GB2179356A

GB2179356A - Polymer/polyol dispersions

Info

Publication number: GB2179356A
Application number: GB08617090A
Authority: GB
Inventors: Mariana Malaga Mellado; Jose Luis Mata Bilbao
Original assignee: ALCUDIA SA
Current assignee: ALCUDIA SA
Priority date: 1985-07-12
Filing date: 1986-07-14
Publication date: 1987-03-04
Also published as: NL8601822A; FR2591603B1; IT8621076A0; ES545144A0; ES8604286A1; GB2179356B; GB8617090D0; DE3623448A1; FR2591603A1; IT1196943B; IT8621076A1

Abstract

Method for obtaining vinylic copolymer dispersions in a polyhydroxyl compound, having an average molecular weight in number, between 2.10<3> and 8.5.10<3>, by reaction of a mixture of monomers containing acrylonitrile, styrene and other monomer, preferably methyl methacrylate, in the presence of an initiator of the formation of free radical. The polymerization is effected at pressure in a polyhydroxyl compound and with a monomeric composition containing from 90-20% of acrylonitrile, 80-5% of styrene and 70-3% of a vinylic monomer different from the above and preferably constituted by methyl methacrylate, the polymerisation being effected by heat treatment regulated according to the nature of the said initiator and the viscosity it is desired to obtain in the resultant product.

Description

SPECIFICATION Improved procedure for the obtainment of vinylic copolymers in a polyhydroxyl compound This invention relates two a procedureforthe obtainment of vinyl copolymers in a polyhydroxyl compound, said vinyl copolymers are formed bya mixture containing from 90to 20% by weight of acrylonitrile, 80to 5% by weight of styrene and 70 to 30% by weight of methyl methacrylate, the polyhydroxyl compound in which the copolymerisation takes place consists of a polyoxyalkenated product the average molecular weight of which in number, determined by determination of final reagentgroupsvaries between 2.103 and 8.5.103; said polyhydroxyl compound constitutes a proportion ofthefinal mixture varying between 95 and 60% by weight; furthermore the copolymerisation takes place under pressure in order to prevent polymerisations in the gas phase. The resultant products convert to flexible polyurethane foams when isocyanate, catalysts and additives are added, and these foams combine excellent properties of hardness without detrimentto theirflexible properties.

Basis ofthe invention Polymer is the name given to a large molecule constituted by repetition of other smaller more simple ones, called monomers. Polymers are formed by two types of reaction, polycondensation and polyaddition. We shall refer to the polymers obtained by polyaddition.

Polyaddition is the name of a reaction in which the chain in formation is produced through an ion ora substance with a disappeared electron called a free radical. The free radical is generally formed by decomposition of a relatively unstable material called an initiator. Said free radical is capable of reacting to open the double bond of a vinyl monomer and be added, with a remaining electron unpaired. In a very shorttime, many monomers become added in succession to the growing chain. Finallytwofree radicals react cancelling each other out in reactivity and they form one or more molecules of the polymer. Vinylic polymers belong to this type of reaction. These are subdivided into homopolymers and copolymers.The first are formed from a single monomer and representative examples are polyacrylnitrile, polystyrene, methyl polymethacrylate etc.

The second are formed from two or more monomers and examples are poly-acrylonitrile-styrene, polyethylene-vinyl acetate, poly-acrylonitrile-butadiene-styrene, etc.

In this description we shall deal with the synthesis and application of a type of polymer obtained by polyaddition through the mechanism of free radicals.

Polyaddition reactions are divided into homogeneous and heterogeneous polymerisations. The first are those in which the mixture of initial reaction is homogeneous and the second those which are not. Some homogeneous systems can become heterogeneous to the extent that polymerisation advances owing to the insolubility of the polymer in the reaction medium.

Homogeneous polymerisations may be in block and solution; heterogeneous in suspension and emulsion.

This description deals with homogeneous polymerisations in solution.

Vinylic polymerisation is an exothermic process as it implies the transformation of bonds into; the polymerisation energy depends on the nature ofthe groups adjacent to the carbons supporting the double bond, which may help the rupture of said double bond by inductive orconjugative effects (Table 1).

Monomer Structural unit -AHn, kcaflmol 1.Ethylene -CH2-CH2 22.7 2. Propylene -CH2-CH(CH3)- 20.5 3. Isobutylene -CH2-CH(CH3)CH2 12.3 4. Butene-1 -CH2CH(C2HS)- 20.0 5. Isoprene -CH2-C(CH3)-CH-CH2- 17.4 6.Styrene -CH2-CH(C6H5)- 16.7 7. alpha-methyl styrene -CH2-C(CH3)(C6H5)- 8.4 8. Vinyl chloride -CH2-CHCI- 22.9 9. Vinyl acetate -CH2CH(C2H3O)- 21.0 1 0.Acrylonitrile -CH2-CH(CN)- 18.4 11. Methyl methacrylate -CH2-C(CH3)(C2H302)- 13.5 12. Ethyl acrylate -CH2-CH(C3H502)- 18.8 13. Methyl acrylate -CH2-CH(C2H302)- 18.8 14. Acrylamide -CH2-CH(CONH2)- 19.8 Polymerisation in solution avoids many ofthe disadvantages of block polymerisation.The solvent acts as a diluent and aids the dissipation of the polymerisation heat, and furthermore its presence, reducing the visco sity ofthe medium, allows easier agitation. Heat control is much simpler in solution polymerisation than in block polymerisation for example, The kinetic diagram of polymerisation by free radicals may be represented as follows: -Initiation I Kd 2RX - Propagation Rx + x M Kp Pxx -Termination Addition Pxx+ yxKtPy Dismutation pxx + Kt Px - H + Py -Transfer PzX+A-HKtrPz-H +Ax The versatility of polymers obtained by solution polymerisation is very varied.For this reason it has been thought two obtain a type ofthese compounds which may be applied in a desiccated field by us and that of polyurethane polymers was used. These polymers are obtained when a compound reacts with polyhydroxyl groups and another with polyisocyanate groups. There exists a correlation between the chemical structure of the initial compounds and the physical properties ofthefinal compound.We shall conductan analysis of these two factors: a) Intermolecularforces, also called "secondary chemical bonds", are the result of the formation of hydrogen bridges, dipolar moments polarisability and Van derWaalsforce. These inter molecularforces tend to bring the chains together in a similarway to primary chemical bonds and therefore increase tensile strength, shear strength, hardness and temperature of vitreous transition, for example in polyacrylonitrile and methyl polymethacrylate. b) the rigidity ofthe chains is mainly originated by rigid structures such as aromatic rings, for example, polystyrene.Logically rigidity favours hardness, tensile strength and reduces elasticity. c) Interlock, the greater it is, the greaterthe hardness and the lessertheflexibility.

From these premisses it is possible to design one ofthetwo compounds, isocyanate or polyhydroxyl compound, enabling us to obtain polyurethanes suited to our needs. As isocyanate is highly reactive to a multitude of compounds such asforexample, ambient humidity, it is preferable to utilisethe polyhydroxyl compound.

The idea expounded in this description is to obtain vinylic polymers by solution polymerisation, using a polyhydroxyl compound as the solvent, in such a way asto obtain a final reactive composition bythe hydroxyl groups againstthe isocyanate and with a series of properties conferred by the vinylic polymer.

Certain compositions of this type have already been developed and are contained in previously published papers and patents.

The principle acrylonitrile polymers have been used in various types of polyhydroxylated compounds.

Thus we may cite the following patents: U.S. 3,304,273 British 1,040,452 Belgian 643,340 Later polyacrylonitrile styrene copolymers have been synthesized in polyhydroxylated compounds, described in the following patents: Canadian 785,836 Belgian 788,115 German 1,152,536/1,152,537 In our case three monomers, acrylonitrile-styrene and methyl methacrylate were employed, selected according to their chemical structure and their infiuence on the physical properties as mentioned in earlier paragraphs Polyacrylonitrile combines strong polarity and a small volume ofthe C= N group, which translates into a high intermolecularforce. It also has a high solubility parameter, giving rise to a high resistancetoorganic solvents.

Polystyrene presents aromatic rings and consequently high rigidity and at the same time intense intermolecular forces. Its thermal conductivity is very low. It is inert with regard to many inorganic reagents.

Methyl polymethacrylate combines properties of high stiffness and hardness together with great resistanceto ageing. In addition it is highly resistant to inorganic reagents, except mineral acids.

In view of the above three paragraphs, it has been thought to synthesize a copolymer containing thethree monomers in a suitable proportion to obtain an optimum balance between the various properties. Said copolymer has been synthesized in solution, using as a solvent a polyhydroxyl compound to provide the hydroxyl groups which later react with the polyfunctional isocyanates.

This invention describes the polymerisation in solution, of a vinylic copolymer consisting of 36 -1% of acrylonitrile, 32 - 0.25% of styrene and 28 - 0.15% methyl methacrylate, using as the solvent a polyhydroxyl compound ofmolecularweightfrom 2.10 to 8.5.10 and an initatorgeneratoroffree radicals.

It is a novelty in this invention to carry outthe reaction under pressure with nitrogen in order to prevent polymerisation in the gas phase.

The polyhydroxyl compounds used as solvents are products obtained when reacting by basic or acid catalysis, polyfunctional initiators with active hydrogens such as monoethylene glycol, monopropylene glycol, diethylene glycol, dipropylene glycol, 1,3 dihydroxypropane, 1,3 dihydroxybutane, 1,2,6 hexanetriol, glycerine, trimethyl propane, pentaentrite, sorbitol, sucrose, neopentyl, glycol, monoethanolamine, diethanolam ine, triethanolamine, mono isopropanolamine, di isopropanolamine, ethylene diamine, toluylene diamine, 1,10 di hydroxydecane, 1,2,4 trihydroxy butane, etc.

The most utilised alkylene oxides arethose of ethylene, propylene, styrene and butylene, whether in the form of homopolymerorcopolymerandthe latter may be-block, random or alternate.

The basic catalysts used are: sodium hydroxide, potassium hydroxide, sodium methoxide, calcium oxide, alkaline carbonates, alkaline salts of fatty acids, dimethylamine, triethylamine, some organometallic com- pounds, etc.

The most commonly employed acid catalysts are: boron trifluoride, stannic chloride, titanium chloride, aluminium sulphate, benzoil chloride, acetic anhydride, boric acid, sodium bisulphate, boron tribromide, etc.

In our case it is estimated that the most suitable polyhydroxyl compounds are those possessing an average molecular weight in number, characterised by the determination offunctional groups, between 2.103and 8.5.103 and mainly those varying between 3.103 and 6.5.103 The compounds described in this patent are employed in the obtainment of cellular compounds of poly urethane, for which it is necessary they they react with polyisocyanates in the presence of the required catalysts.

In the preparation of the cellular compositions of polyurethane, whether block or high resilience, it is es- sential to control closely the stechiometric ratios, i.e. that as a maximum only quantities slightly in excessof the stechiometric requirements of the organic polyisocyanate are used. In other words, that the reagents, polyisocyanate are used. In other words, that the reagents, polyisocyanate and polyhydroxyl compound should be used in relative quantities such that the proportion between total equivalent NCO and total active H are approximately 0.8 to 1.5, preferably 0.9 to 11.2. This proportion is known as isocynate index and is usually expressed as so many per cent of the stechiometric quantity polyisocyanate required to react witch the total active H.

The organic polyisocyanates utilised to produce polyurethanes are organic compounds which have at least two isocyanate groups. These compounds are well known and the most suitable include hydrocarbon diisocyanates (forexample alcoholene diisocyanates and arylene diisocyanates) such as: 1,2 diisocyanatoethane; 1,4 diisocyanatobutane; 2,4 diisocyanatotoluylene; 2,6 diisocyanatotoluylene; 1,3 diisocyanatooxylene; 2,4 diisocyanate-1 -chlorobenzene; 2,5 diisocyanate-1-nitrobenzene; 4,4' diphenyl methylene diisocyanate; 3,3' diphenyl methylene-diisocyanate and polymethylene-polyl-phenylene-diisocyanates.

The stabilisers useful for the production of polyurethanes according to this invention include: tertiary amines, such as trimethylamine; triethylemine; tributyl amine; N-methylmorpholine; N-ethylmorpholine; N-comorpholine; N,N,N', N'-tetramethyl-1 ,3 butane diamine; 1,4 diazobicyclo (2,2,2) octane; pyrridine oxide; N,N,N',N'tetramethyl ethylene diamine; N-methyl-N' dimethylaminoethyl piperazine; N,Ndimethylbenzylamine-bis- (N,N-diethyl amino ethyl) adipate; N,N-diethylbenzykamine; pentamethyl diethyl benzyl amine; pentamethyl diethylenetetramine; N,N-dimethyl cyclohexylamine; N,Ndimethylphenylethylamine; 1,2 dimethyl imidazole, 2-methylimidazole.

Tertiary amines carrying active hydrogen atoms in relation with the isocyanate groups, such as tri ethanolamine; triisopropanolamine; N-methyldiethanol-amine; N-ethyldiethanolamine; N,N dimethylethanolamine; and also their products of reaction with alkylenic oxides. The nitrogenose bases are also considered such astetraalkylammonium hydroxides; alkaline hydroxides such as sodium hydroxide, alkylphenolates such as sodium phenolate oralkaline alcoholates, such as sodium methylate.

The amine catalyst is present in the reaction mixture producing final urethane in a quantity between app roximately 0.05 and 3 parts by weight of active catalyst, to every 100 parts by weight ofthe polyhydroxyl reagent. The usual practice consists of including as an additional component of the reaction mixture a small quantity of certain metallic catalysts which are useful tofavourthe gelling of the foam forming mixture.

The most usual catalysts of this type are the organo metallic compounds, especialiy organictin com- pounds. Preferably tin (II) salts of carboxylic acids, such as tin (II) acetate; tin (11) octoate; tin (II) ethylhexoate; tin (II) laurate and tin (IV) compounds, for example dibutyl stannic oxide; stannic dichlorodibutyl, dibutyl stannicdiacetate, dibutyl stannicdilaurate. They may be used pure orforming mixtures and in general the quantities in these metallic co-catalysts which may be present in the reaction mixture is in the interval of approximately 0.05 to 2 parts byweightforevery 100 parts by weight of the polyhydroxyl reagent.

The formation of the cellular compound is achieved by the presence in the reaction mixture of variable quantities of a blowing or propulsion agent. The basic agent in the waterwhich, as a consequence ofthe reaction with the isocyanate, generates carbon dioxide in situ. Organic propulsion agents are also used,for example acetone, ethyl acetate; substituted alkane halogens, such as methylene chloride; chloroform; vinylidene chloride; monofluoro trichloromethane; chlorodifluoromethane; dichlorodifluoro methane and also butane, hexane, heptane or diethyl ether.

These agentsvapourise owing to the giving off of heat inherentto the reaction. The generally preferred method is the use of water alone, or a combination of water plus a hydrocarbon fluorinating blowing agent.

The amount of propulsion agent used will vary according to the desired density and hardness.

In the production of cellular polyurethane compounds stabilisers are used also, and are selectivewith respectto theformation of a particulartype of foam. The tensioactive agent must maintain the original height of the foam when it has formed. Foams produced with suitable tensioactive agents undergo a minimum of collapse or relaxation atthe top.According to this invention, the useful stabilisers for the effects stated include water soluble polyolether siloxanes, constituted by the union of a copolymer of ethylene oxide and propylene oxide with a remainder of polydimethylsiloxane or in general by "hydrolysable" block copolymers of polysiloxane- polyoxialcohylene such as those described in U.S. patents numbers 2834748 and 2917480; and also "non-hydrolysable" block copolymers of polysiloxane-polyoxyalcohylene, such as those described in U.S. patentnumber3505377.

Other examples of tensioactive additives and stabilisers, and also cell regulators, reaction retardants, sub- stance inhibiting inflammation, plasticisers, colourings and load materials and also substances ofafun- gistatic and bacteriostatic effect and multiple details on the use and way of operation of these additives are described in Kunststoff-Handbuch, volume VII, published byVieweg and Hochtler, Carl Hanser-Verlag, Munich 1965.

Thevinylic monomers employed in the preparation of the compounds described in this invention are utilised in a quantityfrom 5 to 40% by weight of the end product. The most suitable are those having from 10 to 30% mixture ofvinylic monomers out of the total. The most suitable monomer mixtures according to the balance of properties are those carrying from 90 to 20% acrylonitrile, 80 to 5% by weight of styrene and 70to 3% by weight of methyl methacrylate.

The most utilised initiators forming free radicals are compounds such as azobis isobutyronitrile; alphacu mil peroxy neodecanate; din-butyl peroxydicarbonate; di-cyclo hexyl peroxydicarbonate; bis (2ethylhexyl) peroxydi carbonbate; diisopropyl peroxydicarbonate; terbutyl peroxy neodecanate; teramyl peroxypivalate; terbutyl peroxy pivalate; bis (3,5,5 -trimethylhexanoil, peroxide; didecanoil peroxide, dilaucil peroxide; dibenzoii peroxide; terbutyl peroxybutyrate terbutyl peroxy isopropyl carbonate; dicumil peroxide, etc. The quantities employed vary between 0.05 and 2.5% by weight of the end product.

The initiator is selected according to the graft it is desired to obtain on the solvent and also the mean lifetime of the initiator. The graft of the initiator depends mainly on the quantity of CH3 radicals, which it is capable of generating in its decomposition. Thus for example, azobisisobutyronitrile produces very little graft, whereas benzoil peroxide produces a lot. The grafttakes place in the tertiary carbon atoms existing in the oxypropylenated chain ofthe polyhydroxylic compound. The mean lifetime, for its part, is the time neces sary forthe concentration of initiatorto reduce to half at a given temperature, making it possible to control the reaction time.

The reaction temperature is an important parameter for controlling the molecularweight of the vinylic polymer to be obtained and consequently the viscosity ofthe solution obtained. It is found that at lowtem- peratures the molecularweight ofthe polymer increases a lot and consequently the viscosity produced is high. On the contrary, when the temperature is high, the termination reaction is facilitated, so the molecular weight does not increase much and consequently viscosity is reduced. Thetemperature intervals atwhich ohe mayworkvaryfrom 60 to 1 300C, and from 100 to 130 C if reduced viscosities are desired.

Other elements which may act in these polymerisations are chain transferers, which are substances which, when added to the monomers to be polymerised, reduce their molecularweight owing to a transfer reaction, in which a polymer chain in growth loses its activity as it sustains a hydrogen atom of the transferring agent.

The activity of chain transfereragents is highly selective as while for some monomers they behave as these agents, for others they behave as retardants or inhibitors of polymerisation, so their use should be carefully studied.

Below are mentioned a series of examples illustrating the description of the invention we are defining: Definitions To clarify the terminology described in the experiments we utilise the following keys: - Polyol 3500 means a polyester derived from glycerine with propylene oxide and ethylene oxide, the aver age molecularweight of which in number, determined by the hydroxyl index technique is 3500.

- Polyol 5200 means a polyester derived from glycerine with propylene oxide and ethylene oxide, the aver- age molecularweight of which in number, determined by the hydroxyl index technique is 5200.

-ACN means acrylonitrile.

-E means styrene.

-MM means methyl methacrylate.

-ABIN means azobisisobutyronitrile.

Examples All the examples described below were carried out in a stainless steel reactor provided with a stirrer, heating bath, cooling coil, and suitable instrumentation to control the pressure and temperature. In all cases in the reactorthe quantity of polyol described in each example, it is heated in an atmosphere of N2 until the temperature stated in the example and is pressurised with N2 at3 kg/cm2,then atthe sametemperatureand for a period of 6 hours an initiator solution is added formed by polyol, monomer and initiator or mixtures of free radical initiators.

In the cases expressed a tranfer inhibitor agent is previously aded to the polyol placed in the reactor. When the addition has been completed the post reaction and evacuation takes place at the same temperature at which the addition was performed.

TABLE 1 Example 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Polyol 3500 in reactor 1270 1270 1000 1540 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000 1040 Polyol 3500 in SI 330 330 600 60 600 600 600 600 600 600 600 600 600 600 600 ACN in SI 200 200 200 200 200 200 160 120 80 200 200 200 160 160 180 E in SI 180 180 180 180 180 180 220 260 300 180 100 20 140 180 160 MM in SI 20 20 20 20 20 20 20 20 20 20 100 180 100 60 20 Abin 7 10 10 10 5 15 10 10 10 10 10 10 10 10 10 Ter.butylperoxybenzoate in SI - - - 2 - - - - - - - - - - Ter.butylperoxyisopropyl carbonate in SI - - - - 5 - - - - - - - - - n-dodacil merceptane in reactor - - - - - - - - - - - - - - Triethylamine in reactor - - - - - - - - - 2 - - - - Temperature of addition C 120 120 120 120 120 120 120 120 120 120 120 120 120 120 120 Temperature of post reaction C 120 120 120 120 120 120 120 120 120 120 120 120 120 120 120 Time of post reaction hours 1 1 0.5 2 4 4 4 1 1 1 1 4 5 1 2 Temperature of evaucation C 120 120 120 120 120 120 120 120 120 120 120 120 120 120 120 Time of evacuation hours 6 4 3.5 4 4 4 4 4 4 4 4 4 4 4 4 residual ACN ppm - - - - - - - - 2800 - - - - - residual E ppm 104 269 384 194 36 - 25 44 32000 42 35 - 40 50 60 Residual MM ppm - - - - - - - - 1500 - - - - - Index of acidity mg KOH/g 0.04 0.03 0.03 0.02 0.02 0.02 0.02 0.03 (*) 0.02 0.01 0.01 0.02 0.03 0.0 Index of hydroxyl mg KOH/g 38.9 39.0 38.9 38.1 39.1 39.2 39.1 39.2 (*) 39.1 39.2 39.4 39.1 39.3 39.6 Humidity % of weight 0.02 0.02 0.01 0.04 0.03 0.01 0.01 0.02 (*) 0.01 0.02 0.03 0.03 0.03 0.0 Viscosity at 25 C cps 4650 2800 1800 3160 8400 3520 2060 6800 (*) 1900 3500 2500 3600 4200 1750 (*) reaction not completed TABLE 2 Example 16 17 18 19 20 21 22 23 24 25 Polyol 5200 in reactor 1270 1000 1540 1000 1000 1000 1000 1000 1000 1000 Polyol 5200 in Si 330 600 60 600 600 600 600 600 600 600 ACN in Si 200 200 200 200 200 200 200 200 190 180 E in Si 180 180 180 180 180 180 180 180 190 200 MM in Si 20 20 20 20 20 20 20 20 20 20 Abin in Si 10 10 10 7.5 7.5 5 2.5 2.5 8 10 Ter.butylperoxybenzoate in Si - - - - - - - - 2 Ter.butylperoxyisopropyl carbonate in Si - - - 7.5 7.5 5 2.5 2.5 - n-dodacil mercaptane in SI - - - 1 - 0.5 1 - - Triethylamine in SI - - - - - - - - - Temperature of addition C 120 120 120 120 120 120 120 120 120 120 Temperature of post reaction C 120 120 120 120 120 120 120 120 120 120 Time of post reaction hours 1 1 1 3 3 3 3 3 6 1 Temperature of evacuation C 120 120 120 120 120 120 120 120 12 Time of evacuation hours 4 4 6 4 4 4 4 4 4 4 Residual ACN ppm - - - - - 300 684 - - Residual E ppm 30 32 40 215 122 195 710 31 - Residual MM ppm - - - - - - - - - Index of acidity mg KOH/g 0.02 0.03 0.02 0.02 0.03 0.02 0.02 0.01 0.02 0.02 Index of hydroxyl mg KOH/g 26.2 26.3 26.4 26.2 26.2 26.3 26.3 26.4 26.3 26.2 Humidity % of weight 0.02 0.03 0.02 0.02 0.01 0.02 0.01 0.02 0.02 0.02 Viscosity at 25 C cps 3800 2540 2960 30256 9400 8000 6200 2646 3450 2417 TABLE 3 Example Polyol 3500 in reactor 1000 1000 1000 Polyol 3500 in SI 400 400 400 ACN in SI 480 480 480 EinSI 100 100 100 MM in SI 20 20 20 Abin in SI 10 5 15 Ter.butylperoxybenzoate in SI Ter.butylperoxyisopropyi carbonate in SI - n-dodacil mercaptane in SI Triethylamine in SI Temperature of addition C 120 120 120 Temperature of post reaction C 120 120 120 Time of post reaction hours 2 1 1 Temperature of evacuation C 120 120 120 Time of evacuation hours 5 5 4 Residual ACN ppm Residual E ppm Residual MM ppm Index of acidity mg KOH/g 0.02 0.05 0.02 Index of hydroxyl mg KOH/g 34.5 34.8 34.7 Humidity % of weight 0.02 0.03 0.03 Viscosity at 25 C 1760 4850 2110 To illustrate the improvement in the physical properties ofthefoamsformulated with these polyolethers, a series of tests carried out with these is described below; which are contained in the following charts.

CHART 1 FORMULA TION 1 2 3 4 Polyol 3500 100 - - Example2 - 100 - Example3 - - 100 Example - - - 100 Water 4.85 4.85 4.85 4.85 Dabco 33 LV 0.36 0.36 0.36 0.36 Silicone SC 240 1.30 1.30 1.30 1.30 Tin octoate 0.25 0.25 0.25 0.25 TDI (index 106) 58.56 57.09 57.09 57.09 CHART 2 FORMULA TION 5 6 7 8 Polyo13500 100 - - Example - 100 - Example3 - - 100 Example - - - 100 Water 3.95 3.95 3.95 3.95 Dabco WT 0.66 0.66 0.66 0.66 D.M.A.E. 0.20 0.20 0.20 0.20 Silicone SC 240 1.1 1.1 1.1 1.1 Tin octoate 0.28 0.28 0.28 0.28 TDl(index 110) 51.25 49.63 49.63 49.63 CHART3 FORMULATION 9 10 11 12 Polyo13500 100 - - Example - 100 - Example3 - - 100 Example4 - - - 100 Water 3.1 3.1 3.1 3.1 DabcoWT 0.05 0.05 0.05 0.05 D.M.A.E 0.15 0.15 0.15 0.15 Silicone SC 240 1.00 1.00 1.00 1.00 Tin octoate 0.26 0.26 0.26 0.26 TDl(index 110) 40.33 40.30 40.30 40.30 The foams obtained according to charts 1,2 and 3were left to restfor24 hours andthnthe phsicaltests described in charts 4,5 and 6 were performed.

CHART4 7 2 3 4 Dynamic Fatigue H - 2.82 - 3.23 - 3.41 - 2.66 Deformation 25% -34.0 -33.81 -33.95 -34.90 Constant 40% -32.7 -33.03 -34.30 -34.02 (loss of hardness) 50% -28.8 -32.42 -33.33 -31.12 60% -25.3 -23.69 -28.08 -24.52 Resistance to 35% 30.64 34.45 34.45 37.39 Compression 40% 35.00 39.85 40.22 43.41 FORD4CYCLE70% % 40.71 48.07 48.18 49.05 Newtons 65% 69.35 80.44 77.99 82.04 Density kg/m3 29.11 29.92 29.75 29.85 Tension kgf/cm2 1.282 1.284 1.283 1.284 Elongation(%) 138 128 130 130 Resistance to 25% 19.88 23.25 23.30 25.50 penetration 65% 36.65 42.25 43.00 43.50 kgf/322.5cm2 SAG 1.845 1.817 1.845 1.700 Remaining 50% 3.33 3.09 3.07 3.08 Deformation 75% 4.13 3.05 3.05 3.05 Resilience 32 29 30 30 Shearkgf/cm 0.426 0.393 0.426 0.407 CHARTS 5 6 7 8 Dynamic Fatigue H - 4.34 - 7.09 - 7.10 - 7.06 Deformation 125% -34.26 -41.27 -41.50 -41.90 Constant 40% -34.14 -38.61 -38.70 -38.81 (loss of hardness) 50% -32.76 -34.88 -34.65 -34.72 60% -24.81 -17.80 -17.75 -17.62 Resistance to 35% 16.67 38.74 38.62 38.81 Compression 40% 19.62 46.59 46.62 46.65 FORD4CYCLE70% 50% 22.89 53.95 53.94 53.91 Newtons 65% 39.09 91.39 91.26 91.31 Densitykg/m3 25.46 25.07 25.12 25.09 Tension kgf/cm2 0.894 1.150 1.148 1.150 Elongation (%) Resistance to 25% 13.75 24.50 24.39 24.46 penetration 65% 24.80 48.50 48.44 48.51 kgf/322.5 cm2 SAG 1.808 1.980 1.986 1.983 Remaining 50% 2.51 5.24 5.23 5.27 Deformation 75% 3.62 8.18 8.15 8.21 Resilience 32 22 23 23 Shear kgf/cm 0.487 0.347 0.348 0.346 CHART 6 9 10 11 12 Dynamic Fatigue H - 6.20 -11.19 -11.20 -11.17 Deformation 25% -36.48 -49.24 -49.15 -49.20 Constant 40% -35.57 -42.73 -42.92 -42.80 (loss of hardness) 50% -32.94 -42.54 -42.65 -42.25 60% -30.73 -34.99 -34.16 -34.09 Resistance to 35% 18.79 32.21 32.10 32.06 Compression 40% 23.09 40.38 40.62 40.51 FORD 4 CYCLE 70% 50% 27.30 49.37 49.53 49.48 Newtons 65% 46.59 85.62 85.70 85.66 Density kg/m3 22.25 21.43 21.50 21.45 Tension kgf/cm2 1.015 1.057 1.043 1.031 Eiongation(%) 186.2 118.8 119.0 118.5 Resistanceto 25% 12.50 21.50 21.31 21.12 penetration 65% 24.10 39.00 39.22 39.31 kgfl322.5cm2 SAG 1.928 1.814 1.840 1.861 Remaining 50% 4.00 11.17 11.20 11.10 Deformation 75% 6.68 24.21 24.30 24.22 Resilience 34 23 24 24 Shear kgf/cm 0.451 0.422 0.415 0.418 CHART 7 FORMULATION 1 2 3 4 5 Polyo15200 100 50 50 50 50 Example 16 - 5 - - Example 17 - - 50 Example 18 - - - 50 Example 25 - - 50 Water 2.7 2.7 2.7 2.7 2.7 Diethanolamine 1.0 1.0 1.0 1.0 1.0 Glycerine 2.0 2.0 2.0 2.0 2.0 Dabco 33 LV 0.5 0.5 0.5 0.5 0.5 NiaxA.107 0.2 0.2 0.2 0.2 0.2 Silicone SH 207 0.5 0.5 0.5 0.5 0.5 TDl(index 103) 42.2 41.7 41.7 41.7 41.7 The foams obtained according to chart7 were left to stand for 24 hours and then the physical tests described in Chart 8 were performed.

CHART 8 1 2 3 4 5 Dynamic Fatigue H - 1.28 - - - - Deformation 25% -13.16 - - - - Constant 40% - 7.44 (loss of hardness) 50% - 7.05 - - - 60% -10.58 - - - - Resistance to 35% 13.00 27.32 27.46 27.51 27.95 Compression 40% 16.42 35.10 35.31 34.99 35.80 FORD5CYCLE75% 50% 20.84 44.50 44.63 44.20 45.12 Newtons/100 cm2 65% 36.04 77.85 77.98 77.99 79.94 Density kg/m3 42.24 42.58 42.60 42.50 42.74 Tension kgf/cm2 0.769 1.752 1.766 1.761 1.594 Elongation (%) 85 89 90 91 88 Resistance to 25% 8.00 18.73 18.50 18.59 18.30 penetration 65% 20.80 51.00 50.80 50.90 49.20 kgf/322.5 cm2 SAG 2.600 2.723 2.746 2.738 2.689 Remaining 50% 2.27 3.47 3.52 3.42 3.23 Deformation Resilience . 63 63 64 66 Shear kgf/cm 0.158 0.239 0.247 0.250 0.245 Charts 4,5,6 and 8 showthat a general improvement in the properties ofthe foams is obtained by utilising the polyolethers described in this invention, instead of a part or all ofthe conventional polyolether,varying the polyolethers in respect of the monomer content, their composition, initiator and reaction conditions.

Claims

1. Improved procedure for the obtainmentofvinyliccopolymers in a polyhydroxyl compound, having an average molecularweight in number, between 2.10 and 8.5.10 , by reaction of a mixture of monomers containing acrylonitrile, styrene and methyl methacrylate, in the presence of an initiator of the formation of free radicals, characterised because the said polymerisation is effected at pressure in a polyhydroxyl compound and with a monomeric composition containing from 90 - 20% ofacrylonitrile, 80 - 5% of styrene and 70 - 3% of a vinylic monomer different from the above and preferably constituted by methyl methacrylate,the polymerisation being effected by heattreatment regulated according tothe nature ofthe said initiator andthe viscosity it is desired to obtain in the resultant product.

2. Improved procedure for the obtainment ofvinylic copolymers in a polyhydroxyl compound, according to claim 1, characterised because the polymerisation is effected in the presence of inert gas.

3. Improved procedure for the obtainment ofvinylic copolymers in a polyhydroxyl compound, according to the above claims, characterised because the polymerisation is effected ata pressure greaterthan the atmospheric.

4. Improved procedure for the obtainment of vinylic copolymers in a polyhydroxyl compound, according to claims 1,2 and 3, characterised because the mixture ofvinylic monomers is used in a proportion of 5to40% byweight, based on the combined weight of the polyhydroxylic solvent and the monomers.

5. Improved procedure for the obtainment of vinylic copolymers in a polyhydroxyl compound, according to claims 1,2 and 3, characterised because the mixture of vinylic monomers contains by weight 90 - 20% of acrylonitrile, 80 - 5% of styrene and 70 - 3% methyl methacrylate.