RU2330050C1 - Polymeric composition - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: invention concerns non-inflammable polymeric compositions applied in local strengthening of constructions, including three-layer cell panels, in the zones of fastener fixation, ends sealing and cavity filling in polymeric composite parts used in land, marine or air transport. The composition includes, mass parts: resol phenol-formaldehyde resin 100, hollow microspheres 54-135, aluminium oxide hydrate 120-200. High-concentration product of phenol and paraformaldehyde condensation with at least 10% content of water and 86% content of non-volatiles is used as resol phenol-formaldehyde resin. Hollow microspheres are made of glass or ash or polymers.

EFFECT: production of self-extinguishing less-fuming composition with adjustable viscosity; improved spread life of the composition and lower heat generation while burning.

2 cl, 2 tbl, 4 ex

Description

The invention relates to non-combustible polymer compositions with a filler in the form of hollow microspheres (the so-called syntax), designed for local hardening of structures, including three-layer honeycomb panels, in the areas of fasteners installation, sealing of ends and filling voids in parts made of polymer composite materials used on land, sea and air transport.

For these purposes, cold curing compositions based on modified epoxy resins are widely used (US patent No. 5420178, German application No. 2936485, French application No. 2575699).

To suppress flammability and smoke emission, flame retardants are introduced into the composition of epoxy syntactics: halogenated phenols or resins based on them, antimony oxides, phosphorus-containing compounds, etc., which significantly increase their cost, often not excluding the complete release of toxic products [CYTEK Engineered Materials, Selektor Guide, 1995, p. 14-15; 3M Technical Service Bulletin, Adhesives, Coatings and Sealers, 1992, No. 1].

It is known to use as a polymer base syntactics of liquid phenol-formaldehyde resins with reduced combustibility, low smoke and the absence of toxic combustion products, which can significantly simplify the composition and reduce their cost (patent EP No. 630956).

The closest of the analogues adopted for the prototype is a polymer composition comprising a rezol phenol-formaldehyde resin, a hardener, a plasticizer and hollow microspheres, which as a hardener contains the reaction product of sulfophenolurea, formaldehyde and phosphoric acid, and as a plasticizer a mixture of dioxane alcohols and their high boiling esters in the following ratio of components, parts by weight:

rezol phenol-formaldehyde resin one hundred hardener is a reaction product sulfophenolurea, formaldehyde and phosphoric acid 8-10 plasticizer - a mixture of dioxane alcohols and their high boiling ethers 15-25 filler - hollow microspheres 40-50

As hollow microspheres, glass, ash, polymer microspheres can be used (RF patent No. 2186799).

The polymer composition of the prototype is flame retardant and slightly smoky. However, its disadvantages are high heat during combustion and the limited viability of the composition at room temperature. In addition, the low initial viscosity of the composition and its rapid increase during use reduce the efficiency of filling small voids with a size of 2.5-15 mm (honeycomb cells, end surfaces of holes in the mounting hardware).

The technical task of the present invention is to provide a self-extinguishing and slightly smoky polymer composition having increased viability, adjustable viscosity and reduced heat during combustion.

To solve this problem, a polymer composition is proposed, including rezol phenol-formaldehyde resin and hollow glass microspheres, which as a resol phenol-formaldehyde resin contains a highly concentrated condensation product of phenol and paraformaldehyde with a water content of not more than 10% and non-volatile not less than 86% and additionally contains novolac phenol-formaldehyde resin aluminum oxide hydrate in the following ratio, wt.h .:

specified rezol phenol-formaldehyde resin one hundred novolac phenol-formaldehyde resin 33-100 hollow microspheres 54-135 alumina hydrate 100-200

As hollow microspheres, glass, ash or polymer microspheres can be used.

The use of a highly concentrated phenol-paraformaldehyde condensation product as a resol phenol-formaldehyde resin in combination with novolac resin makes it possible to obtain a highly reactive polymer base that combines high viability at room temperature (at least three months) with a high curing rate at 90-150 ° С. During curing, a polymer matrix is formed, combining branched and linear fragments, which provides the claimed composition with sufficiently high strength properties and reduces heat during combustion due to the absorption of energy spent on rebuilding and compaction at high temperatures of linear fragments of the matrix.

The additional introduction of alumina hydrate can significantly improve the technological properties of the composition and makes it possible to adjust the viscosity, if necessary, to the level required to completely fill the voids (honeycomb cells, end surfaces of the holes in the mounting hardware). The introduction of alumina hydrate also makes an additional contribution to the reduction of heat during combustion due to the absorption of heat during its decomposition and the evaporation of the resulting water.

An advantage of the proposed composition is also the possibility of using it in a single technological cycle of forming three-layer honeycomb panels with linings based on phenol-formaldehyde binder.

As rezol phenol-formaldehyde resin in the claimed invention used a highly concentrated condensation product of phenol and paraformaldehyde with a viscosity of not more than 13000 mPa · s at a temperature of 20 ° C, a gelation time of 300-720 s and a mass fraction of free phenol of not more than 11% FS-117 grade according to TU 2221-001-35907133-01.

As a novolac phenol-formaldehyde resin, it is most preferable to use resins according to GOST 18694-80, for example, grades SF-010, SF-014, etc.

It is most preferable to use glass hollow microspheres as microspheres, for example, MS-VP-A9 according to TU 6-48-91-92, MS-A9 according to TU 6-48-108-94 or ash microspheres according to TU 6-15-02- 306-92.

In the proposed composition use aluminum oxide hydrate according to GOST 11841.

The preparation of the claimed composition can be carried out manually or mechanized in a mixer, ensuring the integrity of the microspheres during mixing.

Examples of implementation

Example 1

In a clean dry porcelain, glass or polyethylene container was placed 100 wt.h. resole resin FS-117, added 33 wt.h. novolak resin SF-014, 100 parts by weight alumina hydrate and the mixture was mixed with a spatula for 5-7 minutes to obtain a composition of uniform consistency. Then 54 parts by weight were added to the prepared mixture. microspheres MS-A9 and mixed with a spatula for 6-8 minutes to obtain a homogeneous pasty mass.

The technology for preparing the compositions of examples 2-4 is similar to example 1. The compositions of the claimed composition and prototype are shown in table 1, the properties are in table 2.

Table 1 Name of components The composition according to examples, parts by weight Prototype one 2 3 four Resole resin FS-117 one hundred one hundred one hundred one hundred one hundred Novolac resin SF-014 33 fifty one hundred - - SF-010 - - - fifty Plasticizer - - - - twenty Hardener - - - - 10 Microspheres 44 glass MS-VP-A9 - - 135 - glass MS-A9 54 62 - - ash - - - 62 Alumina hydrate one hundred 200 180 200 - table 2 The properties Examples of the invention Prototype one 2 3 four Viscosity, cP source 12500 13900 14900 13750 10340 after 24 hours 13000 14000 15100 13800 not determined Vitality, h 336 480 540 470 2 Density, kg / m ³ 640 650 680 675 640 The limit of compressive strength, MPa 350 367 358 363 350 Maximum heat release rate, kW / m twenty 17 fifteen 21 76 The total amount of heat generated during the first 2 minutes of combustion, kW · min / m ² 5 6 <3 7 13

From the data of table 2 it follows that the proposed polymer composition retains its original viscosity for at least 24 hours after preparation, while the prototype composition during this time passes first into a gel-like state and then hardens, which makes its use impossible. Moreover, the maximum heat release rate of the claimed composition is 3-5 times lower than that of the prototype, and the total amount of heat released is 2-4 times lower.

The use of the claimed composition allows the molding of three-layer honeycomb panels in a single technological cycle, which reduces energy and labor by 40%.

Claims (2)

1. A polymer composition comprising a resol phenol-formaldehyde resin and hollow microspheres, characterized in that as a resol phenol-formaldehyde resin, it contains a highly concentrated condensation product of phenol and paraformaldehyde with a water content of not more than 10% and non-volatile not less than 86% and additionally contains novolac phenol-formaldehyde resin and aluminum oxide hydrate in the following ratio, wt.h .: specified rezol phenol-formaldehyde resin one hundred novolac phenol-formaldehyde resin 33-100 hollow microspheres 54-135 alumina hydrate 120-200 2. The polymer composition according to claim 1, characterized in that as hollow microspheres it contains glass, ash or polymer microspheres.