RU2265031C1 - Method of preparing polymer-polyol and dispersed polyol composition - Google Patents

Abstract

FIELD: polymer production.

SUBSTANCE: in the first step of two-step polymer-polyol preparation, polyether, notably Laprol 5003 or Laprol 5003/Laprol 3003 mixture, is combined with polymer selected from group, including polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, acrylonitrile-butadiene-styrene plastic, and mixtures thereof, at temperature 100°C. In the second step, at 90°C and pressure 0.2 MPa, monomer selected from group including acrylonitrile, styrene, acrylate, vinylidene chloride, and mixtures thereof is added before addition of catalyst. Resulting mixture is stirred at 100-110°C and pressure 0.25 MPa.

EFFECT: enabled preparation of stable dispersion, reduced process cycle time, and lowered power consumption.

2 cl, 2 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. Elastic foams are widely used mainly in the automotive and furniture industries.

Known methods for producing polymer-polyol and polyol as one dispersion for flexible foam (application RU No. 95113718, CL 08 G 18/40, 18/32, 03/20/97, Bull. No. 8); in which the polymer-modified polyol dispersion contains a polyadditive product dispersed in the polyol. The polyadditive product is present in an amount of about 25-75 wt.% Based on the total weight of the polyadditive product and the polyol. The dispersion has a viscosity of about 4000-50000 MPa * s, and this viscosity remains almost the same after obtaining a polymer modified polymer dispersion.

The dispersion of the polyol and the method for its preparation are oriented towards obtaining a polyurethane polymer in a polyol, which is not always convenient in technology and increases the cost of dispersion due to the high cost of the components.

The closest in technical essence is the polyol as one composition, elastic latex-like polyurethane foam and molded product (US Pat. RU No. 2166516, class C 08 G 18/48, C 08L 71/00, 71/02, 75/08, from 05/10/2001) .

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

The composition comprises: (a) 80-99.5 parts by weight of a polymeric polyol containing a basic polyol. Having a molecular weight in the range of 2500-6500, a primary hydroxyl content of at least 40% and a stable polymer dispersed in it to a total mass of 100 mh; (c) 0.5-20 mph hydrophilic polyol having a molecular weight in the range of 2000-5500 and a primary hydroxyl content of at least 50%. As the polymer in the polyol, polystyrene, styrene acrylonitrile copolymer (SAN) or polyurethane polymer are used. 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 variation in size, which does not contribute to the stability of the properties of the resulting foam and the molded product.

An object of the invention is to obtain a stable dispersion, reducing the time of the technological cycle of obtaining polymer-polyol and reducing energy costs for the process.

The problem is solved in that the method of producing a polymer-polyol comprising two stages, where the polyester is mixed in the first stage, which is Laprol 5003 or a mixture of Laprol 5003 and Laprol 3003, with a polymer selected from the group consisting of polystyrene, styrene-acrylonitrile copolymer , styrene-butadiene copolymer, acrylonitrile-butadiene-styrene plastic or mixtures thereof, at a temperature of 100 ° C, and in the second stage at a temperature of 90 ° C and a pressure of 0.2 MPa, a monomer selected from the group consisting of styrene, acrylonitrile is introduced , acrylate or mixtures thereof, and then the catalyst and the resulting mass are mixed at a temperature of 100-110 ° C and a pressure of 0.25 MPa. Polyol dispersed composition containing 76.6-96.9 m.h. polypropylene glycol with a molecular weight of 2000-6000 and a primary hydroxyl content of at least 40%, 2-20 mph polymer-polyol obtained by the method according to claim 1, and additives.

Distinctive features of the present invention is that the polymer-polyol is produced in two stages, where in the first stage the polyester is mixed, which is Laprol 5003 or a mixture of Laprol 5003 and Laprol 3003, with a polymer selected from the group consisting of polystyrene, styrene- acrylonitrile copolymer, styrene-butadiene copolymer, acrylonitrile-butadiene-styrene plastic or mixtures thereof, at a temperature of 100 ° C, and in the second stage at a temperature of 90 ° C and a pressure of 0.2 MPa, a monomer selected from the group yuchayuschey styrene, acrylonitrile, acrylate, or mixtures thereof, and the catalyst was then added and the resulting mixture is stirred at a temperature of 100-110 ° C and a pressure of 0.25 MPa. Polyol dispersed composition containing 76.6-96.9 m.h. polypropylene glycol with a molecular weight of 2000-6000 and a primary hydroxyl content of at least 40%, 2-20 mph polymer-polyol obtained by the method according to claim 1, and additives.

The preparation of polymer-polyol is associated with lengthy processes of mixing the components, swelling of the polymer, its partial dissolution at elevated temperature and pressure with the formation of a dispersion: a solid polymer in the polyol. However, even prolonged mixing under these conditions does not always lead to the expected result. This is due to the instability of interfacial interaction at the polyol-polymer interface, to delamination during storage, as a result of which the elastic foam formed finally formed does not always meet the technical requirements, and this is especially due to the deformation of the foam under load.

For the stability of the interfacial interaction at the polyol-polymer interface, the present invention proposes the introduction of a second stage in the preparation of the polymer-polyol, in which the monomer is first introduced into the previously prepared mixture of polyol and polymer, and then the catalyst under stirring and at elevated temperatures and pressures carry out the process of polymerization or copolymerization of the monomer. The process also occurs on the surface of solid polymer particles, providing a change in interfacial interaction. Thereby, greater stability at the interface in the polymer polyol is achieved. Selecting a pair of polymer, monomer and polyol based on an individual polyester or mixtures thereof, it is possible to achieve high stability of the polyol as one dispersed composition using the proposed polymer polyol. And the high stability of the polyol as one dispersed composition will allow to obtain high-quality elastic foam urethane that meets the necessary technical requirements.

The invention is illustrated by the following examples.

Example 1. In a reactor with a volume of 0.05 m ³ with a polyester-Laprol 5003 with a molecular weight of 5000 and a primary hydroxyl content of 42-45%, 20 mh are introduced with stirring and a temperature of 100 ° C. polystyrene with respect to polyester. Increase the pressure in the reactor to 0.2 MPa and mix for 10 hours. In the second stage, the temperature in the reactor volume is reduced to 90 ° C, 20 mph of acrylonitrile are introduced with stirring, then the catalyst is tert-butyl peroxide. The resulting mass is stirred at a temperature of 100-110 ° C and a pressure of 0.25 MPa for 6 hours. The results of the experiment are presented in table 1.

Example 2. The conditions are given in example 1. The polyester is a mixture of Laprol 5003 with a molecular weight of 5000 and a primary hydroxyl content of 42-45% and Laprol 3003 with a molecular weight of 3000 and a primary hydroxyl content of 56-60% in a 1: 1 ratio.

The polymer is a copolymer of styrene with acrylonitrile in an amount of 26 m.h. In the second stage, 14 m.h. monomer - a mixture of styrene and acrylonitrile in a ratio of 1: 2. The results of the experiment are presented in table 1.

Example 3. The conditions are shown in example 1. The polymer-styrene-butadiene copolymer, the monomer is acrylic acid. The results of the experiment are presented in table 1.

Example 4. The conditions are shown in example 1. The polymer-acrylonitrile copolymer and acrylonitrile-butadiene-styrene plastic in a ratio of 1: 1. Monomer - a mixture of acrylonitrile with vinylidene chloride in a ratio of 2: 1. The results of the experiment are presented in table 1.

Example 5 (prototype). The conditions are shown in example 2. There is no second stage of polymer-polyol preparation. The amount of copolymer 40 m.h. Mixing time 28 hours. The results of the experiment are presented in table 1.

Example 6. The polyol as one dispersed composition is obtained by mixing:

- polymer-polyol according to examples 1-5 to 10 m.h.

- hydrophilic polyester similar as in examples 1-5 to 80 m.h.

- crosslinking catalyst "Tegostat B 8681", tin octoate 0.25 m.h.

- silicon organic product "Tegostat 2770" - 2 m.h.

The resulting composition has a white color, the polymer content is 6%, the viscosity for different examples is in the range of 2800-4000 cps.

The composition of the reaction mixture to obtain flexible foam is the same for all examples and contains:

polyol as one dispersed composition - 100 mph additives - 2 mph

a mixture of toluene diisocyanate - 80/20 and a polyisocyanate based on metaphenylenediisocyanate - 50 parts by weight

The properties of the obtained elastic foams are shown in table 2.

Table 1
Polymer Polyol Properties Experience number Total time of stages 1 and 2, hour Viscosity at 25 ° С, centipoise Dry residue,% The average particle size of the polymer, microns Smell The stability of the dispersion at 45 ° C for 30 days 1 16 2950 40 3.3 weak + 2 16 3200 40 3.8 weak + 3 16 3250 40 3,5 - + 4 16 3600 40 4 weak + 5 28 4100 40 5.7 not 22

table 2
Characteristics of elastic foam urethanes obtained from reaction mixtures composed of polyl dispersed compositions (Example 6) using polymer polyols obtained in Examples 1-5 Indicators Examples 1 2 3 4 5 Density, kg / m ³ 24 22 22.5 24.5 twenty Elasticity,% 37 34 33 36 32 Compression strain under load N, kPa 10% 0.85 0.7 0.65 0.8 0.55 20% 2.0 1.7 1.7 1.9 1,57 40% 2.9 2,35 2.25 2,5 1.9

A comparison of the performance of polymer-polyols (table 1) obtained by different methods shows that the introduction of polymerisation processes at the second stage improves the stability of the polymer-polyol, reduces the technological time for its production, and hence the energy consumption for the process (examples 1-5).

The obtained polyol ase dispersed compositions based on polymer-polyols according to examples 1-4 allow to obtain elastic foams that are superior in properties, primarily in elastic deformation, similar foams obtained by the prototype.

Claims (2)

1. A method of producing a polymer-polyol, comprising two stages, where in the first stage the polyester is mixed, which is Laprol 5003 or a mixture of Laprol 5003 and Laprol 3003, with a polymer selected from the group consisting of polystyrene, styrene-acrylonitrile copolymer, styrene - butadiene copolymer, acrylonitrile-butadiene-styrene plastic or mixtures thereof at a temperature of 100 ° C, and in the second stage at a temperature of 90 ° C and a pressure of 0.2 MPa, a monomer selected from the group consisting of styrene, acrylonitrile, acrylate, vinylidene fluoride or their laugh si, and then the catalyst and the resulting mass are mixed at a temperature of 100-110 ° C and a pressure of 0.25 MPa. 2. Polyol ase dispersed composition containing 76.6-96.9 wt.h. polypropylene glycol 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 additives.