AU481908B2 - Polymer/polyols and process for production thereof - Google Patents

Description

46,022/72 Polymer/polyol compositions suitable for use in producing polyurethane foams are known materials.

Such compositions can be produced by polymerizing

one or more olefinically unsaturated monomers

dissolved or dispersed in a polyol in the presence

of a free radical catalyst. These polymer/polyol compositions have the valuable property of imparting

to polyurethane foams produced therefrom higher load

bearing properties than are imparted by unmodified

polyols.

The polymer/polyol compositions that have found commercial acceptance to date are primarily compositions produced from polyols and acrylonitrile

or acrylonitrile-methyl methacrylate mixtures. Such compositions are used commercially in producing

foams under conditions such that the heat generated

during foaming is readily dissipated the foams are of relatively thin cross-section) or under

conditions such that relatively little heat is gen-

erated during foaming. An important source of heat in the formation of polyurethane foams is the reaction

of water and Isocyanato groups and this reaction is

often used to generate carbon dioxide which foams

the polyurethane. In such cases, the foam density decreases (and the amount of heat generated increases)

as the amount of water employed is increased. When one of the above-commercially available polymer-

polyol composithns is used under conditions such

that the heat generated during foaming is not

readily dissipated when relatively thin

2. 481908

46,0221n2 slab-stock is being produced) or under conditions

such that a sufficient amount of water is used to

produce a polyurethane foam having a density less

than 1.75 pounds per cubic foot, the heat generated

results in discoloration (scorch) of the foam.

Polymer/polyol compositions produced from polyols and acrylonitrile-styrene mixtures

are also known (see Canadian Patent 785,835). Low density, water-blown polyurethane foams produced from these compositions are also subject to scorch. The known process for producing these compositions

is not completely satisfactory, mainly because of the precipitation of large granules from the reaction

mixtures. Accordingly, such compositions have not

achieved commercial success to date.

It is an object of this invention to provide

a process for producing polymer/polyol compositions that can be used to produce low density water-blown

polyurethane foams having reduced scorch. Other objects of this invention will be

apparent from the description thereof appearing below.

This invention is based on the discovery that polymer/polyol compositions having improved

properties can be produced by the proper selection

of the type and relative amounts of olefinically

unsaturated monomers and by the control of the

temperature used to produce the compositions.

According to the invention there is provided a

process for producing a fluid polymer/polyol composition

from a reaction mixture containing polyol and a monomer

46,02 2/72 mixture which process comprises polymerizing, in the

presence of a free radical catalyst, at a temperature

at which the half life of the catalyst is no longer

than six minutes, and while maintaining a low monomer

to polyol ratio throughout the reaction mixture during

the polymerization, from 10 to 30 weight per cent of a monomer mixture of from 50 to 75 weight per cent of acrylonitrile or methacrylonitrile and from to 50 weight per cent styrene or alpha-methyl styrene, said weight per cents of the nitrile and the styrene

or alpha-methyl styrene being based on the total weight

of those materials, dissolved or dispersed in from to 90 weight per cent of a normally liquid polymeric

polyol having a hydroxyl number from 20 to 150, said

weight per cent of the monomer mixture and polymeric

polyol being based on the total weight of the monomers

and the polyol and said polymer consisting essentially of polymer particles having diameters less than one micron. The polyols useful in producing polymer/polyol compositions in accordance withkthis invention can be a hydroxyl-terminated polyester, a polyhydroxyalkane, a polyphenol, a polyoxyalkylene polyol, or the like. Among the polyols which can be employed are one or more polyols from the following classes of compositions, alone or in admixture, known to those skilled in the polyurethane art.

Alkylene oxide adducts of polyhydroxyalkanes;

Hydroxyl-terminated polyesters; Alkylene oxide adducts of non-reducing sugars and sugar derivatives.;

Alkylene oxide adducts of phosphorus and poly- phosphorus acids; 48 19 08

46,02272 Alkylene oxide adducts thereof of polyphenols; The polyols from natural oils such as castor oil, and the like. Illustrative alkylene oxide adducts of polyhydroxyalkanes include, among others, the alkylene oxide adducts of ethylene glycol, propylene glycol, 1, 3-dihydroxypropane, 1,3-dihydroxybutane, 1,4-dihydroxy- butane, 1,5- and 1,6-dihydroxyhexane, 1,2-, and 1,8-dihydroxyoctane, 1, l0-dihydroxy- decane, glycerol, 4 1,2, -trihydroxybutane, 1,2,6-tri- hydroxyhexane, 1,1,1-trimethylolethane, 1,1,1-trimethylol- propane, pentaerythritol, caprolactone, polycapro- lactone, xylitol, arabitol, sorbitol, mannitol, and the like; preferably the adducts of ethylene oxide, propylene oxide, epoxybutane, or mixtures thereof. A preferred class of alkylene oxide adducts of poly- hydroxyalkanes are the ethylene oxide, propylene oxide, butylene oxide, or mixtures thereof, adducts of trihydroxyalkanes. Illustrative hydroxyl-terminated polyesters are those which are prepared by polymerizing a lactone in the presence of an active hydrogen-containing starter as disclosed in U.S. Patent No. 2,914,556. A further class of polyols which can be employed are the alkylene oxide adducts of the non- reducing sugars, wherein the alkylene oxides have from 2 to 4 carbon atoms. Among the non-reducing sugars and sugar derivatives contemplated are sucrose, alkyl glycosides such as methyl glucoside, ethyl glucoside, and the like, glycol glycosides such as

48 1908

46,02 272 ethylene glycol elucoside, propylene glycol glucoside,

glycerol glucoside, 1,2,6-hexanetriol glucoside, and

the like, as well as the alkylene oxide adducts of

the alkyl glycosides as set forth in U.S. 3,073,788.

A still further useful class of polyols is the polyphenols, and preferably the alkylene oxide

adducts thereof wherein the alkylene oxides have from

2 to 4 carbon atoms. Among the polyphenols which are contemplated are found, for example, bisphenol A,

bisphenol F, condensation products of phenol and

formaldehyde, the novolac resins; condensation products

of various phenolic compounds and acrolein; the simplest

member of this class being the 1,l,3-tris(hydroxyphenyl)

propanes, condensation products of various phenolic compounds and glyoxal, glutaraldehyde, and other

dialdehydes, the simplest members of this class being

the 1,1,2, 2 -tetrakis(hydroxyphenol)ethanes, and the

like.

The alkylene oxide adducts of phosphorus and polyphosphorus acids are another useful class of

polyols. Ethylene oxide, 1,2-epoxypropane, the epoxy- butanes, 3-chloro-1,2-epoxypropane, and the like

are preferred alkylene oxides. Phosphoric acid, phosphorus acid, the polyphosphoric acids such as

tripolyphosphoric acid, the polymetaphosphoric acids,

and the like are desirable for use in this connection.

The polyols employed can have hydroxyl numbers which vary over a wide range. In general, the hydroxyl numbers of the polyols employed in the

invention can range from about 20, and lower, to about

48 1.908

4 6,022/72

1000, and higher, preferably, from about 25 to

about 600, and more preferably, from about 30 to

about 450. The hydroxyl number is defined as the

number of milligrams of potassium hydroxide required

for the complete hydrolysis of the fully acetylated derivative prepared from 1 gram of polyol. The hydroxyl number can also be defined by the equation: OH 56.1 x 1000 x f m.w.

where OH hydroxyl number of the polyol f functionality, that is, average number of hydroxyl groups per molecule of polyol

molecular weight of the polyol The exact polyol employed depends upon the end-use

of the polyurethane product to be produced. The molecular weight or the hydroxyl number is selected

properly to result in flexible, semi-flexible, or

rigid foams or elastomers when the polymer/polyol

produced from the polyol is converted to a poly-

urethane. The polyols preferably possess a hydroxyl

number of from about 200 to about 1000 when employed

in rigid foam formulations, from about 50.to about

150 for semi-flexible foams, and from about 40 to

about 70 or more when employed in flexible foam

formulations. Such limits are not intended to be

restrictive, but are merely illustrative of the

large number of possible combinations of the above

polyol coreactants.

Preferably, the polyols have viscosities

from 100 to 2000 centipoises at 25°C. and are

7. .48 7 1908

46,022172 the ethylene and/or propylene oxide adducts

of dihydroxyalkanes or trihydroxyalkanes. The polyols preferably shoul be.free of groups that catalyze internal cyclization of poly(acrylonitrile)

or poly(methacrylonitrile) [3s described below] and/or

decomposition of the catalysts. Such groups are generally basic groups amino groups). The selection of styrene as a comonomer of choice with acrylonitrile or methacrylonitrile was

based upon cost, availability and relative reactivity

with acrylonitrile. Thus, styrene is inexpensive, readily available in high purity and forms a poly-

merization azeotrope with acrylonitrile. The poly- merization azeotrope of styrene and acrylonitrile

is important because it tends to insure the prepar-

ation of a copolymer of compositional unif6rmity.

Of further consideration in the selection of comonomer

is the glass-transition temperature (Tg) of the

anticipated copolymer. The glass-transition tempera- ture of the copolymer in the polymer/polyol must be

higher than the anticipated foam use temperature in

order to confer load-bearing characteristics. The Tg of a 50/50 weight percent acrylonitrile-styrene

copolymer is approximately 108 0 C. The selection of methacrylonitrile as a comonomer of choice with

styrone or c -methylstyrene is based on its lower color-formation tendency (compared to acrylonitrile)

and favorable copolymerization kinetics with styrene

8 48 1.9 0

46,022/72 and'C-methylstyrene. Methacrylonitrile has also

a high homopolymer glass-transition temperature

(Tg >1000C). The selection of oC-methylstyrene as

a comonomer of choice with acrylonitrile or meth-

acrylonitrile is based on its relative reactivity

with acrylonitrile or methacrylonitrile, high homo-

polymer glass-transition temperature, and low coat.

It also forms a polymerization azeotrope with both

methacrylonitrile and acrylonitrile.

With regard to the relative amounts of the

polyols and monomers used in the process of this

invention, the reaction mixture contains: from to 30 weight per cent of a monomer mixture of

from 50 to 75 weight percent of acrylonitrile

or methacrylonitrile and from 25 to 50 weight

percent styrene or alpha-methyl styrene, said weight

percents of the nitrile and the styrene or alpha-

methyl styrene being based on the total weight of

those materials and from 70 to 90 weight percent

of a normally liquid polyol, said weight percents

of the monomer mixture and polyol being based on

the total weight of the monomer and the polyol. When

less than 10 weight percent of the monomer mixture

is employed in the reaction mixture, less than

desired load bearing enhancement is conferred upon

the polyurethane foam prepared therefrom, and, when

more than 30 weight percent of.the monomer mixture

is employed in the reaction mixture, the resultant

polymer-polyol viscosity is higher than is desirable.

When les3 than 50 weight of the nitrile is employed

.48 1908

46,022/72 in the monomer mixture, less than the desired load bearing enhancement is conferred on the polyurethane

foam prepared therefrom and polymer/polyol viscosity

is higher than desirable, and, when more than

weight percent of the nitrile is employed in the

monomer mixture, the resultant low density poly-

urethane foam (high water level formulation) pre-

pared therefrom will have greater than desired "scorch" (discoloration).

The catalyst useful in producing polymer/polyol compositions in accordance with this invention are the well known free radical type of vinyl polymerization

catalysts, for example, the peroxides such as hydrogen peroxide,.dibenzoyl peroxide, acetyl peroxide, benzoyl hydroperoxide, t-butyl hydroperoxide, di-t-butyl

peroxide, lauroyl peroxide, butyryl peroxide, and the like; azo compounds such as azobisisobutyronitrile,

and the like; the per compounds such as persulfates,

perborates, persuccinic acid, diisopropyl peroxy di- carbonate, and the like; etc. The polymerization

can also be carried out with an inert organic solvent present. Illustrative thereof are toluene, benzene, acetonitrile, ethyl acetate, hexane, heptane, dicyclo-

hexane, dioxane, acetone, N,N-dimethylformamide,

N,N-dimethylacetamide, and the like, including those known in the art as being suitable solvents for the polymerization of vinyl monomers. The only require- ment in the selection of the solvent and the polyol is that they do not interfere with the monomer's

polymerization reaction. When an inert organic

46,022172

solvent is used, it is generally removed from the

reaction mixture by conventional means before the

polymer/polyol is used to produce polyurethane foams. The temperature used in producing

polymer/polyol compositions in accordance with this

invention is any temperature at which the half life

of the catalyst is no longer than six minutes

(preferably no longer than from 1.5 to 2 minutes).

The half lives of the catalysts become shorter as

the temperature is raised. The.maximum temperature

used is not narrowly critical but should be lower

than the temperature at which significant decomposition

of the reactants or product occurs.

The half lives of such catalysts are

known properties of those materials and are measured

by known methods. The half lives are conventionally

measured while the catalyst is dissolved in a solvent

that is substantially non-reactive with the catalyst

and that does not decompose the catalyst. Such

solvents include liquid hydrocarbon and liquid

halohydrocarbons. Reactive liquids liquid

amines) are not suitable solvents.

48 1908

46,02 2/72 The temperature at which the half lives of typical catalysts are six minutes are:

CF-talyst Temperature

Azobisisobutyronitrile 100 0 C. Lauroyl Peroxide 100%. Deconoyl Peroxide lOO9C. Benzoyl Peroxide 1150C. p-Chlorobenzoyl Peroxide 11500. t-Butyl Peroxyisobutyrate 1150C. Acetyl Peroxide 1056C. Propionyl Peroxide 102 0 C. 2,4 -Dichlorobenzoyl Peroxide. 950 C. t-Butyl Peroxypivalate 950C.

12, 48190o8

46,02'2 72 In the process of this invention, the

monomers are polymerized in the polyol. Usually, the monomers are soluble in the polyol. It has been found that first dissolving the monomers in a

minor portion of the polyol and adding the solution

so formed to the remainder of the polyol at reaction

temperature facilitates mixing of the monomers in

the polyol and greatly reduces or eliminates reactor

fouling. When the monomers are not soluble in the

polyols, known techniques dissolution of the insoluble monomers in another solvent) can be

used to disperse the monomers in the polyol prior

to polymerization. The conversion of the monomers to polymers achieved by the process of this invention

is remarkably high conversions of at least of the monomers are generally achieved).

Without wishing to be bound by any

particular theory, it appears that the initial

yellow discoloration of commercially available

polymer/polyols derived from acrylonitrile or

acrylonitrilemethyl methacrylate mixtures and the

scorch of the foams prepared therefrom are both

caused by the internal cyclization of the contained

poly(acrylonitrile) to a "ladder" type polymer contain-

ing the chromophoric conjugated polyimine structure.

A sequence length of this chromophore In excess of

three repeating units is known to absorb visible

light; produce discoloration. It is postulated that the structure of the, chromophore is as follows:

13 48 1908

46,02 21

-CR CH n NN CHr -NNNq

Poly(acrylonitrile) "Ladder type" polymer It is known that the inclusion of a non-cyclizing

monomer into the polymer chain at the proper frequency

can prevent the formation of long sequence runs of the chromophoric cyclized poly(acrylonitrile).

Polymer/polyol viscosity is a complex function of contained polymeric content, initial polyol viscosity,

polymerization temperature, and, in this case, copolymer

composition. While the first two parameters are generally considered to be governed by Haganmacker

equation, the effect of polymerization temperature

and copolymer composition are not so readily understood.

It is believed that the effect of temperature and copolymer composition involve the type and degree of grafting being affected by changing these two sensitive

parameters. It is also recognized that changing the polymer composition affects the copolymer density as well as the particle polarity which, as is known,

will dramatically change dispersion viscosity.

Prior attempts (Canadian Patent 785,835) to prepare a 50/50 styrene/acrylonitrile copolymer/ polyol using azobisisobutyronitrile as a.catalyst

were plagued with reactor plugging, "gravel" sized particle formation and resulted in polymer/polyols that produced foams of less than desired physical

property characteristics (especially with regard to scorch of foams darived therefrom). This prior 14 48 1,908

46,022 72 process was carried out under conditionsessentially

equivalent to the conditions used in the process of the present invention with the exception that

polymerization temperatures in the prior process

were below the temperature employed in the present

invention when azobisisobutyrohitrile is.the catalyst

with the same reaotants. It is believed that the

prior process was troubled by:a relatively slow

rate of monomer polymerization which allowed unreacted

monomers to be incorporated within (dissolved in)

already formed polymer particles. These "plasticized"

polymer particles are subject to shear which affords

a'method of agglomeration resulting in "gravel" for-

mation or, in an extreme case, reactor plugging.

In the prior process, the reactor temperature was

approximately 97.5 where the half-life of

azobisisobutyronitrile is approximately 7.5 minutes.

In a preferred embodiment of the present invention 0 (reaction at 115-120 azobisisobutyronitrile has a

half-life of 1.5 to 1.0 minutes. Further, the prior

process achieved significantly lower conversions of

monomer to polymer than is achieved in the process of

the present invention (85 to 90% vs. over95% This

difference in conversion appears to be responsible for

the significant differences in the particulate nature

of the polymer/polyols prepared in the prior process

compared to the process of the present invention.

That is, the prior process produced compositions

containing over 0.1 inch in diameter) relatively

large granules which precipitated from the liquid S48 19 08

46,022/72 phase of the polymer/polyol whereas the present process produces compositions containing relatively small particles (that is, less than one micron in diameter) which remain suspended in the liquid phase of the polymer/polyol. Thus the relatively small particles and the resulting suspension are characteristic of the invention. It will be appreciated that while the particle size is stated as less than one micron in diameter the polymer may contain very small amounts of larger size particles. The compositions

16 48 1908

46,02 2

of this inventior: are suspensions containing a liquid

phase comprising unreacted polyol having suspended

therein small solid particles comprising homopolymers

and/or copolymers of the nitrile and styrene monomer.

The compositions also contain various polyol-monomer

graft copolymers having different polymer contents.

Those graft copolymer species having a low polymer

content (high polyol content) will be in the liquid

phase of the suspension while those species having

a high polymer content will also be suspended solids.

It is known that as the polymerization

temperature is raised 95 to 115 0 the reactivity ratio values of acrylonitrile and styrene

or for that matter, any two dissimilar monomers

become more equivalent. Such being the case, higher

polymerization temperatures apparently make a more

nearly random copolymer and thereby achieve better

foam properties as regards to foam scorch resistance.

The process of this invention produces

polymer/polyol compositions having properties markedly

different from polymer/polyol compositions produced

from the same starting materials at lower temperatures.

ar-9-ow -omolUtio-of matt er. However, in view of the state of the art and the complex nature of 17 481908

46,022/72 structure-property relationships in these compositions

discussed above, it is difficult to fully characterize

the novel compositions of this invention in terms

of their exact chemical structure.

Hence the compositions of-lthis /invention are best described in terms of the relative amounts and type of polyols and monomers used to produce them and in terms of their most outstanding property,

their ability to impart anti-scorch properties

to polyurethane foams to produce foams having a substantially uniformly white cross-section). In addition, the polymer/polyol compositions of this invention are white or cream colored liquids that have relative]y low viscosities viscosities from 1000 to 2500, preferably from 1000 to 150Cj

centipoises at 25 0 C further, the low density

polyurethane foams ki.e., foams having densities

less than 1.75 pounds per cubic foot) produced from these compositions have very good elongations (from 115% to 150% measured by ASTM D1564-69), tear strengths (from 2.50 to 3.50 nn,,nds per square inch measured by ASTM D1564-69 and 90% compression sets (from to 15 measured by ASTM D1564-69).

The invention also provides a method

for producing a polyurethane foam reacting and foaming: a polymer/polyol composition of this

invention, an organic polyisocyanate, a catalyst for the reaction of and to produce the polyurethane, (cd) a blowing agent and a foam stabilizer. The reaction and foaming operatiorscan

18 48 1,908

46902 2P/2 be performed in any suitable manner, preferably by the one-shot technique. The organic polyisocyanates that are useful in producing polyurethane foams in accordance with this invention are organic compounds that contain at least two isocyanato groups. Such compounds are well known in the art of producing polyurethane foams. Suitable organic polyisocyanates include the hydro- carbon diisocyanates, the alkylene diisocyanates and the arylene diisocyanates) as well as known triiso- cyanates. As examples cf suitable polyisocyanates one can mention 1,2-diisocyanatoethane, 1,3-diisocyanato- propane, 1,2-diisocyanatopropane, 1,4-diisocyanato- butane, l,5-diisocyanatopentane, l,6-diisocyanato- hexane, bis(3-isocyanat opropyl)ether, bis(3-isocyanato- propyl)sulfide, 1, 7-diisocyanatoheptane, 1, cyanato-2, 2-dimethylpentane, 1, 6-diisocyanato-3-methoxy- hexane, 1, 8-diisocyanato octane, 1, 5-diisocyanato-2, 2,4- trimethylpentane, 1, 9-diisocyanatononane, 1, lO-diiso- cyanatopropyl)ether of 1,4-butylene glycol, l,ll-diiso- cyanatoundecane, 1, 12-di-isocyanatododecane bis~iso- cyanatohexyl)sulfide, l,4-diisocyanatobenzene, 2,4- diisocyanatotoluene, 2,6-diisocyanato tolylene, 1, 3-diisocyanato-o-xylene, 1, 3-diisocyanato-m-xylene, 1, 3-diisodyanato-2 -xylene, 2, 4-diisocyanato-l-chloro- benzene, 2, 4-diisocyanato-l-nitrobenzene, and diisocyanato-l-nitrobenzene and mixtures thereof. The catalysto that are useful in producing polyurethane foams in accordance with this invention include:* tertiary amines suci a3 bis(dimethylamino ethyl)ether, trirnethylamine, triethylamine, 1

46,02 2/72 N-me thylmorpholine, N-ethylmorpholine, N,N-dimetjiyl- benzylamine, N,N-dimethylethanolamine, N,N, N'- tetramethyl-l, 3-butanediamine, triethanolamine, l,4 -diazabicycloZL_.2.?7octane, pyridine oxide and

the like; tertiary phosphines such as trialkyiphosphines, dialkylbenzylphosphines, and the like; strong bases such as alkali and alkaline earth metal hydroxides, alkoxides, and phenoxides, acidic metal salts of strong acids such as ferric chloride, stannic chloride, stannous chloride, antimony trichloride, bismuth nitrate and chloride, and the

like; chelates of various metals such as those which can be obtained from acetylacetone, benzoylacetone, trifluoroacetylacetone, ethyl acetoacetate, salicyl- aldehyde, cyclopentanone-2-carboxcylate, acetylacetone- imine, bis-acetylacetonealklene.diimines, Balicyl.- aldehydeimine, and the like, with various- metals such as Be, Mg, Zn, Cd, Pb, Ti, Zr, Sn, As, Bi, Cr., Mo, Mn, Fe, Co. Ni, or such ions as Mo 2 UO 2 and the like; alcoholates and phenolates of various metals such as Ti(OR 4 Sn(OR)4j Sn(OR) Al(OR) 3 and 2 the -like, wherein Iiis alkyl or aryl, and the reaction products of alcoholates with carboxylic acids, beta- diketones, and 2-(N.,N-dialkylamino)alkanols such as- the well known chelates of titanium obtained by said or equivalent procedures; salts of organic acido with a variety of metals siich ab alkali metals, alkaline earth metals, Al, Sn, '48 1.909

46,022/72 Pb, Mn, Co, Ni, and Cu, including, for example, sodium acetate, potassium laurate, calcium hexanoate, stannous acetate, stannous octoate, stannous oleate, lead octoate, metallic driers such as manganese and cobalt naphthenate, and the like; organometallic derivatives of tetravalent tin, trivalent and pentavalent As, Sb, and Bi, and metal carbonyls of iron and cobalt. Among the organotin compounds that deserve particular mention are dialkyltin salts of carboxylic acids, e.g. dibutyltin diacetate, dibutyitin dilaurate,

dibutyltin maleate, dilauryltin diacetate, dioctyltin diacetate, dibutyltin-bis(4-methylaminobenzoate), dlbutyltin-bis(6-methylaminocaproate), and the like. Similarly there may be used a trialkyltin hydroxide, dialkyltin oxide, dialkyltin dialkoxide, or dialkyltin dichloride. Examples of these compounds include tri- methyltin hydroxide, tributyltin hydroxide, tri-

octyltin hydroxide, dibutyltin oxide, dioctyltin oxide, dilauryltin oxide, dibutyltin-bis(isopropoxide), di- butyltinbis(2-dimethylaminopentylate), dibutyltin

dichloride, dioctyltin dichloride, and the like. The tertiary amines may be used as primary catalysts for accelerating the reactive hydrogen/iso-

cyanate reaction or as secondary catalysts in combin- ation with one or more of the above noted metal catalysts. Metal catalysts, or combinations of metal catalysts, may also be employed as the accelerat- ing agents, without the use of amines. The catalysts are employed in small amounts, for example, from 21 48 1.908

46,022/72 about 0.001 per cent to about 5 per cent, based on

weight of the reaction mixture.

Foaming is accomplished by employing a small

amount of a polyurethane blowing agent, such as water,

in the reaction mixture (for example, from about

to about 5 weight per cent of water, based upon

total weight of the polymer/polyol composition), or

through the use of blowing agents which are vaporized

by the exotherm of the reaction, or by a combination

of the two methods. Illustrative polyurethane blowing

agents include halogenated hydrocarbons such as

trichloromonofluoromethane, dichlorodifluoromethane,

dichloromonofluoromethane, dichloromethane, tri-

chloromethane, 1,1-dichloro-l-fluoroethane, 1,1,2-

trichloro-l,2,2-trifluoromethane, hexafluorocyclobutane,

octafluorocyclobutane, and the like. Another class

of blowing agents include thermally-unstable compounds

which liberate gases upon heating, such as N,N'-di-

methyl-N,N'-dinitrosoterephthalamide, and the like.

The generally preferred method of foaming for producing

flexible foams is the use of water or a combination

of water plus a fluorocarbon blowing agent such as

trichloromonofluoromethane. The quantity of blowing

agent employed will vary with factors such as the

density desired in the foamed product. The anti-scorch

properties of the polymer/polyol compositions are

most evident when at least some of the blowing agent

is water and the water is used in an amount that

results in a foam having' a density less than 1.75

pounds per cubic foot. Generally, the use of water 22 481908

46,02 272 in an amount of at least 3.0 per cent by weight

based on the total weight of the polymer/polyol of composition results in a foam having a density

less than 1.75 pounds per cubic foot. It is also within the scope of the invention

to employ small amounts, about 0.001% to

by weight, based on the total reaction mixture, of

a foam stabilizer such as a "Pluronic" or a

"hydrolyzable" polysiloxane-polyoxyalkylene block

copolymer such as the block copolymers described

in U.S. Patents 2,834,748 and 2,917,480. Another

useful class of emulsifiers are the "non-hydrolyzable" such as polysiloxane-polyoxyalkylene block copolymers

the block copolymers described in U.S. Patent 3,505,377; 24, U.S. Patent application 888,067, filed December The 1969 and British Patent Specification 1,220,471.

latter class of copolymers differs from the above-mentioned

polysiloxane-polyoxyalkylene block copolymers in

that the polysiloxane moiety is bonded to the polyoxy- bonds, alkylene moiety through direct carbon-to-silicon bonds. rather than through carbon-to-oxygen-to-silicon

These various polysiloxane-polloxyalkylene block

copolymers preferably contain from 5 to 50 weight

per cent of polysiloxane polymer with the remainder

being polyoxyalkylene polymer. Polyurethane foams produced in accordance

with this invention are useful in the applications in

which foams made from conventional polymer/polyols are

employed and are particularly useful as arms rests,

crash pads and mattresses. AQ I 1a A O J..A1U

23 U A, V U

46,02 2/72

The following Examples illustrate the present invention.

Definitions

As used in the Examples appearing below, the following designations, symbols, terms and abbreviations have the indicated meanings:

Polyol I A polypropylene oxide triol produced from propylene oxide and glycerine and having a molecular weight of about 3,000. Polyol II A polyalkylene oxide triol produced from propylene and ethylene oxides and glycerine and having a molecular weight of about 3,700. The alkylene oxide units are present primarily in blocks and the primary OH content is about 57.5%. The ethylene oxide is used to "cap" the triol. Based on its alkylene oxide content. this triol contains 90 wt-% C3 H6 0 and 10 wt-% C 2HMO. Polyol III A polyalkylene oxide triol produced from propylene and ethylene oxides and glycerine and having a molecular weight of about 4,900. The alkylene oxide units are present primarily in blocks and the primary 0H content is about 75%. The ethylene oxide is used to "cap" the triol. Based on its alkylene oxide content this triol contains 85 wt-% C 3 and 15 wt-% C2 H40.

24 481908

46,022/72

Polyol IV A polyalkylcne oxide triol produced from propylene and ethylene oxides and glycerine and having a molecular weight of about 4,650. The alkylene oxide units are present primarily in blocks and the primary OH content is about Based on its alkylene oxide content, ttis triol contains 86 wt-% C3 H6 0 and 14 wt-% C2 H4 0.

Polymer/Polyol A A commercially available polymer/ polyol produced by polymerizing weight percent acrylonitrile in 80 weight percent Polyol I. Polymer/Polyol B A polymer/polyol produced by polymerizing 20 weight percent styrene in 80 weight percent Polyol I.

Polymer/Polyol C A commercially available polymer/ polyol produced by polymerizing weight per cent acrylonitrile and 10 weight per cent methyl methacrylate in 80 weight percent in Polyol I. Polymer/Polyol D A polymer/polyol produced by weight percent acrylonitrile in 80 weight percent Polyol III. Surfactant I MeSi(OSIMe2 6 2 (OC2 H4 18 (OC3 H6 14 0Bu 3 wherein Me is methyl and Bu is butyl.

46,022in

Surfactant II A mixture of:

3s [CH 7 vt-%(CH3 io--sJ-. 5 (CH3 and S 3i(CH and

S 60(C F 40)0 2 (C 0) 3 H6 29

wt-i of an admixture of;

C 4 H (C2 H 4 (C H0) 3 H (90 wt-i) and

CgH 9 C 6H 4 oC 2 H 470H(10 wt-%)

Surfactant III

AH30 H3CH3 CH3 S iO [Ii- 0 5 H3i 1 2i H 4 C- Si- 2 Si(CH 3 L2 46E9 36 4 3 H 66020 29R 6

wherein R is 90 mole CH 3 groups and 10 mole C-CH 3 groups. TDI A mixture of 80 weight percent 2 4 -tolylene diisocyanate and 20 weight percent 2 6 -tolylene diisocyanate. parts parts by weight "Ionol" 2,6 -di-tert-butyl-4-methylphenol 3CF tris (beta-chloroethyl)phosphate stripped volatile materials removed by heating at reduced

pressure VCN acrylonitrile rpm revolution per minute

48 190S

46,0 2 2 I

0 cps. centipoises at 259 c using number 3 spindle on a Brookfield viscometer; 100 rpm

min. minute

wt. weight

percent

48 1.908

46,02 2/2 Test Procedures

The following test procedures were used in the Examples appearing below:

Test Procedure Indentation Load Deflection ASTM D1564-69 (ILD)

Compression Set

Tensile Strength U

Elongation

Tear Resistance (Strength)

Sac Factor (or Load Ratio)

Humid Age Load Loss

Resilience

CLD (Compression Load

Deflection)

Return (Value)

Foam Color Rating (or Scale: 0-80 units Scorch Rating) 0: No color: 80: Dark Bro Jn

Visual rating Abbreviated Pill ASTM D-2859-70 T

modified ("abbreviated") by

use of 1 test sample rather

than 8 with flame spread

effected by ignited

methenamine pill. Docket No. 3-3 Proposed Motor Vehicle

Safety Standard 302

48 1.908

46,022 2

Porosity A specimen of foam 1/2 inch in thickness is compressed between two pieces of. flanged plastic tubing 2 1/4 inches in diameter This assembly then becomes a component in an air flow system. Air at a controlled velocity enters one end of the tubing, flows through the foam specimen and exits through a restriction. at the lower end of the assembly. The pressure drop across the foam due to the restriction of air passage is measured by means of an inclined closed manometer. One end of the

48 1.908

46,02272 manometer Is connected to the upstream side of the foam and the other end to the downstream side. The flow of air on the upstream side is adjusted to maintain a differential pressure across the specimen of 0.1 inch of water. nrhe air porosity of the foam is reported In units of air flow per unit area of specimen, cubic feet per minute per square foot.

Example 1 To a three-necked, one-liter flask equipped with addition funnel, stirrer, and reflux condenser was

added 321 grams of Polyol I. The polyol was heated to 110C., with a glass-mantle while sparging with oxygen- free nitrogen. After 15 to 20 minutes of sparging with nitrogen, the following mixture was continuously fed to the flask over a 2 hour time span: Polyol I (159 grams); acrylonitrile (60 grams); styrene (60 grams); and

azobisisobutyronitrile (3.0 grams). The temperature of the reaction mixture so formed was maintained at

110 0 C throughout the polymerization. Less than minutes after the feed of the mixture was begun, the

reaction mixture became cloudy with'small, apparently

insoluble, particles and as the polymerisation progressed,

the reaction mixture became opaque with white suspended

solids (less than one micron in diameter). No large particles ("granules") formed. Upoi completion of monomer addition, the reaction mixture was heated at 110 0 C. for an additional 30 minutes and then cooled and then stripped

free of unreacted monomer. The unreacted monomer was stripped for four hours on a rotary evaporator

46,02272 10 mm. of mercury at approximately 100° C. and at less than trapped in absolute pressure. The unreacted monomers were

dry-ice traps. Conversion of monomers to polymer (based on

unreacted monomers recovered in the dry-ice traps) was in so excess of 96.0 per cent. The stripped, white polymer/polyol (No. 2 produced had a Brookfield viscosity of 3,072 centistokes spindle, 100 rpm 25° Example 2

Example 1 was repeated except that six times the amount 115° C. of starting materials and a reaction temperature of

was employed. The polymer/polyol so produced had a viscosity as of centipoises at 25° C. and is referred to hereinafter

"Polymer/Polyol 1". Example 3

Low density flexible polyurethane foams were prepared as from Polymer/Polyol 1 (produced by the process invention

described in Example 2 above) and, for purposes of comparison,

from Polymer/Polyol A (a commercially available polymer/polyol

described above under "Definitions"). The following foam

formulation was used: Polymer/Polyol 100 parts 3500 grams

Water 4.0 parts 140 grams

Surfactant 1 1.0 parts 35 grams

Bis(dimethylamino ethyl)ether .07 parts 2.45 grams

Stannous octoate .35 parts 12.25 grams

TDI 107 Index 1710.0 grams

The foam formulations were converted to

polyurethane foams using the following procedure: Weigh

Surfactant, polymer-polyol and TDI into 8-liter,baffled

48 1908

46,022172 stainless steel beaker and mix 60 seconds at 2,000 rpm with two 2.5 inch 6 blade turbine stirrers,(placed inches apart at base of shaft.) Stop fifteen seconds to de-gas, mix five seconds, add water/ amine catalyst mixture, mix additional five seconds, and add stannous octoate and mix five seconds. Pour foam mixture into 24" x 24" x 20" paper-lined box. Record foam rise time. Allow to cure-overnight at room temperature. "Scorch" sample slices (two inches thick) taken from horizontal center of foam bun. Other foam physical properties were measured on a six inch sample taken from bottom of upper half of foam bun. "Scorch" evaluation is made from center of "scorch" slice sample. The following physical properties of the foams were determined

Table I Improvement Of Foam 2 Foam 1 Foam 2 vs. Foam 1 Polymer/Polyol A I Foam Rise time S70 seconds 78 sec. Foam porosity (ft3 /min/f t 2 45.0 20.9 ILD (lbs) 25% 61.4 69.5 13.2% 114.6 120.0 4.7% 33.0 39.3 19.1% Return Value, 53.8 56.6 Load Ratio (651LD/25ILD) 1.87 1.73 Foam Density, pcf 1.46 1.43 Compression Set, 90% 78.7 16.1 79.5% (reduced) lensile Strength, psi 18.8 22.5 19.7% Elongation, 103 114 10.8% Tear Resistance, lbs/in 2.12 2.85 34.4% Foam Scorch color dark brown cream

48 1908

46,022/2n Example 4

A series of polymer/polyol were prepared using

weight percent Polyol 1 and 20 weight percent of acrylonitrile

or a mixture of acrylonitrile and styrene. The reaction temperature was 115° C. The other reaction conditions were as described in Example 1 above. Table 11A below tabulates the properties of the polymer/polyol so produced.

Table 11A

Product Polymer/Polyol CH 2 =CHCN Styrene Color Viscosity, ctsk D* 6.60 13.40 white 35,200 E* 8.26 11.74 white 19,650 F* 8.26 11.74 white 19,200 G* 20.00 0.00 yellow 9,450 11 10.00 10.00 white 2,370 111 10.00 10.00 white 2,080 1V 12.05 7.95 white 1,440 V 14.00 6.00 cream 1,440 not polymer/polyols of this invention.

The data in Table 11A illustrates the lower viscosities and, as

compared to Polymer/Polyol G, the improved color of the polymer/

polyols of this invention. The data in Table 11A illustrates that there is a definite viscosity minimum that is a function

of the composition of the copolymer. A plot of this data would place the viscosity optimum acrylonitrile-styrene ratio at

about 12.5/7.5, but reasonably low viscosities are obtained at

acrylonitrile/styrene ratios as low as 9/11.

The polymerization temperature of 1150 C. used in the

polymerizations listed in Table 11A was selected as a result of

a brief study concerning the relationship of Polymer/Polyol

33 481.908

46,022 /72 viscosity and polymerization temperatures. The results of thin

study are shown in Table 11B below. This relationship can be

plotted to show an inflection point of the viscosity-tempera-

ture curve at 1150 C. Thus 1150 C was selected as the standard

polymerization temperature for other Examples. The copolymer/

polyol composition in the temperature study was Polyol 1/

styrene/acrylonitrile (80/10/10 weight ratio).

Table 11B

Temperature o C Viscosity

100 8,280 cps

110 3,072 cps

115 2,080 cps

115 2,368 cps

120 2,100 cps

Example

Low density flexible polyurethane foams were prepared

from Polymer/Polyol 1 and, for purposes of comparison, from

Polyol 1, Polymer/Polyol A and Polymer/Polyol B. The following

foam formulations were used:

Component Foam

(parts by weight)

1 2 3 4

Polyol 1 100

Polymer/Polyol A 100 Polymer/Polyol 1 100 Polymer/Polyol B 100 Water 4.0 4.0 4.0 Stannous octoate .325 .35 .35 Bis(dimethylaminoethyl)- .10 .10 .10 ether

48-1908

46,02272 Surfactant 1 1.0 1.0 1.0 1.00

TDI 105 105 105 105

(Index) (Index)(Index)(Index)

The foam formulations were converted to polyurethane foams using the procedure described in Example 3 above. The properties of the foams were as follows: Table 111

Properties Foam 1 2 3 4 3 82.8 48.3 34.5 58.7 Porosity (ft /min./ft.2) Resilience (%ball 45 36.0 34 37

rebound).

ILD (lbs.) 25% 44.5 60.0 62.0 37.3

78.8 108.7 113.5 60.2

29.8 33.4 34.0 16.4

ILD Return 67.0 55.7 54.8 44.0

Sac Factor 1.77 1.81 1.83 1.61

Density lbs/cu.ft. 1.44 1.45 1.43 1.59

Compression Set, 90% 3.63 70.2 23.4 10.2

Tensile Strength, psi 15.4 20.5 19.9 14.2

Percent Elongation 159 127 141 148

Tear Resistance, lbs./in. 2.17 2.29 2.51 1.79

Humid Age Load Loss N/A N/A 23.4 16.7

Foam Color Rating 0 70 5 0

A comparison of the foam physical properties with base

Polyol 1 (Foam 1) with the properties of Foam 4 (styrene

polymer/polyol) indicate that it is unexpected that

substitution of 50 wt. per cent styrene for acrylonitrile in

the polymer contained in the polymer/polyol of Foam 3, not

only does not detract from the foam physical properties of the 48 1908

46, 022/2 100% polyacrylonitrile polymer/polyol (Foam but actually shows improvement in some of these properties. With reference to Foam 4, these changes would, except for the Percent Elongation, not be anticipated.

48 1908

46,022/72 Example 6 Low density flexible polyurethane foams were prepared from Polymer/Polyols II, IV and V and, for purposes of comparison, from Polymer/Polyols A, P and D (see "Definitions" and Example 4 above for the compositior of these polymer/polyols). The following foam formulations were used: Parts by Weight Polymer/Polyol 100 Water Bis(diemthylaminoethyl)ether 0.10 Stannous octoate 0.575 Surfactant II TDI 107 index The foam formulations were converted to polyurethane foams using the procedure described in Example 3 above. The properties of the foams were- as follows:

481.908

46,02 2/72

E'.b '4 S.- '0 0

CU

0% -4 Cu0~ -4 U Cu -4 q0

op -g 0 -4 Go

-4 -4 5- A's i-b

U ~*s GOLf 0 0 tb- En 0 U% U' -4 C- u -4

%0 4' 0 -4 U 0 '-S o cu 0 0 0% En Cu 3Iz Cu 4 ~4

0 i- Cu0U. E

0.

0 4-.

ii 0 4 Cu o o

0 A~ 4]

a~ 0 0J 4

38 48 1.908

46,022/72 These data were "normalized" to a 1.50 pcf density in order to accruately assess trends

in foam properties. "Normalized" means conversion

of those foam physical properties sensitive to

density CLD, tensile strength, elongation

and tear), to a common density, in this case by the division of property data by the following factor: experimental foam density 1.50

It will be noted that as the copolymer composition

decreases significantly below 50 weight percent

acrylonitrile, foam properties such as compression

load deflection, tensile strength, and percent

elongation rapidly decrease. These decreases

parallel the rapid polyol viscosity increase

shown in Table IIA above. The foam data show that

physical properties equal or superior to commercially available Polymer/Polyol A are achieved with Polymer/Polyol II which was produced by the

process of this invention.

481908

46,022/72 EXAMPLE 7

This Example illustrates the practice of

the process of this invention in a continuous manner

using relatively large amounts of starting materials

in two stages. The first state was conducted in a conventional Ifaidler autoclave and the second

state was conducted In a "Marco" reactor, in a Marco Flomaster Reactor, model number 2x290-294

whose operation is generally described in Example 1

of Canadian Patent 785,835).

The following materials Were used in this preparation:

Polyol I Hydroxyl number 52.51 ph 6.2 Alkalinity 0.000071 Color, Pt-Co Water, 0.066 Acrylonitrile

Water content, 0.3 Color, Pt-Co Suspended matter nil Refractive index 1.3894 Inhibitor level, parts per mUllion 37 Styrene

Specific gravity, 20/20*C. 0.9078 Acid nil Purity, by Wt. 99.7 Color, Pt-Co Aldehydes, by Wt. 0.005 Sulfur, ppm 1 Refractive index 1.5475 Azobisisobutyronitrile: Commercially available pro- duct, "VAZO", used. A polymer/polyol of this invention was pro-

duced by feeding a mixture' of 79.311% Polyol I,

40 48 1908

46,022/72 10.344% acrylonitrile, 10.344% styrene and 0.491%

azobisisobutyronitrile to a five-gallon stirred autoclave that

was maintained at 115 20 C. The feed rate was 92 2 lbs per hour. The partially polymerized products of the autoclave

was passed through the 3-gallon capacity Marco reactor,

maintained at 1150 C. The product of the Marco reactor was

then put into 55 gallon drums. Unreacted monomer was stripped from the latter product in a 300 gallon stirred reactor.

Intermittent sampling (30 minute intervals) of the reaction product of the Marco reactor once steady state conditions were

achieved after about 30 minutes of operation) showed that the white polymer/polyol had a uniform sample Brookfield

Viscosity of 1050 50 cps (No. 3 spindle 260 Inspection of the autoclave and the Marco reactor following the 25 hour

continuous polymerization showed little or no polymer deposit

(scrap) residues. Monomer to polymer conversion was in excess

of 95%. The polymer/polyol of this invention so produced is

identified hereinafter as "Polymer/Polyol Vl".

Polymer/Polyols A, C and V1 were used in the following

formulations to make polyurethane foams:

Component Amount (parts by weight) Polyol 100 Water

Bis(dimethylamino ethyl)ether 0.1 Stannous octoate varied* Surfactant 11

TDI 105 Index Concentration varied to make stable foams as in Example 8

below.

48 1908

46,022/72

The formulatiom were converted to polyurethane foams as detailed In Example 3. The properties of the polymer/polyols and the foams were as follows: Polymer/Polyol A C VI. Polymer/Polyol yellow cream white Color Hydroxyl Number 44.9 43.5 43.4 Brookfield Viscosity, 2580 cps. 1800 cps. 1200 cps. 23°C.* Stannous Octoate Con- .275-.375 25-.425 .25-.975 centratlon Range (parts by weight)**

Scorch, Rating 65-70 25 Viscosity after removal of unreacted monomers.

Above the concentration the cells were closed and below this concentration the foam split using the above formulations.

It is an historical finding that, as a

polymer/polyol process is scaled up from the laboratory

reactor from a 1 or 2 liter flask) to a pilot unit to the plant production unit), there is an incre-

mental reduction in product viscosity, notwithstanding

the type of polymer/polyol product being made. A comparison of the viscosities of the products of

Examples 1 and 7 shows the same effects on scale up.

EXAMPLE 8 Flammabillty tests were conducted on Polymer/

Polyol VI (produced in accordance with the process

of this invention as described in Example 7 above).

2 4819 08

46,022/72 The tests were the Abbreviated Pill Test, the

Docket No. 3-3 Test and the ASTM D-1692 Test. The

results are described below.

The foams tested were produced from the

following formulations using the procedure described

in Example 3 above:

Component Parts By Weight

Polyol 100

Water 3

3 CF as indicated

Surfactant Bis(dimethyl aminoethyl)ether 0.1

Stannous octoate

TDI 105 Index Concentration was varied to make stable foams as

follows: With the other formulation components

held constant, the stannous octoate concentration

was varied until the stannous octoate concentration

which resulted in a split-free, "open" foam was

determined.

In Table V are listed the results of an

Abbreviated Pill Test (samples were not preconditioned

and only one sample was tested). This test requires

that a metheneamine pill be ignited in the center

of an eight-inch diameter specimen and the unburned

distance measured. The numbers in the table are the

unburned distances. To pass the pill test this

distance has to be one-inch or greater. A zero

shows that the sample was consumed in the test. With Surfactant II as the surfactant it

is readily evident that Polymer/Polyol VI foams are 43 48 1908

46,02272 the least flammable in this test. By replacing Surfactant II with Surfactant III in the formulations, the Polymer/Polyol VI foams are still superior, but only marginally so over the Polyol I foams. TABLE V ABBREVIATED PILL TEST

Surfactant II Polyol 3CF Content

parts 10 parts 20 parts Unburned Distance Polymer/Polyol VI 2-3/8 in. 3-1/4 in. 3 in. Polymer/Polyol C 0 0 2-7/8 in. Polymer/Polyol A 0 0 3 in. I Pol1-* i .I L 0 3-3/16 3-1/2 Surfactant III Polymer/Polyol VI 3-1/8 in. 3-1/8 in. 3-3/8 in. Polymer/Polyol C 0 3 in. 3-1/8 in. Polymer/Polyol A 0 2-7/8 in. 3-1/4 in. Polyol I 2-3/8 in. 3-1/8 in. 3-1/8 in. The next test in which these foams were evaluated is the National Highway Safety Bureau, Department of Transportation Motor Vehicle Safety Standards ("Docket No. Criteria for passing this test is the burning rate for two horizonatl samples of foam to be less than 4 in/min. The results are recorded in Table VI. In the Surfactant II series, the Polymer/Polyol A foams are obviously the most flammable. With 5 parts 3CF the Polymer/Polyol C foam has the lowest burning rate, but with 10 parts 3CF one specimen of the Polymer/Polyol A foam wa 44 48 90.8

46,022/2 self extinguishing and the other had a rate of 1.81 in/min, whereas the Polyol I samples were both self extinguishing. In the Surfactant III series, the Polymer/Polyol VI foams are slightly superior

to the Polyol I foams.

TABLE VI DOCKET NO. 3-3 TEST Surfactant II 3CF Content lOparts Polyol Average Burning Rate, in./min. Polymer/Polyol VI 1.81 S.E. Polymer/Polyol C 1.46 1.21, S.E. Polymer/Polyol A 2.30 1.81, S.E. 3.57, S.E. Polyol I 2.06 S.E. S.E. Surfactant III Polymer/Polyol VI S.E. S.E. S.E. Polymer/Polyol C S.E. S.E. S.E. Polymer/Polyol A S.E. 1.41, S.E. S.E. Polyol I 1.58 S.E. S.E. S.E. means self extinguishing and indicates that the sample burned less than 1.5 inches.

Two samples tested, one was S.E. and the other burned more than 1.5 inches.

The next test to be employed was the ASTM D-1692. Here five specimens are tested and each has to extinguish before burning five inches. This is usually regarded as the most difficult test of these three tests described in this Example. In Table VII the burning rate,, extent of burn and 481,908

46,0221n

rating are listed for this series of foams. Table VII ;.hows that the Polymer/Polyol A foams are the most flammable and Polymer/Polyol C foams are more flammable than Polymer/Polyol VI and Polyol I foams.

TABLE VII ASTI D-1692 TEST

Surfactant II

3CF Content

parts 10 parts 20 parts Rating, Rate Extent (in.) Polyo1

Polymer/Polyol Ba,319,5 S.E.,2.69,2.0 S.E.,2.51,1. Polyrer/Polyol B,3.12,5 B,2.88,5 S.E.,2.23,2. Polymer/Polyol B,3.50,5 B,2.75,5 B,2.17,5 Polyol I B,2.95,5 S.E.,2.24,2.3 S.E.,1.90,1.

Surfactant III

Polymer/Polyol S.E.,3.46,1.8 S.E.,2.80,1.4 S.E.,2.00,0. Polymer/Polyol S.E.,3.33,2.4 S.E.,2.81,1.7 3.E.,2.28,1. Polymer/Polyol B,3.44,5 S.E.,2.13,2.2 S.E.,1.83,3. Polyol I S.E.,2.35,2.25 s.E.,1.65,1.37 7.E.,1.77,0

B means burning.

48 1908 4.6

46,022 /72 Example 9 The polymer/polyols shown in Table V111 below were

converted to polyurethane foams using the general procedure

described in Example 3 above and using the formulations shown

in Table IX below. The properties of the foams are shown in Table X below. The foam properties show that, overall, the

polymer/polyols of the invention (Polymer/Polyols 1V, V11,

V111 and IX) produced from various polyol starting materials

(Polyols 1, 11, 111 and IV) resulted in good foams.

TABLE Vl11

Polymer/Polyol Base Polyol Viscosity, Composition (wt. Polymer/Polyol SMol. Wt. cps. ratios) (1) A 3,000 2,000 Polyol 1/VCN

(80/20) D 4,950 3,800 Polyol 111/VCH

(80/20) IV 3,000 1,400 Polyol 1/VCN/

Styrene

(80/10/10) Vli (2) 3;700 1,200 Polyol IV/Sty-

rene/VCN

(80/10/10) Vlii (3) 3,740 1,200 Polyol 11/Sty-

rene/VCN

(80/10/10) IX (4) 4,950 2,200 Polyol 111/VCN/

Styrene (80/10/10)

481908 47.

46,022/72 VCN denotes acrylonitrile.

produced by the general process used in Example 2 using the starting materials shown in this Table. produced by the general process used in Example 2 using the starting materials shown in this Table.

produced by the general process used in Example 2 using the starting materials shown in this Table.

48 481908

46,022/72 TABLE IX

Foam Amounts Formulation (parts by weight) 1 2 3 4 5 6

Polymer/Polyol A 100 IV 100 VII 100 VIII 100

D 100

IX 100

H2 0 4.0 4.0 4.0 4.0 4.0

bis(dimethyl amino- .10 .10 .075 .05 .03 .03 ethyl)ether stannous octoate .30 .35 .275 .30 .175 .175

Surfactant I 1.0 1.0 1.0 1.0 1.0

TDI, Index 105 105 105 105 105 1C7

TABLE X Foam Properties Foam** 1 2 3 5 6

Scorch rating 65. 5 5 5 3 2 24 32 29.2 Porosity, ft /min/ft 55 34.5 51.2

Resilience, 32 35 35 35 27 ball rebound ILD 25% (Ibs) 61.0 65.0 60.2 63.2 65.1 69.2

113.2 119.0 97.0 112.0 124.5 136.0

(return) 34 4 35.6 33.0 35.3 32.3 36.4

Return 56.5 54.8 54.8 55.5 49.6 52.6

Load Ratio 1.86 1.83 1.61 1.77 1.91 1.96

Foam produced from the correspondingly numbered foam formulation. 48 19 0

46,022/72 TABLE X (Can't) Foam Properties 1 2 3 4 5 6 Density, peE 1.52 1.43 1.46 1.55 1.65 1.69 Compression Set 36.7 23.4 7.84 9.35 66.7 35.5 Compression, Height Loss,

Tensile*, psi 18.7 20.8 19.8 22.7 18.0 16.9 Elongation*, 120 148 171 148 123 93 Tear*, lbs/in 2.11 2.63 2.88 2.87 3.37 2.96 Hour Humid Age 19.2 23.4 23.5 18.7 N/A N/A Load Loss *Data sensitive to density variation "normalized" to 1.50 pef. Foam scorch rating: 0-80 Scale with 0 being white (no scorch) and 80 being dark brown (severe scorch). An important consideration in the production of polymer/ polyols in accordance with this invention is the improvement- in the conversion of volatile monomer to non-volatile copolymer. This latter finding improves process economics and efficiency. The conversions of the monomer to polymer were as follows in the preparation of the various polymer/polyol compositions described above:

48 1908

4 6,022/72

Polymer/Polyol %Conversion of monomer 1 over 96% 11 over ill over 97% iv about 98% V about Vi over Vii over Vili over ix over The above conversions were calculated based on unreacted monomers recovered as described in Example 1 above.

48 1.908

Claims (1)

1. 46,022/72 The claims defining the invention are as follows

   1. A process for producing a fluid polymer/polyol composition from a reaction mixture containing polyol and a monomer mixture which process comprises polymerizing,

   in the presence of a free radical catalyst, at a temperature at which the half life of the catalyst is no longer than six minutes, and, while adding the monomer mixture slowly to the polyol and stirring the reaction mixture, from 10 to weight per cent of a monomer mixture of from 50 to weight per cent of acrylonitrile or methacrylonitrile and from 25 to 50 weight per cent styrene or alphamethyl

   styrene, said weight per cents of the nitrile and the styrene or alpha-methyl styrene being based on the total weight of those materials, dissolved or dispersed in from 70 to weight per cent of a normally liquid, at room temperature,

   polymeric polyol having a hydroxyl number from 20 to 150, said weight per cent of the monomer mixture and polymeric polyol being based on the total weight of the monomers and the polyol and said polymer having relatively small (as hereindefined)

   polymer particles.

   2. A process as claimed in claim 1 wherein the low monomer to polyol ratio is maintained by conducting the polymerization in a semi-batch manner in a back- mixed reactor while slowly adding the monomer mixture to the polyol.

   481.908

   46,022/7

   i3. A process as claimed in claim 1 wherein the entalvst is azobisisobutyronitrile and the temperature. is at least 1000C.

   13. A process as claimed in claim 1 wherein the monomer mixture contains about 50 weight percent acrylonitrile and about 50 weight percent styrene.

   4. A process as claimed in claim 1 wherein about 20 weight percent of the monomer mixture is polymerized while dissolved or dispersed in about

   weight percent of the polyol.

   A process as claimed in claim 1 wherein

   the polyol is an alkylene oxide adduct of a poly-

   hydroxyalkane.

   8 48

   46,02 272 7. A process as claimed in claim 1 wherein the temperature used in the polymerization is a

   temperature at which the half life of the catalyst'is

   no longer than two minutes.

   8. A process as claimed in claim 3 wherein

   the temperature is from 115 to 120 0 C.

   9. A process for producing a fluid polymer/

   polyol composition as claimed in claim 1 substantially

   as herein described with reference to the Examples.

   DATED this 28 day of September, 1976

   UNION CARBIDE CORPORATION

   JAMES M. LAWRIE CO. PATENT ATTORNEYS

   5448 54 4819 0 g