RU2275391C2 - Method of producing polymer-polyol, dispersed polyol composition, elastic polyurethane, and molded product - Google Patents

Abstract

FIELD: polymer materials.

SUBSTANCE: production of polymer-polyol comprises two staged performed under laminar motion conditions at elevated temperature and pressure. In the first stage, a monomer and catalyst are consecutively added to polyether or polyether mixture with molecular weight 2000-6000 and primary hydroxyl content 40-80%, whereupon mixture is stirred to form adduct. In the second stage, monomer and catalyst are consecutively added to above adduct and resulting reaction mixture is then stirred. Monomer is selected from styrene, acrylonitrile, acrylate, butadiene, and mixture thereof.

EFFECT: enabled production of polymer with stable particle size.

6 cl, 3 tbl, 5 ex

Description

The invention relates to a method for producing polymer-polyols with a high dry matter content, to the preparation of polyol ase dispersed compositions which are suitable for producing highly elastic foam urethanes made from these dispersed compositions and molded articles containing these foam urethanes. Elastic foam urethanes are widely used mainly in the automotive and aviation industries, furniture and other industries.

Known methods for producing polymer-polyols, polyol ase dispersed compositions, foam and molded products, which are obtained by mixing simple, complex polyesters or their mixtures with polymers, modifiers, catalysts of various types, resulting in polyol dispersed compositions, flexible and rigid foam and molded products . (see, for example,

application RU No. 94009469, cl. C 08 G 18/48, 03.20.97, Bull. No. 8;

RU patent No. 2076115, cl. C 08 G 18/22, 03/23/97, Bull. No. 9;

A.S. No. 1647006, class C 08 G 18/22, 05/07/91, Bull. No. 17;

US Pat. RU No. 2001920, class C 08 G 18/08, 10/30/93, Bull. No. 39;

US Pat. RU No. 2050375, class C 08 G 18/48, C 08 K 5/5317, 12/20/95, Bull. No. 35;

US Pat. RU No. 2048482, class C 08 G 18/48, 11/20/95, Bull. Number 32.

Journal of Cellular Plastics, mart 1996, s. 84-96.

Chemical reactions of polymers, vol. 2, M .: Mir, 1967, p. 398-400.

J.X. Saunders, K.K. Frisch. Chemistry of polyurethanes. M .: Chemistry, 1968, p. 390.

In general, a polymer polyol is a dispersion of a solid polymer in a liquid polyol. Such systems are known in the art and are obtained by dissolving polymers such as polystyrene or copolymers thereof in a polyol, by two-step interaction of isocyanate with olamines in a practically inert polyol to form polyurea or polyurethane polymers, or by dissolving the polymer in a polyester medium.

However, often the proposed technologies are either long-term, multi-stage, use scarce materials, which becomes economically not feasible, or the quality of the products obtained is desired.

The well-known "Polyol modified with a polymer, and a method for its preparation" (US Pat. Ru No. 2128192, class C 08 G 18/08, 18/32, C 08 L 75/04, 03/23/99), which describe the polyol modified olamine polymer obtained by polymerization of olamine with a polyisocyanate with an isocyanate index in the range of 55-90 in the polyol, the amount of starting reagents providing a dry matter content in the stabilizer in the range of 1-15 wt.%, to use it as a stabilizer to obtain a polymer-modified polyol . Also described is a method of producing a polymer-modified polyol by polymerizing olamine with an isocyanate in a polyol in the presence of an added stabilizer, wherein a stabilizer is a polyol modified with an olamine polymer obtained by polymerizing olamine with a polyisocyanate with an isocyanate index in the range 55-90 in a polyol with the amount of the starting materials reagents providing a dry matter content in the stabilizer in the range of 1-15 wt.%.

However, this is not always convenient technologically, and the cost of modifiers is high, which increases the price of polymer-polyol in comparison with other types of polymer-modifiers and with the same quality indicators of the final molded products, the increased cost often reduces their competitiveness.

The closest in technical essence is “Polyol as one composition, elastic latex-like polyurethane foam and molded products” (US Pat. Ru No. 2166516, class C 08 G 18/48, C 08 L 71/00, 71/02, 75/08 (C 08 G 18 / 48.101: 100) 05.10.01).

The polyol composition comprises a polyol with a polymer polyol dispersed therein. The polymer-polyol is obtained by dissolving with laminar stirring in a polyol of a polymer or copolymer in an amount of up to 40 parts by weight at elevated temperature and pressure.

The composition contains: (a) 50-99.5 wt. including a polymer polyol containing a basic polyol having a molecular weight ranging from 2500 to 6500, an average nominal functionality F _{n of} at least 2.0 and a primary hydroxyl content of at least 40% and the polymer stably dispersed in it and up to a total weight of 100 wt. hours, (c) 0.5-20 parts by weight hydrophilic polyol (polyester or a mixture of polyesters) having a molecular weight in the range from 2000 to 5500, the ethylene oxide content of at least 40 parts by weight and a primary hydroxyl content of at least 50%. The polymer is polystyrene, styrene-acrylic copolymer or polyurethane polymer. An elastic latex-like polyurethane foam is described comprising said polyol composition and a molded article that contains elastic latex-like polyurethane foam.

However, the process of obtaining a polymer-polyol with a large amount of polymer is associated with the duration of dissolution of the polymer, and the obtained polymer particles in the polyol have a large size dispersion, which does not contribute to the stability of the properties of the resulting foam and molded product.

The objective of the present invention is to develop a method for producing a polymer-polyol, which made it possible to quickly and technologically justified to obtain a product with stable polymer particle sizes. On the basis of the obtained product to obtain a stable polyol as one dispersed composition, flexible polyurethane foam and a molded product with improved performance.

The problem is solved through a method of producing a polymer-polyol, which includes carrying out two stages under conditions of laminar motion at elevated temperature and pressure, where in the first stage a monomer is successively fed into a polyester or a mixture of polyesters with a molecular weight of 2000-6000 and a primary hydroxyl content of 40-80% and then the catalyst, the mixture is stirred to obtain the adduct, in the second stage, the monomer is successively fed into the obtained adduct, and then the catalyst, the resulting reaction mass is mixed, while p is selected from the group consisting of styrene, acrylonitrile, acrylate, styrene or mixtures thereof.

The method according to claim 1, wherein the catalyst is mainly selected from the group of peroxides or nitrogen-containing initiators.

Polyol ase dispersed composition containing 74.6-96.7 parts by weight polyester with a molecular weight of 2000-6000 and a primary hydroxyl content of at least 40%, 2-20 parts by weight polymer-polyol obtained by the method according to claim 1, and up to a total mass of 100 parts by weight crosslinking catalyst and organosilicon surfactant.

The polyol as one dispersed composition according to claim 3, wherein the crosslinking catalyst is tin octoate or dibutyltinvadilaurate.

An elastic foam urethane obtained by foaming a composition containing a polyol as one dispersed composition, a polyisocyanate component and additives, the composition containing a polyol as one dispersed composition according to claim 3.

A molded product containing an elastic foam urethane according to claim 5.

The distinguishing features of the proposed invention is that at the first stage a monomer and then a catalyst are fed sequentially into a polyester or a mixture of polyesters with a molecular weight of 2000-6000 and a primary hydroxyl content of 40-80%, the mixture is mixed to obtain an adduct, and in the second stage, the resulting adduct the monomer is fed sequentially, and then the catalyst, the resulting reaction mass is stirred, while the monomer is selected from the group consisting of styrene, acrylonitrile, acrylate, butadiene, or mixtures thereof.

The catalyst is preferably selected from the group of peroxides or nitrogen-containing initiators.

Polyol ase dispersed composition containing 74.6-96.7 parts by weight polyester with a molecular weight of 2000-6000 and a primary hydroxyl content of at least 40%, 2-20 parts by weight polymer-polyol obtained by the method according to claim 1, and up to a total mass of 100 parts by weight crosslinking catalyst and organosilicon surfactant.

A tin octoate or dibutyltin dilaurate is selected as the crosslinking catalyst.

An elastic foam urethane obtained by foaming a composition that contains a polyol ase dispersed composition, a polyisocyanate component and additives, the composition containing the polyol ase dispersed composition according to claim 3.

The molded product contains an elastic foam urethane according to claim 5.

In general, polymer-polyol is a dispersion of a solid polymer in a liquid polyester, and the polyester is a polyester or a mixture of polyesters. The preparation of the polymer-polyol is usually associated with dissolution of the polymer or copolymer in polyester to form fine solid particles of the polymer (micron size). This is achieved by prolonged mixing under conditions of laminar motion of the process medium in the reactor volume at elevated temperature and pressure. In this case, a polymer-polyol is formed - a white dispersion, the viscosity of which depends on the polymer content in it. The polymer is contained in the polymer-polyol of 2-40%. The content of a sufficient amount of polymer in the polymer polyol can cause the separation of the components over time, this is due to the difference in the surface tension of the interacting media and the difficulty in achieving the micron size of the polymer in the polyol medium. It is possible to obtain polymer-polyol in a neutral polyester medium by carrying out polymerization or copolymerization processes of monomers under the influence of free radical catalysts.

In this case, the polymer or copolymer formed with stirring, elevated temperature and pressure will have a size of not more than 3-4 microns, which will ensure the sedimentation stability of the dispersion. The operation in stage 2 is due to the fact that it is preferable to use a more polar monomer, for example acrylonitrile, and a less polar one, for example styrene, in stage 2. The polymer-polyol dispersion resulting under these conditions is more stable over time. The choice of monomers or their mixtures is primarily associated with the nature of the polyester, and the free radical catalyst is selected based on the process parameters, the rate of polymerization and copolymerization and the depth of the polymerization processes, as well as the type of monomer.

The polyol ase dispersed composition contains polymer-polyol and polyester and may include additional components and excipients used in the manufacture of flexible foam. The polyester must be hydrophilic in nature. This is one of the points for obtaining ultimately flexible foam. Its molecular weight should be in the range of 2000-6000. This is achieved by choosing an individual polyester, for example, laprol-5003 with a molecular weight of 5000 or a mixture of polyesters - laprol 5003 and 3003 (1: 1 ratio) with a total molecular weight of 4000. In this case, the primary hydroxyl content in both cases should be in the range of 40-80 % By changing the brand and ratio of laprols in blends of polyesters, various molecular weights and primary hydroxyl contents can be achieved. The stability of the polyol as one dispersed composition is even more dependent on the state of the polymer in the polymer polyol. This is due to the fact that the preparation of the dispersed composition is associated on the one hand with the dilution of the polymer-polyol with an additional large amount of polyester, which may have a different composition. On the other hand, introducing additional components, you can not only stabilize the dispersed composition, but also destabilize it. The stability of the polyol as one dispersed composition is primarily associated with the particle size of the solid polymer and their interfacial interaction with the liquid polyester.

The formulation of the polyol as one dispersed composition may contain additives: fillers, flame retardants, foam stabilizers, dyes. Given their ambiguous effect on the stability of the dispersed composition, part of them may optionally be introduced into the dispersed composition. Crosslinking catalysts — Organotin compounds, most preferred are, for example, tin octoate or dibutyltin dilaurate. One or more tertiary amine catalysts, for example triethylamine, may be used for said crosslinking catalyst. Additionally, blowing agents, including water, acetone, carbon dioxide, halogenated hydrocarbons, acyclic amines, can be added to the composition, but not necessarily.

The present invention also relates to flexible foam urethanes obtained by foaming a reaction mixture containing a polyol as one dispersed composition, a polyisocyanate component and additives.

As mentioned above, additives to the reaction mixture can be added separately to the polyol as one dispersed composition, to the polyisocyanate or to the reaction mass containing both components. Polyisocyanates can be polyisocyanates commonly used in the manufacture of polyurethanes, for example, toluene diisocyanates (TDI) of various structures, diphenylmethanediisocyanate (MDI) and other aliphatic and aromatic polyisocyanates or mixtures thereof.

The reaction mixture from which the elastic foam is obtained, contains components, parts by weight:

polymer polyol 2-20 polyester 74.6-96.7 crosslinking catalyst preferably tin octoate 0.1-0.4 foam stabilizer 1-3 additives 0.2-2 polyisocyanate in an amount providing isocyanate index 80-120

The elastic urethane foam according to the invention can be obtained as a block foam or as a filling foam. Molded articles, as well as upholstery, seats, sound absorbing panels, etc., containing the above elastic foam urethane, also form part of the present invention.

The invention is illustrated by the following examples.

Example 1. In a reactor with a volume of 0.63 m ³ with polyester - laprol 5003 with a molecular weight of 5000 and a primary hydroxyl content of 42-45% and a viscosity of 1100-1200 cP, a monomer — acrylonitrile in the ratio of 15 wt. hours to 100 parts by weight polyester. After stirring, tert-butyl peroxide is gradually fed into the reactor and the temperature is raised no higher than 90 ° C. The process is carried out with stirring in laminar mode and elevated temperature (not higher than 90 ° C) and pressure (0.2 MPa) for 6 hours with the formation of the adduct. In the second stage, another styrene monomer in the ratio of 22 parts by weight is fed into the adduct at a temperature of 90 ° C. to 100 parts by weight polyester and after stirring, a solution of dicumyl peroxide and styrene is gradually introduced. Styrene in an amount of 5 parts by weight

The resulting reaction mass is stirred in a laminar mode: temperature up to 100 ° C and a pressure of 0.2 MPa. The process takes 10 hours. The results of the experiment are presented in table 1.

Example 2. The process conditions are shown in Example 1. The polyester was selected as a mixture of polyesters: laprol 6003 with a molecular weight of 6000 and a primary hydroxyl content of 40-42% and laprol 2003 with a molecular weight of 2000 and a primary hydroxyl content of 77-82% in a 1: 1 ratio. At 2 stages, a mixture of styrene and butadiene monomers is fed in a ratio of 1: 0.25. The results of the experiment are presented in table 1.

Example 3. The process conditions are shown in example 1. At stage 1, the monomer is acrylic acid in a ratio of 8 parts by weight. to 100 parts by weight polyester and catalyst: azoisobutyronitrile. In the second stage, a monomer mixture of styrene with a-methylstyrene in a ratio of 1: 1 and a ratio of 30 parts by weight to 100 parts by weight polyester and tert-butyl peroxide catalyst. The results of the experiment are presented in table 1.

Example 4. Polyol as one dispersed composition with a solids content of 5% is obtained by mixing 10 wt.h. polymer-polyol (according to example 1) with a molecular weight of 5000, with a primary hydroxyl content of 42-45% and a content of 40% dry polymer, 80 parts by weight hydrophilic polyester with a molecular weight of 5000, with a primary hydroxyl content of 42-45%, a crosslinking catalyst "Tegostat B8681" - tin octoate 0.25 wt.h. and organosilicon product "Tegostat-2770" - 2.3 wt.h.

Similarly, a polyol as one dispersed composition is prepared using polymer polyols according to Examples 2 and 3. The viscosity of the polyol as one dispersed composition for all cases is in the range of 1250-1400 cP. The composition of the expandable formulations for obtaining elastic foam and a molded product is the same for all examples, parts by weight:

polyol as one dispersed composition one hundred additives 2 TDI-80/20 fifty or a mixture of TDI - 80/20 and PIZ-based MDI fifty

Polyisocyanates are used in one case to form molded products, and in the other, flexible polyurethane foam.

The properties of the obtained elastic foam and molded products are shown in tables 2 and 3.

Compression deformation under load (N) is defined as the stress-strain characteristic of a urethane foam, i.e. compression pressure to achieve a given (%) deformation of the sample.

Example 5. The process conditions are shown in example 1. The polymer-polyol is obtained by mixing polyester laprol 5003 with a molecular weight of 5000 and a primary hydroxyl content of 42-45% with a styrene-acrylonitrile copolymer, supplied in an amount of 40 parts by weight. to 100 parts by weight polyester in a reactor with a volume of 0.05 m ³ . Stirring for 28 hours in laminar mode is carried out at a temperature of 110 ° C, a pressure of 0.2 MPa. The results of the experiment are presented in table 1.

A polyol ase dispersed composition and foaming formulation compositions were prepared as in Example 4. The viscosity of the polyol ase dispersed composition was 1450 cP.

The properties of the foam and molded products are shown in tables 2 and 3.

An analysis of the properties of the obtained polymer-polyols shows that their properties largely depend on the method of their preparation. Obtaining a polymer in a polyester by polymerization of monomers provides, all other things being equal, obtaining a stable polymer-polyol dispersion due to the small size of the polymer solid particles and the conditions for their formation.

In addition, the production time of the polymer-polyol (example 5) is significantly longer than in examples 1-3. Obtained in the examples, the difference in the dry residue of the polymer-polyol is not critical.

Elastic foam urethanes and molded from dispersed polyol as one of the compositions and reaction mixtures using polymer polyols in examples 1-3 shows the best elasticity and deformation resistance compared to example 5.

Table 1
Polymer Polyol Properties Experience number Total time of stages 1 and 2, hour Viscosity
at 25 ° C, cP Dry residue,% The average particle size of the polymer, microns The stability of the dispersion at 45 ° C for 30 days one 16 3100 37 3.4 + 2 16 2600 37 3.2 + 3 16 3200 38 2,8 + 5 28 3600 40 5.5 20 days

table 2
Characteristics of elastic foam urethanes obtained from reaction mixtures using polymer polyols according to examples 1-3 and 5. Indicators Examples 2 3 four* 5 Density, ct / m ³ 26 23.5 24.0 21.5 Elasticity,% 39 36 37.5 34 Compression strain under load N, kPa 10% 0.65 0.7 0.85 0.6 twenty% 1,6 1.75 2.0 1.3 40% 2,3 2,4 2.7 1.9 Note: * - experiment 4 is based on the polymer-polyol according to example 1.

Table 3
Characteristics of molded products obtained from reaction mixtures using polymer-polyols according to examples 1-3 and 5. Indicators Examples 2 3 four* 5 Density, ct / m ³ 54 57 58 fifty Elasticity,% 64.5 67 68.5 61 Compression strain under load N, kPa 10% 1.35 1.45 1,5 1.3 twenty% 2,8 3,1 3,1 2.2 40% 3.95 4.4 4.2 3,7 Note: * - experiment 4 is based on the polymer-polyol according to example 1.

Claims (6)

1. A method of producing a polymer-polyol, comprising carrying out two stages under conditions of laminar motion at elevated temperature and pressure, where in the first stage a monomer is fed sequentially into a polyester or a mixture of polyesters with a molecular weight of 2000-6000 and a primary hydroxyl content of 40-80%, and then the catalyst, the mixture is stirred to obtain the adduct, in the second stage, the monomer is successively fed into the obtained adduct, and then the catalyst, the resulting reaction mass is mixed, while the monomer is selected from the group including tyrol, acrylonitrile, acrylate, butadiene, or mixtures thereof. 2. The method according to claim 1, characterized in that the catalyst is mainly selected from the group of peroxides or nitrogen-containing initiators. 3. Polyol ase dispersed composition containing 74.6-96.7 wt.h. polyester with a molecular weight of 2000-6000 and a primary hydroxyl content of at least 40%, 2-20 parts by weight polymer-polyol obtained by the method according to claim 1, and up to a total mass of 100 wt. including a crosslinking catalyst and an organosilicon surfactant. 4. The polyol as one dispersed composition according to claim 3, characterized in that the crosslinking catalyst is tin octoate or dibutyltin tadilaurate. 5. Elastic foam urethane obtained by foaming a composition containing a polyol ase dispersed composition, a polyisocyanate component and additives, characterized in that the composition contains a polyol ase dispersed composition according to claim 3. 6. A molded product containing an elastic foam urethane according to claim 5.