CA2023034A1 - Rigid polyurethane foams prepared from polyvinyl acetate/allyl alcohol polyols and process for making same - Google Patents

Abstract

RIGID POLYURETHANE FOAMS PREPARED FROM POLYVINYL
ACETATE/ALLYL ALCOHOL POLYOLS, AND PROCESS FOR MAKING SAME
Abstract of the Disclosure Polyurethane systems are disclosed utilizing poly-vinyl acetate/allyl alcohol random copolymers to produce rigid polyurethane foams and a process for producing the same. The resulting foams exhibit improved K-factors, util-ized reduced amounts of fluorocarbons as blowing agents, and maintained insulating properties when formulated with increased amounts of water.

Description

Express Mail No. MB179884056 August 10, 1989 ~3~

RIGID POLYURETHANE FOAMS PREPARED FROM POLYVINYL
ACETATE/ALLYL ALCOHOL POLYOLS, AND PROCESS FOR MAKING SAME

Background of the Invention 1. Field of the Invention The present invention relates to rigid poly-urethane foams, and more particularly, to rigid polyurethane foams prepared from polyvinyl acetate/allyl alcohol polyols and the process for making the ~ame.

2. Description of Related Art It is well known that a polyurethane foam having insulating utility can be prepared by reacting an organic polyfunctional isocyanate with a suitable hydroxyl component in the presence of a blowing agent such as a fluorinated hydrocarbon. The fluorinated hydrocarbons produce a desir-able rise in the foamed product, but also play an i~portant role in producing a foam having a low thermal conductivity or K factor. However, the use of fluorinated hydrocarbons adversely impacts the environment. Regulatory agencies have mandated a reduction in fluorinated hydrocarbon use and have called for the eventual elimination of the use of fluorin-ated hydrocarbons. Attempts have been made to substitute various blowing agents, such as water, in an effort to find a replacement for fluorinated hydrocarbons. Most of these ~, ~ ?J c~

attempts have produced unsati6factory results. For io-6tance, while water may be ~ubctituted for fluorinated hydrocarbons as a blowing agent, the CO2 produced by the water decreases the insulating properties of rigid foams.
Reretofore, it has been known that use of copolymer~ in urethane systems could produce improved physical and chemi-cal properties such as increased load upporting capacity, increased tensile strength, increased modulus of tensile elasticity, and increased ~olvent resistance. ~owever, the use of a copolymer, particularly the copolymer used in the instant invention, to improve the resistance to thermal conductivity of the foam has not been recognized.
SummarY of the Invention Rigid polyurethane foams are prepared from poly-vinyl acetate/allyl alcohol polyols. The urethane foam is formulated ~rom a polysl component containing from about 2 to about 100 weight percent of a polyvinyl acetate/allyl alcohol polyol. The polyvinyl acetate/allyl alcohol has at least 2 hydroxyl units.
Objects, features and advantages of this invention are to provide a polyurethane rigid foam cuitable for insul-ating, from a polyurethane system including a polyvinyl acetate/allyl alcohol copolymer, which iB characterized by a ,................... ... ... .

s r ~ ~1 r reduction in the amount of fluorinated hydrocarbons used as a blowing agent, has improved K factors, may be produced by utilizing increased amounts of water as a blowing agent without sacrificing insulation properties, which maintains improved K factors of the foam with aging, produces foams of suitable density, maintains low porosity of foam cells, maintains a suitable gel time and provides an economic co-polymer for urethane systems not heretofore known.
These and other objects, features and advantages will be apparent form the detailed description and appended claims which follow.
Detailed Description of the Present Invention The present invention is directed to rigid poly-urethane foams prepared from a polyvinyl acetate/allyl alco-hol polyol. The urethane foam is formulated from a polyol component containing from about 2 to about 100 weight per-cent of the polyvinyl acetate/allyl alcohol polyol. The copolymers may be hydroxy, isopropoxy, or isopropyl initi-ated. However, the copolymers are believed not to be hydroxy or isopropoxy terminated. The polyvinyl allyl alcohol has at least 2 hydroxyl groups. The polyvinyl acetate/allyl aleohol polyol may contain from about 2 to about 95 weight percent vinyl acetate and from about 5 to .. . . . . __ _ . . . . , ._ .. .. . . . ... . . . ... . .. . .. ... . .

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about 98 weight percent allyl alcohol. Preferably, the copolymer includes form about 10 to about to about 25 weight percent allyl alcohol. The molecular weight of the polyvinyl acetate/ allyl alcohol polyol may range from about 500 to about 2000.
Preferably, the polyvinyl acetate/allyl alcohol random copolymer is prepared by a free radical process using a continuous process tubular reactor system. U.S. Patent No. 3,673,16B discloses a tubular reactor and continuous process for producing polymeric materials which are suitable for use in producing the polyvinyl acetate/allyl alcohol random copolymer. U.S. Patent No. 3,673,168 is hereby incorporated by reference. Ratioed amounts of vinyl acetate monomer and allyl alcohol monomer are continuously fed into a tubular reactor in the presence of a solvent and an initi-ator. The vinyl acetate monomer is randomly polymerized with the allyl alcohol monomer to yield a polyol in the tubular reactor. The polyol crude product 50 produced is continuously withdrawn from the tubular reactor reaction mixture.
The polyurethane foam is prepared by reacting an isocyanate with an active hydroyen containing compound, and the polyvinyl acetate/allyl alkyl random copolymer in the presence of ~lowing agent.

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It has been unexpectedly discovered that the ufie of a polyvinyl acetate/allyl alcohol random copolymer in a urethane foam results in a foam having improved K factors requiring a reduced amount of chlorofluorocarbon as a blow-ing agent, is tolerable to an increased amount of water as a blowing agent without sacrificing insulation properties and maintains a suitable density and porosity. Such advantages can be achieved by utilizing from about 2 percent to about 100 percent, preferably from about 2 percent to about 20 percent, and most preferably from about 5 percent to about 10 percent by weight of the polyvinyl acetate/allyl alcohol random copolymer in the active hydrogen containing component of the urethane system. The amount of polyvinyl acetate/allyl alcohol copolymer utilized in the formulation will vary with the overall polyol system chosen and i~ an amount effective in producing a foam having lower K-factors than foams produced without the copolymer. In most cases, an amount of the copolymer in the range of about 2 to 20 percent weight of the component will be effective.
Polyurethane foams having the above cited desir-able characteristics can be produced utilizing a polyvinyl acetate/allyl alcohol random c~polymer with a variety of isocyanates, polyols, and additional ingredients which are more fully described below.

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In the more than fifty years since Professor Otto Bayer discovered the addition polymerization reaction leading to polyurethanes (1937), the field of polyurethane polymers has become a well established, mature technology.
While the first uses of polyurethanes were in the field of fibers, rigid foams were developed in 1947 and flexible foams in 1952. In the year 1981, world production of poly-urethanes exceeded 3 million metric tons.
By the term "polyurethane" is meant a polymer whose structure contains predominately urethane -[-NH-C-O-l-linkages between repeating units. Such linkages are formed by the addition reaction between an organic isocyanate group R-[-NCO] and an organic hydroxyl group [~O-l-R. In order to form a polymer, the organic isocyanate and hydroxyl group-containing compounds must be at least difunctional. ~ow-ever, as modernly understood, the term Npolyurethane" is not limited to those polymers containîng only urethane linkages, but includes polymers containing allophanate, biuret, _,, _ _ . , , _. .. . . ... .. . .

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carbodiimide, oxazolinyl, isocyanurate, uretidinedione, and urea linkages in addition to urethane. The reactions of isocyanates which lead to these types of linkages are summarized in the Polyurethane Handbook, Gunter Vertel, Ed., ~anser Publishers, Munich, 1985t in Chapter 2, pages 7-41;
and in Polvurethanes: Chemistry and Technolo~y, J.~.
Saunder~ and K.C. Frisch, Interscience Publishers, New York, 1963, Chapter III, pages 63-118. In addition to polyols (polyhydroxyl-containing monomers), the most common iso-cyanate-reactive monomers are amines and alkanolamines. In these cases, reaction of the amino group leads to urea link-ages interspersed within the polyurethane structure.
The urethane forming reaction is generally catal-yzed. Catalysts useful are well known to those ~killed in the art, and many examples may be found for example, in the Polyurethane ~andbook, Chapter 3, S3.4.1 on pages 90-95; and in Polvurethanes: Chemistry and Technolo~y in Chapter IV, pages 129-217. Most commonly utilized catalysts are ter-tiary amines and organotin compounds, particularly dibutyl-tin diacetate and dibutyltin dilaurate. Combinations of catalysts are often useful also.
In the preparation of polyurethanes, the isocyan-ate is reacted with the active hydrogen-containing com-pound(s) in an isocyanate to active hydrogen ratio o from0.5 to 1 to 10 to 1. The "index" of the composition is defined as the -NCO/active hydrogen ratio multiplied by 100. While the extremely large range described previously may be utilized, most polyurethane processes have indices of from 90 to about 120 or 130, and more preferably from 95 to about 110. In the case of polyurethanes which also contain significant quantities of isocyanurate groups, indices of greater then 200 and preferably greater tAen 300 may be used in conjunction with a trimerization catalyst in addition to the usual polyurethane catalysts. In calculating the quan-tity of active hydrogens present, in general all active hydrogen containing compounds other then non-dissolving solids are taken into account. Thus the total i~ inclusive of polyols, chain extenders, functional plasticizers, etc.
Hydroxyl group-containing compounds ~polyols) useful in the preparation of polyurethanes are described in the Polyurethane Handbook in chapter 3, S3.1 pages 42-61;
and in Polvurethanes: Chemistrv and Technology in Chapter II, SSIII and IV, pages 32-47. Many hydroxyl-group contain-ing compounds may be used, including simple aliphatic gly-cols, dihydroxy aromatics, bisphenol~, and hydroxyl-termin-ated polyethers, polyester~, and polyacetals, among :~ .

S, others. Extensive lists of suitable polyols may be found in the above references and in many patents, for example in columns 2 and 3 of U.S. Patent 3,652,639; columns 2-6 of U.S. Patent 4,421,872; and column 4-6 of U.S. Patent 4,310,632; these three patents being hereby incorporated by reference.
Preferably used, in addition to the polyvinyl acetate/allyl alcohol polyol, are hydroxyl-terminated poly-oxyalkylene and polyester polyols. ~he former are generally prepared by well known methods, for example by the base catalyzed addition of an alkylene oxide, preferably ethylene oxide (oxirane), propylene oxide (methyloxirane) or butylene oxide (ethyloxirane) to an initiator molecule containing on the average two or more active hydrogens. Examples of pre-ferred initiator molecules are dihydric initiators such as ethylene glycol, propylene glycol, butylene glycol, neo-pentyl glycol, 1,6-hexanediol, hydroquinone, resorcinol, the bisphenols, aniline and other aromatic monoamines, aliphatic monoamines, and monoesters of glycerine; trihydric initi-ators such as glycerine, trimethylolpropane, trimethylol-ethane, N-alkylphenylenediamines, mono-, di-, and trialkanolamines; tetrahydric initiators such as ethylene diamine, propylenediamine, 2,4'-, 2,2~-, and 4,4'-methylene-_~_ ~;.3d ~ .4 f_~ ' f 'V ~

dianiline, toluenediamine, and pentaerythritol; pentahydricinitiators such as diethylenetriamine; and hexahydric and octahydric initiators such as sorbitol and sucrose.
Addition of alkylene oxide to the initiator mole-cules may take place simultaneously or sequentially when more than one alkylene oxide is used, resulting in block, heteric, and block-heteric polyoxyalkylene polyethers. The number of hydroxyl groups will generally equal the number of active hydrogens in the initiator molecule. Processes for preparing such polyethers are described both in the PolY-urethane ~andbook and Polyureti~.anes: ChemistrY and Technolo~y as well as in many patents, for example U.S.
Patents 1,922,451; 2,674,619; 1,922,459; 3,190,927; and 3,346,557.
Polyester polyols also represent preferred poly-urethane-forming reactants. Such polyester6 are well known in the art and are prepared simply by polymerizing poly-carboxylic acids or their derivatives, for example their acid chlorides or anhydrides, with a polyol. Numerous poly-carboxylic acids are suitable, for example malonic acid, citric acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, maleic acid, fumariG acid, terephthalic acid, and phthalic acid. Numer-.. , . ,, . _ . .. _ _ . . . . . . . . .

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ous polyols are ~uitable, for example the various aliphaticglycols, trimethylolpropane and trimethylolethane, ~-methyl-glucoside, and sorbitol. Also suitable are low molecular weight polyoxyalkylene glycols such as polyoxyethylene glyc-ol, polyoxypropylene glycol, and block and heteric polyoxy-ethylene-polyoxypropylene glycols. These lists of dicar-boxylic acids and polyols are illustrative only, and not limiting. An excess of polyol should be used to ensure hydroxyl termination, although carboxy groups are also re-active with isocyanates. Methods of preparation of such polyester polyols are given in the PolYurethane Handbook and in Polyurethanes: Chemistrv and Technoloqy.
Also suitable as the polyol are polymer modified polyols, in particular the so-called graft polyols. Graft polyols are well known to the art, and are prepared by the in situ polymerization of one or more vinyl ~onomers, pre-ferably acrylonitrile and styrene, in the presence of a polyether or polyester polyol, particularly polyols contain-ing a minor amount of natural or induced unsaturation.
Methods of preparing such graft polyols may be found in columns 1-5 and in the Examples of U.S. Patent 3,652,639; in columns 1-6 and the Examples o~ U~S. Patent 3 t 823,201: par-ticularly in columns 2-B and the Examples of U.S. Patent .. . . .. . . .. . . . . . .

~ '`3 4,690,956; and in U.S. Patent 4,524,157; all of which pat-ents are herein incorporated by reference.
Non-graft polymer modified polyols are also pre-ferred, for example those prepared by the reaction of a polyisocyanate with an alkanolamine in the presence of a polyol as taught by U.S. Patents 4,293,470; 4,296,213; and 4,374,209; dispersions of polyisocyanurates containing pend-ant urea yroups as taught by U.S. patent 4,386,167; and polyisocyanurate disper~ions also containing biuret linkages as taught by U.S. patent 4,359,541. Other polymer modified polyols may be prepared by the in situ size reduction of polymers until the particle size i5 less than 20~m, prefer-ably less than 10~m.
Also useful in preparing polyurethanes are mono-mers containing other functional groups which are reactive with isocyanates. Examples of these are preferably the amines, for example the substituted and unsubstituted toluenediamines and methylenedianilines; the alkanolamines;
the amino-terminated polyoxyalkylene polyethers; and sulf-hydryl terminated polymers, to name but a few. The alkanol-amines and amines, particularly diamines, are particularly u~eful, as the amino group reacts faster than the hydroxyl group and thus these molecule~ can act as isocyanate chain .

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extenders in situ without the need to prepare prepolymers.
Examples of hindered, alkyl substituted aromatic diamines which are particularly u6eful are disclosed in U.S. Patent 4,218,543.
Many i~ocyanates are u~eful in the preparation of urethanes. Examples of such isocyanates may be found in columns 8 and 9 of U.S. Patent 4,690,956, herein incorpor-ated by reference. The i~ocyanates preferred are the commercial isocyanates toluenediisocyanate (TDI) methylene-diphenylenedii~ocyanate (~DI), and crude or polymeric MDI.
Other isocyanates which may be u~eful include isophorone-diisocyanate and tetramethylxylylidenediisocyanate. Other isocyanates may be found in the Polvurethane handbook, Chapter 3, S3.2 pages 62-73 and Polvurethanes: Chemistry and Technology Chapter II, ~ pages 17-31.
Modified isocyanates are also useful. Such iso-cyanates are generally prepared through the reaction of a commercial isocyanate, ~or example TDI or MDI, with a low molecular weight diol or amine, or alkanolamine, or by the reaction of the iEocyanates with themselves. In the former case, isocyanates containing urethane, biuret, or urea link-ages are prepared, while in the latter case isocyanates containing allophanate, carbodiimide, or isocyanurate link-ages are formed.

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Chain extenders may also be useful in the prepara-tion of polyurethanes. Chain extenders are generally con-sidered ~o be low molecular weight polyfunctional compounds or oligomers reactive with the isocyanate group. Aliphatic glycol chain extenders commonly used include ethylene gly-col, propylene glycol, 1,4-butanediol, and 1,6-hexanediol.
Amine chain extenders include aliphatic monoamines but espe-cially diamines such as ethylenediamine and in particular the aromatic diamines such as the toluenediamine6 and the alkylsubstituted (hindered) toluenediamines.
Other additives and auxiliaries are commonly used in polyurethanes. These additives include plasticizers, flow control agents, fillers, antioxidants, flame retard-ants, pigment6, dyes, mold release agents, and the like.
Many ~uch additives and auxiliary materials are discussed in the Polyurethane ~andbook in Chapter 3, ~ 3.4, pages 90-109;
and in Polyurethanes: Chemistry and Technoloqy, Part II, Technology.
Polyurethanes may be prepared in the form of films and coatings, fibers, extruded forms, castings and foams.
Non-cellular or microcellular polyurethanes are prepared in substantial absence of blowing agents, while polyurethane foams contain an amount of blowing agent which i8 ~ nver~ely proportional to the desired foam density. ~lowing agents may be physical (inert~ or reactive (chemical) blowing agents. Physical blowing agents are well known to those in the art and include a variety of saturated and unsaturated hydrocarbons having relatively lo~ molecular weights and bo;ling points. Examples are butane~ isobutane, pentane, isopentane, hexane, and heptane. Generally the boiling point is chosen such that the heat of the polyurethane-form-ing reaction will promote volatilization.
The most commonly u~ed physical blowing agents, however, are currently the halocarbons, particularly the chlorofluorocarbons. Examples are methyl chloride, methyl-ene chloride, trichlorofluoromethane, dichlorodifluoro-methane, chlorotrifluoromethane, chlorodifluoromethane, the chlorinated and fluorinated ethanes, and the like. Bromin-ated hydrocarbons may ~lso be useful. Blowing agents are listed in the Polvurethane ~andbook on page 101. Current research is directed to lowering or eliminating the use of chlorofluorocarbon~ in polyurethane foams.
Chemical blowing agents are generally low molec-ular weight species which react with isocyanates to generate carbon dioxide. ~ater is the only practical chemical blow-ing agent, producing carbon dioxide in a one to one mole ?,~, "; ;

ratio based on water added to the foam formulation. Unfor-tun~tely, completely water-blown foams have not proven ~uccessful in many applications, and thus it is common to use water in conjunction with a physical blowing agent.
Blowing agents which are ~olids or liquids which decompose to produce gaseous byproducts at elevated tempera-tures can in theory be useful, but have not achieved commer-cial success. Air, nitrogen, argon, and carbon dioxide under pressure can also be used in theory, but have not proven commercially viable. Research in such areas con-tinues, particularly in view of the trend away from chloro-fluorocarbons.
Polyurethane foams generally require a surfactant to promote uniform cell sizes and prevent foam collapse.
Such 6urfactants are well known to tho~e skilled in the art, and are generally polysiloxanes or polyoxyalkylene poly-siloxanes. Such surfactants are described, for example, in the Polyurethane ~andbook on pages 98-101. Commercial sur-factants for these purposes are available from a number of sources, for example from Wacker Chemie, the Union Carbide corporation, and the Dow-Corning Corporation.
Processes for the preparation of polyurethane foams and the equipment used therefore are well known to .. .. . .... . . ..

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those in the art, and are described, for example, in the Polvurethane Handbook in Chapter 4, pages 117-160 and in Polyurethanes: Chemistry and Technoloqv, Part II, Tech-nology, in Chapter VII, SIII and IV on pages 7-116 and Chapter VIII, SIII and IV on pages 201-23B.
The following Examples illustrate the nature of the invention. All parts are by weight unless otherwise designated. The following abbreviations were employed in the Examples below~
Polyol A is a polyester derived from a phthalic acid and diethylene glycol, having a hydroxyl number of approximately 240, and a functionality of 2.
Polyol B is a polyester derived from phthalic acid and ethylene glycol, having a hydroxyl number o approx-imately 200, and a functionality of 2.
Polyol C is a polyester derived from diethylene glycol and phthalic acid, having a hydroxyl number of approximately 250, and a functionality of 2.
Polyol D is a polyethylene terephthalate ester derived from PET scrap, having a hydroxyl number of approx-imately 350, and a functionality of 2.
Polyol E is a mixture of dimethyl and diethylene glycol esters of terephthalic acid, having a hydroxyl number of approximately ~10, and a functionality of 2.

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PVAc/AA i a random copolymer of polyvin,yl acetate and allyl alcohol as prepared by Example 1.
DC 1~3 is a fiurfactant avail~le from Dow Corning, Midland, Michigan as DC193.
"POLYCAT 8" is ~ diethylcyclo-hexylamine.
"FREON 11~ OR ~REON" is a fluorocarbon, preferably ~richlorofluoromethane.
Index is the -NCO/active hydrogen ratio multiplied by 100.
"LUPRANATE" ~20S is a polymeric methylene di-phenyldiisocyanate (MDI), containing about 40 percent 2-ring MDI sold by BASF Corporation.
Mixing time is the period in seconds from the start of mixing of the isocyanate and polyol components until a homogeneous solution is achieved.
Gel time i~ the period in seconds from the start of mixing of the isocyanate and polyol components until that state is reached whereby the polyaddition product is no longer flowable.
Ri6e time i8 the period in seconds from the start of mixing of the isocyanate and polyol components until the foam no longer rises.

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Tack free time is the period in seconds from the start of mixing of the isocyanate and polyol components until the 6urface of the foam is totally tack free.
The physical properties were determined using the following ASTM standards: density - ASTM D1622; compression strength - ASTM D1621; K-factor measured at 75P - ASTM
C177-85; porosity - ASTM D2856; Friability - ASTM C421-83.

Example 1 A polyvinyl acetate/allyl alcohol random copolymer useful in the present invention was prepared by a free rad-ical process utilizing a continuous process tubular reactor system. The following reactants were utilized:
Vinyl acetate, 450 grams Allyl alcohol, lS0 grams Isopropyl alcohol, 340 grams 50 percent hydrogen peroxide, 70 grams.
The reactants were added in no special order to a 2,900 ml.
flask and then transferred to a water-cooled feeder vessel and ~tirred. Nitrogen was bubbled through the reaction mixture continuously. The mixture was gravity fed into a diaphragm pump and transferred at 450 psi and at a rate of 300 ml per hour into a tubular reactor heated to 155C. The resction mixture contact time elapsed from entry to e~it in the tubular reactor was approximately 2 hours. A ~lightly viscous yellow liquid was collected at the end of the tube in a colle~tor ves6el. Volatiles were stripped off usiny a rotary evaporator. The resulting viscous oil was dissolved in ethyl acetate and neutralized to a p~ of 8 with aqueous ~odium bicarbonate. The organic layer was extracted, then wa6hed with brine. The organic layer was collected and . , , . . _ . .

G ~ ! S ~ e ' dried over sodium sulfate to give a 40-50 percent yield after stripping off ethylene acetate. The resulting poly-vinyl acetate/allyl alcohol random cspolymer was analyzed with the following results:
Polyvinyl/allyl alcohol copolymer analytical data: GPC WMn - 613 g/mole OH Number = 217 mg KOH/g polyol Percent ~2 = 0.19%
Saponification Number = 451 mg KO~/g polyol.
The polyvinyl acetate/allyl alcohol copolymer 50 formed is hereafter referred to as PVAc/AAD
Exam~le 2 Rigid polyurethane foams were prepared having the formulations and the physical characteristics indicated below.

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, TABLE A ..
Rigid ~Oam ~OrmU1atiOnS

POLYOL C 100 95 _- _ POLYOL B -~ 0Q 95 PVAC/AA -- 5 __ 5 DC_1g3 ~ . 5 1 . 5 1 . 5 P0LYCAT 8 ~.1 1.1 1.1 1.1 ~IATE~ 2.0 2.0 2.0 2.0 ~REON ~ 5 15 15 15 LUPRANATE H20S 93.5 92.~ 81.1 80.9 MIX ~SEC~ ~ 3 ~ 3 CREAM tSEC~ 18 ~1 20 21 6EL (SEC~ 40 4~ 47 50 RSSE ~5~C) 52 ~;9 63 64 FR2A8SLIT)~ 0 0 0 0 DENSITY IPCF~ ~.98 1.82 1.96 1.93 POROS~ t%CC) 88.4 89.2 85.0 94.6 K-~ACTOR (0 DA'~5 ) .119 .120 ~,122 .121 K-FACTOR 110 D~YS) * .133 .117 .166 .134 * ~t 140F

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., . . . _ .. = , .. . , _. _ _ _ . _ . ... ... , ... .. . _ .... .

~ Jc This Example ~hows that when 5 percent by weight of polyvinyl acetate/allyl alcohol random copolymer was added to a polyurethane 6ystems containing Polyol ~ or Polyol C the resultin~ foam had a lower K-factor than corre-sponding polyols containing solely Polyol B or Polyol C
respectively. The addition of the polyvinyl acetate/allyl alcohol did not adver~ely affect the reaction parameters or other physical properties such as density or porosity. K
factors were measured at 0 days and at 75~F.

.. . . . .. .

Example 3 In this Example, varying weight percents o~
PVAc~AA were added to a urethane system containing Polyol C.
The weight percent of water and Freon were also varied.

~ABLE E
Foam 5 6 7 8 Polyol C 100 95 90 80 PYAc/AA 0 5 10 20 DC-193 1.5 1.5 1.5 1.5 POLYCAT 8 0.8 0.8 0.B 0.B
Water 3 3 3 3 FRE~N F-llA 10 10 10 10 Total 115O3 115.3 115.3 115.3 Index 105 1~5 105 105 LUPRANATE M20S 109.1 109~00 10B.B3 108.66 Mix ~sec.] 7 7 7 Gel " 49 56 64 69 Rise " 68 74 78 88 Tack Free " 75 71 75 B0 Resin 149.9 149.9 149.9 149.9 Iso. 141.8 lql.7 141.6 141.3 Density, Core ~pcf) 1.98 1.42 1.62 1.62 Comp Str 10~ Par 50.3 25.3 25.8 26.0 Comp Str 10% Perp 6.2 4.4 4.9 4.3 K~factor, Orig 0.137 0.124 0~126 0.126 10 days* 0.138 0.125 0.126 0.125 30 days* 0.156 0.134 0.127 0.150 ~t 140~

As can be seen from the above data, a urethane system containing from 5 percent to 20 percent PVAc/ M , 3 percent water and 10 percent Freon consistently produced lower ~-factors, at 0 days and after aging for 10 and 30 days at 140~, in comparison to urethane systems containing solely Polyol C at 140F.

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xample 4 In this Example, varying amounts of PVAc/AA were added to a urethane system containing Polyol D.

TABLE C
Foam 9 10 11 12 13 Polyol D 100 98 95 90 80 PVAc/AA 0 2 5 10 20 D C 193 1.5 1.5 1.5 1.5 1.5 POLYCAT 8 0.8 0.8 0.8 0~8 0.8 Water 2 2 2 2 2 FREON F-llA 15 15 15 15 15 total 119.0 119.3 119.3 119.3 119.3 Index 105 105 105 105 105 LUPRANATE N20S 118.5 117.80 116.73 114.94 111.37 ~ix [s~c.l 8 8 8 8 8 Gel " 48 30 34 34 34 Rise ~ 63 45 51 51 54 Tack Free " 72 39 42 40 44 Resin 154.7 155.1 155.1 155.1 155.1 Iso. 154.05 153.1 151.7 149.4 144.8 Density,Core~pcf) 2.09 2.04 2.12 2.05 2.02 Comp Str 10% Par 56.4 47.2 55.0 51.6 50.4 Comp Str 10% Perp 9.1 9.9 7.8 7.8 8.5 K-factor, Orig. 0.139 0.126 0.125 0.131 0.129 10 days* 0.1~9 0.124 0.116 0.126 0.127 30 days~ 0.148 0.131 0.131 0.133 0.138 at 140F

As can be seen from this example, the additi~n of ~ to 20 percent by weight PVAc/AA to a urethane systeM
containing Polyol D consi~tently produced lower K-factors at 0 days and after aging at 10 and 30 days compared to ure-thane systems containing no PVAc/AA.

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xample 5 In this example, varying amounts of PVAc/AA were added to urethane systems containing Polyol E.

TABLE D
Foam 14 15 16 17 18 Polyol E 100 98 95 90 B0 PVAc/AA 0 2 5 10 20 D C 193 1.5 1.5 1.5 1.5 1.5 POLYCAT 8 0.32 0.8 Water 2 2 2 2 2 FREON F-llA 15 15 15 15 lS
total 120.4 119.3 119.5 119.5 119.5 Index 105 105 105 105 105 LUPR~NATE M20S 109.8 109.24 108.43 107.08 104.35 Mix lsec.l 5 8 8 8 8 Gel " 54 73 43 40 41 Rise " 70 95 58 58 63 Tack Free " 77 95 80 50 49 Resin 156.5 155.1 155.4 155.4 155.4 Iso. 142.7 142.0 141.0 139.2 135.7 Density 2.09 2.02 1.92 1.92 1.~7 Comp Str 10% Par 52.2 42.3 48.9 41.2 42.1 Comp Str 10% Perp 8.9 6.9 5.1 408 7.0 K-factor, Orig. 0.129 0.130 0.128 0.131 0.127 10 days* 0.133 0.128 0.126 0.126 0.125 30 days* 0.152 0.141 0.136 0.137 0.142 * at 140F

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This example 6hows that the addition of 2, 5, 10, or 20 percent PVAc/AA produces lower K-factors for aged foams at 10 days and 30 days in comparison to urethane sy5-tems containing Polyol E and no PVAc/AA. Lower K-factors were observed in systems containing 5 percent or 20 percent PVAc/AA and Polyol E compared to 6ystems containing no PVAc/AA at 0 days. Slightly higher K-factors at 0 days were observed in urethane systems c~ntaining 2 percent or 10 percent PVAc/AA and Polyol E in comparison t~ systems con-taining no PVAc/AA.

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Exam~le 6 In this example, varying amount~ of PVAc/AA were added to urethane systems containing Polyol A.

TABLE E
Foam 19 20 21 22 23 Polyol A 100 98 95 ~0 80 PVAc~AA 0 2 5 10 20 D C 193 1~5 1.5 1.5 1.5 1.5 POLYCAT 8 0.8 0.8 0~8 0.8 0.8 Water 2 2 2 2 2 FREON F-llA 15 15 15 15 15 total 119.3 119.3 119.3 119.3 119.3 Index 105 105 105 105 105 LUPRANATE M20S 91 90.86 90.64 90.23 ~g.40 Mix lsec-l 5 8 8 8 8 Gel " 20 - 50 50 50 Rise " 52 - 73 72 74 Tack Free " 75 - 64 - 65 Resin 155.1 155.1 lS5.1 155.1 155.1 IBO . 118 . 3 11B .1 117 . 8 117 ~ 3 116 . 2 DenSitY 2.11 2-14 2-14 2-14 2-09 Comp Str 10% Par 41.0 35~4 34.6 37.7 38.9 Comp Str 10% Perp 3.1 6.7 7.2 6~7 8.0 K-factor, Ori~. 0.122 0.123 0.121 0.122 0.125 10 days* 0.137 0.145 0.123 0.125 0.136 30 days* 0.165 0.175 0.136 0.141 0.163 * at 140~F

-3~-. .

As can be seenr the addition of 5 to 10 weight percent PVAc/AA to a urethane system containing Po].yol A
produced lower K-factors and after aging 10 and 30 days as compared to the urethane system containing no PVAc/AA.

-_x~ l 7 In this example, a urethane foam was made using solely PVAc/AA as the polyol component.

TABLE_F

Foam 24 25 PVAc/AA 100 100 D C 193 1.5 1.5 POLYCA~ 8 0.8 0.8 Water 2 3 Freon 11 A 17 12 Total 121.3 117.3 Index 105 105 LUPRANATE M20 84.31 99.87 Mix lsec.] 12 15 Gel n 116 B5 Tack Free " 182 147 Rise " 191 155 Density, Core (pcf) 1.61 1.79 Compression Strength 10% PAR 16.~ 21.1 10~ PERP 3.1 11.3 K-factor, original 0.147 0.153 10 days* 0.175 0.182 30 days* 0.190 0.203 * at 140~F

As can be seen, a rigid urethane foam can be pro-duced using sole PVAc/AA a~ the polyol component. 5uch a foam has useful thermal properties.

Claims (27)

1. A process for preparing polyurethane foams comprising reacting:
an isocyanate, and an active hydrogen containing component com-prising a polyvinyl acetate/allyl alcohol random copolymer, in the presence of a catal-yst and a blowing agent.

2. A process as set forth in claim 1 wherein said copolymer comprises from about 2 to about 100 weight percent of said component.

3. A process as set forth in claim 1 wherein said copolymer comprises from about 2 to about 20 weight percent of said component.

4. A process as set forth in claim 1 wherein said copolymer comprises from about 5 to about 10 weight percent of said component.

5. A process as set forth in claim 1 wherein said active hydrogen containing component further comprises at least one selected from the group consisting of polyether polyol and polyester polyol.

6. A process as set forth in claim 1 wherein said copolymer is present in about 5 weight percent of said component and said component further comprises at least one selected from the group consisting of a polyester derived from a diethylene glycol and phthalic acid, and a polyester derived from ethylene glycol and phthalic acid.

7. A process as set forth in claim 1 wherein said copolymer is present in about 5 to about 20 weight percent of said component and said component further comprises a polyester derived from polypropylene glycol and phthalic acid, and wherein said blowing agent comprises 3 parts water and 10 parts fluorocarbon per 100 parts of said component.

8. A process as set forth in claim 1 wherein said copolymer is present in about 5 to about 20 weight percent of said component and said component further comprises a polyethylene terephthalate ester derived from PET scrap.

9. A process as set forth in claim 1 wherein said copolymer is present in about 5 to about 20 weight percent of said component and said component further comprises a mixture of dimethyl and diethylene glycol esters of tere-phthalic acid.

10. A process as set forth in claim 1 wherein said copolymer is present in about 5 to about 10 weight percent of aid component and said component further comprises a polyester derived from a phthalic acid and diethylene gly-col.

11. A process as set forth in claim 1 wherein said copolymer is present in an amount effective in producing a foam having lower K-factors than foams produced by said method without said copolymer present in said component.

12. An urethane foam prepared from the reaction product of an isocyanate, and an active hydrogen containing component com-prising a polyvinyl acetate/allyl alcohol random copolymer, in the presence of a catal-yst and a blowing agent.

13. A foam as set forth in claim 12 wherein said copolymer comprises from about 2 to about 100 weight percent of said component.

14. A foam as set forth in claim 12 wherein said copolymer comprises from about 2 to about 20 weight percent of said component.

15. A foam as set forth in claim 12 wherein said copolymer comprises from about 5 to about 10 weight percent of said component.

16. A composition as set forth in claim 12 wherein said active hydrogen containing component further comprises at least one selected from the group consisting of a poly-ether polyol and a polyester polyol.

17. A foam as set forth in claim 12 wherein said copolymer is present in about 5 weight percent of said component and said component further comprises at least one selected from the group consisting of a polyester derived from a diethylene glycol and phthalic acid, and a polyester derived from ethylene glycol and phthalic acid.

18. A foam as set forth in claim 12 wherein said copolymer is present in about 5 to about 20 weight percent of said component and said component further comprises a polyester derived from diethylene glycol and phthalic acid, and wherein said blowing agent comprises 3 parts water and 10 parts fluorocarbon per 100 parts of said component.

19. A foam as set forth in claim 12 wherein said copolymer is present in about 5 to about 20 weight percent of said component and said component further comprises polyethylene terephthalate ester derived from PET scrap.

20. A foam as set forth in claim 12 wherein said copolymer is present in about 5 to about 20 weight percent of said component and said component further comprises a mixture of dimethyl and diethylene glycol esters of tere-phthalic acid.

21. A foam as set forth in claim 12 wherein said copolymer is present in about 5 to about 10 weight percent of said component and said component further comprises a polyester derived from a phthalic acid and diethylene gly-col.

22. A foam as set forth in claim 12 wherein said copolymer is present in an amount effective in producing a foam having lower K-factors than foams produced by said method without said copolymer present in said component.

23. A rigid urethane foam produced by reacting an isocyanate, an active hydrogen containing component com-prising a polyvinyl acetate/allyl alcohol random copolymer, and a blowing agent comprising water and a fluoro-carbon wherein said foam has a lower K-factor than foams produced from formulations having from about 1 to about 50 percent by weight more of said fluorocarbon and no polyvinyl acetate/allyl alcohol random copolymer.

24. A foam as set forth in claim 23 wherein said water comprises from about 2 to about 3 weight percent of said reactants and said fluorocarbon comprises about 10 weight percent of said reactants.

25. A foam as set forth in claim 23 wherein said copolymer comprises from about 2 to about 20 weight percent of said component.

26. A foam as set forth in claim 23 wherein said copolymer comprises from about 5 to about 10 weight percent of said component.

27. A foam as set forth in claim 23 wherein said active hydrogen containing component further comprises at least one selected from the group consisting of a polyether polyol and a polyester polyol.