RU2423403C2 - Polyurethane composition for producing anti-noise coatings through moulding - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to polymeric compositions based on moulding polyurethane elastomers and can be used to produce anti-noise coatings for use in shipbuilding industry, as well as other engineering fields. The polyurethane composition for producing anti-noise coatings through moulding contains a urethane prepolymer obtained by reacting 1.2 moles of 4,4'-diphenylmethane diisocyanate and 1.0 mole of polydiethyleneglycoladipinate with molecular weight 1600, and a liquid hardener which is a mixture of di- and triethanolamines in molar ratio 1:1.5, a solution of trioxymethylphosphine and polypropylene glycol with molecular weight 1000 in molar ratio of 0.9:0.1. The composition contain filler - T-900 technical carbon in amount of up to 3%.

EFFECT: obtaining a composition with high adhesion to metallic and non-metallic surfaces, good dynamic characteristics (low value of dynamic modulus and high level of mechanical loss) and fire-resistance, which provides a coating with good anti-noise properties.

2 cl, 2 tbl

Description

The invention relates to polymer compositions based on injection-molded polyurethane elastomers with high physical and mechanical characteristics, increased adhesion to metal and nonmetallic surfaces, and can be used to obtain noise insulation coatings, including large ones, both in the shipbuilding industry and in other fields technicians.

Known polyurethane composition according to the patent of Russian Federation No. 2339664, IPC C08L 75/04, C09D 175/04, C08K 3/36, 2006 based on polyurethane with increased adhesion to metal surfaces, which can be used for the manufacture of protective coatings. The composition contains a polyfuritic urethane prepolymer, a liquid hardener based on 3,3'-dichloro-4,4'-diaminodiphenidomethane and polyoxytetramegylene glycol with a molecular weight of 1000 at a molar ratio of 0.95: 0.1, aerosil and additionally contains as an adhesive glycidyl methacrylate additives; and di- (2-ethylhexyl) phthalate as a plasticizer. The composition provides high strength and adhesive properties of polyurethane.

The disadvantages of the composition include its low viability (15-20) min, which does not allow to obtain when pouring large-sized products, and high values of hardness (91-92) conv. units Shora A.

Also known is a composition intended for the manufacture of a sound-absorbing coating (application RU 2007101712/04 C1, IPC C08G 18/80, 2006), which contains a blocked polyurethane prepolymer, a plasticizer, an acrylic polymer and a filler, a blocking catalyst, an epoxy resin, a foaming agent, a dry diluent and a blocked polyisocyanate, different from a blocked polyurethane prepolymer. This composition has high strength and adhesive characteristics, but does not provide the required dynamic properties (low shear modulus and a high level of mechanical loss), which is necessary to solve the problem.

The disadvantage is the fact that it is a thermoset composition. This method of curing limits the possibility of using the casting composition for the repair of products under operating conditions and presents, in some cases, significant technical difficulties in their manufacture associated with filling and returning molds. A significant disadvantage of the composition is the absence in its composition of components that provide fire resistance. Based on the foregoing, the composition in question cannot be used to solve the problem.

Closest to the claimed composition in composition, manufacturing method and level of technical parameters is "Polyurethane composition" (patent RU No. 2280048C1, IPC C08L 75/02, C08L 75/08, C08G 18/72, 2006) - a prototype containing 2.4 -toluylene diisocyanate in a mixture with 1,6-hexamethylene diisocyanate in a molar ratio of (0.8-0.9): 0.1 and 3.3'-dichloro-4,4'-diaminodiphenylmethane as a solution in polyoxytetramethylene glycol in a molar ratio ( 0,067-0,07) :( 0,029-0,03), respectively, as a liquid hardener in the following ratio of components, wt. hours:

polyoxytetramethylene glycol one hundred 2,4-toluene diisocyanate 25.1-34.3 1,6-hexamethylene diisocyanate 2.8-6.7 Liquid hardener: 3,3'-dichloro-4,4'-diaminodiphenylmethane 18.0-18.7 polyoxytetramethylene glycol 28.8-30.0.

The composition provides injection molded elastomers and products from them with high strength characteristics, operability in the operating temperature range of ± 45 ° C and has a high viability of 60 minutes at 25 ° C.

However, an elastomer based on a known composition is characterized by a low level of dynamic characteristics (shear modulus and mechanical loss coefficient) and they do not have fire resistance.

The objective of the invention is the creation of a polyurethane composition with high physical and mechanical properties, increased adhesion, high dynamic characteristics (low values of the dynamic modulus and a high level of mechanical loss), fire resistance, providing noise insulation properties of coatings for use in various fields of technology.

This is achieved by the fact that the known polyurethane composition for producing noise-protective coatings by injection technology, including a urethane prepolymer and a liquid hardener, the urethane prepolymer obtained by the interaction of 1.2 moles of 4,4'-diphenylmethanediisocyanate and 1.0 mole of polyethylene diethylene glycol adipate (PDEGA) with molecular weight 1600, and the liquid hardener is a mixture of di- and triethanolamines in a molar ratio of 1: 1.5 and trioxymethylphosphine with polypropylene glycol with a molecular weight of 1000 in a molar ratio of 0.9: 0.1, respectively . Governmental, with the following ratio of components, wt%:

urethane prepolymer 73.70-77.35 liquid hardener rest.

In addition, a filler in the form of carbon black, mainly of the T-900 brand, was added to the composition in an amount of up to 3%.

The proposed polyurethane composition is a two-component system consisting of a urethane prepolymer and a liquid hardener. The urethane prepolymer obtained in a closed batch reactor is, like a liquid hardener, an independent ingredient in the composition. Pre-made ingredients are stored separately and combined in the process of obtaining a polyurethane polymer.

The prepolymer obtained by the interaction of 1.2 moles of 4,4'-diphenylmethane-diisocyanate (MDI) and 1.0 mole of polydiethylene glycol adipate (PDEGA) is a stable prepolymer system that must be stored without changing reactivity for a long time (up to 6 months). The use of PDEGA as the main chain polyol allows to provide the polyurethane elastomer with the highest cohesion energy density and, thus, to obtain high values of strength and mechanical loss with low values of hardness and dynamic shear modulus, which provide a solution to the problem. A high level of adhesive properties is achieved by introducing MDI into the composition as a diisocyanate, which reduces the rigidity of its structure and gives flexibility to the elastomer.

Moreover, the elastomer has a high resistance to thermal oxidative degradation and chemical resistance. The use of MDI, which is safer in toxic effects than 2,4-toluene diisocyanate, allows you to expand the range of properties of the elastomer in the direction of increasing such as adhesion, strength and operational (increase heat resistance and weather resistance). The determining factor for achieving a high level of strength and adhesion properties of the finished product is the creation of prepolymers of a mesh structure through the use of a small excess of MDI.

Obtaining a liquid hardener in the form of a mixture of di- and triethanolamines in a molar ratio of 1: 1.5 provides an increase in the dynamic and physico-mechanical properties of the polyurethane composition.

The introduction of a solution of trioxymethylphosphine and polypropylene glycol with a molecular weight of 1000 in a molar ratio of 0.9: 0.1 in the composition as an additional structural component to di- and triethanolamines provides fire resistance of the polyurethane elastomer.

The T-900 brand carbon black introduced into the composition in an amount of up to 3% colors the elastomer in a dark color and improves the resistance of the products to ultraviolet radiation.

At the same time, ensuring high values of tensile strength, adhesive properties, fire resistance and the necessary dynamic characteristics, namely low values of shear modulus and high values of mechanical loss coefficient, are realized by experimental selection of component ratios and composition manufacturing technology.

The novelty of the technical solutions set forth in this invention is that as a result of its implementation, a solution to the technical problem is achieved, namely, the creation of a composition with high dynamic properties (low values of the dynamic module and a high level of mechanical loss), fire resistance, a high level of physical and mechanical and adhesive properties that provide products with enhanced performance.

The technical nature of the invention is illustrated by the following experimental data.

Table 1 Composition components Content in composition,% (mass fraction) 1 (prototype) parts by weight (molar ratio) Case Studies 2 3 four 5 6 Polyoxytetramethylene glycol 100 (0,1) 2,4-toluene diisocyanate 25.1-28.2 (0.144-0.162) 1,6-hexamethylene diisocyanate 3.0-3.6 (0.018-0.02) Liquid hardener composition: 3,3'-dichloro-4,4'-diaminodiphenylmethane 18.2 (0.068) Polyoxytetramethylene glycol 29.2 (0.029) Urethane prepolymer composition: A mixture of 1.0 mol of polydiethylene glycol adipate and 1.2 mol of 4,4'-diphenylmethanediisocyanate - 74.6 77.35 75.53 73.70 76.88 Liquid hardener of the composition: A mixture of di- and triethanolamines in a ratio of 1: 1.5, trioxy-methylphosphine (TOF), polypropylene glycol with a molecular weight of 1000 at a molar ratio of it with a TOF of 0.9: 0.1 - 25,4 22.65 24.47 26.30 23.12

Table 1 shows the formulation of the polyurethane compositions, table 2 - the characteristics of the reaction mixtures and polyurethane elastomers obtained on their basis, in comparison with the prototype. For comparison, similar tests were carried out for the composition of the prototype.

table 2 Properties of reaction mixtures and polyurethane materials based on them The compositions of table 1 for examples one 2 3 four 5 6 Operating temperature range, ° C ± 45 ± 40 -40 ... + 80 -40 ... + 80 -40 ... + 80 -20 ... + 30 Pot life of the reaction mixtures, min, at 25 ° C 60 35 40 40 40 thirty Tensile strength at break at a temperature of (20 ± 5) ° C, MPa (GOST 270) ≥43.0 thirty 47 47 47 35 Elongation at break,%, at a temperature of (20 ± 5) ° C ≥480 260 500 500 500 250 Relative residual elongation at break,%, at a temperature of (20 ± 5) ° C 4-6 8 10 6 10 8 Shore A hardness, conv. units (GOST 263) 73-78 60 55 45 fifty 65 The bond strength with the metal, MPa (GOST 209) 6.4-7.4 4.0 13.0 14.1 15.1 3.0 The bond strength during delamination, kgf / cm (GOST 6768) 5,0 5,0 7.0 7.0 6.5 4.8 Fire resistance (GOST 12.1.044)
a) self-extinguishing time of standard samples after removal from the flame of a gas burner, min
b) the combustibility index, (K _cf ≤1 - hardly combustible, K _cf > 1 - combustible) > 20
_Cfr > 1 less than 2
To _compare ≤1 Dynamic shear modulus G, MPa, (RD NAME 170-2008) 6-10 2.7-8.0 2.5-4.0 1.5-3.0 2.4-3.5 3.0-8.0 Mechanical loss coefficient, tgδ (RD NAME 170-2008) 0.05-0.1 0.09-0.12 0.18-0.20 0.16-0.23 0.13-0.20 0.08-0.15

From the data of table 2 it is seen that in the claimed compositions achieved high physico-mechanical, adhesive properties, fire resistance of the elastomer, which are combined with high dynamic properties, namely a low value of the dynamic shear modulus and a high value of the mechanical loss coefficient.

Tests of the inventive polyurethane composition based on a prepolymer and a liquid hardener showed that it has a high level of dynamic properties (provided by a low shear modulus and a high coefficient of mechanical losses), fire resistance, and also improved strength, adhesive and technological properties, which allows to create coatings based on it with high soundproofing properties.

Introduction to the composition of carbon black T-900 in an amount of up to 3.0 wt.% Does not lead to a significant change in the properties of the composition and allows to increase the resistance of products from this material to ultraviolet radiation.

Claims (2)

1. A polyurethane composition for producing noise-protective coatings by injection technology, including a urethane prepolymer and a liquid hardener, characterized in that the urethane prepolymer is obtained by the interaction of 1.2 moles of 4,4'-diphenylmethanediisocyanate and 1.0 mol of a polydiethylene glycol adipate with a molecular weight of 1600, and a liquid the hardener is a mixture of di- and triethanolamines in a molar ratio of 1: 1.5, a solution of trioxymethylphosphine and polypropylene glycol with a molecular weight of 1000 at their molar ratio of 0.9: 0.1, respectively, when blowing ratio, wt.%:
urethane prepolymer 73.70-77.35 liquid hardener rest 2. The polyurethane composition according to claim 1, characterized in that it contains a filler in the form of carbon black predominantly T-900 in an amount of up to 3%.