HU206223B - Self-quenching heat and sound insulating urea formaldehyde synthetic resin foam composition - Google Patents

Abstract

The material comprises equal parts of A and B, where A is a mixt. of carbamide-formaldehyde, surface active agent and a resin modifier and B is a mixt. of an acid catalyst, surface active material and a resin modifier. Part A is in the form of ammonium sulphate salts and part B is in the form of boric acid

Description

The present invention relates to a self-extinguishing category of thermal and acoustic insulating resin foam composition of urea formaldehyde resin, primarily for use in construction, in particular for on-site synthetic resin foam, which composition consists of "A" and "Β" components to be combined at 5 locations.

There are stringent requirements for resin foams, which can be used for post-heat insulation and soundproofing, and for the complete filling of irregular cavities. The foam structure must be composed of micelles which are sufficiently fine, not shrinkable subsequently, and of sufficient strength. In addition, it must meet the fire protection requirements of buildings and structures at a marketable cost and price. 15

The intended technical tasks can be achieved most economically with aminoplast (urea-formaldehyde) resin foams. Such a solution is described in ljsz 3979341. U.S. Patent Nos. 2834794; German patent. In these embodiments, the resin foam is formed from an aqueous solution containing 40% by weight of urea formaldehyde, such as, .beta.-component, and about 10% by weight of component "B" containing an acid catalyst, a surfactant. The known solutions differ in the additives used! which are intended to provide, in part, the desired mechanical properties and, in part, to bind free formaldehyde, such as those disclosed in U.S. Patent No. 1,582,445. English patent. However, these solutions use expensive materials and complicated process steps. These were addressed by the 194924 ljsz. Hungarian patent for the combined use of anionic and nonionic surfactants and a suitably selected acid catalyst.

As stated above, 35 urea-formaldehyde resin foams having the appropriate properties are known in the art but do not meet fire control regulations. There is no known known resin foam suitable for fire control purposes. To date, there are only known solutions for flame retardancy of resin foams 40 in which the finished resin foam is blown and impregnated with a flame retardant. On the one hand, this does not give a satisfactory result, and on the other hand, when filling the cavities, when the resin foam is formed in the cavity itself, it cannot be used.

The Lexicon of Chemical Chemistry mentions the use of flame retardants in several places (Vol. I, pp. 144-145, 375-376, p. 385, vol. III, pp. 30-31), such as ammonium phosphate. , diammonium phosphate, on the other hand 50 borax, boric acid. It also mentions the ammonium salt as a catalyst for the production of aminoplasts. However, there is no data or reference in the prior art for the flame retardancy of synthetic resin foams, in particular urea-formaldehyde resins. 55

Experience has shown that flame retardant and foam generation impose conflicting requirements. Additives recommended by the literature for flame retardant inhibit the formation of the required foam structure, foam properties 60 y / y. The aforementioned additives which can be successfully used for aminoplasts are not applicable if the resin foam is to be made from the aminoplast.

It is an object of the present invention to provide a resin foam composition that satisfies both mechanical and fire control requirements without significantly increasing costs.

We have discovered that the fire resistance requirements can be met with the otherwise inexpensive and good mechanical properties of urea-formaldehyde resin foam, so there is no need to switch to more expensive, more delicate and harmful side effects resin foam (such as polystyrene, urethane polymerizate, etc.) has been successful in maintaining the gelling of the foamed resin at the required rate.

Surprisingly, it has been found that although the cited prior art materials described herein (ammonium phosphate, boric acid, borax, or combinations thereof) adversely affect the formation of resin foam and product properties within a strictly defined range of pH and concentration, the object of the invention can be achieved with the combination of additives according to the invention.

Our experiments have shown that a small amount of flame retardant does not give the desired flame retardancy, but at a greater extent impairs the foam structure. When used in combination, the additives degrade the effect of each other, presumably due to excessive ionic strength and excessive dry matter content. However, the combination of ammonium sulfate and boric acid, previously unknown in this application, results in a significant improvement in flame retardancy in an amount that does not impair the formation of urea-formaldehyde resin foam and its well-known mechanical properties in a non-flammable version.

Accordingly, it is an object of the present invention to provide a composition for the preparation of a self-extinguishing thermal and acoustic insulation urea-formaldehyde resin foam, which composition consists of the A and B components to be combined at the foam generation site. and component A comprises urea formaldehyde precondensate and resin modifying agent (s), component B comprises an organic acid catalyst and a surfactant, wherein component A is present in an amount of from 0.1 to 10% by weight of ammonium sulfate, and component B contains from 0.1 to 5% by weight of boric acid.

Preferably, the composition of the present invention is characterized in that component A contains from 1.5 to 3.5% by weight of ammonium sulfate.

Preferably, the composition of the present invention is characterized in that component B contains from 0.6% to 1.5% by weight of boric acid.

Preferably, the composition of the present invention is characterized in that the surfactant is a mixture of at least one anionic surfactant and at least one nonionic surfactant. '

Another preferred embodiment of the composition of the invention is characterized in that b1

The acidic catalyst is a compound of the alkylbenzenesulfonic acid type.

The present invention is illustrated in more detail by the following examples, without, however, limiting the scope of the invention to the examples presented.

Example 1

The following example illustrates the prior art composition and preparation of urea-formaldehyde resin.

Preparation of Component: 670-690 parts by weight of a 30-32% by weight aqueous solution of formalin are injected into the apparatus and the pH is adjusted to 7.5-8.5 with 30% NaOH. 210-230 parts by weight of urea are added and the mixture is heated to 8085 ° C with constant stirring. This temperature is maintained for 10 minutes while the pH is controlled and maintained between 7.5 and 8.5. Subsequently, to effect acidic condensation, 25% w / w NH ₄ Cl solution was added until the pH reached 3.5-4.0.

The condensation occurs at 80-85 ° C for 40 minutes. Then the pH was adjusted to 8.0 with NaOH 30%, then adding 95 to 100 parts by weight of urea is heated again at 80-85 ° C for 20 minutes, and then 5 parts by weight CaCl ₂ and 1 cent part by weight of carboxymethylcellulose is added. The mixture was cooled to 20 ° C while the pH was adjusted accurately. This yields 40% by weight of resin component A with up to 0.5% free formaldehyde, having a refractive index of at least 1.423 (20 ° C) and a viscosity of 2060 mPa (20 ° C).

Component B: 60 parts by weight alkylbenzenesulfonic acid (ABS) parts by weight nonionic surfactant (NT) parts by weight anionic surfactant (AT) dissolved in 915 parts by weight water.

The flame resistance is given in accordance with MSZ 14800/4 as the "duration of independent combustion, in seconds", for comparing the prior art and the embodiments of the invention.

The resin foam obtained with the components A and B of Example 1 has acceptable flame resistance, but the foam is brittle and aging is significant. Comparative data are shown in Table 1.

Example 2

The prior art is a variant of the composition of Example 1, wherein component B is the same as Example 1 and component A is different from Example 1 in that it contains 10% by weight of polyethylene glycol (PG) as a resin modifying agent. (The PG used has a molecular weight of 300-500).

As a result of the additive, the mechanical properties of the resin foam of Example 2 changed favorably with the product of the composition of Example 1: the elasticity of the foam decreased to about a fifth. On the other hand, its high flame retardancy was greatly reduced due to the high organic matter content.

We have tried the mechanical one

The resin foam of Example 2 is prepared by treatment with flame retardants known in the art (Examples 3 and 4).

Example 3

Component A: as in Example 2 and up to% diammonium hydrogen phosphate

Component B: as in Example 2 and% by weight borax

Example 4

Component A: Example 2 and% by weight of Diammonium hydrogen phosphate

Component B: as in Example 2 and 1% by weight boric acid 1% by weight borax

The products obtained with the compositions of Examples 3 and 4 exhibit poor mechanical properties and insulable insulation. This is due to the fact that the fresh resin foam formed has an excessively long gelling time of 40-50 minutes in Example 3 and 60-80 minutes in Example 4. During this time, at its formation, a highly dispersed foam structure is transformed into a coarse dispersion system and thus does not provide the desired favorable properties.

Embodiments of the composition of the invention are illustrated in FIGS. examples. The resin foams obtained with these compositions have a gelling time of 5 to 10 minutes so that there is no possibility of reducing the degree of dispersion.

Example 5

Component A: as in Example 2 and weight% ammonium sulfate Component B: as in Example 2 and

0.9% by weight boric acid

Example 6

Component A: as in Example 2 and

1.5% by weight boric acid

Example 7

Component A: as in Example 2 and weight% ammonium sulfate Component B: as in Example 2 and

0.9% by weight boric acid

Example 8

Component A: as in Example 2 and by weight ammonium sulfate

Component B: as in Example 2 and

1.5% by weight boric acid

Example 9

Component A: as in Example 2 and 0.3% by weight of borax in ammonium sulfate

HU 206 223 Β

Component B: Example 2 and 0.7% by weight boric acid

Example 10

Co-component A: 2, as in Example, and by weight ammonium sulfate.

0.5% by weight borax

Component B: Example 2 and 1.2% by weight boric acid

The last two examples (9 and 10) also give unfavorable results, since the gelling time is 20-30 minutes, which already allows for significant structural degradation. Consequently, boric acid is not a substitute for borax and cannot be used in component A of the composition.

The compositions of the Examples of Comparative and Invention are compared in Table 1 based on the properties of the obtained urea-formaldehyde resin foam. Of the usual characteristics (bulk weight, vapor diffusion resistance, water uptake, elasticity, shrinkage, compressive strength, etc.), bulk density and shrinkage are mentioned as the most typical. A shrinkage value greater than 1% is not allowed, otherwise the foam will separate from the wall of the cavity. On the other hand, the flame resistance characteristic of the flame retardant efficiency is indicated. The result of the present invention is striking when one considers fire resistance and shrinkage together and compares these properties with the counter-examples. To facilitate this, we have given as an empirical characteristic the product of the fire resistance and shrinkage values. The last column shows the gelling time, which excludes the use of the compositions of Examples 3, 4 and 9, 10 due to poor foam structure and poor elasticity and compressive strength.

The composition according to the invention is novel because no urea-formaldehyde composition suitable for the production of aminoplast foam which contains only boric acid and ammonium sulfal as a refractory component is not known in the prior art.

The known flame retardant solutions, although offering a wide variety of flame retardants and their various variations, do not provide prior art guidance that would have provided an adequate flame retardancy of the desired mechanical properties of the aminoplast resin foam without the inventor's creative activity.

According to the present invention, the composition results in a resin foam having mechanical and aging properties that are equivalent to those of the most excellent resin foam, yet having an improved degree of flame retardancy over known prior art solutions.

The significance of the invention is that it also makes the aminoplast family, which is otherwise most advantageous in terms of ease of manufacture and inexpensiveness of raw materials, suitable for building material production and in applications in heat and soundproofing construction, where in many cases other resins with less favorable mechanical properties had to be used.

Claims (5)

PATIENT INDIVIDUAL POINTS 1, A composition for the production of self-extinguishing heat- and sound-insulating urea-formaldehyde resin foam consisting of components A and B to be combined at the site of foam generation, and component A is urea-formaldehyde precondensate and resin modifier (s), component B-60 comprising an organic acid catalyst and a surfactant, wherein component A of the composition comprises from 0.1 to 10% by weight of ammonium sulfate, and component B contains from 0.1 to 5% by weight of boric acid. 2. A composition according to claim 1, characterized in that the A content of ammonium sulfate is 1.5-3.5% by weight. EN 206 223 Β Composition according to claim 1 or 2, characterized in that the boric acid content of the B component is 0.6-1.5% by weight. 4. Referring to 1-3. Composition according to one of Claims 1 to 3, characterized in that the surfactant is a mixture of at least 5 amionic surfactants and at least one nonionic surfactant. 5. Composition according to any one of claims 1 to 3, characterized in that the acid catalyst is an alkylbenzene sulfonic acid compound.