JP2000212244A - Polymethylene polyphenyl polyisocyanate composition for preparing hard polyurethane foam, process for preparing hard polyurethane foam and hard polyurethane foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hard polyurethane foam excellent in fire resistance, heat resistance, flame retardance, low smoking properties. SOLUTION: In the preparation of a hard polyurethane foam by reacting at least one polyisocyanate with a polyol, a polyisocyanate composition comprising 30-80 wt.% dimethylene triphenylene triisocyanate and 0.1-10 ppm metal component is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polymethylene polyphenyl polyisocyanate composition for producing a rigid polyurethane foam, a method for producing a rigid polyurethane foam using said polymethylene polyphenyl polyisocyanate composition, and said polymethylene polyphenyl polyisocyanate. The present invention relates to a rigid polyurethane foam obtained using an isocyanate composition. More specifically, even when using alternative fluorocarbons such as 1,1-dichloro-1-fluoroethane as a physical foaming agent or water as a chemical foaming agent as a foaming agent, by using a specific polyisocyanate composition, A rigid polyurethane foam or a rigid polyisocyanurate foam (hereinafter, referred to as a heat-resistant, flame-retardant, low-smoke-resistant, good-strength, dimensional-stable, and heat-insulating material)
Rigid polyurethane foam) and a method for producing the same.

[0002]

2. Description of the Related Art Rigid polyurethane foam is widely used as a heat insulating material for refrigerators, freezer warehouses, building materials, etc. and as an airless spray application because of its light weight and excellent heat insulation performance, dimensional stability and workability. However, if the flame resistance, heat resistance, flame retardancy, and low smoke emission are improved, it is expected that the fields of use and applications will further expand.
Generally, in order to improve the flame retardancy of a rigid polyurethane foam, a method of adding a flame retardant such as an inorganic water-containing compound to improve the flame retardancy (for example, Japanese Patent Application Laid-Open No.
No. 118519) is known. However, although rigid polyurethane foams obtained by these methods have improved flame retardancy, the smoke density tends to increase with time during combustion. In addition, the mechanical properties tended to be lower than when no flame retardant was used. Furthermore, in order to reduce the smoke-generating property of the rigid polyurethane foam, phosphate esters, ammonium polyphosphate, p-nitroanilinesulfonic acid, etc. are added, and when the foam comes into contact with a flame, these additives cause the foam to carbonize. (For example, Japanese Patent Application Laid-Open No. 2-18)
No. 0875), a method of adding a heat-resistant inorganic powder and suppressing the combustibility of the foam to thereby reduce the smoke-generating property is known. However, when the additives are used as described above, increasing the amount of the additives causes a problem that the storage stability of the raw material mixture decreases. Therefore, a method of introducing a heat-resistant structure such as an isocyanurate ring into a polyurethane resin skeleton to suppress thermal decomposition and reduce smoke generation (for example, JP-A-6-306132) has been studied. In this case, when a conventional polyisocyanate is used, it is difficult to introduce a high-concentration isocyanurate ring into the polyurethane resin skeleton, and a sufficient reduction in smoke generation has not been achieved.

[0003]

At present, it is desired to obtain a rigid urethane foam having good flame resistance, heat resistance, flame retardancy and low smoke emission without lowering the storage stability of the raw material mixture. ing. In recent years, chlorofluorocarbon (CF) has been used as a blowing agent to protect the ozone layer of the earth.
Class C) regulations are in place. As of the end of 1995, CFCs have been completely abolished, and as a substitute, the use of hydrochlorofluorocarbons (HCFCs) has become mainstream in the domestic market. However, HCFCs have an ODP (ozone depletion potential) other than zero, and it has already been determined that they will be subject to regulation in the near future. As alternatives to HCFCs, hydrofluorocarbons (HFCs), and foaming agents with zero ODP such as hydrocarbons (HC) and CO2 have been considered. As described above, in the present situation where the foaming agent is remarkably changed, it is desired to develop a raw material of a rigid urethane foam and a method for producing a rigid urethane foam whose flame resistance, heat resistance, flame retardancy, and low smoke generation do not depend on these foaming agents. Was rare.

[0004]

Means for Solving the Problems As a result of diligent studies to achieve the above object, the present inventors focused on a polymethylene polyphenyl polyisocyanate composition and developed a polymethylene polyphenyl polyisocyanate composition having a specific composition. By using the same, it has been found that a rigid urethane foam having good flame resistance, heat resistance, flame retardancy, and low smoke emission can be obtained without deteriorating the storage stability of the raw material mixture, thereby completing the invention. The polymethylene polyphenyl polyisocyanate composition for producing a rigid polyurethane foam, the method for producing a rigid polyurethane foam, and the rigid polyurethane foam according to the present invention are as follows. (1) Polymethylene polyphenyl polyisocyanate composition for producing a rigid polyurethane foam having a dimethylene triphenylene triisocyanate content of 30% by weight or more and 80% by weight or less and a metal content of 0.1 ppm or more and 10 ppm or less. object. (2) the content of dimethylenetriphenylene triisocyanate is 30% by weight or more and 80% by weight or less, and the content of a metal component is 0.1 ppm or more and 10 ppm or less;
0% by weight of diphenylmethane diisocyanate
The polymethylene polyphenyl polyisocyanate composition for producing a rigid polyurethane foam according to (1), wherein the content is more than 50% by weight. (3) the content of dimethylenetriphenylene triisocyanate is 30% by weight or more and 80% by weight or less, and the content of metal is 0.1 ppm or more and 10 ppm or less;
0% by weight of diphenylmethane diisocyanate
The polymethylene polyphenylpoly for producing a rigid polyurethane foam according to (1) or (2), wherein the content of the higher polymethylene polyphenylene polyisocyanate is more than 0% by weight and not more than 50% by weight. Isocyanate composition. (4) In a method for producing a rigid polyurethane foam from an isocyanate, a polyol, a foaming agent, a catalyst and a foam stabilizer, (1) to (3)
A method for producing a rigid polyurethane foam, comprising using the polymethylene polyphenyl polyisocyanate composition described in the above. (5) In a method for producing a rigid polyurethane foam from an isocyanate, a polyol, a foaming agent, a catalyst and a foam stabilizer, the isocyanate (1) to (3)
A rigid polyurethane foam obtained using the described polymethylene polyphenyl polyisocyanate composition.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. (Polymethylene polyphenyl polyisocyanate composition) The polymethylene polyphenyl polyisocyanate composition for producing a rigid polyurethane foam of the present invention is a dimethylene triphenylene triisocyanate composition from the viewpoint of preventing solidification of the polymethylene polyphenyl polyisocyanate composition. Is preferably 80% by weight or less,
When the content is 30% by weight or more, the obtained rigid polyurethane foam has a higher effect on flame resistance, heat resistance, flame retardancy and low smoke generation. Therefore, the content of dimethylene triphenylene triisocyanate is not less than 30% by weight and not less than 80% by weight.
The range is as follows. Furthermore, by using a polymethylene polyphenyl polyisocyanate composition having a content of metal as a by-product in the polymethylene polyphenyl polyisocyanate composition manufacturing process in the range of 0.1 ppm or more and 10 ppm or less, flame resistance and heat resistance can be improved. A rigid polyurethane foam having excellent properties, flame retardancy, and low smoke emission can be obtained. Therefore, the metal content is in the range of 0.1 ppm or more and 10 ppm or less. Preferably, the content of dimethylenetriphenylene triisocyanate is 30
% By weight and not more than 60% by weight, the content of the metal component is not less than 0.1 ppm and not more than 10 ppm, more preferably the content of dimethylenetriphenylene triisocyanate is not less than 35% by weight and not more than 50% by weight. Content is 0.1 ppm or more and 10 ppm or less. The metal content used in the present application is ppm by weight.

[0006] The polymethylene polyphenyl polyisocyanate composition for producing a rigid polyurethane foam is, in addition to dimethylene triphenylene triisocyanate and a metal component, diphenylmethane diisocyanate or diphenylmethane diisocyanate and dimethylene triphenylene triene in the polymethylene polyphenyl polyisocyanate composition. It preferably contains higher polymethylene polyphenylene polyisocyanate excluding isocyanate. When the other component is diphenylmethane diisocyanate, if the content of diphenylmethane diisocyanate is 50% by weight or less, the polymethylene polyphenyl polyisocyanate composition tends to be easily prevented from being solidified and the like, and the handling tends to be easy. Therefore, the content of diphenylmethane diisocyanate is generally more than 0% by weight and 50% by weight or less, preferably 15% by weight or more and 50% by weight or less, more preferably 25% by weight or less.
At least 45% by weight.

When the other component is higher polymethylene polyphenylene polyisocyanate, the higher polymethylene polyphenylene polyisocyanate is contained in order to keep the viscosity of the polymethylene polyphenyl polyisocyanate composition relatively low and maintain good operability. 50% by weight
The following is preferred. Therefore, the content of higher polymethylene polyphenylene polyisocyanate is generally more than 0% by weight and 50% by weight or less, preferably 10% by weight or more and 40% by weight or less, more preferably 1% by weight or less.
5% by weight or more and 35% by weight or less.

Here, higher polymethylene polyphenylene polyisocyanate refers to polynuclear polyisocyanates having four or more nuclei such as polymethylene polyphenylene tetraisocyanate and polymethylene polyphenylene pentaisocyanate. It is preferably tetranuclear or more and octanuclear, and is preferably a mixture of plural nuclei.

It is particularly preferred that the polymethylene polyphenyl polyisocyanate composition for producing a rigid polyurethane foam contains diphenyl methane diisocyanate and higher polymethylene polyphenylene polyisocyanate in addition to dimethylene triphenylene triisocyanate and an acid component. In each case, the content of diphenylmethane diisocyanate is more than 0% by weight and 50% by weight.
Or less, and the content of higher polymethylene polyphenylene polyisocyanate is more than 0% by weight and 50% by weight or less, preferably, the content of diphenylmethane diisocyanate is 15% by weight or more and 50% by weight or less and The content of polymethylene polyphenylene polyisocyanate is 10% by weight or more and 40% by weight or less,
More preferably, the content of diphenylmethane diisocyanate is from 25% by weight to 45% by weight, and the content of higher polymethylene polyphenylene polyisocyanate is from 15% by weight to 35% by weight.

In the polymethylene polyphenyl polyisocyanate composition for producing a rigid polyurethane foam of the present invention, any other than the above can be used insofar as the effects of the present invention are not impaired. For example, a polymethylene polyphenyl polyisocyanate composition in which a part of the isocyanate groups of the polymethylene polyphenyl polyisocyanate composition is modified to urea, urethane, buret, allophanate, carbodiimide, ureton imine, or the like can be used. In addition, a prepolymer having an isocyanate group at the molecular terminal obtained from the polymethylene polyphenyl polyisocyanate composition, a monol, and a polyol described below can also be used as part or all of the isocyanate composition. Further, if necessary, auxiliary agents such as a foam stabilizer may be added for use.

(Metal Content and Method for Measuring the Metal Content) The metal content used in the present invention is specifically a metal having a higher ionization tendency than Au which may be mixed in the process of producing the polymethylene polyphenyl polyisocyanate composition. K, C
a, a metal complex containing Na, Mg, Zn, Fe, Co, Pb, Cu, etc., metal complexes such as metal chlorides and metal hydroxides, such as FeCl2. The metal content is the weight of the metal contained per unit weight.

(Polyol) In producing a urethane foam using the polymethylene polyphenyl polyisocyanate composition for producing a rigid polyurethane foam of the present invention, all known polyols usually used as urethane raw materials can be used. Specifically, as the polyether polyol, for example, ethylene glycol, diethylene glycol, triethylene glycol,
Polypropylene alcohol such as propylene glycol, dipropylene glycol, tripropylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, α-methylglucoside, sucrose, aromatic amines such as tolylenediamine, ethylenediamine, triethanolamine And polyether polyols having a hydroxyl value of 300 to 800 mgKOH / g obtained by addition-polymerizing an alkylene oxide to a single or mixed system of aliphatic amines. As the polyester polyol, all known polyester polyols can be used, but a hydroxyl value of 200 to 50 formed by a condensation reaction of the above polyhydric alcohol with a low molecular weight carboxylic acid such as adipic acid or phthalic acid.
0 mgKOH / g polyester diol, polyester triol and the like. These polyether polyols and polyester polyols can be used in combination.

(Blowing agent) As the blowing agent used in the present invention, already known hydrochlorofluorocarbons, preferably 1,1-dichloro-1-fluoroethane, and further hydrofluorocarbons, preferably 1,1,1
1,2-tetrafluoroethane or 1,1,1,
3,3-pentafluoropropane, furthermore, hydrocarbons, preferably cyclopentane, furthermore CO ₂
Is preferred. Moreover, you may use these mixtures.

(Catalyst) As the catalyst, all known catalysts usually used for urethane foaming can be used. For example, trimethylaminoethylpiperazine, triethylamine, tripropylamine, N-methylmorpholine, N-ethylmorpholine, triethylenediamine, tetramethylhexamethylenediamine, dimethylcyclohexylamine, diazobicycloundecene,
Amine compounds such as triazines such as 3,5-tris (dimethylaminopropyl) hexahydro-s-triazine; aziridines such as 2-ethylaziridine; quaternary ammonium compounds such as tertiary amine carboxylate; allyl glycidyl Ether, polyalkylene glycol diglycidyl ether, alkali metal salts such as styrene oxide, lead compounds such as lead naphthenate and lead octylate, tin compounds such as dibutyltin diacetate and dibutyltin dilaurate, and alcoholate compounds such as sodium methoxide; Phenolate compounds such as potassium phenoxide, iron chloride,
Examples thereof include metal halides such as zinc chloride, zinc bromide, and tin chloride, and metal complex compounds such as acetylacetone metal salts. These catalysts can be used alone or in combination of two or more kinds.
0.001 to 15.0 parts by weight to 0 parts by weight is appropriate.

(Foam stabilizer) As the foam stabilizer, conventionally known silicon-containing organic surfactants are used. For example, SZ-1127, SZ-1142, and SZ-1127 manufactured by Nihon Unica Ltd.
Z-1605, SZ-1642, SZ-1649, SZ
-1655, L-580, L-5740, L-542
SF-2935F, SF-2938F, S manufactured by Toray Dow Corning Silicone Co., Ltd.
F-2940F, SF-2945F, SF-2908,
SRX-294A, SH-190, SH-192, SH
F-327, F-, manufactured by Shin-Etsu Chemical Co., Ltd.
345, F-305, etc. are suitable. These foam stabilizers are used in an amount of 0.1 to 100 parts by weight of the total of the polyol and the polymethylene polyphenyl polyisocyanate composition.
01 to 10 parts by weight.

(Other additives at the time of polyurethane production) In the method of the present invention, a co-catalyst, a flame retardant,
Auxiliaries such as plasticizers, stabilizers, fillers, and coloring agents can be added. Examples of the co-catalyst include a carbonate compound such as ethylene carbonate and propylene carbonate and a phosphoric acid compound such as a phosphoric ester and a phosphite.

(Method for Producing Rigid Urethane Foam) The method for producing a rigid urethane foam of the present invention is produced as follows. Solution A of the polymethylene polyphenyl polyisocyanate composition of the present invention, solution B of the polyol component, solution A and / or solution B in advance of a foaming agent, a catalyst and a foam stabilizer, and if necessary, other auxiliaries. And the two liquids are mixed using an apparatus described below,
It is obtained by curing. The ratio of the isocyanate group to the active hydrogen group in the present invention is (NCO / OH equivalent ratio)
Is in the range of 0.7 to 5.0, preferably 1.0 to 3.0.
Is particularly preferred. NCO / OH equivalent ratio of 0.8
If it is less than 5, the obtained foam may not have sufficient physical properties, and if it exceeds 5.0, the brittleness is increased and the adhesiveness tends to decrease, which is not preferable. In producing rigid polyurethane foam from the above raw materials,
Any device that can be mixed uniformly can be used. For example, a small mixer or a low-pressure or high-pressure foaming machine for producing general urethane foam can be used. Further, prior to mixing, heating can be performed if necessary.

[0018]

By using a polymethylene polyphenyl polyisocyanate composition of a specific composition, the flame resistance, heat resistance, flame retardancy and low smoke emission of a rigid polyurethane foam obtained from the composition are improved. . or,
Since the polymethylene polyphenyl polyisocyanate composition of the present invention is a uniform and stable liquid having a relatively low viscosity and a high boiling point, it is easy to handle and excellent in operability, and has good compatibility with the polyol component. Therefore, it is useful as an isocyanate for producing a rigid polyurethane foam. Furthermore, the rigid urethane foam obtained according to the present invention exhibits excellent properties such as excellent foam shrinkage resistance, dimensional stability and flame retardancy even when the amount of the foaming agent is increased.

[0019]

The present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. In the examples and comparative examples, the following raw materials were used.

<Components Used in Liquid B> Polyester polyol: TEROL2 manufactured by Oxid
50 (hydroxyl value: 250 mg KOH / g, viscosity: 500
0 cps / 25 ° C) Foam stabilizer: SZ-1642 manufactured by Nippon Unicar Catalyst A: POLYCA manufactured by Air Products
T41 Catalyst B: MINICO K-65 manufactured by Active Materials Chemical Co., Ltd. Blowing agent: HCFC-141b (1,1-dichloro-1-fluoroethane) manufactured by Mitsui Dupont Fluorochemicals

(Example 1) 200 g of the liquid B (polyol component) having the compounding ratio shown in Table 1 was adjusted, and the liquid temperature was kept at 25 ° C. The liquid temperature was also shown in Table 2 at 25 ° C. 200 g of the liquid A of the composition (polymethylene polyphenyl polyisocyanate composition) was added and mixed at a high speed for 5 seconds, and immediately poured into a free foaming box (size: 250 × 250 × 250 mm) to foam. At the time of the high-speed mixing operation, the viscosity of the mixture was relatively low, and the handleability was further excellent as compared with Example 3. In addition, the ratio NCO / OH equivalent ratio of the isocyanate group and the hydroxyl group was set to 2.0. Table 2 shows the results of a combustion test of the foam left for 24 hours in a constant temperature chamber at 23 ° C. and a humidity of 65% after foaming according to JIS A-1321.

(Examples 2 and 3) Liquid A having composition used (polymethylene polyphenyl polyisocyanate composition)
A foam was manufactured in the same manner as in Example 1 except that
The burning results of the foam were evaluated. Table 2 shows the results.

(Comparative Example 1) As shown in Table 2 of Liquid A (polymethylene polyphenyl polyisocyanate composition), solidification occurred and a foam could not be produced.

(Comparative Examples 2 to 5) Liquid A having composition used (polymethylene polyphenyl polyisocyanate composition)
A foam was manufactured in the same manner as in Example 1 except that
The burning results of the foam were evaluated. Table 2 shows the results.

[0025]

[Table 1]

[0026]

[Table 2]

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Makoto Maruyama 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture Inside Mitsui Chemicals Co., Ltd. (72) Kenichi Sugiura 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Chemicals F Term (Reference) 4J034 BA02 BA03 CA04 CA05 CA15 CB03 CB04 CB05 CB07 CB08 CC03 CC08 CC12 CC61 CC65 DA01 DB04 DB05 DB07 DF01 DF16 DF20 DF22 DG14 EA07 HA01 HA02 HA07 HA08 HA14 HC12 HC64 HC65 HC67 HC71 KA01 KB02 K18 KA01 KB02 K02 KD NA06 QB16 QB17 QB19 QC01

Claims (5)

[Claims] (1) the content of dimethylenetriphenylene triisocyanate is 30% by weight or more and 80% by weight or less;
A polymethylene polyphenyl polyisocyanate composition for producing a rigid polyurethane foam, wherein the metal content is 0.1 ppm or more and 10 ppm or less. 2. The dimethylenetriphenylene triisocyanate content is 30% by weight or more and 80% by weight or less,
The polymethylene for producing a rigid polyurethane foam according to claim 1, wherein the content of the metal component is 0.1 ppm or more and 10 ppm or less, and the content of diphenylmethane diisocyanate is more than 0% by weight and 50% by weight or less. Polyphenyl polyisocyanate composition. 3. The content of dimethylenetriphenylene triisocyanate is 30% by weight or more and 80% by weight or less,
The metal content is 0.1 ppm or more and 10 ppm or less, the content of diphenylmethane diisocyanate is more than 0% by weight and 50% by weight or less, and the content of higher polymethylene polyphenylene polyisocyanate is more than 0% by weight and 50% by weight. % Or less, the polymethylene polyphenyl polyisocyanate composition for producing a rigid polyurethane foam according to claim 1 or 2. 4. A process for producing a rigid polyurethane foam from an isocyanate, a polyol, a foaming agent, a catalyst and a foam stabilizer, wherein the polymethylene polyphenyl polyisocyanate composition according to claim 1 is used as the isocyanate. A method for producing a rigid polyurethane foam. 5. A process for producing a rigid polyurethane foam from an isocyanate, a polyol, a foaming agent, a catalyst and a foam stabilizer, wherein the polymethylene polyphenyl polyisocyanate composition according to claim 1 is used as the isocyanate. A rigid polyurethane foam, characterized by being obtained.