GB2072194A - Vinyl Terminated Reactive Liquid Polymers - Google Patents

Abstract

Vinyl terminated reactive liquid polymers are prepared by reacting a hydroxyl terminated reactive liquid polymer with either a mixture of, or a pre-reaction product of, an iso-cyanate and an ethylenically unsaturated hydroxyl compound. In Examples, the starting polymer is an ethylene oxide adduct of a carboxy-terminated butadiene/acrylonitrile/2-hydroxyethyl acrylate copolymer.

Description

SPECIFICATION Vinyl Terminated Reactive Liquid Polymers The vinyl terminated reacting liquid polymers (VTRLPs) are commercial products which can be made to cure to solid elastomers. Their utility is mainly in sealants, caulks, potting compounds, coatings, as tougheners for unsaturated polyester resins, as well as in printing inks curable with ultraviolet light or electron beam.

U.S. Patents 3,910,992 and 4,129,713 disclose one commercial process for preparing VTRLPs which involves the addition reaction of a carboxyl terminated reacting liquid polymer (CTRLP) with glycidyl acrylate, as illustrated below:

This reaction is conducted at elevated temperature of about 50 to 1 500C for a duration of 10 to 20 hours. This polymeric reaction product has a highly reactive vinyl terminated functional group which can easily polymerize at an elevated temperature. Since it is undesirable to have the terminal vinyl group polymerize prematurely, attempts have been made to carry out this reaction at lower temperature with other reactants.

This invention relates to a process for the preparation of VTRLPs which involves a coupling reaction between an isocyanate, a vinyl containing alcohol, and a hydroxyl terminated reactive liquid polymer (HTRLP).

More specifically, the inventive process includes the steps of reacting a HTRLP, an unsaturated alcohol, and a diisocyanate at a temperature ranging from about room temperature to about 70at.

In accordance with one embodiment of the invention the VTRLPs are prepared by a one-step or two-step process by reacting a diisocyanate, an alpha, beta ethylenically unsaturated hydroxyl compound, and a hydroxyl terminated liquid polymer. The VTRLPs have molecular weight of about 1,000 to 20,000, as determined with a Mechrolab Vapor Pressure Osmometer. Their bulk viscosity is about 500 to 8,000,000 cps, measured at 270C using Brookfield model LVT viscometer with spindle #4. Preferred polymers have bulk viscosity of about 5000 to 2,000,000 cps and, more preferably, about 10,000 to 1,000,000 cps at 270C. These polymers have hydroxyl equivalent weight of about 200 to 10,000.

The two-step coupling reaction of a HTRLP, a diisocyanate and a vinyl-containing alcohol involves the initial formation of an adduct by the reaction of the alcohol and the diisocyanate and the subsequent reaction between the adduct and the HTRLP. The two-step process is illustrated below:

adduct

In the one-step process, reaction takes place between the three reactants, as illustrated below:

The VTRLPs can be prepared in a two-step or a one-step process with or without a solvent. As shown above, in the two-step process, the alcohol is reacted with a diisocyanate to form an adduct which is reacted with a HTRLP to form the final product. The two-step process, when conducted without a solvent, is more difficult to carry out.Although formation of the adduct is easily accomplished, the second step reaction of the adduct with the HTRLP is complicated by attendant high viscosity which impedes agitation and impairs the quality of the final product. The use of a solvent may eliminate this problem.

In the one-step process, the reactants are charged into a reactor in the following order: HTRLP, vinyi-containing alcohol, and diisocyanate. It is preferred to add a solvent to the reactive liquid polymer before adding the other reactants. Viscosity of VTRLPs from the one-step process is usually higher than from the two-step process. Reduction of viscosity can be achieved, when desired, by increasing the amount of vinyl-containing alcohol relative to diisocyanate. Lower viscosity of the resulting VTRLPs can be also achieved by using lower viscosity HTRLPs.

In the novel one-step and two-step processes, about 1 mole of vinyl-containing alcohol is reacted with 1 mole of diisocyanate, and 1/2 mole of HTRLP. To reduce viscosity of the resulting VTRLP, as discussed above, the molar ratio of the alcohol to diisocyanate (OH/NCO) should be increased from 1 to 1 to something in excess of that preferably up to 1.5 moles of alcohol per mole of diisocyanate, and more preferably, from 1.05 to 1.3 moles of alcohol per mole of diisocyanate. Although rate of reaction is acceierated at higher temperature, optimum temperature for this process is from below OOC to 1 500C, preferably from room temperature of about 200C to about 700 C.

Stability of the VTRLPs depends on the stability of the vinyl groups and the unreacted isocyanate groups. The vinyl groups can be stabilized by radical inhibitors, such as e.g. hydroquinone, benzoquinone, catechol, toluhydroquir.one, methyl ether of hydroquinone, trinitrobenzene, picric acid, and phenothiazine, whereas stability problem of the unreacted isocyanate groups can be controlled by minimizing the content thereof. This can be accomplished by reacting residual isocyanate groups with such materials as for example methanol, p-toluenesulfonic acid, ethylene glycol, and triethanol amine.

Side reactions of the unreacted residual isocyanate groups must be averted to avoid gelation of the VTRLPs in a matter of few hours. Concentration of residual isocyanate can be determined by infrared spectrum of the ratio of isocyanate group absorbence (ANCO) at 2260 cam~' to cyano group absorbence (ACN) at 2240 cm~1. The cyano groups originate from acrylonitrile and/or radical initiator. The lower this ratio is the more stable will be the product. For instance, the product of Example 8 below had an ANco/AcN ratio of about 0.06 and its stability was excellent after a month of storage at room temperature and at elevated temperature of about 600C. When the high residual isocyanate content is reduced or eliminated, stability of such products is significantly improved.

Although the process of this invention can be conducted in the absence of a solvent it is preferred to carry out the reaction in the presence of a solvent for the reactants. The amount of the solvent can vary widely since a diluent is added to facilitate physical aspects of handling and agitating the reactants.

When used, amount of solvent can vary from 20 to 400.parts by weight per 100 parts of HTRLP, preferably, 50 to 1 50 parts. When a solvent is used, the solvent should not contain any groups which would react with the isocyanate groups or in any way interfere with the reaction. Thus, the solvent should not contain any hydroxyl, carboxyl, or amine groups which might interfere with these reactions.

This limits suitable solvents to esters, ethers, hydrocarbons, and similar solvents containing non reactive, non-functional groups, with respect to isocyanate group.

Illustrative examples of polymerizable solvents which can be employed in these processes include alkyl acrylates and methacrylates containing 1 to 12 carbon atoms in the alkyl group, styrene, alkyl styrene containing 1 to 6 carbon atoms in the alkyl group, halo and haloalkyl styrene containing 1 to 6 carbon atoms in the alkyl group, divinylbenzene, cyclohexyl acrylate and methacrylate, acrylonitrile, vinylidene chloride, vinyl acetate, vinyl stearate, vinyltoluene, hexanediol diacrylate and dimethacrylate, polyethyleneglycol diacrylate, vinyl propionate, tetrahydrofurfuryl methacrylate, diethylene and triethylene glycol diacrylate, diiallyl fumarate, 1 ,3-butyleneglycol diacrylate and dimethacrylate, trimethylolpropane triacrylate, and neopentylglycol diacrylate. Non-polymerizable solvents can also be used.Illustrative of such solvents include benzene, toluene, xylene, dioxane, methyl ethyl ketone, ethyl acetate, and ethyl benzene. A preferred solvent is styrene. Other preferred solvents are a mixture of styrene and methyl methacrylate and a mixture of styrene and divinylbenzene.

As will be shown, there is a variety of available HTRLPs, all of which can be used in the reaction with a vinyl-containing alcohol and a diisocyanate to prepare VTRLPs. For instance, HTRLPs can be prepared by post-reacting CTRLPs, by free-radical polymerization of monomers using hydroxyl containing initiators, by solution polymerization using lithium or organometallic catalysts and post reacting the reaction product to form the hydroxyl groups, by polymerizing a vinyl-containing monomer with for example a hydroxyl-containing trisulfide and/or disulfide. Examples of HTRLPs include those that are prepared by addition reaction between ethylene oxide and a CTRLP. The CTRLPs, in turn, can be prepared by free radical polymerization using carboxyl-containing initiators and/or modifiers, as disclosed in U.S. Patent 3,285,949 and German Patent 1,150,205. The CTRLPs can also be made by preparing polymers via solution polymerization using lithium or organometallic catalysts and post treating the polymers to form carboxyl groups, as disclosed in U.S. Patents 3,135,716 and 3,431,235.

Specific examples of HTRLPs which are reacted with the vinyl-containing alcohol and a diisocyanate to form VTRLPs include hydroxyl terminated polybutadiene-acrylonitrile containing about 20% acrylonitrile and about 80% butadiene; hydroxyl terminated polybutadiene-acrylonitrile-hydroxyethyl acrylate containing about 18% acrylonitrile, about 80% butadiene and up to a couple of percent hydroxyethyl acrylate; hydroxyl terminated polybutadiene-styrene containing about 70% butadiene and about 30% styrene; hydroxyl terminated polyepichlorohydrin; hydroxyl terminated polybutadiene and hydroxyl terminated polybutadiene-alkyl acrylates.

U.S. Patent 2,844,632 describes preparation of HTRLPs of bis(hydroxyalkyl naphthyi)disulfide by reacting a chlorosulfonyl naphthyl acetic acid in presence of lithium aluminum hydride catalyst. U.S.

Patent 3,551,471 describes preparation of HTRLPs by reacting CTRLPs with ethylene oxide in presence of a tertiary amine catalyst. Brookfield viscosity of such HTRLPs is up to about 50,000 to 80,000 cps at 270C. U.S. Patent 3,135,716 discloses solution polymerization of a vinyl compound in the presence of an organometallic catalyst and then post-reacting the product to replace the metal ions with hydroxyl groups to yield HTRLPs. U.S. Patent 3,431,235 discloses a reaction of a polydiene resin, such as hydroxyl terminated 1,2-polybutadiene, with an organic chain extender, such as toluene-2,4diisocyanate, in the presence of a free radical initiator.The reaction product is a stable elastomeric material which can be cured to a hard material at elevated temperature comprising mainly cross-linked linearly extended chains of fused cyclohexane groups interconnected by the chain extending groups.

U.S. Patent 3,669,153 teaches preparation of HTRLPs by reacting a CTRLP with a diol in presence of an acid catalyst. More specifically, the CTRLP of butadiene and polyalkyl acrylate is reacted with a 5 to 10 fold excess of a difunctional hydroxy compound containing 3 to 6 carbon atoms in presence of an effective amount of an acid catalyst. U.S. Patent 4,120,766 is directed to HTRLPs which are prepared by polymerizing a vinyl monomer with a hydroxyl-containing disulfide in the presence of ultraviolet light. These HTRLPs have viscosities in the range of 500 to 2,500,000 cps at 270C and hydroxyl equivalent weights in the range of 200 to 10,000.

Suitable hydroxyl compounds for the preparation of VTRLPs are monohydroxyl compounds containing ethylenic unsaturation and being devoid of substituents which are reactive with an isocyanate group. The hydroxyl group can be located on any carbon atom of the alkyl group although, preferably, it is located on the terminal carbon atom away from ethylenic unsaturation. More specifically, suitable alcohols are vinyl-containing monohydroxyl compounds selected from hydroxyalkyl esters of unsaturated acids, hydroxyl-containing alkenes, and vinyl aromatic alcohols. The hydroxyalkyl esters of unsaturated acids are preferably monohydroxyl compounds containing 1 to 12 carbon atoms, preferably 2 to 8 carbon atoms in the alkyl group.One or more of the carbon atoms in the alkyl group can have substituents thereon selected from halogens, nitrate, carbonate, substituted or unsubstituted alkyl groups of 1 to 4 carbon atoms, alkoxy, alkenoxy, and substituted and unsubstituted phenoxy groups. Examples of such substituents include acryloxy, methacryloxy, allyloxy, butoxy, methoxy, ethoxy, propyl, methyl, butyl groups, and methacrylate-alkylene or acrylatealkylene groups of 1 to 4 carbon atoms in the aikylene moiety, such as in pentaerythritol triacrylate. The unsaturated acids from which the esters are derived contain 2 to 8 carbon atoms and include aliphatic and aromatic acids such as for example acrylic, methacrylic, cinnamic, and crotonic.

Suitable vinyl-containing monohydroxyl compounds are alkenes containing 1 to 12 carbon atoms, preferably 1-alkenes containing 2 to 8 carbon atoms with the hydroxyl group on the terminal carbon atoms.

Suitable vinyl-containing monohydroxyl compounds are vinyl aromatic alcohols having the formula

where R1 and X are individually selected from hydrogen, halogens, and alkyl radicals of 1 to 4 carbon atoms; and n is a number from 0 to 12, preferably 0 to 4. There can be up to four X groups on the aromatic ring.

In a preferred embodiment, suitable hydroxyl compounds are selected from substituted and unsubstituted monohydroxyalkyl acrylates and methacrylates containing 1 to 12 carbon atoms in the alkyl group, preferably 2 to 4. Specific examples of suitable hydroxyl compounds for the preparation of VTRLPs include 1-hydroxyethyl acrylate and methacrylate, hydroxypropyl and hydroxybutyl acrylates and methacrylates, 1 -methacryloxy dodecanol-2, 2-hydroxyethyl acrylate and methacrylate, 3acryloxy-2-hydroxypropyl methacrylate, 3-methacryloxy-2-hydroxypropyl methacrylate, 3-crotonoxy- 2-hydroxypropyl acrylate, 3-acryloxy-2-hydroxypropyl cinnamate,3-allyloxy-2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate and methacrylate, 4-hydroxy-2-methylbutyl acrylate, 4-hydroxyoctyl acrylate, pentaerythritol triacrylate, 8-hydroxyoctyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxy-3 (O-chlorophenoxy)propyl acrylate, 3-ch loro-2-hydroxypropyl acrylate and methacrylate, hydroxymethyl acrylate and methacrylate, allyl alcohol, 4-hydroxyl butene-1, vinyl phenols, and vinyl benzyl alcohol.

Suitable isocyanates are, for example, aliphatic, cycloaliphatic and aromatic diisocyanates and polyisocyanates, preferably diisocyanates. Examples of suitable diisocyanates include 4,4'-methylene (bis(phenylisocyanate), toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, naphthalene-1,5diisocyanate, methylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, cyclohexyl-2,4-diisocyanate, 4,4'-methylene bis(cyclohexyl diisocyanate), cyclohexylene-1,4diisocyanate, butyl benzene-2 ,4-diisocyanate, dodecyl benzene-2,4-diisocyanate, benzofuran-2,6diisocyanate, naphthalene-1 ,8-diisocyanate, fluorene-2,5-diisocyanate, anthracene-1 ,4-diisocyanate, 3,3'-dimethoxy-4,4'-diisocyanato diphenyl, 2,4-diisocyanatostilbene, 4,4'-diisocyanato dibenzyl, anthracene-9,1 0-diisocyanate, 4,6-dimethylphenylene-1 ,3-diisocyanate, benzidene diisocyanate, 4,4' diisqcyanato diphenyl ether, 2,4-dimethylphenylene-1 ,3-diisocyanate, 2,4'-diisocyanato diphenyl ether 4-ethoxyphenylene-1 ,3-diisocyanate, 4-chlorophenylene-1 ,3-diisocyanate, cumene-2,4diisocyanate, naphthalene- 1 ,5-diisocyanate, and 3-isocyanatomethyl-3 ,5,5-trimethyl cyclohexyl isocyanate.

In order to illustrate the invention disclosed herein more completely, the following Examples are being presented which demonstrate preferred embodiments of preparing VTRLPs by the reaction of a HTRLP with a diisocyanate and a hydroxyalkyl acrylate.

Example 1 This example demonstrates preparation of a VTRLP by a two-step bulk polymerization reaction of toluene-2,4-diisocyanate (TDI) with 2-hydroxyethyl acrylate and then with a HTRLP.

43.5 grams (0.25 mol) of the toluene-2,4-diisocyanate was added dropwise to a mixture of 29.0 grams (Q.25 mol) of the 2-hydroxyethyl acrylate (HEA) and 0.03 gram of phenothiazine stabilizer with stirring over a period of fifteen minutes at 400C in dry air. After addition of the mixture was complete, the temperature was raised to 650C and maintained there for about one hour until concentration of NCO groups dropped to 15%, as determined by wet analysis procedure described on p. 57 in Organic Functional Group Analysis, by F. E. Critchfield, published by MacMillan Company in 1963, with the exception that tetrahydrofuran solvent and bromocresol green indicator were used.The resulting adduct was cooled to room temperature and then 316 grams (0.25 equivalent) of HTRLP was added thereto and the mixture was reacted at 600C with slow agitation to yield an opaque VTRLP product of high viscosity on the order of 1,000,000 cps at 270C. The HTRLP used was addition reaction product of ethylene oxide and a CTRLP, the HTRLP containing about 18% acrylonitrile, about 80% butadiene and up to about 2% 2-hydroxyethyl acrylate.

Examples 2 to 11 A two-step solution polymerization process is demonstrated by these examples whereby toluene2,4-diisocyanate was reacted with 2-hydroxyethyl acrylate to form an adduct followed by the reaction of the adduct with a HTRLP.

The HEA-TDI adduct was prepared as in Example 1 by reacting 43.5 grams (0.25 mol) of the toluene-2,4-diisocyanate with a mixture of 29.0 grams (0.25 mole) of the 2-hydroxyethyl acrylate and 0.03 gram of phenothiazine, which mixture was added dropwise to the diisocyanate over a period of 1 5 minutes at 400C in dry air. After completing addition of the mixture, temperature thereof was raised to 650C and maintained there for about one hour at which time NCO concentration dropped to about 1 5%. The adduct was then cooled to room temperature. To a solution of 29.0 grams (0.1 equivalent) of the adduct in 75.5 grams of styrene was added dropwise with stirring a solution of 126.5 grams (0.1 equivalent) of HTRLP in 80 grams of styrene over a period of two hours at room temperature in dry air.

After the addition was completed, the reaction was continued for another eight hours at room temperature. Viscosity of this VTRLP was 1,070 cps at 270C. Same HTRLP was used at in Example 1.

Data for this and other experimens similarly conducted is summarized in Table A below where amounts are given in parts by weight, unless otherwise indicated: Table A Styrene Solution 2-Step Process Exp. No. 2 3 4 5 6 7 8 9 10 11 HEA-TDI adduct 29.0 87.0 29.0 29.0 29.0 29.0 29.0 29.0 23.2 23.2 NCO% 14.6 14.5 14.5 14.5 14.5 14.5 14.5 14.5 14.5 14.5 HTRLP 126.5 379.5 126.5 167.8 190.0 203.0 175.3 175.0 140.0 150.4 Lot No. 64-110 64-110 64-110 90-27 90-33 90-33 90-33 90-33 90-33 90-33 Phenothiazine, ppm 75 75 75 500 500 500 60 60 500 500 Styrene, % 50 50 50 50 50 50 50 50 50 50 Total OH/NCO 1.0 1.0 1.0 1.0 1.0 1.11 1.16 1.07 1.07 1.07 1.11 Addn order # mode HTRLP to HTRLP to NCO to HTRLP to NCO to NCO to HTRLP to NCO to NCO to NCo to NCO NCO HTRLP NCO HTRLP HTRLP NCO HTRLP HTRLP HTRLP (D. 2 hr) (D. 2.5 hr) (O) (D. 3 hr) (O) (O) (D. 2.5 hr) (D 1.5 hr) (O) (O) Temp, C RT RT RT RT 35 35 35 35 RT RT Time, hours 11 18 19 21 6 4 3 4 8 8 ANCO/ACN 0.1 - - 0.22 0.09 0.07 0.06 0.07 0.09 0.09 Brookfield Viscosity 1,070 1,070 2,100 3,700 1,200 1,250 1,200 1,025 7,400 5,000 at 27 C, cps 5,500 gel gel gel 1,250 1,200 1,025 7,400 5,000 Aged 1,600 - (8) (1) (3) (3) (10) (1) (1) (1) (days) (10) D:dropwise (addition time) O:one portion RT:room temperature As is apparent from Table A, when HTRLP was added to the adduct dropwise, as in Examples 2 and 8, the resulting VTRLP showed reasonably good stability. However, when the adduct was added to HTRLP dropwise or in one portion, the resulting VTRLPs gelled within a few days. It, therefore, appears that the sequence of adding ingredients is important and it appears that if near term gellation is to be avoided, addition of the adduct to HTRLP should be avoided.

Same HTRLPs were used herein as in Example 1. Their physical properties are set forth in Table B, below: Table B Lot No. 64--1 10 90-27 90-33 90-37 OH ephr" 0.079 0.057 0.070 0.073 COOH ephr* 0.002 0.007 0.001 0.006 Brookfield Viscosity at 270C, cps 158,000 158,000 168,000 113,000 H20 content, % 0.126 0.095 0.116 *ephr denotes equivalents per 100 parts of resin Examples 12 to 18 A single step process for preparing VTRLPs is demonstrated by examples herein which were carried out by charging the materials il. the following order with agitation: HTRLP, solvent, 2- hydroxyalkyl acrylate and a diisocyanate.

Pursuant to the procedure established for the one-step process, the reaction was carried out by adding 17.4 grams (0.1 mole) of toluene-2,4-diisocyanate to a mixture of 126.5 grams (0.1 equivalent) of HTRLP, 11.6 grams (0.1 equivalent) 2-hydroxyethyl acrylate, and 12 milligrams (75 ppm) of phenothiazine in 155.5 grams of styrene. The mixture was initially at room temperature and the diisocyanate was added dropwise in dry air with stirring. After addition of the diisocyanate, temperature of the mixture rose to 320C in about one-half hour. The reaction was completed in four hours. Viscosity of the resulting VTRLP was 4,750 cps at 200C. Data for these experiments is set forth in Table C, below, where amounts of materials are given in parts by weight, unless otherwise indicated: Table C Styrene Solution 1-Step Process

Exp. No. 12 13 14 15 16 17 18 HTRLP 126.5 100 300 300 300 300 100 Lot No. 90-27 90-27 90-27 90-27 90-27 90-27 90-37 HEA 11.6 7.7 21.6 21.6 21.6 21.6 7.4 TDI 17.4 11 29.7 28.5 29.7 28.5 9.9 Styrene 155.5 119.3 351.3 350.1 351.3 350.1 117.3 OH/NCO 1.0 1.07 1.11 1.07 1.11 1.16 Addn mode, (hr) - - - - - - -One Portion- - - - - - - - dropwise # 6-portion (1:45) (1:45) Temp, C RT RT RT RT RT RT 25-35 Time, hr. 4 23 24 24 23 23 12 Br. Viscosity at 3,350 1,920 1,725 1,560 1,520 930 270C, cps Please refer to Table B for definition of HTRLPs.

Experiments 19 to 22 These experiments demonstrate preparation of a VTRLP by means of a 2-step solution process whereby a mixture of 2-hydroxyethyl acrylate and phenothiazine stabilizer is added to 4,4'-methylene diphenyl diisocyanate (MDI) to form an adduct. To the adduct in styrene solution is added in one portion or dropwise a styrene solution of HTRLP previously described, and the reaction is completed, as described in the previous examples.Data in summary form for these examples is given in Table D, below, where amounts are given in parts by weight, unless otherwise indicated: Table D Styrene Solution 2-Step Process

Exp No. 19 20 21 22 HEA-MDI Adduct 109.8 29.3 29.3 29.3 NCO, % 11.5 10.7 10.7 10.7 HTRLP 379.5 140.2 150.1 150.1 Lot No. 64-110 90-33 90-33 90-33 Phenothiazine, ppm 75 500 500 500 Styrene, % 47 50 50 50 OH/NCO 1.0 1.07 1.11 1.11 MDI addn. - - - - - One Portion - - - - - - - # dropwise Temp., C 22-30 22-35 24-27 22-28 Time, hour 6 8 8 5 ANcJAcN 0.11 0.06 0.06 0.128 Br. Viscosity 270C, cps 11,000 7,000 4,000 3,550 Aged 12,400 10,400 7,200 7,800 days 10 5 5 3 NCO Treatment 0.5% 100 ppm 100 ppm 300 ppm Methanol Ethylene Ethylene Triethanol Glycol Glycol Amine 4,4'-Methylene diphenyl diisocyanate is a white or light yellow fused solid at room temperature and a clear yellow liquid above 360C. It was melted for use in the examples herein.As is evident from the above table, the ratio of hydroxyl/isocyanate is inversely proportional to viscosity of the resulting vTRLP. For example, an increase of hydroxyl/isocyanate ratio from 1.0 to 1.11 decreased viscosity of the resulting VTRLP from 11,000 cps to 4,000 cps at 270C. Reaction temperature during the initial 2 to 3 hours of reaction should be maintained below about 250C to hold viscosity of the product below about 3,000 cps at 270C. In a preferred embodiment, temperature during the first 2 to 3 hours of reaction should be about 20 to 220C. The reaction temperature can thereafter be raised to a range of 30 to 400C in order to more quickly complete the reaction.

Examples 23 to 29 These examples demonstrate the one-step solution process using 4,4'-methylene diphenyl diisocyanate (MDI) with 2-hydroxyethyl acrylate and HTRLP, described previously, which was carried as described in the corresponding examples above. The data for these examples is summarized in Table E, below, where amounts of the materials are given in parts by weight, unless otherwise noted: Table E Styrene Solution 1-Step Process Exp. No. 23 24 25 26 27 28 29 HTRLP 300 300 700 300 300 300 300 Lot No. 90-33 90-33 90-33 90-33 90-33 90-37 90-37 HEA 22.8 22.8 50.4 21.6 21.6 22.2 22.2 MDI 48.9 48.9 95.6 41.0 41.0 42.7 42.7 Phenothiazine, ppm 500 500 500 500 500 500 500 Styrene, % 50 50 50 50 50 (tol.*) 50 50 OH/NCO 1.00 1.00 1.11 1.11 1.11 1.20 1.20 MDI addn. one-portion dropwise one-portion one-portion one-portion one-portion dropwise Temp., C 22-33 21-38 35-42 22-33 22-32 22-38 21-22 Time, hours 3 2 3 5 5 7 8 ANCO/ACN - - 0.05 0.07 0.05 0.2 0.56 Br. Viscosity at 27 C, cps 9,000 12,000 9,000 5,000 3,400 2,500 2,400 Aged, - - 27,500 5,2500 3,700 2,300 3,700 Days 2 3 3 12 1 NCO Treatement - - 200 ppm 200 ppm 200 ppm 500 ppm none p-toluene tri-ethanol tri-ethanol tri-ethanol sulfonic amine amine amine acid *tol. denotes toluenes

Claims (23)

Claims

1. Process for preparing a vinyl terminated reactive liquid polymer comprising reacting an isocyanate with a hydroxyl compound containing ethylenic unsaturation and a hydroxyl terminated reactive liquid polymer.

2. Process according to claim 1 wherein the isocyanate is a diisocyanate.

3. Process according to claim 2 wherein the diisocyanate is an aliphatic or aromatic diisocyanate

4. Process according to claim 1,2 or 3 wherein the hydroxyl compound is a hydroxyalkyl ester of an unsaturated acid, a hydroxyl-containing alkene or a vinyl aromatic alcohol.

5. Process according to claim 4 wherein the hydroxyalkyl ester of an unsaturated acid contains 1 to 12 carbon atoms in the alkyl group and the unsaturated acid is an aliphatic or aromatic acid which contains 2 to 8 carbon atoms; the hydroxyl-containing alkene contains 1 to 12 carbon atoms; the viny aromatic alcohol is defined by the formula

where R1 and X each represent hydrogen, halogen, or an alkyl radical containing 1 to 4 carbon atoms; and n is a number from 0 to 12.

6. Process according to claim 5 wherein the hydroxyalkyl ester contains 2 to 8 carbon atoms in the alkyl group; the alkene contains 2 to 8 carbon atoms with the hydroxyl group on the terminal carbon atom and the vinyl aromatic alcohol contains up to four X groups in the aromatic ring with n being a number from 0 to 4.

7. Process according to claim 5 or 6 wherein at least one of the carbon atoms in the alkyl group of the hydroxyalkyl ester has a halogen, nitrate, carbonate, substituted alkyl group of 1 to 4 carbon atoms, alkoxy, alkenoxy, or substituted or unsubstituted phenoxy group substuent thereon.

8. Process according to claim 7 wherein the substituent is an acryloxy, methacryloxy, crotonoxy, allyloxy, methoxy, propoxy or butoxy group.

9. Process according to claim 7 or 8 wherein the hydroxyalkyl ester is a substituted or unsubstituted hydroxyalkyl acrylate or methacrylate containing 1 to 1 2 carbon atoms in the alkyl group.

10. Process according to claim 9 wherein there are 2 to 4 carbon atoms in the alkyl group.

11. Process according to any of claims 1 to 10 wherein the hydroxyl terminated reactive liquid polymer has a bulk viscosity in the range of 5000 to 2,500,000 cps.

1 2. Process according to any of claims 1 to 11 wherein the HTRLP is a hydroxyl terminated polybutadiene-acrylonitrile, hydroxyl terminated polybutadiene-acrylonitrile-hydroxyethyl acrylate, hydroxyl terminated polybutadiene-styrene, hydroxyl terminated epichlorohydrin polymer, hydroxyl terminated polybutadiene, or hydroxyl terminated polybutadiene-alkyl acrylate.

1 3. Process according to any of claims 1 to 12 wherein the relative mol ratio of the reactants is about 2 mols of the isocyanate, about 2 mols of the hydroxyl compound and about 1 mol of the hydroxyl terminated liquid polymer.

14. Process according to claim 1 3 wherein about 1.05 to 1.3 mol of the hydroxyl compound is reacted for each mol of the isocyanate.

1 5. Process according to any of claims 1 to 14 wherein the reaction is effected at a temperature of about 200C to about 700 C.

1 6. Process according to any of claims 1 to 1 5 wherein the hydroxyl compound is reacted with the isocyanate to form an adduct and HTRLP is then reacted with the adduct in the presence of a solvent to form the VTRLP.

1 7. Process according to any of claims 1 to 1 5 wherein reaction between the isocyanate, the hydroxyl compound and the hydroxyl terminated reactive liquid polymer is effected in one step in the presence of a solvent.

1 8. Process according to claim 1 6 or 17 wherein the solvent is free of any groups reactive to isocyanate groups.

1 9. Process according to claim 18 wherein the amount of solvent is from 20 to 400 parts by weight per 100 parts of HTRLP.

20. Process according to claim 1 9 wherein the amount of solvent is from 50 to 1 50 parts by weight per 100 parts of HTRLP.

21. Process according to any of claims 1 8 to 20 wherein the solvent is styrene or a mixture of styrene with methyl methacrylate or divinylbenzene.

22. Process for preparing vinyl terminated reactive liquid polymers substantially as herein described with reference to and as illustrated in any of the Examples.

23. Vinyl terminated reactive polymer prepared by a process according to any of the preceding claims.