Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J123/00—Adhesives based on homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Adhesives based on derivatives of such polymers
  • C09J123/02—Adhesives based on homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Adhesives based on derivatives of such polymers not modified by chemical after-treatment
  • C09J123/18—Homopolymers or copolymers of hydrocarbons having four or more carbon atoms
  • C09J123/20—Homopolymers or copolymers of hydrocarbons having four or more carbon atoms having four to nine carbon atoms
  • C09J123/22—Copolymers of isobutene; Butyl rubber ; Homo- or copolymers of other iso-olefines
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J123/00—Adhesives based on homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Adhesives based on derivatives of such polymers
  • C09J123/02—Adhesives based on homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Adhesives based on derivatives of such polymers not modified by chemical after-treatment
  • C09J123/18—Homopolymers or copolymers of hydrocarbons having four or more carbon atoms
  • C09J123/20—Homopolymers or copolymers of hydrocarbons having four or more carbon atoms having four to nine carbon atoms
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J153/00—Adhesives based on block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Adhesives based on derivatives of such polymers
  • C09J153/02—Vinyl aromatic monomers and conjugated dienes
  • C09J153/025—Vinyl aromatic monomers and conjugated dienes modified
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2666/00—Composition of polymers characterized by a further compound in the blend, being organic macromolecular compounds, natural resins, waxes or and bituminous materials, non-macromolecular organic substances, inorganic substances or characterized by their function in the composition
  • C08L2666/02—Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2666/00—Composition of polymers characterized by a further compound in the blend, being organic macromolecular compounds, natural resins, waxes or and bituminous materials, non-macromolecular organic substances, inorganic substances or characterized by their function in the composition
  • C08L2666/28—Non-macromolecular organic substances

Definitions

• This invention relates to hot melt adhesive compositions which include a hydrogenated block copolymer such as Kraton G, about 25 to about 250 parts by weight of a hydrocarbon resin of a petroleum or coal tar distillate, aliphatic dienes and mono and diolefins, cyclic olefins of 5 or 6 carbon atoms and hydrogenated polycyclics per 100 parts by weight of the hydrogenated block copolymer, and about 25 to 200 parts by weight of a polybutene or polyisobutylene per 100 parts of the hydrogenated block copolymer.
• a hydrogenated block copolymer such as Kraton G
• a hydrocarbon resin of a petroleum or coal tar distillate aliphatic dienes and mono and diolefins
• cyclic olefins of 5 or 6 carbon atoms
• hydrogenated polycyclics per 100 parts by weight of the hydrogenated block copolymer
• this invention relates to pressure sensitive adhesive compositions wherein said mixt ⁇ re of Kraton G, said hydrocarbon resin and said polybutene or polyisobutylene is dissolved in a non-reactive solvent at a concentration level of about 5 to about 25 grams per 100 ml. of non-reactive solvent.
• synthetic adhesives used in packaging can be classified into four categories: water based, solvent based, reactive and hot melt adhesives. Of these four, currently the water based are used most extensively. Usually the water based adhesives are based on emulsion polymers and are applied to porous cellulosic sub strates. Energy from the outside in some fashion is applied to the system to evaporate the water in order that a strong bond may be formed. Besides this energy requirement for the formation of the bond, there is another complication with the use of water based adhesive. For a uniform coating a good uniform wetting of the substrate surface is desired, which is not easily achieved.
• hot melt adhesives are generally applied (as the name implies) by conventional extrusion or coating techniques in the temperature range of 250 to 450oF on one of the surfaces to be bonded. The other surface is brought into contact with the hot surface for a sufficient period of time for the melt to cool, so that, upon solidification, a strong and durable bond is formed.
• resins suitable for hot melt adhesive applications are that they contribute (i) good tackifying characteristics for the polymer, (ii) good physical properties, e.g., good tensile strength at ambient conditions for the formulations, and (iii) reduction in the viscosity at fabrication temperatures.
• pressure sensitive adhesives should have good cohesive and tackifying properties at ambient conditions. These adhesives should also have good flow characteristics if they are to be used in the bulk state; otherwise they should possess sufficient consistency when dissolved in suitable solvents so that they can be coated or sprayed on the surfaces to be bonded.
• resins suitable for pressure sensitive adhesive applications are that they contribute (i) good tackifying characteristics for the polymer; and (ii) good physical properties, e.g., good tensile strength at ambient conditions for the formulations.
• Certain commercial block copolymers such as Shell's Kraton, Phillip's Solprene and DuPont's EVA copolymers attain the above objectives to a good extent.
• the adhesives prepared from blends incorporating these polymers have very good adhesive and strength properties at room temperature and can be processed by conventional melt coating and extrusion techniques because of their good flow characteristics. Because of this excellent combination of properties exhibited by ABA type when B represents a polydiene or a polyolefin block and A represents a polystyrene block, the use of Kxatons at present in the industry for various pressure sensitive adhesive applications is growing.
• the conventional block copolymers which are currently being used in adhesives technology because of their inherent structure, have one serious drawback with re spect to their use as a satisfactory adhesive candidate.
• Most of the conventional Kraton polymers are block copolymers of polystyrene and a polydiene.
• the polydiene component in Kratons is either polybutadiene or polyisoprene. Since both polybutadiene and polyisoprene are highly unsaturated, the Kraton block copolymers comprising either one of these two polymers are highly susceptible to thermal and oxidative degradation. This imposes many constraints on the adhesive users.
• This invention relates to hot melt adhesive compositions, which includes a hydrogenated block copolymer such as Kraton G; about 25 to about 250 parts by weight of hdyrocarbon resin of a petroleum or coal tar distillate, aliphatic dienes and mono and diolefins, cyclic olefins of or 6 carbon atoms and hydrogenated polycyclics per 100 part by weight of the hydrogenated block copolymer and about 25 to about 200 parts by weight of a polybutene or polyisobutylene per 100 parts of the hydrogenated block copolymer.
• Pressure adhesive compositions may be prepared which comprise such mixture of ingredients dissolved in a non-reactive solvent at a concentration level of about 5 to about 25 grams per 100 ml. of non-reactive solvent.
• the present invention relates to unique and novel hot melt adhesive compositions which comprise a blend of a hydrogenated block copolymer, a polybutene or polyisobutylene and a hydrocarbon resin, wherein to the compositions can be optionally added an oil, and/or a filler thereby modifying the rheological and physical properties of the ho melt adhesive compositions.
• solvent based pressur sensitive adhesive compositions may be prepared by dissolving such a mixture of ingredients in a non-reactive solvent as aforesaid.
• the hydrogenated block copolymers of the instant compositions are block copolymers of polystyrene and a poly diene which is typically selected from the group consisting of polybutadiene and polyisoprene, wherein the unsaturated mid block of either polybutadiene or polyisoprene is hydrogenated to yield a saturated mid block.
• hydrogenated block copolymers are manufactured by Shell Chemical Company and sold under the trade name: Kraton G.
• the hydrogenated block copolymers have an Mn as measured by GPC of about 25,000 to about 300,000, more preferably about 30,000 to about 200,000, and most preferably about 50,000 to about 150,000.
• polybutene polymer having a molecular weight in the range of 500 to 50,000 in appropriate portions could be used.
• the polybutenes used in the present invention were polybutene, Oranite 32 and Oranite 128; also Indopol H-1900 which is quite similar to Oranite 128 and is produced by Amoco.
• polystyrenes The major component of polybutenes can be readily represented by polyisobutylene structure, and because of this similarity of polybutenes and polyisobutylenes, various grades of polyisobutylenes manufactured by various chemical companies could be used.
• the properties of this blend are very similar to those prepared by Amoco polybutenes.
• the aggressiveness of tack and properties of most of these adhesive blends can be controlled by suitable control of the amount and type of the various ingredients used and/or by addition of effective external plasticizers.
• the polybutene or polyisobutylene is incorporated into the hot melt adhesive composition or into the pressure sensitive adhesive composition at a concentration level of about 25 to about 200 parts by weight of the polybutene or polyisobutylene per 100 parts by weight of the hydrogenated block copolymer, more preferably about 50 to about 100, and most preferably about 60 to about 90.
• tackifying resin having a softening point of about 0 to about 160°C, more preferably about 50 to about 140°C and most preferably about 70 to120°C.
• a variety of commercial tackifier resins is available. Some of these resins contain and/or pinene base polyterpene resins as the main ingredieht while others are derived from the polymerization of petroleum or coal distillates which consist of aliphaticdienes, mono- and di-olefins and cyclic olefins having about 5 to about 6 carbon atoms. The latter type of tackifiers has primary piperylene and/or isoprene structure.
• a general but excellent description of tackifying resins derived from petroleum derivatives can be found in, for example, Encyclopedia of Polymer Science and Technology, Vol. 9, pages 853-860, chapter by John Findlay, published by John Wiley & Sons, NY (1968).
• Typical, but non-limiting, trade names of these commercial tackifiers are Wingtack of Goodyear, Escorez of Exxon, Piccolyte of Hercules and Zonrez of Arizona Chemicals. Recently these and various other companies have also started marketing relatively higher softening point resins and very light colored resins. These are generally modified aliphatic hydrocarbon resins and/or hydrogenated polycyclics. The physical appearance of these commercial tackifying resins varies, depending upon their softening point; they can be either viscous liquids or light-colored solids at room temperature. Most often their initial color (Gardner) is about 3.0 to about 7.0 and the density from about 0.7 to 1.0 gm/cm 3 at room temperature.
• the acid number of these resins is usually less than 1.
• the molecular weight of these commercial tackifying resins is not homogeneous; it spreads the number average molecular weight Mn from about 300 to about 5000 and more preferably about 500 to about 2000 and most preferably about 700 to 1600.
• the colorless resins e.g., hydrogenated resins such as Escorez 5380 and Escorez 5320 of Exxon Chemical Co. U.S.A.
• hydrocarbon tackifier resins are incorporated into the hot melt adhesive composition or pressure sensitive adhesive composition at about 50 to about 150 parts by weight per 100 parts by weight of the hydrogenated block copolymer, more preferably about 60 to about 125 and most preferably about 75 to about 100.
• fillers which are selected from the group consisting of talcs, ground calcium carbonate, water precipitated calcium carbonate,delaminated, calcined or hydrated clays, silicas, and carbon blacks, and mixtures thereof. These fillers are incorporated into the blend composition at about 1 to about 150 parts by weight per 100 parts by weight of the hydrogenated block copolymer, more preferably at about 20 to about 150; and most preferably .at about 30 to about 100. Typically, these fillers have a particle size of about 0.03 to about 20 microns, more preferably about 0.3 to about 10, and most preferably about 0.5 to about 10.
• oil absorption as measured by grams of oil absorbed by 100 grams of filler is about 10 to about 100, more preferably about 10 to about 85 and most preferably about 10 to about 75.
• Typi cal fillers employed in this invention are illustrated in Table I. E. Oil Extended Adhesive Compositions
• the blend composition of the instant invention can also include oils to further improve low temperature properties and tack characteristics of the resulting adhesive.
• oils to further improve low temperature properties and tack characteristics of the resulting adhesive.
• Levels of oil of less than about 25 parts by weight per 100 parts of the hydrogenated block copolymer can be incorporated, more preferably about 1 to about 20 parts. Oils are particularly useful when high levels of petroleum resin tackifiers are used since such materials can harden the resulting composition. Oils can -usually further soften and reduce the cost. In some cases, oils can significantly contribute to the degree of tackiness of the final product and thus are helpful in formulating various adhesive products. Typical oils that can be used may be low viscosity aromatic, naphthenic or paraffinic petroleum oils, having, less than 2 weight percent polar type compounds. Typical oils are illustrated in Table II.
• the hot melt adhesive compositions can be used by conventional polymer fabricating techniques. After the blending is complete, the adhesive mass can either be extruded and/or calendered to a uniform thickness on top of the substrate which would be paper, cloth, aluminum foil or glass fabric.
• the temperature and the throughput of the extrusion are variable depending upon the viscosity of the tackifying mass and the desired coating thickness. Typi cally the temperature of extrusions and rolls may be from about 200° to 400°F.
• the substrates or backings to which the pressure sensitive adhesive compositions are applied may be of various porous or nonporous types and they may be organic or inorganic in nature.
• these materials are those which are customarily employed in pressure sensitive tapes, either the cloth or paper backed types or tape back ings made of synthetic materials, for example, polyesters such as the copolymer of ethylene glycol with terephthalic acid, vinyl such as a copolymer of vinylidene chloride and vinyl chloride, or a copolymer of vinylidene chloride with acrylonitrile, cellophane, cellulose acetate, polyvinyl chloride, polyvinyl acetate, polypropylene, polyethylene, ethylene-propylene plastic copolymer.
• polyesters such as the copolymer of ethylene glycol with terephthalic acid, vinyl such as a copolymer of vinylidene chloride and vinyl chloride, or a copolymer of vinylidene chloride with acrylonitrile, cellophane, cellulose acetate, polyvinyl chloride, polyvinyl acetate, polypropylene, polyethylene, ethylene-propylene
• Sheetings and tapes of cloth or textiles of either natural or synthetic fiber origin, such as glass fiber cloth, wood and finally sheets or strips of metals such as steel, copper, aluminum, and alloys thereof can also be employed.
• the backings employed are those which, heretofore have been conventionally employed in preparing pressure sensitive labels, tapes, sheetings and the like and the selection of any particular substrate material is not a specific novel feature of the present invention .
• Detailed Description of the Invention The advantages of both the physical properties and adhesive characteristics of the compositions of the present invention can be more readily appreciated by reference to the following examples and tables. Unless otherwise specified, all measurements are in parts per hundred by weight.
• Example 1 In a first series of tests, various typical binary adhesive blends of Kraton G polymer and commercial tackifying resins were made. The compositions of these blends are shown in Table 1 and various adhesive properties are shown in Table 2. From Table 2, it is noticed that these blends give respectable properties with respect to, for example, compatibility, green strength, bond strength, etc. These materials also appear to have low melt viscosities at typical processing temperatures as was observed during their hot mill rolling. The ease in milling also suggests that they have good processing characteristics as well. However, as can be readily observed from the last column of Table 2, these blends are very poor in regard to their tacky nature.
• Blends 24-1, 24-3 and 24-5 are dry; blends 24-2, 24-4 and 24-6, wherein the loading of the resin was increased by 40% from their respective blends (1, 3 and 5) show only slight improvements. These blends do exhibit a very slight degree of tack in the melt state but nonetheless they exhibit far lower tack values at room temperatures than the values typically demanded from the industrial applications viewpoint.
• Example 2 Since binary blends of Kraton G polymer and tackifying resins failed to show any respectable degree of tackiness, attempts were made to make tertiary blends of Kraton G, tackifying resins and polybutenes.
• Table 3 various tertiary (adhesive) blend compositions of Kraton G system are shown.
• a third component a low molecular weight polymer, polybutene
• the bond strength values reported in Tables 2 and 4 were obtained by a method similar to ASTM D-429 adhesion tests.
• the samples were sandwiched between mylar sheets and pressed to a thickness of about 25 mils using a hot press. Rectangular strips of 1/2 inch width and 3 inches long were cut and 90° peel tests were performed on an Instron at room temperature. The resin-free sections of the mylar film were clamped into air jaws to avoid any slippage during pulling. The samples were pulled at 5 inches/minute crosshead speed. The force and elongation of the samples were recorded on a strip recorder. The force necessary to separate the mylar sheets was taken as the bond strength of the blend and a measure of its cohesive strength and adhesive nature. The final plateau values are reported. The qualitative nature of the tackiness of the blends was determined by technician's subjective "finger test" method.
• Kraton G is a block copolymer of the structure ABA in which A is a block of styrene (total 15% by weight) whos number average molecular weight is in the range of 10,000 to 30,000. B is a block of hydrogenated polybutadiene in poly isoprene (85%) having a number average molecular weight of about 125,000.
• Vistanex-LM is a low molecular polyisobutylene and is an Exxon proprietary material described in detail in various U.S. patents. Amoco polybutenes are viscous, non-drying, water white, liquid butylene polymers. They are composed predominantly of high molecular weight mono-olefins (85-98%), the balance being isoparaffinic.
• Amoco polybutenes can be represented by polyisobutylene structure.
• Arkon P-85 and Escorez resins are commercial tackifiers having a melting point in the neighbo hood of 80-90°C. These are hydrocarbon resins derived from petroleum or coal tar distillates, aliphatic dienes and mono-olefins of 5 or 6 carbon atoms.
• Example 3

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• 1982
  • 1982-11-09 IT IT49456/82A patent/IT1189416B/it active
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