EP0807149A1

EP0807149A1 - Silane modified petroleum resins

Info

Publication number: EP0807149A1
Application number: EP96903701A
Authority: EP
Inventors: Anne Vera Macedo
Original assignee: Exxon Chemical Patents Inc
Current assignee: ExxonMobil Chemical Patents Inc
Priority date: 1995-02-01
Filing date: 1996-01-24
Publication date: 1997-11-19
Also published as: WO1996023845A1

Abstract

The invention is a hot melt adhesive composition suitable in road-marking compositions characterized by comprising a silane-modified petroleum resin and, optionally, one or more elastomeric thermoplastics. It is additionally the process for preparing a functionalized petroleum resin comprising the steps of: 1) providing into a reaction vessel, after post-reaction stripping of unreacted monomers and by-products from a petroleum resin polymerization or hydrogenation reactor, a petroleum resin having either or both of aliphatic or olefinically unsaturated carbon-carbon bonds; 2) adding to said vessel 0.05 to 1.0 wt.%, based upon resin weight, of silane monomers having sites reactive with the petroleum resin; (3) mixing thoroughly the two at a temperature of at least 160 °C; and, 4) recovering the petroleum resin-silane reaction product. The hot melt adhesive composition is useful in the road-marking compositions for improving adhesion of glass beads to road surfaces for improved endurance.

Description

SI ANE MODIFIED PETROLEUM RESINS

Technical Field

This invention relates to petroleum resins having silane functionality so as to be effective as tackifiers or binders in adhesive compositions where increased adhesion to glass components are desired, for example in road-marking compositions where glass beads are employed. A facile method of industrial preparation of the silane modified petroleum resin is part of the invention.

Background of the Invention

One of the performance criteria of thermoplastic road-marking (TRM) compositions, is the Night Time Visibility which is measured by the coefficient of reflectivity (also termed "retro-reflectivity"). Glass beads that are dispensed on white or yellow traffic lines when those are applied on the road provide this reflectivity. However, the glass beads are extracted by automotive tire shock with time and loss of reflectivity is encountered before the TRM otherwise loses effectiveness.

Typical TRM compositions are disclosed in GB 2 061 295 A. These compositions are said to comprise a hydrocarbon resin, plasticizer, pigment, filler and glass beads, and optionally an additional maleic acid resin, a hydrogenated or non hydrogenated rosin ester or other resins modified with rosin or a terpene resin. The hydrocarbon resin includes petroleum resins, and optionally include those with polar monomers such as maleic acid/anhydride, vinyl acetate, methyl methacrylate or alkyl alcohol. The polar monomers are aimed at improving the miscibility with a pigment or filler, but no specific examples illustrate the use of these modified resins.

Cross-linkable tackifying resins disclosed in J55073716-A are obtained by modifying (a) tackifying resins with (b) the silane compounds having an olefinic unsaturated bond and a hydrolysable organic compound which is subsequently cross linked with water or similar agents. Prior to cross-linking the uncross linked silane- modified tackifying resins are suggested for use in adhesives, paints, additives for paints, and surface-treating agents for inorganic filler, due to compatibility and fluid properties. Component (a) includes rosin resins, natural resins, petroleum resins, terpenephenol resins, styrene resins, phenol resins, and xylene resins. The preferred silane compounds include e.g. vinyltrimethoxysilane, vinyltris(methoxyethoxy)silane. Components (a) and (b) are graft-copolymerised in the presence of a radical initiator (e.g. dicumyl peroxide) with vigorous stirring at 50 to 200 °C. The reaction time 1 to 20 hours. This is illustrative of typical graft reaction conditions. Glass beads are mentioned as one of several suitable inorganic fillers. When used as adhesives the resin compositions can be prepared by adding ethylene vinyl acetate copolymer, or synthetic rubber. The cross-linkable resin can also be used in traffic paints to speed solidification of the paint surface and to increase durability and resistance to abrasion, the taught cross-linking presumably providing these improved properties. The level of silane-grafting is said to be desirable in the range from 0.1 to 80 wt.%. The sole resin example, Embodiment 2, illustrates a hydrocarbon resin having 33.0 wt.% grafted silane. However, excessive amounts of silane when added to the resin in the process of preparation significantly decrease melt viscosity and softening point while increasing undesirable color of the resultant resin thus limiting the usefulness of the resins for road-marking applications.

In view of the need to improve the adherence of glass beads to road surfaces with adhesive compositions capable of application under standard conditions and to develop commercially feasible methods of providing modified petroleum resins suitable in such, the following invention was developed.

Invention Disclosure

The invention is a thermoplastic adhesive composition suitable for use as road-marking compositions and characterized by comprising as a primary tackifier a silane-modified petroleum resin and, optionally, an elastomer of one or more polymeric thermoplastics selected from the group consisting of styrene block copolymers, ethylene-vinyl ester copolymers, and ethylene homopolymers and copolymers with C, to C₄₀ alpha-olefins or alpha-beta unsaturated monomers. It is additionally the process for preparing the silane modified petroleum resin comprising the steps of 1) providing into a reaction vessel, after post-reaction stripping of unreacted monomers and by-products from a petroleum resin polymerization or hydrogenation reactor, a petroleum resin having either or both of aliphatic or olefinically unsaturated carbon-carbon bonds; 2) adding to said vessel 0.05 to 1.0 wt.%, based upon resin weight, of organofunctional silane monomers having sites reactive with the petroleum resin; 3) mixing thoroughly the two at a temperature of at least 160 °C; and, 4) recovering the petroleum resin-silane reaction product.

Description of the Invention

The silane modified petroleum resin of the invention preferably contains less than 1.0 wt.% graft silane functionality, based upon weight of the resin, and more preferably contains from about 0.1 to 0.75 wt.% of silane functionality, most preferably 0.2 to 0.5 wt.%. When too great an amount of graft silane functionality is present the softening point of the graft modified petroleum resin is excessively depressed (as much as 13 °C at 5 wt.% functionality). Also the adhesion to glass properties are diminished when the silane modified petroleum resin has been prepared in accordance with the preferred method of preparation, described below, when excessive amounts of reactive silane compositions are added.

The petroleum resin is preferably one derived from the steam cracking of petroleum fractions and subsequent thermal or Friedel-Crafts catalytic polymerization of substantially aliphatic monomer streams based upon C₄ to C₆ olefins and diolefins from those fractions. Such resins are made by well known methods and are commercially available. See for example, Encycl. of Poly. Sci. & Enp'g.. v. 7, 758-769 (J. Wiley & Sons, 1987) and Kirk-Othmer Encvcl. of Chem. Tech. , v. 13, 717-743 (J. Wiley & Sons, 1994). Particularly suitable aliphatic resins include the Escorez® 1000 resins of Exxon Chemical Co., most preferably the C₅ aliphatic based Escorez® 1102 RM resin, and the PICCOPALE® resins of Hercules Chemical, particularly PICCOPALE® 100. Though aliphatic resins with residual olefinic unsaturation are preferred as the unmodified petroleum resin source, other petroleum resins containing either or both of residual olefinic unsaturation and saturated aliphatic bonds, for example the aromatic modified aliphatic resins, or the highly hydrogenated aromatic resins, both well known in the industry and patent literature, can be modified to contain the silane functionality and will be suitable. The suitable resins typically have a softening point (R &B) from 80 to 120 °C and have a molecular weight distribution less than 3.5 and molecular weight (no. avg.) of 500 to below 2000 as measured by Size Exclusion Chromatography ("SEC" ) (using tetrahydrofuran as eluent, polystyrene standards, and Refractive Index detection) .

As addressed in the prior art including the background discussion above, the road marking compositions containing the silane modified resin of the invention additionally comprise optional substrate elastomers and various additives selected from the group consisting of antioxidants, fillers, pigments, dispersing agents, plasticizers and oil extenders, and optionally, waxes and modified rosin or rosin ester second tackifiers. Such components typically can be used in the following ranges : 5 to 40 wt.% resin (optionally including second tackifier), 0 to 4 wt.% elastomeric thermopolastic, 0 to 10 wt.% plasticizer, 0 to 50 wt.% extender oil, 1 to 15 wt.% pigment, 10 to 50 wt.% filler and/or mineral aggregate, and 0 to 5 wt.% stabilizer and/or antioxidant. Glass beads are added in an amount typically in the range of 10 to 35 wt.%.

The selection of elastomer and resin for this invention can be coordinated, for example, the use of the preferred aliphatic, silane-modified resin of the invention, is typically with polyethylene copolymers, low styrene (10 to 24 wt.% styrene Styrene block copolymer) styrene-isoprene-styrene or styrene-butadiene- styrene (preferably where the butadiene block is at last partially hydrogenated) triblock copolymers (SBC) or low vinyl acetate (at or below about 28 wt.% NA/ ethylene-vinyl acetate copolymer) to take advantage of compatibilities, observed more in adhesive compositions typically having greater amounts of elastomer, between the elastomeric aliphatic mid block of the SBC or of the aliphatic polyethylene segments of the polyethylene copolymers and the ethylene-vinyl acetate copolymers (EVA). Where higher styrene SBC or higher vinyl acetate EVA are to be used, then the aromatic modified aliphatic petroleum resins modified with the silane functionalities of the invention are can be selected so as to take advantage of compatibilities of the resin aromatic component with the styrene end blocks of the SBC and the vinyl acetate of the ENA. Blends of elastomers are also suitable, for example, the co-compatiblities of SBC and ENA with the aromatic modified aliphatic resins can be utilized to prepare compatible blends. Such elastomeric blend hot melt compositions will typically contain as the elastomeric component predominantly ENA, optionally with a wax modifier such as a low molecular weight polyethylene wax, with minor amounts of SBC, typically at less than 20 wt.%, more preferably less than 16 wt.%, of the overall elastomer component. Improved low temperature flexibility and thus endurance can be provided for road markings based upon ENA formulations where low temperature conditions are common. See additionally the ENA/SBC blend disclosure of co-pending application U.S. Ser. No. 08/ 280,695 filed 26 July 1994, incorporated by reference for purposes of U.S. patent practice.

The elastomeric substrate copolymers are articles of commerce and are made in accordance with well known processes. Typically the elastomeric copolymers will be selected from the group consisting of styrene block copolymers, ethylene- vinyl ester copolymers (including typically those comprising ethylene and methyl acrylate or higher alkyl acrylates), and ethylene homopolymers and copolymers with C, to C^ alpha-olefins or alpha-beta unsaturated monomers. Polyethylene waxes are also suitable as a substrate in place of or blended with the elastomeric copolymers.

Suitable commercial elastomer products include the Vector® triblock SBC copolymers of Dexco Polymers, the Kraton® and Cariflex® triblock SBC copolymers of Shell Chemical, the Escorene® EVA and ethylene-vinyl acrylate

TM copolymers and Exact polyethylene copolymers of Exxon Chemical Company. See the SBC copolymers of EP-A-0 499 326 for suitable polymers, particularly for dry blended thermoplastic pavement marking compounds.

Antioxidants include those known in the art, typically the amine and phenol compounds, including those know as hindered amine or phenol compounds, used commercially in the adhesives industry. Particularly suitable commercial compositions include the hindered phenols from Ciba-Geigy sold under the tradename Irganox®, e.g., Irganox® 1010 and Irganox® 1076. Antioxidants are sometimes also known as oxidation stabilizers or inhibitors in the adhesive industry, such are similarly useful, see for example the descriptions in U.S. patents 5,143,968 and 5,292,819, GB 2 059 430 A and J55073716-A. Ultraviolet light stabilizers or Hindered Amine Light Stabilizers (HALS) are also suitable. These include such commercially available compounds as Tinuvin® 326, Tinuvin® 327, Tinuvin® 770 DF, and Chimassorb® 944 from Ciba-Geigy Company. Antioxidants and stabilizers are used in sufficient amounts to improve the loss of properties due to heating during TRM preparation and exposure to sunlight over time after applied. Typically those amounts are from 0.05 to 5 parts by weight to 100 parts by weight of the overall composition.

Extender oils and/or plasticizers are also suitable in industry recommended amounts for purposes of improving fluidity and coating ability on the fillers in the TRM and are well known in the art. Typical extender oils are the aromatic, napthenic and paraffinic oils. Plasticizers include the phthalate esters such as dioctyl phthalate and dibutyl phthalate. These are typically used in amounts of 0.5 to 25 parts by weight per 100 parts by weight of the overall composition, preferably 5 to 15 parts by weight per 100 parts by weight. See the descriptions in U.S. patents 5,143,968, 5,292,819, GB 2 061 295 A and J55073716-A.

Pigments and fillers, that is fillers other than the glass beads providing the reflectivity, are selected and used in accordance with the knowledge in the art. Typically the pigments and fillers are selected so as to contribute or improve the white or yellow coloration used for road and highway markings. Thus the metal oxides, phosphates, silicates, sulfates, sulfides and carbonates of such metals/metalloids as titanium, zinc, aluminum, chromium, calcium, barium, silicon etc., are typical. Mineral fillers are also suitable, included are the counterparts of the compounds listed above, e.g., quartz, silica, alumina, kaolin, ground calcite or calcium carbonate marble, etc. See for example GB 1 474 903 and GB 2 061 295 A.

Dispersing agents are preferably included as additives to assure uniform dispersion of the pigment and filler compounds in the TRM composition. The metal salts of fatty acids, such as metal stearates (for example zinc neodecanoate) are suitable and will be selected in accordance with manufacturer recommendations according to the filler and/or pigments being used.

The rosins suitable as a second tackifier for the invention compositions include any of those known in the art to be suitable as tackifying agents, and includes preferably those that have been modified by hydrogenation, disproportionation or dismutation, fortification, dimerization or polymerization (including those that have been partly or fully esterified). The modified rosins and rosin derivatives are preferred. The rosin acids are particularly suitable for compositions of the invention. Mixtures of any of the foregoing will also be suitable. The principal sources of the rosin include gum rosin, wood rosin, and tall oil rosins which typically have been extracted or collected from their known sources and fractionated to varying degrees. Additional background can be obtained from technical literature, e.g., Kirk-Othmer Encycl. of Chem. Tech., vol. 17, pp. 475-478 (John Wiley & Sons, 1968). Rosin and rosin derivative products suitable in accordance with the invention are available commercially, for example, Foral®, Pentalyn®, and Staybelite® of Hercules, Inc., U.S.; and Sylvatac® of Sylvachem Corp., U. S.; Bevitack®, Bevilite®, Bevipale® of Bergvick Kemi AB, Arizona Chem. Co., U.S.; Gresinox®, Dertoline®, Dertopoline®, Granolite®, Hydrogral®, Dertopol®, Polygral®, of DRT S.A., France; Oulutac® of Oulu OY, Sweden; Tergum®, Terlac®, Tergraf® of Resinas Sinteticas S.A., Spain; and; Residis® of Union Resinera Espagnola S.A., Spain.

Industrial application of the blended TRM composition of this invention is predominantly in road-marking. Though any order of addition of TRM components, minus the glass beads, may be followed, preferably the TRM compositions are prepared in a three step process, the silane modified petroleum resin is prepared first, and then melt blended with any elastomeric component. The other additives may be added to the modified resin before or during or after the melt blending. The resin or its elastomer-containing blend (with or without the additives) may be cooled, solidified and pelletized or pulverized for subsequent, even on site at the road marking location, dry blending followed by melt processing of the final composition, the additives may be added as convenient. In either case the final TRM composition is applied as a hot melt in accordance with standard knowledge to the pavement, road or highway being marked and the glass beads are dispensed atop the TRM while it is still molten or soft enough for them to adhere. See in particular the descriptions in EP-A-0499 326 and GB 2 059 430 A.

Preparation of the Silane Modified Petroleum Resin

In a preferred method of preparation, the unmodified resin, directly from a stripping tower downstream of the polymerization or hydrogenation reactor and typically at a temperature from 160 to 220 °C, preferably between 180 °C and 200 °

C, is added with the organofunctional silane compounds containing reactive functionality into a stirred tank, with or without the antioxidant, dispersing agent and other additives. The reaction pressure can vary, typically the reaction is conducted under reflux conditions at or above atmospheric pressure. Preferably the additives are omitted until the reaction is largely completed in order to avoid interference in the grafting reaction. The concentration of silane compound to be provided for the reaction is typically in the ranges described above so as to avoid unwanted modification of the resin properties while assuring improved adhesion to glass. Thorough mixing is conducted for from typically 15 minutes to two or more hours, preferably for at least an hour. An addition reaction of silane functionality to the resin occurs to both of either ethylenic unsaturation sites or aliphatic carbon- carbon atom bond sites, -C(H)=C(H)- and -C(H2)-C(H2)-, in the resin. A complete chemical mechanism for the addition reaction is not proposed, though two routes appear possible. It appears that a thermal "ene" graft or addition reaction occurs with the olefinic sites. Additionally, there may be also some residual free radical source created by the high temperatures in the polymerization or hydrogenation reactor, for example traces of hydroperoxides, which is carried into the modification reactor vessel and initiates free radical grafting at either ethylenic unsaturation sites or saturated carbon-carbon bond sites, the latter via hydrogen abstraction. Alternatively, a free radical source may be added to enhance hydrogen abstraction, as discussed in the background art, but should be done in minimal amounts so as to achieve low levels of silane incorporation, typically amounts empirically determined to be sufficient to reach the described level of silane grafting.

Accordingly saturated resins, e.g., specifically including those that have been hydrogenated after polymerization so as to significantly reduce residual olefinic unsaturation, including those prepared by Friedel-Crafts catalytic polymerization those and those prepared by thermal polymerization, can be modified by this process where the mixing with the functional silane compounds is done at the temperatures disclosed, either after the exit from either the catalytic polymerization reactor or hydrogenation reactor and effective stripping treatment, or subsequently. Efficient, low cost production is achieved by mixing the organofunctional silane compounds with the petroleum resins, immediately after polymerization or hydrogenation, since additional heating is either largely unnecessary or needed only in minimal amounts.

Energy and equipment costs associated with auxiliary heating and handling are minimized.

The organofunctional silane compounds containing reactive functionality are those capable of the addition reaction with the olefinic unsaturation or aliphatic saturated carbon-carbon bond sites in the petroleum resin. Since the possible reactions appear to be (i) graft reaction at the olefinic unsaturated sites of the resin or (ii) free radical grafting at either that or an aliphatic -C(H-,)-C(H₂)- site, the silane compounds can be represented by the formula R-Si-X,., where R is an organofunctional group reactive with ethylenic unsaturation or capable of free- radical initiated reaction with the aliphatic sites and X is a functional group covalently bound to the silicon atom, typically alkoxy groups, which are hydrolyzable and can react with inorganic substrate such as glass. Suitable reactive organofunctional groups include vinyl and epoxy groups. Commercially available organofunctional silanes include DYNASYLAN® MEMO-E

(H₂C=C(CH₃)COO(CH₂)₃Si(OCH₃)₃, 3-methacryloxyρropyltrimethoxysilane); DYNASYLAN® VTMO (CH^CHS OCH^, vinyltrimethoxysilane); and

DYNASYLAN® GLYMO (H.C— CH— CH^CH^ Si(OCH₃)₃), 3- glycidyloxypropyl-trimethoxysilane, available from HUELS, or the DOW CORNING® organofunctional silanes from DOW CORNING company

The following examples are presented to illustrate the foregoing discussion. All parts, proportions and percentages are by weight unless otherwise indicated. Although the examples may be directed to certain embodiments of the present invention, they are not to be viewed as limiting the invention in any specific respect.

Examples

The following examples illustrate preparation of silane modified petroleum resins and preparation of TRM compositions comprising them.

The modification of the resin by organofunctional silanes utilized the following basic process :

1. a sample of newly made molten resin such as Escorez ® 1102 RM was taken before the addition of the additives (antioxidants and/or road- marking additives) at the bottom of the stripping tower;

2. the organofunctional silane was added at the required level and the mixture was stirred at high temperature to keep the resin in the molten form; and,

3. the additives were added to the resin.

4. Additionally, the resin can be finished according to typical finishing procedure ( for example, known flaking or prilling processes).

The organofunctional silanes are generally selected as described above.

However it is preferred to use a high boiling point compound from a scale-up standpoint to avoid loss of product during the preparation of the modified resin, and to use a high temperature flash point product for safer handling.

As described the invention preparation method permits the obtaining of silane grafted resins without significantly affecting the neat resin properties, ie, initial color, color stability, softening point, melt viscosity and molecular weight. The resulting product is subsequently treated in the typical manner for a non- modified resin, i.e., addition of additives, such as antioxidants, UN stabilizers or any other additive needed for the road-marking application and finishing. The neat properties of the modified resin thus made can be maintained after storage for several months. EXAMPLE-1

250 g of Escorez 1102 RM resin (Reference- 1) taken from the bottom of the stripping tower at the production site was charged in a glass reactor equipped with a cooler, a thermometer and a heating mantle. A flow of nitrogen was used for stirring. A cold trap filled with dry ice was installed to recover the possible loss of silane. The resin was kept molten at 170°C or 200°C as indicated in Table- 1 for 45 min. The organofunctional silane was the DYNASYLAN MEMO-E, (3- methacryloxypropyl-trimethoxysilane). It was added to the resin step wise under nitrogen flow for 10, 30 or 60 min. as specified in Table- 1. The modified resin was cooled down, poured into a sample can. An additives package consisting of the antioxidant (Irganox® 1076) and dispersing agent (zinc neodecanoate, from TISSCO, France) was then added. In this example and the ones that follow the additive package remained the same and contained 0.3 wt.% antioxidant and 0.4 wt.% dispersing agent, both based upon total resin weight. The resin was left for solidification. Subsequent characterization by proton NMR (nuclear magnetic resonance) and FTIR (Fourrier-Transform Infra-red) analyses indicated that a graft reaction product was produced.

Typical neat resin properties of the resin of this example, and the following, were measured. They are :

■ Initial Color (measured on the Gardner scale with HUNTERLAB™ colorimeter, toluene solution 50/50 wt.%),

° Color Stability (measured after heating the resin at 175°C for 5 hours in a ventilated oven),

■ Softening Point (Ring & Ball, ASTM E-28),

° Melt viscosity at 160°C (Brookfield viscometer, spindle 21),

° Molecular weight (Number average by SEC).

EXAMPLE-2

As in Example- 1, 200 g of resin Reference- 1 was put in a flask. The same procedure was used except that the stirring was done mechanically instead of nitrogen bubbling. The resin was kept molten for 30 min. at 170°C then the

DYNASYLAN SILFIN®, (92.5 wt.% vinyltrimethoxysilane formulated with 7.5 wt.% dicumyl peroxide), was added to the mixture stepwise. The stirring was maintained for 15 min., the additives were added into the flask and the mixture was stirred for another 5 min. The resin was poured into a sample can and left for solidification. Neat resin properties were measured same way as in Example- 1. Data are reported in Table-2.

EXAMPLE-3/Comparative Example (4/2)

As in Example-3, 2 kg of the resin of Example- 1, Reference- 1, -3 and -4, was put in a 4 liter flask and kept molten at 170°C, 180°C or 200°C as specified in Table-3 for 50 min. Silane DYNASYLAN MEMO-E was added, stirring was maintained for 20 min., and additives were added. The resin was stirred for another 10 min. before being poured into a sample can. It can be readily observed from Table-4, example (4/2) that the introduction of 5 wt.% organofunctional silane resulted in an increase in initial color and significant decrease in both softening point and melt viscosity. This is believed to derive from the presence of unreacted organofunctional silane components in the resin product.

EXAMPLE-4

As in Example-2, 2 kg of resin, Reference-3, was put in a 4 liter flask and kept molten at 200 °C for about 1 hour. Silane DYNASYLAN SILFIN was added, stirring was maintained for 20 min., and additives were added. The resin stirred for another 10 min. before poured into a sample can.

EXAMPLE-5

40 kg resin, Reference- 5, was taken from the bottom of the unit stripping and further treated in a pilot equipment as described in Example-3. 0.25 wt.% DYNASYLAN MEMO-E was added to the molten resin at 200 °C under nitrogen for 1 hour. The appropriate additives were added subsequently and the blending was maintained for another 30 min. The resin was cooled down at about 140 °C, spread on a plate, cooled down to room temperature and further crushed. Results of Table- 5 report the analyses of the various samples from the pilot batch.

EXAMPLE-6

Neat resin properties of some modified resins described in the above examples were measured again after several months storage to test the stability. The results of Table-6 clearly shows that neither the resin softening point, nor the resin viscosity changed significantly after 4 months storage. EXAMPLE-7

Adhesion to glass was quantified by measuring the strength necessary to extract a glass rod from a thermoplastic blend prepared as described above. The results are expressed in % taking as reference a thermoplastic blend made with a non modified hydrocarbon resin, Escorez 1102 RM type, (100%). Results (Table-7) were compiled based on a uncoated glass. It is well known that various glass coatings of various chemical nature are available from the glass industry. Even improved results would be achieved in conjunction with coated glass where the coatings are designed for improved adhesion with silane compounds.

Thermoplastic road-marking materials were prepared based on the representative formulation described below. Properties of the blends such as Color Parameters, Initial and after Aging, Softening Point and Viscosity were measured and compared to a reference blend made with the non-modified resin. The results in Table-8 show that there were only insignificant differences in properties other than improved glass adhesion when the modified resin according to the above description was used.

The thermoplastic road-marking bends were prepared with the following formulation .

Sand 59 wt.%

Calcium Carbonate 15 wt.%

Titanium Dioxide 5 wt.%

Flexon® 876 (*) 3.5 wt.%

Resin 17.5 wt.%

100 wt.%

(*) :a paraffinic oil available from Exxon Chemical Co.

TABLE 3

Ref. 2 (2/1) (2/2) Ref. 3 (3/1) (3/2) (3/3) (3/4) (3/5)

Silane (wt %) - 0.5 0.25 - 0.5 0.25 0.5 0.25 0.25

Temperature (°C) - 200 200 - 200 200 200 200 200

Blending time (min) - 80 80 _ 70 70 78 85 75

Initial color (G) 6.5 6.9 6.9 4.7 6 6 5.2 5.2 5.7

Color Stability (G) 11.1 10.6 10.5

Softening Point (°C) 105 103 104 101 100 101 100 102 100

Melt viscosity at 160°C (mPa s) 2015 1650 1885 1425 1282 1362 1402 1427 1340

Mn 1390

TABLE 4

TABLE 5

Ref. 5 (5/1) (5/2) (5/3)

Silane (wt %) - 0.25 0.25 0.25

Temperature (°C) - 200 200 200

Blending time (min) - 60 60 60

Initial color (G) 4.6 4.6 4.6 4.6

Color Stability (G) 12 10 10J 10.2

Softening Point (°C) 103 102 103 102

Melt viscosity at 160°C (mPa.s) 2462 2035 1970 2017

TABLE 6

(a) measured directly after preparation (b) measured after 5 months

TABLE 7

Ref. (2/1) (3/1) (2/2) (3/2) (3/6) (3/7) (3/8)

Silane type - Memo-E Memo-E Memo-E Memo-E Silfin Silfin Silfin

Silane (wt %) - 0.5 0.5 0.25 0.25 0.925 0.4625 0.231

Peroxide (wt%) - - - - - 0.075 0.0375 0.019

Adhesion (%) 100 86 131 157 147 112 148 153

TABLE 8

TRM Reference (8/1) (8/2) (8/3) (8/4) (8/5)

Resin Reference Ref. 3 (3/4) (3/6) (3/8) (5/2)

Silane Type - MEMO- SILFIN SILFIN MEMO- E E

Silane (wt %) - 0.25 0.925 0.4625 0.231

Peroxide (wt%) 0.075 0.0375 0.019

Softening Point (°C) 82 84 84 84 84

Zahn Viscosity at 180°C (s) 26 36 31 33 35 Zahn Viscosity at 200°C (s) 14 15 16 16 20

Initial Color Parameters

X 78 76 77 76 79

Y Luminance 80 78 79 78 81

Z 84 81 83 81 86

Whiteness Index 46 41 42 38 49

Yellowness Index 13 14 14 15 12

Color Parameters after ageing (*)

X 76 74 75 75 76

Y Luminance 77 76 77 77 78

Z 79 77 78 78 38

Whiteness Index 36 32 32 33 38

Yellowness Index 16 17 17 17 16

(*) : 6 hours at 200°C

Claims

CLAIMS :

1. A thermoplastic adhesive composition suitable as a road-marking composition comprising a hydrocarbon resin, extender oil and or plasticizer, pigment, filler and pigment, characterized in that the resin is a silane- modified petroleum resin containing from 0.05 to 1.0 wt. %, based upon total resin weight, of silane functionality.

2. The composition of Claim 1, wherein the filler comprises sand.

3. The composition of Claims 1 or 2, additionally comprising one or more elastomeric thermoplastic selected from the group consisting of styrene block copolymers, ethylene-vinyl ester copolymers, and ethylene homopolymers and copolymers with C - C40 alpha-olefins or alpha-beta unsaturated monomers.

4. The composition of Claim 3, additionally comprising an elastomeric thermoplastic component in an amount that is 4 wt.% or less of the total composition weight blend and is ethylene vinyl acetate copolymer, styrene block copolymer, a blend consisting of not more than 80 wt.% ethylene vinyl acetate copolymer and less than 20 wt.% styrene block copolymer (both percentages based upon total weight of the elastomer component), polyethylene wax, or a blend of more than one of the foregoing.

5. The composition of any of Claims 1 - 4 additionally comprising a second tackifier.

6. A process for preparing a silane-modified petroleum resin characterized by consisting essentially of 1) providing into a reaction vessel, after post- reaction stripping of unreacted monomers and by-products from a petroleum resin polymerization or hydrogenation reactor, a petroleum resin having either or both of aliphatic or olefinically unsaturated carbon-carbon bonds; 2) adding to said vessel silane monomers having sites reactive with the petroleum resin; 3) mixing thoroughly the two at a temperature above 160 ° C for a period of time not less than about 15 minutes; and, 4) recovering the petroleum resin-silane reaction product.

7. The process according to Claim 6, wherein said silane monomers are added in an amount of 0.05 to 1.0 wt.%, based upon total resin weight.

8. The process according to Claims 6 or 7, wherein the petroleum resin is catalytically polymerized aliphatic resin.

9. The process according to Claims 6 or 7, wherein the petroleum resin is thermally polymerized aliphatic resin.

10. The process according to any of Claims 6-9, wherein the petroleum resin is hydrogenated prior to step 2).