JPH06271639A - Production of inorganic substance-packed flame-retardant rigid urethane foam - Google Patents

Abstract

PURPOSE:To obtain the subject product having improved flame retardance and reduction in physical properties of foam suppressed as much as possible by using a specific, a prescribed inorganic filler and water as a blowing agent. CONSTITUTION:A raw material mixture comprising (A) a polyisocyanate, (B) a sucrose-based polyether polyol, (C) a blowing agent containing at least 1-2.5 pts.wt. of water based on 100 pts.wt. of the component B and (D) 30-70 pts.wt. of an inorganic filler composed of an aluminum compound (e.g. aluminum hydroxide) based on the composition except the component C is expanded to give the objective product. The component B uses sucrose as a reaction initiator and is obtained by adding propylene oxide. A volatile blowing agent such as difluorodichloromethane is usually used besides water as the component C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant rigid urethane foam, and more particularly to an inorganic-filled flame-retardant rigid urethane foam used as a building material and having a high degree of flame retardancy. Especially flame retardancy based on JIS A-1321 (flame retardancy test method for interior materials of construction and construction method) 2
It is intended to provide those who pass Class A.

[0002]

2. Description of the Related Art Rigid urethane foam is widely used as various heat insulating materials and building materials because it has many features such as heat insulating property, moldability, light weight and high strength.
However, various problems have been pointed out for this material,
In particular, from the viewpoint of preventing fire disasters in recent years, improvement has been particularly demanded in terms of resistance to flame retardancy, and various flame retardant foams have been developed. Various methods have hitherto been attempted in order to improve flame retardancy. For example, when foaming a rigid urethane foam, there is a method of adding various flame retardants to raw materials in advance. As this method, for example, (1) a method of using one kind or two or more kinds of a phosphoric acid compound, a halogen compound, a halogenated phosphoric acid compound, antimony trioxide, etc., and (2) a polyol as a raw material Halogen-containing polyol in part or all,
A method of using a phosphorus-containing polyol, and a method of introducing an isocyanurate bond into a foam (3) are known.

[0003]

However, none of the above-mentioned methods has made it possible to obtain a flame-retardant foam which sufficiently satisfies the increasingly demanding flame-retardant requirements in recent years. With some foams having isocyanurate groups introduced, the desired flame retardant foam may be obtained under extremely limited conditions such as when the thickness of the foam is small or when a thick surface material is used. there were. Further, in order to further improve the flame retardancy, it is necessary to use a large amount of expensive flame retardant, which causes the physical properties of the foam to be deteriorated and the raw material cost to be high.

The present invention overcomes the above drawbacks,
An object of the present invention is to provide a method for producing a flame-retardant rigid urethane foam which has excellent flame retardancy, minimizes deterioration of general physical properties of foam, is inexpensive, and has a wide range of application.

[0005]

Means for Solving the Problems As a result of earnest studies for improving the flame retardancy of rigid urethane foams, the present inventors have found that the types of raw polyols are limited and the amount of water used as a blowing agent is limited. The present inventors have completed the present invention by discovering a remarkable synergistic effect that cannot be achieved by the conventional flame-retardant method, due to the limitation of the type of inorganic filler and the blending amount thereof. The present invention relates to a method for producing an inorganic material-filled flame-retardant rigid urethane foam by foaming a raw material composition containing a polyisocyanate, a polyol, an inorganic filler and a foaming agent, wherein the polyol is a sucrose-based polyether polyol. And at least water is used as the foaming agent, and the blending amount of water is 1.0 to 100 parts by weight of the polyol (hereinafter, simply referred to as “parts”).
It is 2.5 parts, an aluminum compound is used as the inorganic filler, and the compounding amount of the aluminum compound is 30 to 70% by weight based on the raw material composition excluding the foaming agent.

In the above-mentioned "sucrose-based polyether polyol", sucrose is used as a main reaction initiator (glycerin, water, ethylene glycol, etc. may be used together if necessary), and alkylene oxide is added. Polyether polyols obtained by using the same as those used in the usual production of rigid urethane foam can be used as they are. Since the reaction initiator sucrose is a solid,
Since it is difficult to add alkylene oxide as it is, glycerin, water, ethylene glycol and the like can be appropriately used in combination, but a higher sucrose ratio in the reaction initiator is preferable. As an example, the sucrose ratio is preferably 50 mol% or more.

Further, as the alkylene oxide,
Although ethylene oxide, propylene oxide, butylene oxide and the like can be used alone or in combination, it is common to use propylene oxide, which is preferable in terms of cost and foam physical properties.

The sucrose-based polyether polyol has a hydroxyl value of 300 or more, preferably 350 or more. If a polyol having a hydroxyl number of less than 300 is used, the foam has poor dimensional stability. Further, a polyol other than the sucrose-based polyether polyol can be used as the auxiliary polyol, but it is preferable that the amount thereof is as small as possible and at most 50% or less.

An aluminum compound is used as the "inorganic filler". As the aluminum compound, aluminum hydroxide, aluminum oxide, aluminum sulfate, aluminum carbonate, aluminum nitrate, aluminum silicate or the like can be used. The blending amount is 30 to 70% by weight based on the raw material composition excluding the volatile foaming agent and water (foaming agent), that is, the resin constituent component. If it is less than 30% by weight, the flame retardant effect is small, and if it exceeds 70% by weight, the mixing property is deteriorated, which is not preferable.

Usual industrial chemicals can be used as they are as the aluminum compound. The average particle size is 10 in order to improve the dispersibility in the polyurethane raw material.
It is preferably about 200 μm. The aluminum compound may or may not be surface-treated (silane treatment, fatty acid treatment, titanate treatment, etc.), but this surface treatment improves the dispersibility in the polyurethane raw material. Is more preferable, so that it is preferable.

As the "foaming agent", at least water is used, and usually water and a volatile foaming agent are used. As this water, distilled water or ion-exchanged water is preferable. Although tap water, ground water, etc. may be used as they are, they are not preferable because they may lack stability of the amine catalyst and the like. The amount of water to be added is 1.0 to 2.5 parts, preferably 1.5 to 2.0 parts, relative to 100 parts of polyol. The reason for limiting the amount of water used in this way is that the flame retardancy of the foam is inferior when it is less than 1.0 part and when it exceeds 2.5 parts. This is because the amount of smoke generated increases particularly in the above flame retardancy test. Further, as this volatile foaming agent,
Known, commonly used neutralizing liquids for foaming are used, for example, fluorocarbon carbon such as difluorodichloromethane, trichloromonofluoromethane, 1,1 dichloro-1.
Examples include chlorofluorohydrocarbons such as fluoromethane and 2,2 dichloro-1,1,1 trifluoroethane, alkylene chlorides such as methylene chloride, and hydrocarbons such as isopentane.

As the "polyisocyanate", various known ones, for example, Polymeric MDI can be used. Furthermore, as other raw material components, a reaction catalyst, a foam stabilizer, other auxiliaries and the like can be appropriately blended. As this reaction catalyst, various tertiary amines and / or
Alternatively, an organometallic compound can be used. As the foam stabilizer, various silicone-based surfactants can be used.

The isocyanate index (hereinafter, simply referred to as Index) of the raw material composition (formulation) of the rigid urethane foam is 10 as in the case of the usual urethane foam formulation.
It can be used in the range of 0 to 150, particularly preferably in the range of 105 to 130. In the present invention, it is not necessary to set this Index as high as in the isocyanurate composition. If this Index is less than 100, the dimensional stability of the foam may deteriorate, and if it exceeds 150, the flame-retardant smoke generation amount may increase, which is not preferable.

[0014]

In the present invention, it has been possible to produce a rigid urethane foam having excellent flame retardancy by limiting the types of the polyol and the inorganic filler, their blending amounts, and the water blending amount. Has not yet been fully elucidated. At present, the use of sucrose-based polyols has the effect of increasing the amount of carbonization residues during foam combustion, and the use of water has the effects of stabilizing foaming and achieving low density and improving flame retardancy. The use of the filler can be expected to suppress the amount of heat generated during combustion, the amount of smoke emitted, and the ignition property, and it is presumed that the synergistic effect of these can exert the excellent effect of the present invention.

In order to realize the effects of the present invention, a sandwich panel using face materials such as colored zinc iron plates on both sides is usually used in the present invention. This sandwich panel is now very widely used as a building material such as a roofing material, an outer wall material, a flooring material, a partitioning material, and a heat insulating material for a refrigerating warehouse. As a conventional sandwich panel, in order to pass the flame retardant class A in the flame retardancy test, isocyanurate foam is used as the core material,
It was necessary to make the total thickness of the panel 30 mm or less. Therefore, it was inevitably expensive. According to the present invention, it is possible to pass the above flame retardancy test without limiting the total thickness of the panel by the rigid urethane foam formulation. Therefore, increase in manufacturing cost is avoided and panel specifications (thickness etc.)
It is possible to exert a high degree of flame retardancy without restriction.

[0016]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples. The parts or% in the examples and comparative examples represent parts by weight and% by weight, respectively. (1) Preparation of flame-retardant performance test body In this example, a flame-retardant performance test body was prepared as follows. First, a colored zinc iron plate (commercial item) having a thickness of 0.5 mm was cut into 220 × 220 mm and used as a face material. The above-mentioned two colored zinc iron plates were set to have a predetermined thickness in the center of an aluminum mold having internal dimensions of about 300 × 300 mm (variable in the thickness direction). At this time, four spacers having a predetermined thickness were used. Among these, Tables 1-8
Etc. (Examples 1 to 24 and Comparative Examples 1 to 11 shown below) were injected with a hard urethane foam raw material composition having a predetermined formulation by a hand mixing method to perform integral foam molding. The raw material composition temperature at this time was set to 20 ± 2 ° C., and the aluminum mold temperature was set to 45 ± 5 ° C. Then, the foam was cut into a size of 220 × 220 mm along the size of the colored zinc iron plate to obtain a test body. In addition, the test piece for additional test is 25m based on the standard based on the following test method.
Three mφ holes were provided.

The raw materials used in each Example and Comparative Example are as follows. "Polyol A": Sucrose type "Polyol # 480J" manufactured by Sumitomo Bayer Urethane Co., Ltd., having an OH value of 480 and a viscosity of 50,000 cp (25 ° C). "Polyol B"; a sucrose-based polyol from Asahi Glass Co., Ltd., "EXCENOL 455S", which has an OH value of 455 and a viscosity of 31,000 cp (25 ° C). Polyol C: Asahi Glass Co., Ltd.'s sucrose-based polyol, "EXCENOL 375S", having an OH value of 37.
5. The viscosity is 2350 cp (25 ° C.). Polyol D; a sorbitol-based polyol from Asahi Glass Co., Ltd., “EXCENOL 500S”, having an OH value of 50.
0, viscosity is 39,000 cp (25 ° C). Silicone foam stabilizer: "SH-193" manufactured by Toray Dow Corning Silicone Co., Ltd. was used. Polymeric MDI; "Millionate MR-100" manufactured by Nippon Polyurethane Industry Co., Ltd. was used.

(2) Flame-retardant performance test method Regarding the test body manufactured as described above, JIS A13
A surface test and an additional test (referred to as a perforation test) were carried out based on the flame-retardant class A of 21 (interior material for buildings and flame-retardant test method for construction method). In the present invention, each performance item is abbreviated as follows. Tdθ-Temperature area over standard temperature curve (° C min) CA-Smoke emission coefficient per unit area AFT-Afterflame time (sec)

(3) Examples 1 to 4 and Comparative Examples 1 to 3 In these test examples, the flame retardancy was evaluated by varying the water content in the range of 0 to 3.0 parts. Example 1 First, the raw material composition according to Example 1 shown in Table 1 (Index: 1
Test piece (sandwich panel) with a total thickness of 35 mm using 0.5 mm colored zinc iron plates (2 sheets)
Was prepared for each 3 sheets.

A surface test and an additional test (perforation test) were performed using this test body, and the following results were obtained. The results are shown as an average value of 3 samples each. (A) Foam density (kg / m ³ ) 35.1 (B) Surface test result Tdθ 75 (less than 100 *) CA 36 (less than 60 *) AFT 25 (less than 30 *) (C) Additional test result (Table 1 Tdθ 100 (Less than 150 *) CA 45 (Less than 60 *) AFT 55 (Less than 90 *) (D) Judgment Pass In addition, in the above, the * mark indicates the acceptance standard of the same standard.

In the case of Example 1, both the surface test and the additional test pass a certain standard as described above. In the course of conducting these series of experiments, the surface test can be passed with almost no problem with such a test piece using thick iron plate face materials on both sides. Therefore, in the following Examples and Comparative Examples, only the results of the additional test (piercing test) will be shown. Regarding the following examples and comparative examples, those that passed the additional test were subjected to the surface test, and it was confirmed that all of them passed except the comparative example 3, but the results are also shown in each table. Not not.

Examples 2 to 4 and Comparative Examples 1 to 3 Using the raw material compositions shown in Table 1, test specimens for additional tests were manufactured in the same manner as above, and additional tests were conducted. The results are shown in Table 1. It was shown to. According to these results, the amount of water added was 1.
In the range of 0 to 2.5 parts (Examples 1 to 4), it passed the flame retardant class A. On the other hand, Comparative Examples 1 and 2 (0 part and 0.5 part, respectively) with a small amount of water added failed the additional test. In addition, in Comparative Example 3 (when the amount of water added is 3.0 parts), the additional test passed, but the surface test failed.

[0023]

[Table 1]

(4) Examples 5 to 7 and Comparative Examples 4 to 5 Using the raw material compositions shown in Table 2, in particular, the Index was 105.
Change from 130 to 130 and carry out the same procedure,
Good results were obtained in the range of 2.5 parts (Examples 5 to 7).
On the other hand, in Comparative Example 4 (no addition of water) and Comparative Example 5 (the amount of water added was 3.0 parts), which did not exist, the addition test failed.

[0025]

[Table 2]

(5) Examples 8 to 10 and Comparative Examples 6 to 7 The raw material compositions shown in Table 3 were used, and in particular, aluminum hydroxide was blended in an amount of 0 to 63%. Shown in the table. According to this result, the compounding amount of aluminum hydroxide was 30 with respect to the composition excluding water and the volatile foaming agent.
In the range of up to 63% by weight (referred to as%), all of them passed the flame retardant class A. On the other hand, Comparative Example 6 (no addition) and Comparative Example 7 (1
5% addition) failed.

[0027]

[Table 3]

(6) Examples 11 to 13 Using the raw material compositions shown in Table 4, in particular, using aluminum oxide in place of the aluminum hydroxide of the previous examples (Examples 8, 3 and 9), the same procedure was carried out. The results are shown in the same table. According to this result, when the blending amount of aluminum oxide was 30 to 59%, all of the flame retardant second grade A passed, as in the case of aluminum hydroxide.

[0029]

[Table 4]

(7) Example 14 and Comparative Examples 8 to 10 Using the raw material compositions shown in Table 5, particularly, using aluminum sulfate, magnesium hydroxide, boric acid and silicon dioxide as the inorganic filler, the same procedure is carried out. The results are shown in the same table. When aluminum sulfate was used (Example 14), it passed the flame-retardant secondary class A, but when other aluminum compounds were used (Comparative Examples 8 to 10), it failed. Further, when magnesium hydroxide and silicon dioxide were used, the viscosity of the polyurethane raw material increased remarkably, and it was not possible to add more than the amount shown in the table.

[0031]

[Table 5]

(8) Examples 15 to 16, Comparative Example 11 Using the raw material compositions shown in Table 6, in particular, instead of the sucrose-based polyether polyol A, polyols B and C (both are sucrose-based). And D (sorbitol type), and the results are shown in the same table.
When the sucrose-based polyether polyols (B and C) were used (Examples 15 and 16, respectively), both passed. On the other hand, when the non-sucrose-based sorbitol-based polyether polyol (D) was used, it failed.

[0033]

[Table 6]

(9) Examples 17 to 19 In the test examples described above, the total thickness of the sandwich test bodies was 3
Although the test piece having a size of 5 mm has been used for evaluation, in this example, as shown in Table 7, the total thickness of the test piece was changed to 25 to 60 mm, and the same test was performed, and the results are shown in the same table. According to this result, even if the total thickness of the test piece was changed, all of them passed.

[0035]

[Table 7]

(10) Examples 20 to 22 In this example, the density of the flame-retardant rigid urethane foam is about 30.
The same test is performed by changing in the range of up to 50 kg / m ³ .
The results are shown in Table 8. According to this result, all pass in this wide density range.

[0037]

[Table 8]

(11) Examples 23 and 24 In this example, instead of 120 parts of trichloromonofluoromethane used in Example 12, 108 parts of 1,1 dichloro-1-fluoromethane (volatile blowing agent B) (implementation) Example 23) and 125 parts of 2,2 dichloro-1,1,1-trifluoroethane (volatile foaming agent C) (Example 24) were used to foam-mold as in Example 12 and similarly test. went. The results are shown in Table 9 below.

[0039]

[Table 9] Table 9 --------------------------------------------- Example No. Example 23 Example 24 --- Type of Volatile Foaming Agent Volatile Foaming Agent B --------------------------- volatile blowing agent C --------------------------------- panel density (kg / m ³⁾ 36.7 38 .4 Tdθ 102 97 CA 50 52 AFT 75 68 Judgment Pass Pass ----------------------------------------------- According to the report, any volatile blowing agent was used.

(11) Example 25 In this example, 10 parts of tris (2chloroethyl) phosphate was added to the raw material composition of Example 12 as an addition type flame retardant.
Using the composition added in part, foam molding was performed in the same manner, and an additional test was conducted in the same manner. According to this result, the result of the additional test was almost the same as that of the case of Example 12, and it passed.

The present invention is not limited to the specific examples described above, and various modifications may be made within the scope of the present invention depending on the purpose and application.

[0042]

As described above, according to the manufacturing method of the present invention, it is possible to significantly improve the flame retardancy and to manufacture a practical flame-retardant rigid urethane foam. That is, in the present production method, a foam which passes flame retardant Class 2 A can be produced, the density and thickness of the foam can be set in a wide range, and deterioration of the physical properties of the foam can be suppressed to the minimum to enhance the flame retardancy. it can.

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Claims (2)

[Claims] 1. A method for producing an inorganic material-filled flame-retardant rigid urethane foam by foaming a raw material composition containing a polyisocyanate, a polyol, an inorganic filler and a foaming agent, wherein the sucrose-based polyether is used as the polyol. A polyol is used, at least water is used as the foaming agent, and the amount of the water is 1.0 to 2.5 parts by weight with respect to 100 parts by weight of the polyol, and an aluminum compound is used as the inorganic filler. And the blending amount of the aluminum compound is 30 with respect to the raw material composition excluding the foaming agent.
A method for producing a flame-retardant rigid urethane foam filled with an inorganic material, characterized in that: 2. The method for producing an inorganic material-filled flame-retardant rigid urethane foam according to claim 1, wherein one kind or two or more kinds selected from aluminum hydroxide, aluminum oxide and aluminum sulfate is used as the aluminum compound.