamine, methylenedianiline, diphenyletherdiamine, etc.);
(5) Aliphatic polyamines having 4 to 20 carbon atoms (isophoronediamine, cyclohexylenediamine, cyclohexylmethanediamine, etc.);
(6) Heterocyclic amines having 4 to 20 carbon atoms (such as piperazine and aminoethylpiperazine).
[0011]
(Iv) Polycarboxylic acids
(1) C4-C18 aliphatic polycarboxylic acid (for example, succinic acid, adipic acid, sebacic acid, glutaric acid, azelaic acid, etc.);
(2) Aromatic polycarboxylic acids having 8 to 18 carbon atoms (terephthalic acid, isophthalic acid, trimellitic acid, pyromellitic acid, etc.)
[0012]
As the polyester polyol, a condensed polyester polyol obtained by reacting the polyhydric alcohol 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.
[0013]
Examples of polybutadiene polyol include copolymers of butadiene and other vinyl monomers such as styrene and acrylonitrile having a terminal hydroxyl group ((butadiene / vinyl monomer (weight ratio) = 0.1 to 1) and hydrogenated products thereof. Can be mentioned.
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] copolymerized [hydroxyalkyl (meth) acrylate / vinyl monomer (polymerization ratio) = 0.05 to 0.5].
[0014]
Furthermore, as a polymer polyol obtained by polymerizing an ethylenically unsaturated monomer in these polyols, a vinyl monomer such as acrylonitrile or styrene in the presence of a radical initiator in at least one of the polyols exemplified above. Can be polymerized and stably dispersed.
[0015]
As radical initiators, 2,2-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-methylbutyronitrile), 1, 1′-azobis (cyclohexane-1-albonitrile), 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; persulfate, perfo An inorganic peroxide such as oxalate can be used.
[0016]
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, a PO adduct of amines, and It is a co-adduct of EO and PO.
[0017]
Specific preferred examples of the above (A) include PO adducts of glycerin, trimethylolpropane, pentaerythritol, sorbitol, sucrose, bisphenol A, and triethanolamine.
[0018]
The hydroxy value of (A) is 200-1000. The lower limit is preferably 250 and the upper limit is 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.
[0019]
Further, in the present invention, together with the above-described high molecular weight active hydrogen compound (A), the low molecular polyol itself [for example, (i) among the low molecular weight active hydrogen-containing compounds having a molecular weight of 400 or less] is used as the active hydrogen component. Can be used together.
[0020]
Examples of the polyisocyanate compound (B) that is another component of the polyurethane of the present invention include aromatic polyisocyanates, aliphatic polyisocyanates, alicyclic polyisocyanates, araliphatic polyisocyanates, and modified polyisocyanates thereof. Is mentioned.
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.
[0021]
Aliphatic polyisocyanates include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexane diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethylcaproate, bis Examples include 2-18 aliphatic polyisocyanates such as (2-isocyanatoethyl) fumarate and bis (2-isocyanatoethyl) carbonate.
[0022]
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.
[0023]
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 modified products of these polyisocyanates include modified products containing a carbodiimide group, a uretdione group, a uretoimine group, a urea group, a burette group, an isocyanurate group, and the like.
Among these, preferred are aromatic polyisocyanates, and particularly preferred is crude MDI.
[0024]
The melamine used for this invention is a powder form, and an average particle diameter is 1-100 micrometers normally, Preferably it is 5-50 micrometers. When the average particle size is 1 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.
The compounding quantity of a melamine is 8-20 mass% normally in a urethane resin composition, Preferably it is 10-18 mass%. Sufficient flame retardancy can be obtained at 8% by mass or more, and sufficient molded product strength can be obtained at 20% by mass or less.
[0025]
The aluminum hydroxide and magnesium hydroxide used in the present invention are in powder form, and the average particle size is usually 0.5 to 10 μm, preferably 0.6 to 8 μm. When the average particle size is 0.5 μm or more, the viscosity becomes moldable by the mechanical floss method, and when it is 10 μm or less, the surface after cutting is not rough.
Aluminum hydroxide and magnesium hydroxide may be used alone or in combination, but are preferably used alone.
The total amount of aluminum hydroxide and magnesium hydroxide is usually 3 to 30% by mass, preferably 5 to 28% by mass, in the urethane resin composition.
When 3% by mass or more, sufficient flame retardancy is obtained, and when it is 30% by mass or less, the hardness of a molded product that can be cut is obtained.
[0026]
The average particle size of the zeolite used in the present invention is usually 2 to 50 μm, preferably 5 to 30 μm. When the average particle size is 2 μm or more, the viscosity can be molded by the mechanical floss method, and when it is 50 μm or less, the surface after cutting is not roughened.
The compounding quantity of a zeolite is 0.8-20 mass% normally in a urethane resin composition, Preferably it is 1-18 mass%. When 0.8% by mass or more, sufficient flame retardancy is obtained, and when it is 20% by mass or less, the hardness of the molded product is suitable for cutting workability.
[0027]
Zeolite may be used for the production of polyurethane resin for resin molding for the purpose of dehydrating water in the active hydrogen compound before reacting with isocyanate, but in the present invention, zeolite is a small amount. It is an essential component for improving the flame retardancy in the blending amount.
When the content of melamine is large, the strength of the molded product is lowered, and when the content of aluminum hydroxide and magnesium hydroxide is high, the strength of the molded product is lowered and the machinability is deteriorated. However, by using zeolite in combination with melamine, aluminum hydroxide, and magnesium hydroxide, the content of melamine, aluminum hydroxide, and magnesium hydroxide required to exhibit flame retardancy when not using zeolite is reduced. And the above disadvantages are improved.
[0028]
The ratio of (A) and (B) in the production of polyurethane can be variously changed, but the isocyanate index [(equivalent ratio of NCO group / active hydrogen atom-containing group) × 100] is from the viewpoint of resin strength. , Preferably 80-140, more preferably 85-120.
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 molded product can be produced by reacting in a closed mold using a low-pressure or high-pressure molding apparatus.
[0029]
In the production of a polyurethane resin molded article, a catalyst usually used for polyurethane 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; metal salts of carboxylic acids such as sodium acetate, lead octylate, zinc octylate, cobalt naphthenate, stannous octoate, dibutyltin dilaurate; alkali metals or alkaline earth metals such as sodium methoxide and sodium phenoxide Alkoxides or phenoxides of quaternary; quaternary ammonium salts such as tetraethylhydroxylammonium; imidazoles such as imidazole and 2-ethyl-4-methylimidazole; tetraphenyltin Tributyl antimony oxide, tin such as stannous octoate, and organic metal compounds containing metals such as antimony.
These catalysts can be used alone or in combination.
The blending amount of the catalyst is usually 5% by mass or less, preferably 0.001 to 4% by mass with respect to the total mass of (A) and (B).
[0030]
Other additives that can be used include fillers, lubricants, foam stabilizers, hollow microspheres, colorants, anti-aging agents, plasticizers, bactericides, antioxidants, antifoaming agents, and reaction retarders. .
Examples of the filler include carbon black, talc, 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, Examples thereof include hollow microspheres made of inorganic materials such as shirasu and carbon.
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 Is mentioned.
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, Amine ketones such as 2-dihydroquinoline polymer; 2,6-di-tert-butyl-4-methylphenol, 4,4′-thiobis (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis Hindered phenols such as (3-methyl-6-t-butylphenol); dithiocarbamates such as nickel dibutyldithiocarbamate and the like.
[0031]
The content of these additives in the composition is such that the filler is preferably 30% by mass or less, more preferably 2 to 25% by mass; the lubricant is preferably 20% by mass or less, more preferably 0.2 to 15%. The foam stabilizer is preferably 3% by mass or less, more preferably 0.1 to 2% by mass; the hollow microsphere is preferably 25% by mass or less, more preferably 0.2 to 20% by mass; Each of the agent, anti-aging agent, plasticizer, bactericidal agent, antioxidizing agent, antifoaming agent and reaction retarder is preferably 3% by mass or less, more preferably 0.1 to 2% by mass.
[0032]
The resin molded product obtained from the resin-forming composition of the present invention has a density of 0.05 g / cm. ^Three ~ 1.35 g / cm ^Three Even non-foaming density 1.35 g / cm, even if it is a lightweight resin foam or a syntactic foam reduced in weight only with hollow microspheres ^Three Although it may be a molded article as described above, a resin foam or a syntactic foam is preferable in order to improve cutting workability by reducing the density.
[0033]
Among the molded products, as a method for producing a foam, volatile properties such as fluorocarbons, hydrogen atom-containing halogenated hydrocarbons (alternative chlorofluorocarbons), and low boiling point hydrocarbons can be used during and / or before mixing the polyol component and the organic polyisocyanate component. And a foaming agent foaming method in which water as a carbon dioxide gas generation source is added, and a mechanical floss foaming method in which an inert gas such as air or nitrogen is blown during mixing of the above components.
[0034]
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 of continuously taking out the foamed liquid from the outlet of the foaming machine by continuously injecting an inert gas into the foaming machine simultaneously.
[0035]
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.
[0036]
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.
[0037]
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 sum of the volume of the inert gas and the total composition volume. When it is 10% or more, machinability is improved, and when it is 70% or less, fine and uniformly dispersed bubbles are easily obtained.
[0038]
The molded product obtained in the present invention is usually cut (machined) by an NC milling machine or a machining center among computer-controlled machine tools called NC machines, or cut using a saw, a chisel, a planer, etc. The finished surface is smoothed with sandpaper and finally becomes 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.
[0039]
When the obtained model is used for a design model of an automobile or the like, it is further painted and finished and used for design evaluation. When used as a vacuum mold, a vacuum evacuation hole having a diameter of about 1 mm is further formed to form a vacuum mold.
[0040]
The flame-retardant resin molded product obtained from the flame-retardant polyurethane resin composition of the present invention can be used for, for example, a model, a resin mold, or a building material obtained by cutting.
[0041]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited to this. Below, a part shows a mass part.
[0042]
The composition and symbols of the raw materials used in Examples and Comparative Examples are as follows.
Polyol (1): Polyether polyol having a hydroxy value of 400, in which PO is added to glycerin
Polyol (2): Polyether polyol having a hydroxy value of 280 obtained by adding PO to bisphenol A
Organic polyisocyanate: Polymethylene polyphenyl isocyanate “Millionate MR-200” [manufactured by Nippon Polyurethane Industry Co., Ltd.]
Melamine: Melamine with an average particle size of 18 μm [Mitsui Chemicals, Inc.]
Aluminum hydroxide: Aluminum hydroxide “C-303” having an average particle diameter of 3 μm [manufactured by Sumitomo Chemical Co., Ltd.]
Magnesium hydroxide: Magnesium hydroxide “Kisuma 5A” with an average particle size of 0.9 μm [manufactured by Kyowa Chemical Industry Co., Ltd.]
Zeolite: PURMOL 3 [manufactured by CU Chemie Ueticon AG]
Phosphorus flame retardant: tricresyl phosphate [manufactured by Kanto Chemical Co., Inc.]
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: average particle size 20 μm, density 0.24 g / cm ^Three Acrylic microballoon "Matsumoto Microsphere MFL-80GCA" [Matsumoto Yushi Seiyaku Co., Ltd.]
[0043]
The performance evaluation test of the molded product was performed according to the following method.
(1) Thermal deformation temperature
Conforms to JIS K6911
(2) Izod impact strength
Conforms to JIS K6911
(3) Flame resistance
Compliant with UL94
(4) Cutting resistance (cutability)
Cut the molded product into 30 mm length x 80 mm width x 10 mm thickness, and use it as a test piece. ]], The resistance value (N) in the blade feed direction during cutting of this test piece was measured with an NC machine [“NCE23-1H type router” manufactured by Kikukawa Iron Works]. (Cutting blade: 16mmφ carbide slow-away tip, single blade, rotation speed: 5000rpm, feed rate: 2000mm / min, cutting depth 3mm)
[0044]
Examples 1-4
Among the compositions shown in Table 1 (the blending amount is parts by mass), the <active hydrogen component> of polyol to hollow fine particles is put into a planetary mixer, stirred for 10 minutes at 130 rpm, stirred and degassed at 30 mmHg or less for 5 minutes, A liquid mixture of <active hydrogen component> was obtained.
Next, this mixed solution of active hydrogen components and the organic polyisocyanate component are put into a planetary mixer, mixed with stirring at 30 rpm or less and 130 rpm for 5 minutes, and poured into a 50 mm × 50 mm × 200 mm mold at 80 ° C. Heat cured for 2 hours. This was left to cool at room temperature for 8 hours and demolded to obtain a resin molded product.
Table 1 shows the evaluation results of the molded product.
[0045]
Examples 5 and 6
The active hydrogen component and the organic polyisocyanate component were obtained in the same manner as in Examples 1 to 4 with the composition shown in Table 1 (the blending amount was parts by mass).
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 active hydrogen component and the organic isocyanate component are added in a total of 10 to 20 L / min. Continuously fed to the inlet of the mixing head.
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 resin molded product.
Table 1 shows the evaluation results of the molded product.
[0046]
Comparative Examples 1-4
The active hydrogen component and the organic polyisocyanate component were obtained in the same manner as in Examples 1 to 4 with the composition shown in Table 1 (the blending amount was parts by mass).
[0047]
[Table 1]

[0048]
The molded products obtained by mixing with the plenary mixers of Examples 1 to 4 combined with a specific amount of zeolite, and the molded products obtained by the mechanical floss methods of Examples 5 and 6 both have excellent flame retardancy. As a matter of course, a sufficient heat distortion temperature is exhibited, and even a molded article obtained by the mechanical floss method exhibits excellent impact strength.
On the other hand, the molded article of Comparative Example 1 using the phosphorus-based flame retardant of Patent Document 1 has a remarkably low heat distortion temperature and is slightly inferior in impact strength. In addition, the molded article of Comparative Example 2 to which the technology of Patent Document 2 in which only the combination of melamine and aluminum hydroxide is applied clears the flame retardancy by increasing the content of melamine and aluminum hydroxide, but the impact strength is low. Inferior.
In Comparative Example 3 in which the amount of zeolite used in combination is small, the flame retardancy is insufficient. On the other hand, in Comparative Example 4 in which the amount of addition is too large, the cutting resistance is large and there is a problem in cutting workability.
[0049]
【The invention's effect】
As described above, the resin molded product of the present invention has an effect that sufficient flame retardancy is obtained without causing a decrease in thermal deformation temperature and a decrease in impact strength, and a model obtained by cutting, Useful as a resin mold or building material.

Claims (4)

  In the polyurethane resin composition comprising the active hydrogen compound (A) and the organic polyisocyanate (B), melamine is 8 to 20% by mass, aluminum hydroxide or magnesium hydroxide is 3 to 30% by mass, and zeolite is 0.8 to A flame-retardant polyurethane resin composition for cutting, characterized by containing 20% by mass.   A flame-retardant resin molded product obtained by curing and molding the composition according to claim 1.   The resin molded product according to claim 2, 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 obtained by cutting the molded product according to claim 2.