JPS6215220A - Production of flame-retardant polyurethane foam - Google Patents

Abstract

PURPOSE:To obtain the titled foam, having improved cushioning property, productivity, etc., suitable for automotive interior trim materials, heat insulating material, etc., and scarcely emitting toxic gases even on combustion. CONSTITUTION:For example, 100pts. glycerol based polyether polyol is premixed with 30pts. melamine expressed by the formula as a flame retardant, 4pts. water as a foaming agent, 0.45pts. amine catalyst and 1.5pts. silicone, and 0.3pt. tin catalyst is then added and mixed therewith. 50pts. isocyanate is then added and stirred to foam the mixture and give the aimed foam.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides a flame-retardant polyurethane foam (hereinafter collectively referred to as "automobile interior material, etc.") useful as an interior material for automobiles, a heat insulator, a building material, etc. (hereinafter collectively referred to as interior material for automobiles, etc.). (hereinafter referred to as polyurethane foam).

[Conventional technology]

Conventionally, flexible polyurethane foams include halogen type, organic phosphorus type, antimony type, and inorganic type, and rigid polyurethane foams include halogen type, organic phosphorus type, cyanurate type, and inorganic type. It is well known that polyurethane foam is manufactured as a final material using polyols, isocyanates, and other necessary components, but whether the final polyurethane foam is flexible or rigid depends on the number of functional groups in each component. , determined by appropriate selection of molecular weight, skeletal structure, etc. Based on these facts, the compositions, physical properties, etc. of each of the above-mentioned series of conventional polyurethane foams will be explained below, dividing them into soft and hard types.

(a) Flexible polyurethane foam ■Halogen type: Contains 50 parts of isocyanate and 10 to 20 parts of halogen type as starting materials per 100 parts of polyol, and has excellent productivity based on ease of mixing of each component. Furthermore, since it contains a large amount of halogens such as chlorine and bromine, it belongs to the category of being difficult to burn, but when it burns, it tends to generate a large amount of toxic gas.

Furthermore, depending on the amount of halogen-based substances added, so-called "waist"
It becomes a weak polyurethane foam.

■Organic phosphorus type: Contains 50 parts of isocyanate and 10 to 20 parts of organic phosphorus type as starting materials per 100 parts of polyol, and does not emit toxic gas even when burned, but has a good plasticizing effect and is weak in "firmness". In addition, organic phosphorus compounds exhibit flame retardant effects.

(2) Antimony-based: Contains 50 parts of isocyanate and 10 to 25 parts of an antimony-based compound as starting materials per 100 parts of polyol, but productivity is lacking because the antimony-based compound is difficult to mix. Furthermore, in order to make the flame retardance of antimony-based polyurethane foam equivalent to that of the above-mentioned halogen-based polyurethane foam, it is necessary to add 15 parts or more of a halogen-based substance such as chlorine. Therefore, it tends to produce large amounts of toxic gas when burned. In addition, antimony-based compounds 10 to 25
However, when a polyurethane foam is added, a weakly flexible polyurethane foam is obtained, and although it is generally soft, it becomes relatively hard and has poor cushioning properties.

■Inorganic type: Manufactured using polyols, isocyanates, aluminum hydroxide, calcium carbonate, soda carbonate, etc. as starting materials, but inorganic types are similar to the antimony-based formulations mentioned above and are difficult to mix with other additive components, so compared to halogen-based compounds. and productivity is significantly lower. In addition, this series has cushioning properties,
Although its water absorption and flame retardancy are inferior to the halogen-based and antimony-based materials mentioned above, it does not contain any halogen-based materials, so no toxic gas is emitted when it burns. However, the foaming ratio is low, the density is high, and the flexibility is poor. It is also expensive in terms of cost.

Table 1 shows the physical properties of each of the above-mentioned series for comparison.

(The following is a blank space) Table 1 (b) Rigid polyurethane foam ■ The halogen type, organic phosphorus type, and inorganic type are the same as those explained for the flexible polyurethane foam.

■Cyanurate type: Contains 150 parts of isocyanate (isocyanate that forms an isocyanurate ring) per 100 parts of polyol, and since strict reaction conditions are required during production, productivity can be judged to be low from this point of view. Also, since it contains a large amount of isocyanate, it is difficult to burn, but when it burns, toxic gas (cyan gas) is generated. It has good flame retardancy and water absorption resistance.

Table 2 shows the physical properties of each of the above series for comparison.

Table 2 By the way, one of the purposes of the present invention is to provide a polyurethane foam that can be used as an interior material for automobiles, etc. In order to achieve this purpose, the typical physical properties required of the polyurethane foam are as follows. belongs to.

That is, productivity, cushioning properties, water absorption resistance, moisture absorption resistance, presence or absence of toxic gas generation during combustion, flame retardancy, cost, and dehalogenation properties. Among these, moisture absorption resistance and cushioning properties are properties required for softness, and water absorption resistance is properties required for hardness. Other characteristics are required of both.

Productivity is determined by the ease of mixing of each starting material component and the degree of strictness of reaction conditions, etc. High productivity makes it easy to achieve cost reduction and also makes it possible to homogenize the composition of polyurethane foam as the final material. This is advantageous in terms of planning. Cushioning properties affect the windows used in automobile interior materials, etc. If the cushioning properties are too good, the "waist" will be too weak, and if the cushioning properties are poor, the "waist" will be too strong, making it unsuitable for actual use. If the hygroscopicity/water absorption is too good, corrosion of metal parts will be promoted. The presence or absence of toxic gas generation and flame retardancy have become particularly important in recent years, taking into account the safety of automobiles, insulation materials, and building materials during combustion, and it is desirable to minimize the generation of toxic gas during combustion. It will be done.

When selecting polyurethane foam as an automotive interior material, etc., it is necessary to comprehensively consider the various physical properties listed above, including productivity, flame retardancy, cost, cushioning properties, water absorption resistance, and moisture absorption resistance. Of the above series, halogen-based and organic phosphorus-based polyurethane foams are highly suitable for both soft and hard materials. However, organic phosphorus-based materials require a large amount to be added, and their plasticizing effect tends to weaken their "stiffness." From this point of view, halogen-based polyurethane foams have been frequently used in conventional automobile interior materials.

However, halogen-based additives contain large amounts of corrosive components such as chlorine, bromine, and phosphoric acid-halogen reactants, and these tend to gradually bleed out from polyurethane foam, so they are less likely to corrode metal parts. It has the disadvantage that it progresses quickly and has a strong tendency to discolor surface materials such as leather and textiles. When flame laminating is performed, halogen gas and halogen odor are generated, deteriorating the working environment.

Therefore, in recent years, there has been much research into using polyurethane foam, which is not halogen-based but has the above properties equivalent to or superior to halogen-based ones, as interior materials for automobiles, and various melamine-based polyurethane foams have been proposed. has been done.

Conventional melamine-based polyurethane foams are produced using polyols, isocyanates, and melamine derivatives as starting materials, and do not contain halogens, that is, meet the requirements for dehalogenation, and have the same productivity as halogen-based polyurethane foams. The cushioning properties are superior to halogen-based materials, and the flame retardancy is equivalent to halogen-based materials, but even when burned, a large amount of toxic gas is not generated from the halogen-based culm. Table 3 compares and contrasts the physical properties of such conventional melamine-based materials with those of halogen-based materials.

(Hereinafter, blank spaces) Table 3 As mentioned above, polyurethane foams whose physical properties are equivalent to those of halogen-based materials, other than those related to halogen-removal properties and generation of toxic gas during combustion, are suitable for automobile interior materials, etc. From this point of view, conventional melamine-based polyurethane foams can be fully used as interior materials for automobiles.

[Problem that the invention seeks to solve]

However, as mentioned above, the melamine type uses a melamine derivative as a flame retardant in addition to polyols and isocyanates as starting materials. Melamine derivatives are produced using melamine shown by the following formula, that is, 2,4.6-)riamino-1,3,5-)riazine as a raw material, and since melamine has poor reactivity as a whole,
Equipment costs and other necessary costs for obtaining melamine derivatives are expensive. On the other hand, melamine derivatives lose their stability after about a week. It also tends to foam abnormally. Therefore, polyurethane foams containing melamine derivatives as starting materials tend to be expensive.

The present invention aims to solve this problem.

[Means for solving problems]

In order to solve the above problems, the gist of the present invention is that the starting material contains a polyol, a polyisocyanate, and a flame retardant, and the flame retardant is melamine represented by the following formula.

〔Effect of the invention〕

According to the above means, since it is not necessary to synthesize a melamine derivative from melamine, there is no need for synthesis equipment for this purpose, and as a result, a reduction in the cost of polyurethane foam is achieved. In addition, by appropriately selecting the blending ratio of starting materials, manufacturing conditions, etc., the polyurethane foam produced by the method of the present invention can have the same flame retardancy as the above-mentioned halogen-based polyurethane foam, that is, it can be used as an interior material for automobiles, etc. It has various physical properties required for.

An experimental example will be explained below.

[Experimental Example 1] This experimental example relates to the production of flexible polyurethane foam.

Glycerin-based polyether polyol (trade name Sumifen 3086 manufactured by Sumitomo Bayer Urethane) is 10
0 parts, 30 parts of melamine, water as a blowing agent ()I
zO) 4 parts, 0.45 parts of amine catalyst (product name DABCO33LV manufactured by Nippon Nyukazai ■ & Sankyo Air Products), silicone (product name 5 manufactured by Toshi Silicone ■) 1-1
A raw material system containing 1.5 parts of 90) was placed in a container of 21,
Preliminary mixing was carried out for 5 to 7 seconds at 0 rpm, and 0.3 parts of a tin catalyst (trade name T-9, manufactured by Nitto Kasei) was added thereto.
Mixed for 4 seconds on Orpm. Next, 50 parts of isocyanate (trade name T-80 manufactured by Sumitomo Bayer Urethane@) was added and stirred at 2000 to 300 Orpm for 7 to 8 seconds. The foam raised by this stirring was put into a wooden box and cured in the open at 150°C for 10 minutes. The raw material system temperature was 22 to 25°C, the cream time was 12 seconds, and the rise time was 74 seconds. The above-mentioned cream time is the rise time when the raw materials are stirred with a high-speed mixer to make them milky, and the rise time is the time when the foam rises and reaches its maximum height.

Regarding the flexible polyurethane foam manufactured by the above method,
Tests were conducted on the following items.

Test items: Cushioning properties, water absorption, moisture absorption, flame retardancy, presence or absence of toxic gas generation during combustion Test method: Cushioning properties (soft): Based on JIS A 64015.5 compressive residual strain test.

Water absorption (hard): Based on JIS A 95416.4 water absorption. Test pieces(
100X 100X25) was immersed in clear water for 10 seconds, left for 30 seconds on a wire mesh with an inclination of 30°, weighed, and again compared with the weight after immersed in clear water for 24 hours.The difference in weight is expressed by comparing the surface area. 3 gr/100 ctl or less is good.

Moisture absorption it (soft): Test piece (100x 100x20) at 50°C, 98% R
Place it in H for 24 hours and compare the weight difference.

Flame retardancy (soft): Conforms to FMVSS-302 safety standards for automobile interior parts. In this test method, a combustion distance of 2 inches or less is nonflammable, a flame extinguished in 60 seconds or less is flame retardant, and a combustion speed of 4 inches/
If it is less than min, it is determined to be slow combustion.

Flame retardancy (hard): Conforms to JIS A 95146.8. After applying the flame of a Bunsen burner with a fishtail light for 60 seconds, the flame is removed and the time (seconds) until the test flame goes out and the length (mm) of the longest burning length are measured.

Those with a combustion time of 120 seconds or less and a combustion length of 60 mm or less are considered acceptable.

Presence or absence of toxic gas generation: Cut the sample into approximately 5 mm square pieces, and cut the sample into approximately 0.0 mm square pieces. Weigh the Igr accurately and put it into a porcelain boat. The sample was placed in a horizontal cylindrical electric furnace heated to 400°C and air was pumped in at 0°54i! /mi
The combustion gas is incinerated while flowing at a speed of 0. lN
-Gas collection was performed by passing it through a NaOH solution. Cyanide was analyzed using the pyridine pyrazolone method, and chloride ions were analyzed using ion chromatography.

The test results are shown in Table 4.

(Hereafter, margin) Table 4 In the above table, ■ and ○ are equivalent to Table 1.

Table 4 shows that the flexible polyurethane foam (soft slab) produced by the method of the present invention in Experimental Example 1 is comparable in cushioning properties and moisture absorption resistance to the halogen foams shown in Table 3, and does not generate toxic gas. Since the foaming ratio is higher than that of the melamine type shown in Table 3 and is flame retardant, it is suitable for automobile interior materials, etc.

[Experimental Example 2] This experimental example uses commercially available products (Thermolin #101 as a flame retardant,
This paper relates to the production of a flexible polyurethane foam (phosphorus/halogen type), and the foaming method was the same as in Experimental Example 1.

Table 5 shows the blending ratio, workability, and physical properties of each component as a starting material.

Table 5 shows that the products manufactured according to the present invention are comparable in workability and physical properties to commercially available products, and are suitable for interior materials for automobiles. However, if less than 130 parts of melamine is mixed in, it will not pass the flame retardant standard.

[Experimental Example 3.4] This experimental example relates to the production of flexible polyurethane foam. The foaming method was the same as in Experimental Example 1.

Less than 30 parts of melamine alone will fail the flame retardant standard, so adding organic phosphorus or chlorine auxiliaries will reduce the amount of melamine to 10 parts.
Even at 20 parts, the flame retardance is improved without significantly reducing productivity.

[Experimental Example 5.6] This experimental example relates to the production of flexible polyurethane foam for frame lamination, and the foaming method was the same as that of Experimental Example 1.
According to. Conventionally, flame retardant foam for flame laminates has a negative adhesive strength when using powdered flame retardants, but in this experimental example, a combination of melamine, organic phosphorus, and chlorine was used to improve workability and adhesive strength. It is possible to produce flame-retardant foams with high flame retardant properties.

Table 5 summarizes the starting materials, test results, etc. for Experimental Examples 1 to 6.

(Hereafter, margin) Table 5 In the above table, ○ indicates that the test has been passed.

[Experimental Example 7.8] This experimental example relates to the production of rigid polyurethane foam. The foaming method was the same as in Experimental Example 1.

Polyether polyol premix product (R liquid) 100
part of melamine to 30 parts of isocyanate (crude M
DI:I liquid) 100 parts were mixed and foamed to obtain a hard foam. Raw material temperature 20℃, cream time 42 seconds,
The rise time was 154 seconds and the specific gravity was 54.7 kg/m3.

The flame retardancy of the obtained rigid polyurethane foam was determined according to JIS^
Judgment was made in accordance with 95146.8. This determination is as described above, but there is no difference from commercially available flame retardant foams. Similarly, when 50 parts of melamine is used, it shows much better flame retardancy than ordinary flame retardant foam, and is certified as JIS A 9.
It was found that it passed the ASTM NB standard, which is stricter than the 514 standard. In addition, in the above, cream time 45 seconds, rise time 1600 seconds, density 40.7 kg/
It was m'.

[Experimental Examples 9, 10, 11] The present experimental examples relate to the production of rigid polyurethane foam. The foaming method was the same as in Experimental Example 7.

Normally, 30 parts of melamine does not make much of a difference from the flame retardant foam, so adding ammonium phosphate salts or chlorine-based auxiliaries will result in AST of 30 parts, 20 parts, and 10 parts of melamine.
Pass the MNB standard.

Table 6 summarizes the starting materials, test results, etc. for Experimental Examples 7 to 9.

(Margin below) Table 6 In the above table, ○ indicates that the test has been passed.

Table 7 shows the types and main raw materials of polyurethane foam.

(Hereinafter, blank spaces) The appropriate amount of melamine to be added to the raw materials in Table 7 is 30 to 100 parts per 100 parts of polyol in the case of a flexible polyurethane foam and melamine alone without an auxiliary agent. If it is less than 30 parts, flame retardancy will not be improved, and 1
If the amount exceeds 0.00 parts, the mixing condition of other components will deteriorate, leading to a decrease in productivity. When the amount is 30 to 100 parts, flame retardancy is improved without significantly reducing productivity. In addition, the amount of melamine added using chlorine (chlorinated paraffin, chlorinated polyethylene, etc.) or organic phosphorus (positive Fda ester, halogen-containing phosphate, etc.) as an auxiliary agent is 5 to 5 parts per 100 parts of polyol. 30 copies is appropriate.

In this case, the chlorinated paraffin may be added in an amount of 5 parts or less (however, the total amount including the auxiliary agent is 11 parts or less). The reason why the required amount of melamine is reduced when an auxiliary agent is used is that
This is because an improvement in flame retardancy can be expected due to the synergistic effect of the auxiliary agent and melamine. When the required amount of melamine is reduced, post-processing of urethane foam, such as high-frequency processing,
It is effective for frame lamination processing and improves productivity.

Furthermore, reducing the amount of melamine added also leads to cost reduction.

Further, in the case of rigid polyurethane foam, when melamine is added alone without any auxiliary agent, the amount added is 30 to 100 parts per 100 parts of polyol.

When melamine is used in combination with an auxiliary agent, the amount of melamine added is 10 to 30 parts. In the case of hard materials, the amount of auxiliary agent is 15 parts or less. The critical significance of the amount added is the same as in the case of flexible polyurethane foam.

Claims (1)

[Claims] (1) A method for producing a flame-retardant polyurethane, characterized in that the starting material contains a polyol, a polyisocyanate, and a flame retardant, and the flame retardant is melamine represented by the following formula. ▲Contains mathematical formulas, chemical formulas, tables, etc.▼