IMPROVEMENT IN OR RELATING TO PETROLEUM RESINS

Abstract: Light colour polar petroleum resins with improved properties are obtained by reacting a mixture containing tri- and tetra-cyclopentadiene and less than 20 wt.% based on the total content of cyclopentadiene oligomers of dicy­ clopentadiene with an α. β. unsaturated carboxylic acid. The carboxyl group in the product provides a reactive site for further reactions to produce resins suitable in applica­ tions such as pressure sensitive adhesives, hot melt adhe­ sives, ink resins etc and these further reactions and uses of the resins also form the subject of this invention.

Description: Improvement in or Relating to Petroleum Resins The present invention relates to improvements in polar synthetic petroleum resins, to the improved resins so obtained and their uses. In particular the invention relates to improvements in the production of resins from oligomers of cyclopentadiene especially the production of synthetic rosin and rosin ester substitutes. Cyclopentadiene and alkyl derivatives thereof such as methylcyclopentadiene or codimers with C5-c6 conjugated dienes are obtained as byproducts of oil refining. It has been known for many years that cyclopentadiene may be polymerised thermally or catalytically to produce resins which have found widespread use in adhesive formulations; pressure sensitive, hot melt, emulsion type, or ink resins, in road marking formulations and in many other applications. It is also well known that cyclopentadiene may be dimerised and the dicyclopentadiene then polymerised, again thermally or catalytically to produce resins. There have also been many proposals to modify such petroleum resins to produce more reactive polar compounds which are useful in ink resins and water based system. It has also been proposed to hydrogenate the resins to improve colour and to incorporate other unsaturated monomers with the cyclopentadiene that is polymerised to control the molecular weight distribution of the polymer according to the proposed use of the resin. Recently there have been many proposals to modify certain oligomers of cyclopentadiene to render them polar and more useful in adhesive formulations where the improved compatibility with rubbers and ethylene/unsaturated ester copolymers that is allegedly achieved will be highly beneficial. United States Patent 3,884,970 for example relates to the carboxyl at ion of tricyclopentadiene with carbon monoxide to produce synthetic materials of structure similar to natural rosin ester. The tricyclopentadiene may be obtained by heating cyclopentadiene or dicyclopentadiene at 200"C. The carboxylated resin based on at least 80% tricyclopentadiene has a narrow molecular weight distribution and is said to be useful in pressure sensitive adhesives and in hot melt adhesives as its glycerin ester. Japan Kokai 80 39,243; 81 10,514; 81 16,654; 81 32,523; and 81 34,717 United States Patents 4,148,767, 4224430 and 4246367 and European Patent Application 0020945 relate to hardenable polyester resins obtained by reacting dicyclopentadiene with an &alpha; d unsaturated carboxylic acids such as maleic acid and then reacting with a polyhydric alcohol. European Patent Application 003012 relates to dicyclopentadiene acrylates made from mixtures of cyclopentadiene containing from 60 to 95 wt.% of dicyclopentadiene. German Patent Application 2950703 carboxylates dicyclopentadiene with an OC , } unsat- urated dicarboxylic acid to give improved compatibility with ethylene/vinyl acetate copolymers for use in hot melt adhesives. United Kingdom Patent Specifications, 1,446,080, and 1450994, and Belgian Patent 820, 127 suggest reacting a mixture of cyclopentadiene oligomers or resins with and } unsaturated acid and then reacting with a monohydric alcohol to provide a polar resin useful in inks. All the Examples use mixtures of cyclopentadiene oligomers containing high concentrations of dicyclopentadiene or resins based on dicyclopentadiene which are of too high molecular weight to provide the required tackifying properties and compatibility with elastomers and ethylene/vinyl acetate copolymers to be useful in adhesive formulations. We have now found that by the use of certain proportions of the oligomers of cyclopentadiene in a mixture that is reacted with an & , } unsaturated acid, polar resins are obtained which may optionally be further reacted to give resins useful in a wide variety of applications. The resins have increased softening point combined with narrow molecular weight distribution leading to improved compatibility with rubbers and copolymers of ethylene and unsaturated esters especially ethylene and vinyl acetate for use in both pressure sensitive and hot melt adhesive formulations. The present invention therefore provides a process for the production of polar petroleum resins comprising reacting a cyclopentadiene oligomer mixture containing (i) from 0% to 100% by weight of tricyclopentadiene (ii) from 100% to 08 by weight of tetracyclopentadiene (iii) from 0% to 50% by weight of pentacyclopentadiene and less than 20% by weight of dicyclopentadiene with a carboxylic acid or anhydride, the percentages being of the total cyclodiene content in the mixture. The preferred ratio of the cyclopentadiene oligomers will depend upon the use to which the polar petroleum resin whether further reacted or not is to be put. The term cyclopentadiene includes alkylcyclopentadienes such as methyl cylopentadiene which may replace some or all of the unsubstitued cyclopentadiene, similarly codimers of cyclic; l1t- adiene with other C4,Cs or C6 diolefines such as butadiene, isoprene or pentadiene may be used although we prefer that the mixture contain from 10 to 90 wt.% more preferably from 30 to 70 wt.% of tricyclopentadiene and from 10 to 90 wt.%, more preferably from 30 to 70 wt.% of tetracyclopentadiene. The pentacyclopentadiene content is less than 50 wt.% and, especially for use in adhesives, it is preferred that it be less than 30 wt.% which results in improved compatibility with ethylene vinyl acetate copolymers. The mixture of oligomers may be obtained by heating cyclopentadiene and/or dicyclopentadiene the alkyl derivatives thereof or codimers described above under carefully controlled conditions. The relative proportions of tricyclopentadiene and tetracyclopentadiene that are obtained depend upon the temperature, the duration of the heating and whether or not a solvent is used. For example although United States Patent 3884970 states that tricyclopentadiene may be obtained by heating cyclopentadiene or dicyclopentadiene at 200 C we find that mixtures predominantly of tricyclopentadiene and tetracyclopentadiene may be obtained by heating cyclopentadiene or dicylopentadiene for a certain length of time at between 170 to 300 C preferably 180"C and 220 C. For example we have found that if cyclopentadiene is heated for 4 hours under the following different conditions the following mixtures are obtained. The mixture of oligomers generally has a number average molecular weight as measured by Gas Chromatography of from 150 to 300 preferably from 190 to 250. Temperature Time Solvent Dicylo- Tricylo- Tetracyclo- Pentacyclo C Hr wt% Pentadiene Pentadiene Pentadiene Pentadiene Wt% Wt% 180 4 None 82 18 200 4 None 34 56 7 3 220 4 None 1 52 35 12 180 4 Xylene (50) 64 29 7 180 6 n 47 38 12 3 195 2 " 46 43 11 195 4 " 22 46 22 10 215 1 " 33 48 19 215 4 " 12 38 25 25 225 4 n 5 40 25 30 The mixture that is reacted with the carboxylic acid in the process of the present invention may contain higher oligomers of cyclopentadiene such as hexacyclopentadiene although the quantity of these higher oligomers should not be above 30% based on the total cyclodiene content of the mixture. The carboxylic acid that is reacted with the mixtures of cyclopentadiene oligomers maybe an acid or an anhydride and is preferably an d p unsaturated acid such as maleic acid which may be obtained from a mixture of maleic anhydride and water. Non limitative examples of unsaturated acids that may be used include C3-C30 acids such as acrylic acid, methacrylic acid, tetrahydrophthalic acid, bicylo (2,2,1) hept-5-ene-2,3 dicarboxylic acid, endomethylene tetrahydro-phthalic acid, fumaric acid,crotonic, citracanoic, itaconic, aconitic mesaconic acids, phthalic acids (ortho, meta and para), fatty acids and mixtures of these acids may be used. Since the unsaturated acids are fairly reactive, catalysts such as Friedel Crafts Catalyst (e.g. BF3 or BF3 organic complexes), Lewis acids (e.g. sulfuric acid, para toluene sulfonic acid, sulfonic polystyrenes, fluoro sulfonic acid) and the like are not necessary although they may be used. Saturated C1 to C30 mono-, di-, or polycarboxylic acids such as oxalic, succinic, adipic, malic, malonic acids, hexahydrophthalic acid, methyl hexahydrophthalic acid, azelaic acid, sebacic acid pyromellitic, trimellitic, and citric acid might be also used but they exhibit a slower reactivity than d k ss unsaturated acids and catalysts as well as higher condensation temperature are required for the reaction. Furthermore, degradation in resin colour can result and so thed ,} unsaturated acids are preferred. Blends ofM , unsaturated carboxylic acids and saturated carboxylic acids may also be used. The-acids could be linear, branched, aliphatic, alicyclic, aromatics, and can contain halogen or any other polar group such as hydroxyl, amino, nitro, ether, or the like. Although C1 to C30 acids are preferred high molecular weight acids such as the alkyl succinic acids or anhydrides may be used. The &alpha;,ss unsaturated carboxylic acid may be reacted in any of the well known ways and our preferred method is to combine a solution of the cyclopentadiene oligomers with the acid at the melting temperature of the acid. Reaction is fairly rapid (generally less than one hour) and is generally exothermic. The reaction of the acid with cyclopentadiene nucleus qenerallv proceeds EMI7.1 EMI7.2 <tb> as <SEP> follows <tb> <SEP> 00CR <tb> RCOO <SEP> H <tb> and when a dicarboxylic acid is used a half ester is obtained as follows EMI8.1 which frequently have an acid number varying from 25 to 250 (mgKOH per gram of product) depending upon the ratio of acid to cyclopentadiene unit. The free carboxylic acid group on the half ester provides a reactive site for a large variety of subsequent reactions yielding a wide range of products. The molar ratio of carboxylic acid to cyclopentadiene units in the mixture that should be used depends upon the use to which the modified resin is to be put and on any subsequent reactions that are envisaged. As a general guide we prefer to react between 0.2 and 2.0 preferably 0.5 and 1.2 mole of acid per mole of cyclopentadiene in the mixture. For subsequent esterification for use in adhesive formulations we prefer for cost reasons to react with maleic acid at around 1300C. The duration of the reaction must also be controlled because we find that the longer the reaction time the greater the proportion of the diester that is formed and although the diester increases the softening point its presence is bad for compatibility with ethylene/viny] acetate copolymers so impairing its use in hot melt adhesives. The reaction time is preferably controlled to give the optimum proportion of the half ester and the diester. Optimum conditions for other outlets depend upon the melting point of the selected acid and its reaction rate. When maleic acid is selected it can be used as pure form or prepared in situ at 50 to 70-C by reacting maleic anhydride and water. The carboxyl modified resins thus obtained, especially the half esters are reactive and may be further reacted to provide resins suitable for use in a wide variety of applications such as inks, adhesives, rosin ester substitutes, alkyds, hardenable polyester obtained by condensation of polymerisative auto-oxidizable compositions, curable products, etc. In particular the resin may be esterified by reaction with a mono- or polyhydric alcohol. Similarly if the modified resin has been produced by the Diels-Alder condensation of an, unsaturated dicarboxylic acid with the mixture of cyclopentadiene oligomers one or both of the free carboxylic acid groups may be esterified hereagain offering a wide variety of possible reactions and products. For example a free acid function may be reacted with a polyol and anhydrides to produce polyesters, bases (e.g. caustic, potassium hydroxide and ammonia ..) to produce water soluble salts, metal oxides or hydroxides (e.g. MgO), amines or diamines, urea to produce polyamides, acrylic or methacrylic acids to produce corresponding acrylates and methacrylates (see U.S. 4,071,489 4,097,677), polyol and organic isocyanates to produce polyurethanes, epoxides to produce polyethers. The molecular weight of the ester so obtained may be increased by heating or other polymerisation mechanisms such as free radical, catalytic, U.V., electron beam or gamma radiation polymerisation. The increase in molecular weight depends upon the time and temperature of heating and we have found that the softening point is dependent on the length of heating. We prefer to heat between 1500 to 300'C preferably 1800C-2600C for 0.5 to 10 hours preferably 0.5 to 2 hours depending on the molecular weight desired. Temperature and time may be reduced by using catalysts. These reactions are not limitative and might involve any other chemical reaction feasible with the preformed acid and/or alcohol function. The molecular weight of the reactants may be controlled according to the proposed use of the final product. When monoalcohols or polyhydric alcohols are used they may be any C1 to C30 preferably C4 to C18 saturated, unsaturated, aliphatic, aromatic, mixed aliphatic/aromatic alcohol having linear or branched chain structure. Examples of suitable polyols are diols such as glycols as well as ether glycols such as ethylene glycol, propylene glycol, neopentyl glycol, 1,3 butylene glycol, 1,6 hexanediol, diethylene glycol, dipropylene glycol. Other conventional polyols might be for example glycerol, pentaerythritol, sorbitol and the like. Monoalcohols are preferred for obtaining the optimum mole cular weight and properties balance for resin useful in adhesive formulation, particularly pressure sensitive adhesives and hot melt adhesives where the resins act as tackifiers in mixture with elastomers or ethylene vinyl acetate co polymers. We have found that the choice of the physical properties of the resin depend upon the choice of the alcohol; long chain aliphatic alcohols (saturated, unsaturated, linear, branched, aliphatic or aromatic) are preferred when liquid or viscous resins are required wherea-s cyclic alcohols such as cyclohexanol, benzyl alcohol and dicyclopentadiene alcohol are preferred for producing solid polar resins. In adhesive formulations it is important that the resin have as high a softening point as possible consistent with the desired tackifying properties and that it also be compatible with the natural and/or synthetic rubber with or without the need for a solvent as the case may be. It has been found that resins according to the present invention have such a particularly desirable combination of properties. In the production of resins for adhesives we prefer to react the mixture of cyclopentadiene oligomers with from 0.2 to 2.0 preferably from 0.5 to 1.2 moles ofd p unsaturated acid per mole of cyclopentadiene in the mixture. We then prefer to react the product of this reaction with from 0.2 to 3.0 preferably 0.6 to 1.5 moles of an alcohol. We prefer to use a cyclic alcohol such as cyclohexanol or dicylopentadienyl alcohol since these have a good combination of tackifying and compatibility for use in adhesives. The resins prepared by the process of this invention as such or after hydrogenation (double bond stabilisation) may have a wide range of end uses and applications. They can be applied on paper, metal, thermoplastic, PVC, woven and non woven fabrics, glass, etc. as protective coatings or for bonding such materials together. Typical applications are hot melts, carpet backing, coatings with drying oil formulation, paints, book binding, road marking, products assembly (e.g. wood working), printing inks, paper sizing or any applications involving natural or synthetic resins and/or rubbers such as caulks, sealants or rubber tackification. More especially their use as elastomer tackifiers should be employed with natural rubber or synthetic rubbers (polyisoprene, EPDM, butyl, chlorobutyl, bromobutyl, neoprene, SBR and thermoplastic block copolymers for example SIS styrene/isoprene/styrene rubber (e.g. Shell Cariflex TR 1107), SBS styrene/butadiene/styrene (e.g. Shell Cariflex TR1102), saturated styrene/olefins/styrene (e.g. Shell Kraton G) or the like and their mixture. These resins provide outstanding tackiness with such elastomers at variable resin/rubber ratios. Other applications involving such resins are pressure sensitive adhesives, hot melt adhesives, hot melt pressure sensitive adhesives, label adhesives, contact adhesives, low temperature adhesives, latex adhesives, surgical tapes and masking tapes. They can be applied in solvent or in emulsion form (water based adhesives). The resins are compatible with acrylics and can be applied in blends. Since these resins are compatible with ethylene vinyl acetate copolymers (EVA) they may be used in hot melt adhesives as well as hot melt pressure sensitive adhesives (HMPSA) which are EVA based. In pressure sensitive adhesive formulations 30 to 200 parts by weight of the resin of the present invention may be used per 100 parts of the rubber, preferably 40 to 120 parts; if necessary oils may also be added. Similar proportions are preferably used in hot melt adhesives where the second component is generally an ethylene/vinyl acetate copolymer. Latex adhesives and emulsion adhesives can be prepared by emulsifying in water the thermoplastic rubber with or without oil in the presence of a diluted solution of a soap such as rosin salt or by adding a conventional emulsifier. Another way to prepare the emulsion is to form "in situ" the necessary salt by adjusting the acid number of those ester resins and reacting them with caustic, potassium hydroxide, ammonia, amines or the like. New carboxylated rubbers existing on the market can be also used for preparing emulsions containing these resins. The emulsion may also be prepared in situ by polymerising the ester resin in water in the presence of catalysts such as potassium persulphate or other Redox catalysts. The ester may also be copolymerised by this process in the presence of vinyl unsaturated monomers such as vinyl acetate, styrene and alkyl styrenes, -olefins, acrylic and methacrylic acid, acrulates and methacrylates, vinyl chlolride maleates and fumarates, acrylamide, acrylonitride etc. The resin may also be used in hot melt roadmarking formulations where they are mixed with a pigment such as titantium dioxide. Typically a formulation contains from 25 to 300 parts by weight of pigment for each part of the resin and preferably the pigment is powdered titanium dioxide. The resin may be the ester or half ester and where a half ester is used it may first be modified to the monovalent (potassium, sodium or ammonium) or polyvalent (magnesium, calcium, zinc or aluminium) salt. The present invention is illustrated but in no way limited by reference to the following Examples. Example 1 Various cyclopentadiene concentrates comprising 50 wt.% solutions in xylene were reacted for 2 hours at 120-130'C with one mole of maleic acid. After xylene recovery by vacuum distillation light coloured half esters having the softening point given in the following table were obtained. A concentrate of a 50 wt.% solution of pure dicylopentadiene 10 was similarly treated for the sake of comparison. Poly CPD Distribution (Wt.%) DCPD 100 10 19 4 CPD Trimer - 52 34 40 CPD Tetramer - 24 21 25 CPD Pentamer - 14 26 31 Half-ester Properties Softening Point* liquid 44-60 127 120 Gardner Colour** 1 1 2 2 Acid Number *** 245 159-177 180 (*) ASTM D-E.28 (**) 50 wt.% in toluene mg mg KOH per gram of product Maleic acid can be replaced by maleic anhydride (1 mole) and water (1.2 mole) at 50-70 C. Example 2 A 50 wt.% solution in Xylene of the following mixture of cyclopentadiene oligomers. Poly CPD distribution (wt.%) DCPD 18 CPD Trimer 43 CPD Tetramer 23 CPD Pentamer 16 was reacted for 2 hours at 120-130 C with maleic acid as in Example 1. The half ester so obtained was then heated at 1700C for certain periods of time to give products with the following properties. Half Ester Properties Hours heating 1 2 3 4 5 Softening Point* 85 102 108 115 125 Acid number** 163 147 143 140 137 * ** ASTM D-E.28 mg mg KoH per gram of product Example 3 This example illustrates the influence of alcohol nature upon resin softening point, compatibility with ethylene vinyl acetate copolymer of different vinyl acetate content and pressure sensitive adhesive properties. DCPD or polyCPD was reacted with one mole of maleic acid as described in Example 1 and the half ester then reacted with 1.5 mole of alcohol (n-decanol,2 ethyl hexanol, cyclohexanol or DCPD alcohol). The esterification has been carried out at atmospheric pressure, the water being removed by azeotropic distillation with the xylene solvent. The ester produced had an acid number of 20 (value corrected due to presence of solvent and alcohol excess). Solvent and alcohol in excess were eliminated by vacuum distillation.and the final unsaturated ester stabilised by adding 0.5 wt.% phenolic antioxidant (Ciba Geigy Irganox 1076). Table 1 compares the esters obtained using cyclohexanol or dicyclopentadiene alcohol with other linear alcohols such as decanol or 2 ethyl hexanol. TABLE 1 1 2 3 4 5 6 7 8 9 10 CPD Distribution (wt.%) DCPD 100 21 - 11 4 100 11 11 11 11 Tri CPD - 63 71 52 40 - 52 43 52 52 Tetra CPD - 16 28 24 25 - 24 27 24 24 Penta CPD - - 1 13 31 - 13 19 13 13 Esterifying alcohol Decanol - - - - - - - - X - 2 ethyl hexanol - - - - - - - - - X Cyclohexanol X X X X X X - - Dicylopentadiene alcohol - - - - - - X X - Resin properties Softening point C(1) liquid 39 48 55 73 46 70 95 liquid liquid Gardner colour(2) .. 2 2 1.5 2 2 2 1.5 Solubility (toluene/Exsol)(3) +/+ +/+ +/LS +/LS +/+ +/LS +/LS Application Properties Wax cloud point C(4) 88 86 83 195 230 EVA 220/resin/microwax 30/45/25 wt.% EVA compatibility(5) Vinyl Acetate Content 19% VA I C/H C/H H H H H 28 C C C H H H H 40 C C C H C C H 50 C C C H C C/H H (1) ASTM D-E28 (2) Gardner colour at 50 wt.% resin concentration in toluene (3) Solubility at 50 wt.% resin in solvent (either Toluene or Exsol) Exsol D40 =ESSO dearomatised white spirit - boiling range 155-200 C + = complete solubility LS = limited solubility (4) Temperature recorded in Celsius Degree at which log of a clear molten blend of EVA 220/resin/microwax (melting point 76 C) 3g/4.5g/2.5g becomes cloudy during cooling - EVA 220 is a Dupont ethylene vinyl acetate containing 28 wt.% vinyl acetate and having a melt index according to ASTM D-1238 of 125-175. (5) Check by visual appearance of a blend of resin and an ethylene vinyl acetate copolymer (EVA) - Blend consists of 3 g resin and 3g EVA - Temperature 180, 100 and 20 C. I = incompatible H = Hazy C = compatible (clear). Example 4 Pressure Sensitive Adhesives To assess pressure sensitive adhesive properties a sample of natural rubber of adequate Mooney viscosity, a petroleum resin produced according to the present invention and an antioxidant were dissolved in n-heptanetoluene (90:10 wt %), The pressure sensitive adhesive film used for tack measurement was prepared by evaporating overnight at room temperature a thin layer of the rubber/resin solution spread on a cellophane or a polyester film. The adhesive mass was 30 g/m2. The pressure sensitive adhesive properties measured are those set out in the "Test Methods for Pressure Sensitive Tapes" as developed by the Specifications and Technical Committee of the Pressure Sensitive Tape Council 5th Edition and more specifically: o 1800 Peel strength (PSTC-1) o 90 Peel strength (PSTC-2) o Tack Rolling Ball (PSTC-6) o Shear adhesion (PSTC-7) o Quick stick (PSTC-5) o Polyken Tack As measured on Polyken Probe Tack Testing TMI-Testing Machine Inc Amityville New York The adhesive formulations were either based on natural rubber (NR) (65 Mooney viscosity) or random. styrene butadiene rubber SBR 1011 which was applied from a 15 wt.% toluene solution. In either instance the resin content was 100 phr (100 resin parts for one hundred parts of rubber). In Table 2 the pressure sensitive adhesive properties formulations containing the polar resin described in Table 1 are compared with those of commercial natural rosin esters currently on the market whose properties are as follows: Trade Name Product Softening point CC FORAL 85 Glycerol ester of rosin 81 FORAL 105 Pentaerithritol ester of rosin 103 Staybelite Hydrogenated glycerol ester 84 ester 10 of rosin Pentalyn H Hydrogenated pentaerithritol 104 ester of rosin Table 2 Pressure sensitive adhesive properties Resin sample (from table 1) 1 2 3 4 5 6 7 8 Competitive Resins Foral 85 X - - Foral 105 - X - Staybelite ester 10 - - X Pentalyn H - - - X NR 180 C Peel strength (grams/cm) 340 440 320 430 125 - 280 345 180 300 250 180 Polyken tack (grams) 660 990 680 550 450 - 440 600 100 220 440 50 Rolling ball tack (cm) 1.5 2.5 2.5 2.5 2 - 11 3 > 30 10 3.5 > 30 Shear adhesion (hr) 19 22 16 14 0 - 4 25 4 14 11 35 SER 1011 180 C Peel strength (grams/cm) 1075 1085 820 1200 1030 2250 2650 2830 805 2910 1075 635 Polyaken tack (grams) 880 990 550 880 600 800 880 900 1100 990 680 700 Rolling ball tack (cm) 1.5 6.5 > 30 7.5 2 2 2.5 1.5 3.5 2 2 12 Shear adhesion (hr) 16 16 19 20 0.2 1 2 2 4 22 20 5 Example 5 Similar pressure sensitive adhesive formulation to those of Example 4 were prepared but with a synthetic thermoplastic block styrene-isoprene-styrene rubber (Cariflex or KRATON TR1102) having a styrene content as measured by Nuclear Magnetic Resonance (N.M.R.) of 29 wt.%. The adhesive formulation contained 60% hexane/toluene solvent (80/20 wt.%), 15% KRATON TR1102, 22% resin and 3 wt.% ESSO FLEXON oil and had the following properties Resin sample (from Table 1) 4 5 7 90" Peel strength (grams/cm) 360 220 260 Polyken tack (grams) 640 400 200 Rolling ball tack (cm) 3 20+ 20+ Quick stick (grams/2.5 cm) 1100 450 100 Shear (hr) 250+ 250+ 250+ Example 6 Label adhesives A label adhesive formulation based on a 15 wt.% toluene solution of a random styrene butadiene rubber (SBR 1011) and these polar resins was evaluated. The resin ratio 80 parts resin for 100 part rubber. Resin sample (from table 1) 4 5 7 Pentalyn H 90C Peel strength (grams/cm) 460 400 460 500 Polyken tack (grams) 660 700 820 740 Rolling Ball tack (cm) 2 3 2 5 Quick stick (grams/2.5 cm) 900 800 950 1100 Shear (hr) 3 5 4 7 Example 7 Hot melt adhesive properties evaluation A hot melt adhesive formulation based on an ethylene vinyl acetate copolymer containing 28 wt.% vinyl acetate and having a Melt Index of 25 as measured by ASTM D-1238 (ESSO Escorene UL 02528) was prepared. The formulation is: Escorene UL 02528 45 wt.% Polar Resin 45 wt.% Paraffin Wax (melting point 65"C) 10 wt.% Antioxidant (Ciba Geigy 0.5 wt.% Irganox 1076) and its physical and adhesive properties are as follows: Resin sample (from table 1) 4 5 7 Foral 85 Viscosity at 180 0C mPa.s 14000 16200 16300 13200 Adhesive properties Max open time at 1800C (s)* 8 13 12 13 Min set time, related to max open time,** (s) 2 1 1 1.5 T Peel(1) speed 2inch/min on aluminium (grams/cm) 530 540 540 925 on polyethylene (grams/cm) 600 150 650 850 Mechanical properties 2 in/min Tensile strength(2) (gram/cm2) 462 565 560 567 Elongation(2) (%) 1080 910 850 800 Cold flexibility C*** < -27 -22 -26 -27 (1.) T-Peel ASTM D-1876 method (2) Tensile strength and Elongation:- ASTM D-638 method * Time during which second substrate may be applied and a bond achieved. ** Time needed to achieve bond between two substrates coated with the adhesive formulation. *** Temperature at which adhesive formulation becomes brittle. Table 3 Acid (anhydride) Maleic Fumaric Phthalic * None X X Cyclohexanol X X X X X Cyclohexanol X X X DCPD alcohol X X X X X DCPD alcohol X X X Resin Properties Softening point ( C) 45 liquid 45 130 viscous liquid Acid number 24 9 25 9 227 149 43 20 (mgKOH/g) Solubility (toluene/ +/LS/+ +/+/+ LS/LS/+ Ls/I/Ls/I/I/I+/+/+ +/LS/++/+/+ Exsol/acetone) EVA compatibility (1) (1) (1) VA% 19 C/H C/I I C/I I I C I H " 28 C/H C I C/H(1) I C C C H " 40 C C I C C C C C C " 50 C C I C C C C C C Adhesive properties SBR 1011 100 phr 180 Peel strength None(2) 1375 800 1450 1930 2300 (grams/cm) Polyken tack (grms) n 700 700 700 550 700 Rolling ball tack n 2 3 3 30+ 1.5 (cm) Shear (hr) U 1 1 1 1 1 (1) at 20 C (2) adhesive film crystallisation * Each "X" indicates in each column that one mole of the particular alcohol was used for one carboxyl group present in the acid. Example 8 1 mole of poly CPD containing essentially CPD trimer (71 wt.%), CPD tetramer (28 wt.%) and CPD pentamer (1 wt.%) was condensed with 1 mole of maleic acid and the product condensed with 1.5 mole of cyclohexanol as in Example 1. The product had a softening point of 48"C, a Gardner colour 2 and an acid number of 10. This polar resin was completely soluble in toluene, EXSOL and Acetone at 50 wt.t concentration. Slight haziness is however noticed with Exsol or acetone solvent. It is also completely compatible with all the ethylene vinyl acetate copolymers described in Table 1. The properties of a pressure sensitive adhesive containing this product and SBR 1011 rubber as used in example 4 were 1800 Peel strength (grams/cm) 2650 Polyken tack (grams) 850 Rolling ball tack (cm) 1.5 Shear (hr) 0.5 Example 9 For comparison phthalic acid, maleic acid, and fumaric acid have been esterified with cyclohexanol and/or dicyclopentadiene alcohol in order to form the corresponding diesters and the properties of the resins obtained and those of adhesive containing. them are shown in Table 3. Example 10 1 mole of poly CPD consisting of 56 wt.% CPD trimer, 31 wt.% CPD tetramer, 13 wt.% CPD pentamer was reacted with one mole phthalic acid at 1500C to form the half ester. An exothermic reaction results and temperature rapidly reaches 200 C at which it is held for 1 hour. The acid number of the half ester obtained was 117. Further esterification is then performed by reaction for 2 hours at 160-170 ec with 1.5 moles cyclohexanol. The ester obtained after excess recovery under vacuum at 60 C had an acid number 27. Its pressure sensitive adhesive properties in an SBR 1011 formulation similar to that of Example 4 are 1800 Peel strength (grams/cm) 3200 Polyken tack (grams) 1000 Rolling ball tack (cm) 12 Shear (hr) 3 Example 11 For comparison the half ester obtained from pure DCPD after condensation with 1 mole of maleic acid (130 -2 hr) was esterified with 0.5 mole glycerol until the residual acid number was 25. The physical properties of the half ester were Softening point C = 77 Gardner colour = 4.5 Compatibility with ethylene vinyl acetate copolymers as well as pressure sensitive adhesive properties based on natural rubber was poor. Examples 12 to 14 illustrate that the unsaturated polar resin can be thermally (or catalytically) polymerised to upgrade the resin softening point and other properties according to needs. Example 12 Maleic acid was reacted with the poly CPD as described in Example 1 for 2 hours at 1300C and esterification performed with cyclohexanol according to the procedure indicated in Example 3. The temperature was then rapidly increased to 250"C and maintained for 3 hrs, samples being removed ater 1 and 2 hours. The poly CPD composition used was: DCPD (wt.%) 18 CPD trimer " 43 CPD tetramerU 23 CPD pentamerU 16 Heating time at 250"C (Hr) 0 1 2 3 Softening point (etc) 52 67 85 100 180- Peel strength (grams/cm) 3015 760 685 580 Polyken tack (grams) 770 1000 1080 330 Rolling ball tack (cm) 3 3 3 8 Shear (hr) 2 5.5 12.5 32 It may be seen that by heating shear cohesion is increased at the expense of 180 Peel strength. Example 13 A poly CPD containing 34 wt.% DCPD, 45 wt.% CPD trimer, 12 wt.% CPD tetramer, 4 wt.% CPD pentamer was esterified and thermally treated using the conditions shown in Example 12 except that the condensation time of maleic acid was 0.5 hr. As is shown in the following table all pressure sensitive adhesive properties based on SBR 1011 rubber are upgraded. especially the 1800 Peel strength ( > 3000 grams/cm). Heating time at 2500 0 1 2 3 Softening point ("C) 35 57 75 90 Gardner colour 1.5 5.5 6.5 7 1800 Peel strength 2290 3020 3375 3270 (grams/cm) Polyken tack (grams) 1000 1000 1000 300 Rolling ball tack (cm) 1.5 2 1.5 14 Shear (hr) 1 3 11 13 It may be seen that by reducing the amount of CPD pent amber and the maleic acid condensation time the shear is increased along with the peel strength. Example 14 The process of Example 13 was applied to DCPD. In these conditions liquid plasticizers exhibiting surprisingly extremely high 180e Peel strength are obtained (SBR 1011 bases). Again cyclohexanol is the esterification alcohol. Heating time at 2500C 0 1 2 3 4 5 Softening point C liquid liquid viscous 53 70 80 liquid 180' Peel strength 1050 1490 1807 1830 (dry films) (grams/cm) Polyken tack (grams) 650 700 900 450 Rolling ball tack (cm) 3 2.5 2.5 30+ Shear (hr) 0.3 0.5 2 7 Example 15 Example 13 was repeated with the cyclohexanol being replaced by 2 ethyl hexanol. Liquid products of increased viscosities are obtained. After 8 hours heating at 250"C the liquid plasticiser gave good SBR tackifying properties (SBR 1011 bases). Gardner colour 8 1800 Peel strength (grams/cm) 2170 Polyken tack (grams) 600 Rolling ball tack (cm) 12 Shear (hr) 5 The produce is completely soluble in toluene, Exsol and acetone. Example 16 Example 13 was repeated except that the extent of the esterification with cyclohexanol has been changed in order to assess the effect of acid number upon physical properties. Heating was limited to 2 hours for pressure sensitive adhesive properties optimisation. Heating time at 2500C (hrs) 2 2.30 2 Softening point (-C) 75 83 77 Acid number (mg KOH/g) 22 36 Gardner colour 6.5 7 1800 Peel strength (grams/cm) 3375 3500 2980 Polyken tack (grams) 1000 990 990 Rolling ball tack (cm) 1.5 7 3.5 Shear (hr) 11 8 16 All the polar resins according to the present invention described in the above Examples are compatible in any proportion with current natural rosins, natural rosin esters, polyterpene resins as well as with hydrocarbons resins including aliphatic resins, mixed aliphatic/aromatic resins, aromatic resins, hydrogenated hydrocarbon resins. Typical examples are the petroleum resins manufactured and sold by ESSO as "Escorez" (Registered Trade Mark) 1102, 1202, 1304, 1310, 1401, 2101, 2203, 7105, 8000, 5000. This list is not limitative and is only given for example. As is shown in the following Examples blending the resins is an efficient way to balance overall physical properties and performance in standard applications such as those described in this patent application. Example 17 Sample no.3 (softening point 48µC) described in table 1 (example 3) was blended at 50 wt.% concentration with different ESSO Escorez resins 2101, 1401 5300, 5320.and the properties of the blend are set out in Table 4. TABLE 4 POLAR RESIN/HYDROCARBON RESIN BLENDS POLAR RESIN/HYDROCARBON RESIN BLEND (50/50 wt. %) Polar Resin (1) X X X X X Escorez 2101 X X Escorez 5300 X X Escorez 5320 X X Escorez 1401 X X RESIN PROPERTIES Softening point C 48 96 102 123 118 49 70 82 66 Wax cloud point C 88 86 93 92 83 84 87 30/42/25 wt.% EVA compatibility VA % 19 C/H C C C C/H C/H C/H C/H 28 C C LC LC C C/H C/H H 40 C I I I C I I I 50 C I I LC I I I PSA properties: SER 1011 100phr. 180 Peel strength, (grams/cm) 2650 1000 3300 515 760 1050 985 3200 2330 Polyken tack (grams) 880 1080 400 900 900 900 900 900 600 Rolling Ball tack (cm) 2.5 2.5 2 4 > 30 4 3.5 3 30+ Shear (hr) 2 5 8 7 15 3 3 6 3 (1) Sample 3 from Table 1 of Example 3 Example 18 The polar resin sample no.3 described in Example 3 and Table I was blended (50/50 wt.%) with a commercial acrylic solution (Gelva 1151 and Gelva 2286 manufactured by Monsanto). The two products are fully compatible and pressure sensitive adhesive properties measured by the PSTC Rolling Ball tack are excellent. Ball tack 2 cm. Example 19 Preparation of polyCPD acrylate and methacrylate These (meth) acrylates of polyCPD have been prepared according to the method described in European patent 0,003,012 1.2 mole of acrylic acid (173 grams) or 1.2 mole of methacrylic acid (206 grams) were heated at 60"C in presence of 0.5 g Ciba Geigy phenolic antioxidant Irganox 1076 and 0.6 wt.% or 4 grams BF3/etherate catalyst. 1 mole of polyCPD of 178 average molecular weight and following composition has been progressively added to the unsaturated acid/catalyst solution. The reaction has been pursued 1 hour at 60"C. Composition Xylene Wt.% 48 DCPD 24 CPD Trimers 20 CPD Tetramers 6 CPD Pentamers 2 Then the reaction medium was washed three times with 200 ml water and neutralised with an ammonia solution containing 4 wt.% NH3. After solvent recovery by vacuum distillation a brown viscous liquid has been obtained. In both cases Infra Red spectra have shown the appropriate polyCPD acrylate and methacrylate structures. Example 20 Preparation of polyCPD ethylene glycol ether The method described in U.S. patent 4,261,872 for preparing the dicylopentadiene ethylene glycol ether has been applied to the polyCPD polymer described in Example 19. 4 moles of ethylene glycol (124 grams) have been combined with 0.5 grams Ciba Geigy Irganox 1076 antioxidant and 7.2 grams BF3/etherate catalyst and heated to 90"C. To this glycol/catalyst blend 0.5 mole (170 grams) of the polyCPD solution used in Example 19 was added over three hours and the mixture then held at 90"C for 2 hours. The reaction medium was then washed 2 times with 250 ml water and neutralised with an ammonia solution containing 4 wt.% ammonia. The polyCPD ethylene glycol ether was recovered as a viscous semi-solid product by solvent elimination under vacuum. Double bond stabilisation: The polar resin of the present invention may be stabilised by hydrogenation of the residual reactive double bond. Alternatively any other conventional chemical reactions involving addition reactions to double bond (e.g. halogenation - see European patent 0,026,295, or addition of sodium bisulfite) may be used. Example 21 50 grams of polyCPD (sample of softening point 750C described in example 14) diluted with 50 grams xylene was hydrogenated at 1000C in presence of 5 wt.t of Raney Nickel. The Raney nickel catalyst had been prepared according to the caustic washing procedure described in the Text-book of Practical Organic Chemistry by A. I. Vogel p.870 Publisher Longmans - 3rd Edition The hydrogenated polar resin had been recovered after solvent recovery under vacuum. Typical properties obtained at different hydrogenation conditions are herewith described. Nuclear Magnetic Resonance (N.M.R.) analysis confirms that hydrogenation occured (maleate/fumarate double bond disappearance). No hydrogenation Temperature (-C) 50 100 150 Pressure (bars) 40 20 20 Time (HR) 2 2 2 Softening Point (OC) 75 70 71 69 Gardner colour 10.5 10.5 10.5 10.5 Wax cloud point (-C) 250+ 250+ 250+ 205 PSA Properties SBR 1011-100phr 180- Peel Strength (grams/cm) 2600 1000 920 350 Polyken tack (grams) 1500 660 440 750 Ball tack (cm) 3 3.5 4 8 Shear (hour) 8 14 13 8 Example 22 The polyCPD-cyclohexyl maleate ester of softening point 75"C described in examples 13 and 21 was hydrogenated with a commercial Harshaw reduced nickel catalysts containing about 50-53 wt.% nickel. The hydrogen has been performed in xylene solvent at different ester concentration and different hydrogenation conditions. Reference 1 2 3 Ester concentration 20 20 50 (wt%) Catalyst concentration 1.0 2.0 2.0 (wt.% on solution) Temperature ("C) 190 170 170 Pressure (bars) 20 20 50 Time (hr) 5 5 5 Softening point ("C) 75 74 89 75 Gardner colour 10.5 9.5 7 5+ Wax cloud point ("C) > 250+ 170 > 250+ 140 PSA Properties - SBR 1011-lOOphr 180µ Peel strength 2600 1080 1380 300 (grams/cm) Polyken tack (grams) 1500 550 1550 110 Ball tack (cm) 3 17.5 3 15 Shear (hr) 8 5 3 3.5 Example 23 Uncured polyCPD -cyclohexyl maleate of S.P. 510C is copolymerised with vinyl or unsaturated monomers. In these experiments the unsaturated polyCPD-cyclohexyl maleate ester is blended with variable concentrations of vinyl monomers and heated for 2 hours at 1500C under nitrogen blanketing. Floral 85 PolyCPD-cyclohexyl maleate 1 1 1 1 1 1 (uncured) (mole) Styrene (mole) - 1 - - - - Vinyl Toluene (mole) - - 1 0.5 - Butyl methacrylate (mole) - - - - 1 Octene 1 (mole) - - - - - 1 S.P ( C) 51 95 110 75 70 118 85 Gardner Colour 2 5- 2 2.5 3+ 4 Wax Cloud Point ( C) 75 > 250 > 250 > 250 > 250 > 250 < 75 PSA Properties - SBR 1011 - 100 phr 1800 Peel strength 1725 1400 985 820 880 580 780 Polyken Tack 800 350 100 1050 1020 480 1400 Ball Tack 3.5 5.5 > 30 9.0 4 4.5 2.5 Quick Stick 240 60 385 510 310 480 Shear 1.5 85 2 2 3.5 2 3.5 As shown copolymerising the ester with styrene improves the cohesion of the pressure sensitive adhesive formulation based on SBR-1011. Good results have been also obtained with contact adhesive formulations based on a vinyl toluene polychloroprene standard formulation such as: Polychloroprene (Bayerprene 321) 100 parts Magnesium oxide 8 Zinc oxide 4 n Ester 40 " Most outstanding properties are good solution stability (no phase separation), good compatibility with polychloroprene and good adhesion to polar substrates such as aluminium. Example 24 A cured polyCPD-cyclohexyl maleate of 73"C softening point was blended with a 15 wt.% SBR 1011 toluene solution (ester/rubber ratio 100 phr) and the resulting pressure sensitive adhesive formulation applied on to a Dupont Mylar(R) polyester film. After drying 15 minutes at 80"C the film is then applied to different substrates according to the PSTC method described in Example 4. The adhesion recorded in Newtons/cm is measured with the T-Peel method. (ASTM method D1876). Substrate PVC Polypropylene Polyester Aluminium T-Peel 12 13 11.5 15.5 Example 25 A liquid polyCPD-2 ethyl hexyl maleate ester produced as described in 10 of table 1 was polymerised in situ in aqueous solution in presence of potassium persulfate as catalyst. (Suspension or emulsion processes are feasible). The polymerisation is performed by polymerising 100g of ester with 100 grams water containing 0.5 grams potassium persulfate, 2 grams of sodium carbonate as pH controlling agent and 0.5 grams soluble starch. The ester is continuously fed to the water solution maintained at 85"C and the polymerisation is pursued 1 hour under stirring and nitrogen blanketing. 50 parts of this emulsion containing 50 wt.% solid is then blended with either a commercial emulsion of carboxylated latex Revinex 97D40(R) supplied by Doverstrand Limited (U.K.). Typical PSA properties are after film drying: Ester/Revinex ratio wt% 50/50 50/100 180- Peel strength (grams/cm) 290 390 Polyken tack (grams) 380 480 Ball tack (cm) 5 4 Shear (hr) 4.6 4.2 Example 26 Various polyCPD-maleic half esters prepared from different CPD oligomer distribution have been tested successfully in hot melt road marking formulations. The blends develop white (low yellowness index) non tacky strips which are exhibiting good solvent resistance and the products can be used as such or as in blends with conventional hydrocarbon resins. Acid number can vary from 0.5 to 180 depending on blending ratio and half ester manufacturing conditions. The products were compared with blends containing Escorez 1102, Quintone C200 and maleic fortified rosin (F.R.). The basic formulation used in this example is based on the following blend: 79 wt.% aggregate (Tio2, CaCo3, sand, glass beads) 17 wt.% resin (half esters or competitive products) 4 wt.E cotton seed oil. Quintone Escorez F.R. C200 1102 Comparative products Half Esters Softening point 91 115 120 Acid number 54 134 42 (mg KOH/grams) Gardner colour 1 4 2 Formulations Yellowness index 0.049 0.059 0.061 0.093 0.092 0.090 Whiteness 0.086 0.085 0.084 0.087 0.087 0.086 As shown in Examples 23 and 25 polyCPD-maleate esters contain a reactive double bond which can be polymerised with unsaturated monomers either in the presence of heat or free radical catalyst. It is anticipated that those products can also be polymerised, copolymerised, crosslinked in presence of vinyl or unsaturated monomers, unsaturated elastomers or polymers (Thermoplastic rubbers such as Cariflex TR 1102, TR 1107, polyisoprene elastomers, polydienic resins, unsaturated polyesters, diallyl phthalates ...) in presence of for example U.V. curing, gamma radiation and electron beam curing. Those curings can be carried our in the presence of conventional U.V. photoinitiator/and optionally in the presence of polyfunctional monomers such as divinyl benzene, polyfunctional acrylates and methacrylates or any other suitable polyunsaturated monomers.

Claims: WHAT WE CLAIM IS 1A process for the production of polar petroleum resins comprising reacting a cyclopentadiene oligomer mixture containing (i) from 0% to 100% by weight of tricyclopentadiene (ii) from 100% to 0% by weight of tetracyclopentadiene (iii) from 0% to 50% by weight of pentacyclopentad iene and less than 20% by weight of dicyclopentadiene with a carboxylic acid or anhydride, the percentages being of the total cyclodiene content in the mixture. 2 A process according to claim 1 in which the mixture contains from 10 to 90 wt.% more preferably from 30 to 70 wt.% of tricyclopentadiene and from 10 to 90 wt.%, more preferably from 30 to 70 wt.% of tetracyclopentadiene. 3 The process according to claim 1 or claim 2 in which the pentacyclopentadiene content of the mixture is less than 30 wt.%. 4 A process according to any of the preceding claims in which the mixture of oligomers has a number average molecular weight of from 150 to 300. 5 A process according to claim 4 in which the mixture of oligomers has a number average molecular weight of from 190 to 250. 6 A process according to any of the preceding claims in which the carboxylic acid is an TI unsaturated acid. 7 A process according to claim 6 in which the acid is maleic acid. 8 A process according to claim 5 or 6 in which the acid is reacted with the mixture of cyclopentadiene oligomers by combining a solution of the cyclopentadiene oligomers with the acid at the melting temperature of the acid. 9 A process according to any of the preceding claims in which between 0.2 and 2.0 moles of acid are reacted per mole of cyclopentadiene in the mixture. 10 A polar petroleum resin whenever prepared by a process according to any of the preceding claims. 11 The polar petroleum resin according to claim 10 which is a half ester and the carboxylic acid is a dicarboxylic acid. 12 The polar petroleum resin according to claim 10 or claim 11 which has been hydrogenated. 13 A process for the production of polyesters comprising reacting the half ester according to claim 11 or claim 12 with a polyol and/or an anhydride. 14 A process for the production of polyamides comprising reacting the half ester acording to claim 11 or claim 12 with an amine, a diamine or urea. 15 A process for the production of polyurethanes comprising reacting the half ester according to claim 11 or claim 12 with a polyol and an organic isocyanate. 16 A process for the production of polyethers comprising reacting the half ester according to claim 11 or claim 12 with an epoxide. 17 A process for the production of esters comprising reacting the half ester according to claim 11 or claim 12 with a monoalcohol or polyhydric alcohol. 18 A process according to claim 17 in which the alcohol is a long chain aliphatic alcohol. 19 A process according to claim 17 in which the alcohol is a cyclic alcohol. 20 A process according to claim 19 in which the alcohol is cyclohexanol. 21 A process according to any of claims 15 to 20 in which from 0.2 to 2.0 moles of an , unsaturated acid are reacted per mole of cyclopentadiene in the mixture and the product is reacted with from 0.2 to 3.0 moles of an alcohol. 22 An esterified resin whenever produced by a process according to any of claims 15 to 21. 23 The product of claim 22 whenever hydrogenated. 24 The use of an esterified resin according to claim 22 or claim 23 as a tackifier for natural or synthetic rubbers in adhesive formulations. 25 The use of an esterified resin according to claim 22 or claim 23 as a tackifier in hot melt adhesives. 26 A hot melt adhesive containing 30 to 200 parts by weight of an esterified resin according to claim 22 or claim 23 and 40 to 120 parts of an ethylene vinyl acetate copolymer. 27 The use of an esterified resin according to claim 22 or claim 23 as a binder in a hot melt road marking formulation. 28 A hot melt road marking formulation containing 25 to 300 parts by weight of pigment for every part of an esterified resin according to claim 22 or claim 23. 29 A hot melt road marking formulation according to claim 28 in which the pigment is Titanium Dioxide.

Inventors: LEPERT, ANDRE
Applicants: EXXON RESEARCH AND ENGINEERING COMPANY
Application year: 1983
Main classification: C08L45
IPC codes: C08F232, C08G63, C08F240, C08F8, C09D11, C08G69, C09J201, C08G65, C08G18