JPH10168150A - Composition for flame retarding rigid polyurethane foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition, capable of manifesting the high flame retardance and uniformization of cells in the interior of a foam without deteriorating mechanical properties and useful for a heat reserving and a heat insulating materials by using a specific phosphorus-based complex flame retardant. SOLUTION: This composition for a rigid polyurethane foam consists essentially of (A) a polyhydroxyl compound, (B) a polyiscyanate, (C) a urethanizing catalyst, (D) a flame retardant, (E) a foam stabilizer and (F) a foaming agent. A complex flame retardant prepared by compounding (D1 ) an ammonium polyphosphate such as a (melamine-modified) ammonium polyphosphate or a coated ammonium polyphosphate with (D2 ) red phosphorus [so as to provide preferably (96:4) to (75:25) weight ratio of the components D1 :D2 ] is used in an amount of, e.g. 1-80 pts.wt. based on 100 pts.wt. component A ad the component D.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a composition for a flame-retardant rigid polyurethane foam. More specifically, the present invention relates to a composition for a flame-retardant rigid polyurethane foam, which comprises ammonium polyphosphate and red phosphorus in a specific ratio.

[0002]

2. Description of the Related Art Rigid polyurethane foams have excellent heat insulating properties due to their low thermal conductivity.
LPG or LNG tank, LPG or LNG tanker, refrigerated ship, refrigerated vehicle, refrigerated warehouse, various chemical plants,
It is used for various types of heat insulators and heat insulators for electric refrigerators and construction. However, the rigid polyurethane foam has poor flame retardancy, and studies for imparting flame retardancy have been conventionally conducted.

As a method for making the rigid polyurethane foam flame-retardant, an organic or inorganic compound, for example, a boron-containing compound, a phosphorus-containing compound, a halogen-containing compound, zinc oxide, antimony oxide, or the like is compounded in the composition. There are known ways to do this. However, this method has a high degree of heat resistance, especially for housing materials and structural materials for electrical equipment,
When used for parts requiring mechanical properties and design, there are the following drawbacks. That is, mechanical properties, especially impact resistance, are significantly reduced. Further, the cells inside the foam become non-uniform, and voids are likely to be generated in the skin when the foam with the skin is formed.

[0004] On the other hand, as another method for making a rigid polyurethane foam flame-retardant, for example, phosphorus or a polyhydroxyl compound, which is a raw material of the rigid polyurethane foam, such as tris (dipropylene glycol) phosphite is added to phosphorus or an organic polyisocyanate. There is a method of making a flame retardant by a reactive flame retardant to which a halogen atom is added. However, this method requires a complicated process for preparing the raw material itself, which increases the cost and decreases the mechanical properties of the foam.

[0005]

DISCLOSURE OF THE INVENTION The present inventors have made intensive studies in order to solve the above-mentioned problems that the physical properties of the rigid polyurethane foam are deteriorated and the cells inside the foam become uneven. As a result, using a composite flame retardant in which ammonium polyphosphate and red phosphorus are blended in a specific weight ratio has a high flame retardant effect, and has reduced mechanical properties and reduced non-uniformity of cells inside the foam. The present inventors have found that a hard polyurethane foam can be obtained as a composition for flame-retardant hard urethane foam, and based on this finding, have completed the present invention. As is apparent from the above description, the object of the present invention is to have a high degree of flame retardancy even if the amount of the flame retardant is reduced,
An object of the present invention is to provide a composition for a flame-retardant rigid polyurethane foam from which a rigid polyurethane foam having reduced mechanical properties and non-uniformity of cells inside a foam can be obtained.

[0006]

[Means for Solving the Problems]

(1) polyhydroxyl compounds, polyisocyanates,
A composition for a rigid polyurethane foam comprising a urethane-forming catalyst, a flame retardant, a foam stabilizer, and a foaming agent as essential components, wherein the flame retardant is a composite flame retardant comprising ammonium polyphosphate and red phosphorus. Composition for flexible rigid polyurethane foam. (2) The first composition, wherein the weight ratio of ammonium polyphosphate to red phosphorus constituting the composite flame retardant is 96: 4 to 75:25.
Item 7. The composition for flame-retardant rigid polyurethane foam according to Item 1. (3) Any one of the above items 1 or 2, wherein the ammonium polyphosphate constituting the composite flame retardant is ammonium polyphosphate, melamine-modified ammonium polyphosphate, coated ammonium polyphosphate or a mixture of two or more thereof. The composition for a flame-retardant rigid polyurethane foam according to the above. (4) The composition for a flame-retardant rigid polyurethane foam according to any one of the above (1) or (2), wherein the red phosphorus constituting the composite flame retardant is red phosphorus, coated red phosphorus or a mixture thereof.

[0007] In order to obtain the composition for a flame-retardant rigid polyurethane foam of the present invention, the compounding ratio of ammonium polyphosphate to red phosphorus in a weight ratio of 96: 4 to 75:25, preferably 90:10 is used. A flame retardant is added to the polyhydroxyl compound in a proportion of 1 to 80 parts by weight, preferably 2 to 60 parts by weight, based on 100 parts by weight of the polyhydroxyl compound. If the compounding ratio of the composite flame retardant is less than 1 part by weight, sufficient flame retardancy cannot be obtained. Is greatly reduced.

The ammonium polyphosphate constituting the composite flame retardant used in the present invention includes ammonium polyphosphate, melamine modified ammonium polyphosphate, carbamyl polyphosphate, coated ammonium polyphosphate, or a mixture of two or more of these. In particular, coated ammonium polyphosphate is preferably used because of its water insolubility. Here, the coated ammonium polyphosphate is obtained by coating or microencapsulating ammonium polyphosphate with a synthetic resin, and the water solubility of these ammonium polyphosphate at 25 ° C. is 0.5% by weight or less. As a resin that can be used for microencapsulation, a thermosetting resin that hardly permeates water and forms a film having excellent water resistance is preferable, for example, an alkyd resin, an allyl resin, a urea resin, a melamine resin, an epoxy resin,
Thermosetting resins such as phenolic resins, unsaturated polyester resins, silicone resins, urethane resins, xylene resins, and furan resins, or modified resins thereof, which are ion-modified to anions or cations, or special types such as high-condensation types It is possible to select at least one of a denatured one and a denatured one (explain what the other one is). Among these resins, melamine resin, urea resin, urea resin, urethane resin, and phenol resin are preferably used from the viewpoints of water resistance of the resin, strength of the film, and formation of a denser film.

Further, when coating the ammonium polyphosphate with a thermosetting resin, it is particularly preferable to select a resin which is close to the polarity (solubility parameter, SP value) of the urethane resin. That is, by making the polarity of the ammonium polyphosphate surface close to that of the urethane resin, the dispersibility in the resin can be increased, and a decrease in physical properties can be suppressed.

As the ammonium polyphosphate, a commercially available product may be used. Examples of the commercially available product include Sumisafe P (trade name, manufactured by Sumitomo Chemical Co., Ltd.) and Sumisafe PM
(Trade name, manufactured by Sumitomo Chemical Co., Ltd.), Hoscheck P /
30 (trade name, manufactured by Monsanto), Hoscheck P / 4
0 (trade name, manufactured by Monsanto), Nonnen W-3 (trade name, manufactured by Marubishi Yuka Kogyo Co., Ltd.) Terage C60 (trade name, manufactured by Chisso Corporation), Terage C70 (trade name, manufactured by Chisso Corporation) )) And Hostafram AP462 (manufactured by Hoechst).

The red phosphorus constituting the composite flame retardant used in the present invention may be untreated or one containing black phosphorus (red phosphorus), one that has been surface-treated with an inorganic substance and / or an organic substance (hereinafter referred to as coated red phosphorus). Are used. Particularly, coated red phosphorus is preferably used in terms of safety and ease of handling. As the red phosphorus, a commercially available product may be used, and as the commercially available product, Novaled (trade name, Rin Kagaku Kogyo Co., Ltd.)
Nova Excel (trade name, Rin Kagaku Kogyo Co., Ltd.)
And Hishigard (trade name, manufactured by Nippon Chemical Industry Co., Ltd.).

The method of adding the composite flame retardant may be any method, but it is preferable to disperse ammonium polyphosphate and red phosphorus in the polyhydroxyl compound in advance.

The polyhydroxyl compound, polyisocyanate, urethanizing catalyst, foaming agent, foam stabilizer and the like used in the present invention can be arbitrarily selected from those conventionally used in compositions for rigid polyurethane foams. Can be.

Examples of the polyhydroxyl compound include polyether polyol and polyester polyol. Examples of typical polyether polyols include propylene glycol, glycerin, trimethylolpropane, pentaerythritol, α-methyl glycoside, sorbitol, polyols such as sucrose,
Amino alcohols such as diethanolamine, triethanolamine, tripropanolamine, etc .; amines such as ethylenediamine, 1,6-hexanediamine, diethylene and lamine, triethylenetetraamine, toluylenediamine, methylenebisaniline, phosphoric acid, and pyrroline Phosphorus compounds such as acids or partial esters thereof,
And polyether polyols obtained by adding ethylene oxide, propylene oxide, butylene oxide and the like to these mixtures. Glycerin,
A halogen-containing polyether polyol obtained by adding epichlorohydrin or the like to a polyol such as trimethylolpropane, pentaerythritol or sorbitol in the presence of a cationic catalyst such as BF ₃ can also be mentioned.

Examples of polyester polyols include diols such as ethylene glycol, propylene glycol, diethylene glycol and butylene glycol; triols such as trimethylolpropane, hexanetriol and glycerin; Adipic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, HET
Acid, succinic anhydride, maleic anhydride, polyester polyol having terminal hydroxyl groups obtained by condensation with phthalic anhydride, etc., polyester obtained by ring-opening polymerization of cyclic lactones using glycerin, pentaerythritol, sorbitol, etc. as an initiator Is mentioned. further,
Castor oil, castor oil modified polyol, epoxy modified polyol, silicone-based polyol, acrylic modified polyol, and the like can also be mentioned.

The polyisocyanate is a compound having at least two --NCO groups (isocyanate groups) in one molecule. Representative examples thereof include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and xylylene diisocyanate. Isocyanate (XD
I), hexamethylene diisocyanate and the like. These polyisocyanates may be used in combination of two or more. In addition, a prepolymer obtained by reacting the above isocyanate with various active hydrogen compounds in an NCO group-excess state, or a modified isocyanate partially partially allophanated or trimerized can also be used.

The mixing ratio of the polyisocyanate is based on the number of moles of isocyanate groups (generally NCO) per mole of active hydrogen capable of reacting with isocyanate contained in the composition.
It is desirable to mix them in such a manner that a value called an index) is 0.9 to 1.3.

Examples of the urethanization catalyst include amine urethanization catalysts such as triethylamine, N-methylmorpholine, N-ethylmorpholine, triethanolamine, dimethylethanolamine, monomethylethanolamine, diethylenetriamine, monoethanolamine, and diethanolamine. , Tripropylamine, tributylamine, triethylenediamine, tetramethylbutanediamine, N, N-dimethylbenzylamine, N,
N, N ', N'-tetramethylhexamethylenediamine, N, N, N', N'-tetramethylethylenediamine and the like can be mentioned.

Also, organometallic urethanization catalysts such as dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dichloride, tin octoate, lead octoate, and lead naphthenate can be used.

The mixing ratio of the urethanization catalyst is difficult to determine unambiguously because the degree of activity is significantly different depending on the type of catalyst used. However, as a guideline for properly determining the mixing ratio, it is necessary to mix the composition. It is desirable that the time from the start until foaming starts (generally called cream time) is 1 to 30 seconds. Incidentally, in the case of triethylenediamine which is a general-purpose catalyst, the compounding ratio is 0.2 to 5 parts by weight based on 100 parts by weight of the polyhydroxyl compound.

Examples of the foam stabilizer include an oxyalkylene copolymer of polydimethylsiloxane and a fluorine-based surfactant. The compounding ratio of the foam stabilizer is 0.1 to 5 parts by weight with respect to 100 parts by weight of the polyhydroxyl compound, and below this, the cells of the foam obtained from the composition become rough, The probability of occurrence of voids increases. In addition, even when the amount is significantly exceeded, the foam-regulating effect reaches a plateau.

Examples of the foaming agent include fluorinated hydrocarbons, low boiling compounds such as methylene chloride, and water.

The composition for a flame-retardant rigid polyurethane foam of the present invention may further comprise silica or talc as an extender of the composition, iron oxide yellow as a coloring pigment of the composition, if necessary, in addition to the above-mentioned components. One or more auxiliary components such as iron oxide brown can be contained.

As the method for producing a flame-retardant rigid polyurethane foam using the composition for a flame-retardant rigid polyurethane foam of the present invention, conventionally known methods, namely, a slab foaming method, a conventional injection foaming method, and a froth method An injection foaming method and a spray foaming method can be used.

Examples and comparative examples will be shown below to specifically explain the present invention, but the present invention is not limited by these examples. The evaluation in Examples and Comparative Examples was performed by the following method.

(1) Flame retardancy Complies with the surface test (heating for 10 minutes) of Japanese Industrial Standard JIS A1321 (flame retardancy test method for building interior materials and construction methods). The thickness of the test body was 30 mm.

(2) Flame retardancy: Complies with the vertical flame test specified in "flame test of plastic materials for equipment parts" of UL94V UL Subject (Underwriter Laboratories, Inc.).

Examples 1 to 5 and Comparative Examples 1 to 3 O-phthalic acid-based polyester polyol (OH value: 443 mg KOH / g) was used as a polyhydroxyl compound.
With respect to 0 parts by weight, ammonium polyphosphate (Terage C60, trade name, manufactured by Chisso Corporation) and Nova Excel 140 (trade name, manufactured by Rin Kagaku Kogyo Co., Ltd.) as red phosphorus were mixed as shown in Table 1 below. In a proportion to the polyester polyol, and a homogenizer, NISSEI AM-11.
(Product name, manufactured by Nippon Seiki Seisakusho) at 5000 rpm
, And then silicone-based foam stabilizer L-580 (trade name, manufactured by Nippon Yunika Co., Ltd.) as a foam stabilizer and Kaorizer No. 1 as a urethane-forming catalyst. 2 (trade name, manufactured by Kao Corporation) and Kao Riser No. No. 3 (trade name, manufactured by Kao Corporation), water and dichloromethane were mixed at a mixing ratio (parts by weight) shown in Table 1 as a foaming agent, and the mixture was stirred quickly, and then crude MDI (NCO content: 31.1%) ) Was added and stirred for about 20 seconds to prepare a composition for a flame-retardant rigid polyurethane foam. This was poured into a 30 cm square container and freely foamed to obtain a flame-retardant rigid polyurethane foam. After leaving the obtained foam at room temperature for 2 days, the foam was cut into a predetermined shape to prepare a test piece. Flame retardancy test and UL94V evaluation were performed using the obtained test pieces. The results are shown in Table 1.

[0029]

EFFECT OF THE INVENTION The composition of the present invention exhibits high flame retardancy by blending ammonium polyphosphate and red phosphorus in a specific ratio as a composite flame retardant, even though the amount of the composite flame retardant is low. This is a composition for a flame-retardant rigid polyurethane foam from which a rigid polyurethane foam can be obtained. Therefore, this composition is suitable for a heat insulating material for various uses such as LPG.
Or flame retardancy to obtain a rigid polyurethane foam that is more suitable as a heat insulating material for LNG tanks, LPG or LNG tankers, refrigerated ships, refrigerated vehicles, refrigerated warehouses, various chemical plants, electric refrigerators, buildings, etc. It is a composition for a rigid polyurethane foam.

[0030]

[Table 1]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08K 3/32 C08K 3/32 C08L 75/04 C08L 75/04 // (C08G 18/32 101: 00)

Claims (4)

[Claims] 1. A composition for a rigid polyurethane foam comprising a polyhydroxyl compound, a polyisocyanate, a urethanization catalyst, a flame retardant, a foam stabilizer, and a foaming agent as essential components, wherein the flame retardant comprises ammonium polyphosphate and red phosphorus. A composition for a flame-retardant rigid polyurethane foam, which is a composite flame retardant. 2. The composition for a flame-retardant rigid polyurethane foam according to claim 1, wherein the weight ratio of ammonium polyphosphate to red phosphorus constituting the composite flame retardant is 96: 4 to 75:25. 3. The method according to claim 1, wherein the ammonium polyphosphate constituting the composite flame retardant is ammonium polyphosphate, melamine-modified ammonium polyphosphate, coated ammonium polyphosphate, or a mixture of two or more thereof. Item 7. The composition for flame-retardant rigid polyurethane foam according to Item 1. 4. The composition for a flame-retardant rigid polyurethane foam according to claim 1, wherein the red phosphorus constituting the composite flame retardant is red phosphorus, coated red phosphorus or a mixture thereof.