SU825557A1 - Composition for producing porous phenoplastic material - Google Patents

Description

(54) COMPOSITION FOR PREPARING THE FOAM

The invention relates to the preparation of compositions based on high molecular weight polymer products, namely, casting foams based on cold-cured phenolic resins phenol-formaldehyde resins, which have enhanced strength characteristics and resistance to the effects of an open flame and high temperatures. The invention can be used in those areas of technology where light fire resistant structures are required that are resistant to high temperatures and oxidizing gas media (aircraft, shipbuilding, transportation, industrial and civil engineering). Phenolic foams are widely used in engineering as heat insulating materials, as compared with industrial foams based on other polymers, they have a sufficiently high thermal-oxidative stability, are heat resistant and belong to the group of flame-retardant materials. However, with prolonged exposure to open flame and in high temperatures, the foamed foams are charred and: almost completely destroyed. The charred and carbonized areas crack, smolder, which is an additional source of fire. A significant disadvantage of penofenoplasts is that they have low strength properties and a relatively high bulk density. The above disadvantages of phenolic foams limit their use. In this connection, there is an urgent need to develop such a composition for the preparation of penofenoplast, which would allow not only to significantly reduce their fire hazard, to obtain non-caking, slow-burning foams, but also to improve the material's high performance. Compositions are known for the preparation of phenolic foams with enhanced flame retardant properties that include inorganic substances, for example liquid glass l. The disadvantages of such compositions are a noticeable decrease in the expansion ratio and, consequently, an increase in the density of foams, deterioration of the macrostructure of the material and a relatively low efficiency of the flame extinguishing effect of the injected substances.

Inorganic fillers typically dramatically increase the duration of smoldering after the flame source has been removed.

Penophenoplasts containing aluminum chromophosphate-binder 2 have a reduced flammability,

In order to obtain such foams, extreme temperatures and time-consuming curing of the resins are required in order to achieve satisfactory strength properties. The compositions used are not echo logical and do not satisfy modern requirements with regard to the flammability indexes of the materials obtained.

To obtain phenolic foams with increased resistance to the action of an open flame, phenol resins modified during the synthesis process can be used, phosphorus-containing fragments are introduced into the molecular structure, for example, the condensation product of tetramethylol phosphonium chloride with phenol Z.

The disadvantage of this foam is the complication of its production technology and, consequently, a sharp rise in the cost of the material. Industrial production of such resins is not adjusted.

The closest to the technical essence of the present invention is a composition for the preparation of foam plastic, including a phenol-formaldehyde resin of the resolver type, a foaming-opening agent and a flame retardant, which is an ester of pentaerythritol, alkylphosphonic and methacrylic acid-phosphacrylate 4. A significant drawback of this composition is that obtaining a homogeneous mixture of the components due to the very high viscosity of phosphacrylate (175 centipoise at 75 ° C). This necessitates a significant increase in the duration and intensity of mixing the prepolymer with the flame-extinguishing component, which leads to an increase in energy consumption for the production of penofenoplast and, consequently, an increase in the cost of production. Phenolic foams based on the used composition comprising 2-5 wt.h. Phosphaatelate after flame removal removes self-extinguishing, but continues to smolder for 2-3 seconds.

The purpose of the invention is to obtain on. the basis of the non-glowing composition when removing the flame of a flame-retardant foam with high strength properties.

This goal is achieved in that the composition for the preparation of a penofenoplast, including a phenol-formaldehyde resin of a resole type, a foaming curing agent and a flame retardant, contains 2-phosphonoxyethyl methacrylate as a flame retardant

the following ratio of components, mass. 4 .:

phenol formaldehyde resin rezol type100

Foaming Curing Agent15-25

2-phosphonoxyethylmethacrylate3, 3-16, 7 The process of obtaining non-aging, non-combustible, increased strength foams consists in mixing, at a normal temperature, appropriate amounts of the above components and pouring the resulting composition into the cavity of the form or design, where the foam is foamed and cured.

Example 1. 100 wt.h. phenol-formaldehyde prepolymer ФРВ1А (ТУ-б-05-1104-75) is mixed with 3.3 mass parts 2-phosphonoxyethyl methacrylate for 2 minutes until a homogeneous mass is formed. After this, 20 wt.h. of foaming curing agent-VAG-Z (MRTU 6-05-1116-68) and the composition is additionally stirred for 30-40 seconds. The resulting composition is poured into an open form in which the foaming and curing of the foam.

For final curing, the foam is additionally heat treated at 80-90 ° C for 8 hours. Samples for testing for combustibility and physicomechanical parameters are cut out from the foam foam and their thermo-oxidative stability is determined.

The flammability tests are carried out by the oxygen index method, according to GOST 21793-76 and by the fire tube method (GOST 17088-71). After the gas burner has been removed, the decay time of samples is recorded.

The physicomechanical properties of penofenoplasts are determined in accordance with GOST-409-68, GOST 18564-73 on an AS-102 instrument at a strain rate of 1 cm / min.

Thermo-oxidative stability of foams is evaluated by thermogravimetric method using an MOM-4 derivatograph. Heating rate - 3 s / min. Derivative patterns are used to determine the temperature of the onset of the intensive decomposition (Tnr.) And the temperature corresponding to the maximum decomposition rate of the foam (P) samples.

For comparison under similar conditions, a foam without flame extinguishing component is prepared and tested.

After the flame of the gas burner is removed, a foam-foam sample instantly fades and there is no smoldering. The original sample smolders 60-80 s. T for the initial sample of foam and foam containing 2-phosphonoxyethyl methacrylate are 490 ° C and 492 ° C, respectively. The results of the tests of the penofenoplates are shown in the table. Example 2. In a similar manner to example 1, the preparation and foaming of the composition, which contains 6.7 mass parts, is carried out. 2-phosphonoxyethyl methacrylate. When foaming composition; the time of the beginning and the end of foaming of the foam is recorded. The beginning of foaming occurs after 2 minutes 40 seconds, the end - 4 minutes 30 seconds. The similar indicators for the initial composition are respectively 2 minutes 50 s and 4 min 50 s. These data indicate that the administration of 2-phosphonoxyethyl methacrylate does not significantly affect the foaming behavior of the composition. and T d of the initial foam and penofenoplast containing flame extinguishing agent are, respectively, 293 °, 490 and 294 °, 487 ° С. The results of determining the flammability and physico-mechanical parameters are given in the table. The foam sample does not smolder after the flame has been removed. Example 3. Preparing a composition containing 10 wt.h. 2-phosphonoxyethyl methacrylate per 100 wt.h. Example 6. Foam plastic podpigiot analogously to example 1. Prepare a composition, mixing 100 mass.h. the prepolymer FRV-1L with 3.3 wt.h. 2-phosphonoxyethyl methacrylate and 15 wt, j of the pre-polymer FRV-1A, and operations are performed as in Example 2. The foaming rate of the foam is 21.1 compared to 18.1 for the original composition. The test results are shown in the table. The decay of the sample is missing. Example 4. Foam l is prepared as in Example 1. The composition contains 13.3 wt.h. 2-phosphonoxyethyl methacrylate. The foaming begins 2 minutes 45 seconds after the start of mixing and lasts 4 minutes 40 seconds. The foaming rate is 21.4. equal to 492 ° C. The sample is not smoldering. The test results are shown in the table. Example 5. Mix 100 mass.h. the prepolymer FRV-1A, 16.7 mass, including 2-phosphonoxyl methyl methacrylate and 20 wt.h. foaming and curing agent VAG-3. The preparation of samples for testing and their testing is carried out analogously to example 1. The oxygen index of the resulting foam is 45, which is 1.2 times more than for the original foam. The test results are shown in the table. The sample after flame removal does not smolder. including foaming curing agent VAG-3. The foam has a density of 77.6 kg / m, the mass loss when tested according to the fire tube method is 11.7%, after removing the flame, the sample does not smolder.

Example 7. Foam was prepared analogously to example 6. In the composition, 25 mass parts were introduced. foaming curing agent VAG-3, Polyfoam has a density of 52.4 kg / cm after removing the flame, the sample does not smolder, the mass loss when tested by the method of the Fire tube is 13.4%.

The above data shows that the use of 2-phosphonoxyethyl methacrylate makes it possible to obtain a flame-retardant, non-flammable, penofenoplast having high strength properties after flame removal. The flame injected component does not lengthen the foaming and curing of the foam. The process of preparation of the composition, in contrast to the known, does not require intensive and prolonged mixing of the components to obtain a homogeneous material.

The effectiveness of the flame extinguishing effect of the proposed compound is superior to phosphacrylate. For example, when the content of 10 mass, h. 2-phosphonoxyethyl methacrylate, the weight loss of the foam of the phenoplast when tested by the fire tube method is 13.7% instead of 14.5% for phosphacrylate.

At the same time, the use of 2-phosphonoxyethyl methacrylate not only increases the strength of the foam, but also simultaneously reduces its density, which makes it possible to obtain light and durable, non-smoldering, slow-burning materials, and to save raw materials for the manufacture of products. In this respect, it should be noted that with an increase in the concentration of the administered compound, the efficiency of the simplifying effect increases. For example, with the introduction of 10 mass.

. including the flame of the quenching component, the relative strength (the ratio of the strength of the material to the density) in the case of 2-phosphonoxyethyl methacrylate is 0.0034 MPa / kg / m, in the known 0024 MPa / kg / m.

The proposed flame extinguishing component does not impair the thermo-oxidative stability of the penofenoplast.

Claims (4)

1. US patent number 3766100, cl. 260-2.5, published. 1973. 2. USSR author's certificate number 349699, cl. From 08 J 9/06, 1970. 3. USSR author's certificate number 160306, cl. From 08 J 9/04, 1960. 4. USSR author's certificate number 531823, cl. C 08 J 9/06, 1976 (prototype).