DE2812398A1 - FLAME RETARDANT NEOPRENE FOAM WITH LOW SMOKE DEVELOPMENT - Google Patents

Description

Latex foams are used for a variety of purposes, used underneath for seat cushions. In particular, one uses such masses for the production of Seat cushions for automobiles and mass transit vehicles.

An example of other polymers that are used for such applications is polychloroprene, the known under the non-proprietary name "neoprene".

A disadvantage that is characteristic of neoprene foams and of elastomers in general is that that these materials are flammable and produce large amounts of smoke. For the production of flame-resistant neoprene foam fen are different methods, e.g. B. the addition of fillers, including urea-formaldehyde synthetic resin, Diammonium phosphate and ammonium sulfate.

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Dresdner Bank (Munich) Account 3939 844 Postacheck (Munich) account 670-43-804

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Examples of other methods of making neoprene flame resistant are methods in which the neoprene is mixed with melamine-aldehyde condensation products and with compounds that release ^P 2 ° 5 under fire conditions,

Examples of known flame retardant compounds that serve to support the improvement of the flame resistance of elastomeric foams, are aluminum hydroxide compounds, which are generally used together with antimony trioxide. Such additives are also used to make polyethylene flame resistant.

Modified aluminum hydroxide compositions have also been used to make flame retardant compositions. The aluminum hydroxide is modified by treating it with a small amount of a mixture of ethoxylated fatty acid amines and treated with an amino alcohol. The alumina modified on the surface is used as a filler used for latex foam compounds.

According to the invention it has been found that a flame retardant Low smoke neoprene mass can be made by using aluminum trihydroxide as a sole, flame-retardant filler is used without the need for further flame-retardant additives to use.

In order to achieve the desired properties of low smoke development and flame resistance, For every 100 parts by weight of rubber, at least about 60 parts by weight, preferably about 60 to 100 parts by weight Aluminum trihydroxide used. With these proportions, a suitable degree of flame resistance is obtained and smoke development to an appropriate extent

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is low, in combination with acceptable physical properties for use as a seat cushion,

The invention relates to a neoprene foam mass, which is flame-resistant and which in the event of fire to a low smoke development. In particular, the invention relates to neoprene foams from gel-free type, which are not only made flame-resistant through the use of aluminum trihydroxide (ATH), but also develop significantly less smoke than commercially available foams.

Gel particle-free foams are made by whipping or foaming a rubber latex and then dewatering and curing the foam rubber thus obtained. Process for the production of gel-free foam rubbers are well known to those skilled in the art.

A typical gel-free neoprene mass is illustrated in Table 1.

Type will

Table 1

Components

Neoprene 357

Aerosol 18
(3)

(2)

Calgon
Minex 3

(4)

Solem SB-632

(5)

Sb ₂ O ₃

KOH

Aquarex WAQ

Naugawhite

ZnO

Modicol VD

Thicarbanilide

Catechol

(8th)

(9)

Parts by weight 100

2.50

0.50
50
25th

0.25

1.14

1, 00

7.5

0.11

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(1) High strength polychloroprene homopolymer that is in one anionic, colloidal system using potassium salts of disproportionated resin acids, of fatty acid salts and from polymerize salts of alkylnaphthalenesulfonic acid as emulsifiers, solids content% by weight, pH 12.5 at 25 ° C., density 1.14 at 25 ° C., Brookfield viscosity 65 cps (spindle # 1).

(2) N-Octadecyl Disodium Sulphosuccinate - American ο Cyanamid Corp.

(3) Sodium Hexametaphosphate - Calgon Corp.

(4) Dry, Milled Nepheline Syenite - American Syenite Corp.

(5) Aluminum trihydroxide - Solem Industries

(6) Sodium salt of the sulfate monoester of a mixture of various fatty alcohols, mainly from lauryl alcohol - Du Pont

(7) Alkylated Phenol - Uniroyal Chemical (8) Sodium Polyacrylate - Nopco Chemical

(9) Ν, Ν'-diphenylthiourea

example 1

A gel particle-free neoprene foam formulation was prepared containing Minex, Solem SB-632 and Sb ₃ O., in the amounts shown in Table 1.

The flame index and smoke index of this control formula

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lation was determined for different densities. The smoke test and the radiation plate test are described below.

Smoke test:

The smoke test was performed using the method specified by the National Bureau of Standards for the Operation of the NBS Smoke Density Chamber (according to NFPA-258).

As noted in the tables below, the flame test (F) and no flame test (NF) carried out.' The attenuation of a light beam by smoke, which was caused by the effect of the test conditions, was measured on the test material, with or without flame formation, accumulated in a closed chamber. the Results are expressed in terms of specific optical density (Ds), which is different from a geometric factor and derived from the measured optical density (absorbance); di-it is the individual measurement that is responsible for the "smoke concentration" is most characteristic. In particular, Ds is used at the time of 4 minutes because this parameter required by the US Department of Transportation's guidelines for mass transit systems has (DOT Memorandum TSC-76-LFS-6, July 6, 1976, "Guidelines for Flammability and Smoke Emission Specifications") The photometric scale used to measure smoke according to this test procedure is similar to the optical density scale, which applied to human eyesight.

Radiant panel:

The radiant panel test was carried out according to the method of ASTM E-162-67, but as for section 4.9.2 of ASTM E-162-67, wire gauze used for shielding and the back and sides of the sample were

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compliance with the guidelines of the DOT (see the memorandum of the Ministry of Transport described above) wrapped in aluminum foil.

The test procedure uses a radiant heat source is used, in front of which an inclined sample of the material is placed. The specimen is aligned so that an ignition is forced near its upper edge and that the flame front advances downwards. A flame spread index (Is) is calculated as the product of two factors, one factor being derived from the The speed of advance of the flame front, while the other factor relates to the speed, with which heat is generated by the tested material. A value of Is less than 10 will generally be regarded as excellent.

The results of these tests are shown in Table 2. Table 2

Flame and smoke index of the control formulation at various densities

25 foam density (g / cm ³ ) radiation plate, Is Ds4 '(smoke index) T (F)

((NF)

30 Example 2

This example shows the effect of a higher ATH content. A formulation was made which was identical to the control formulation but in which Minex was replaced with additional ATH. The results are shown in Table 3.

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0 , 11 9 0 , 160 - 0.176 1 , 3 1 , 7 270 340 220 250

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1 table

Effects of replacing Minex with ATH

Minex / ATH / Sfc> ₂ 0 ₃ (parts by weight per 100 parts by weight neoprene) Foam density (g / an ³ )

Radiant panel, Is 10 Ds4 (smoke index) f (F)

(NF)

119 control A. 3 50/25/5 0/75/5 0, 0.160-0.176 0.146 1" 1.7 0 270 340 240 220 250 190

Formulation A compares with the control formulation both in terms of flame resistance and 15 represents a significant improvement in terms of lower smoke development.

Example 3

20 Formulations were made in which both Minex and Sb ₃ O _{3 were} replaced with additional ATH. The results are shown in Table 4.

Table 25

Effects of omitting antimony oxide and Minex

control

Minex / ATH / 3b ₂ O ₃ (parts by weight 50/25/5 30 per 100 parts by weight neoprene) Foam density (g / cm ³ ) 0.160-0.176 radiation plate, Is 1.7 Ds4 '(smoke index) / ( F)

I (NF) 35

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A. B. C. 0/75/5 50/25/0 0/75/0 0.146 0.175 0.157 0 4.4 2.3 0 340 220 0 250 140

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These numerical values show that it is not necessary to use the expensive antimony oxide in these formulations, to obtain excellent flame resistance (Is <10). In addition, there is a certain improvement smoking behavior when removing the antimony oxide from formulations that have a higher ATH content.

Example 4

Samples were prepared to demonstrate the benefit of further increasing ATH levels with respect to Smoke formation and flame retardation. The results are shown in Table 5.

Table 5

Effect of increasing the content of ATH

20 Minex / ATH / Sb ₂ O ₃ (parts by weight per 100 parts by weight of neoprene) Foam density (g / cm ³ ) Radiant panel, Is Ds4 '(smoke index) f (F)

25 ((NF)

C. D. 0/75/0 0/100/0 0.157 0.176 2.3 2.5 220 150 140 110

The figures make it clear that, even with a high density of the foam, by increasing the ATH content achieved both excellent flame resistance and a further improvement in smoking behavior.

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Claims (3)

TD ,,. Vt f * Patent attorneys: llEDTKE - DÜHLING -! VNNE "URUPE Dipl.-Ing.H. Tiedtke Dipl.-Chem. G. Bühling Dipl.-Ing. R. Kinne Dipl.-Ing. P. Grupe Bavariaring 4, P.O. Box 20 24 0ό 8000 Munich 2 Tel .: (0 89) 53 96 53 Telex: 5-24845 tipat cable: Germaniapatent Munich March 21, 1978 B 8810 / case F-5426 Claims Q ^. Latex composition which is suitable for use in the production of polychloroprene foams, characterized in that it contains a polychloroprene latex and an additive which consists essentially of aluminum trihydroxide, the aluminum trihydroxide in an amount of at least 60 parts by weight per 100 parts by weight. Parts of polychloroprene is mixed into the latex. 2. latex composition according to claim 1, characterized in that the aluminum trihydroxide in an amount of about 60 parts by weight to about 100 parts by weight per 100 parts by weight of polychloroprene is mixed into the mass. 3. Flame retardant polychloroprene foam with low smoke generation, made from a latex compound according to claim 1 or 2, characterized in that it contains about 60 parts by weight to about 100 parts by weight of aluminum trihydroxide contains per 100 parts by weight of foam rubber. _{XI / 17} - ^ SOiNAL INSPECTED 809839/0941 Dresdner Bank (Munich) Account 3939 844 Postscheck (Munich) Account 670-43-804