USH1581H - Process for the reduction of diene polymer hot melt adhesive color (II) - Google Patents

Process for the reduction of diene polymer hot melt adhesive color (II) Download PDF

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Publication number
USH1581H
USH1581H US08/148,742 US14874293A USH1581H US H1581 H USH1581 H US H1581H US 14874293 A US14874293 A US 14874293A US H1581 H USH1581 H US H1581H
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US
United States
Prior art keywords
color
alpha
polymer
polymers
hot melt
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US08/148,742
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English (en)
Inventor
Jeffrey G. Southwick
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Shell USA Inc
Original Assignee
Shell Oil Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shell Oil Co filed Critical Shell Oil Co
Priority to US08/148,742 priority Critical patent/USH1581H/en
Assigned to SHELL OIL COMPANY reassignment SHELL OIL COMPANY ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: SOUTHWICK, JEFFREY GEORGE
Priority to TW083109553A priority patent/TW280828B/zh
Priority to PCT/EP1994/003650 priority patent/WO1995012644A1/en
Application granted granted Critical
Publication of USH1581H publication Critical patent/USH1581H/en
Abandoned legal-status Critical Current

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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
    • 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
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00—Use of organic ingredients
    • C08K5/16—Nitrogen-containing compounds
    • C08K5/17—Amines; Quaternary ammonium compounds
    • C08K5/18—Amines; Quaternary ammonium compounds with aromatically bound amino groups
    • 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
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/02—Non-macromolecular additives
    • C09J11/06—Non-macromolecular additives organic

Definitions

  • This invention relates to the reduction of color formation in hot melt adhesive formulations which contain diene polymers, especially block copolymers of conjugated dienes and vinyl aromatic hydrocarbons. More particularly, it relates to the reduction of such color formation by the addition of a specific aromatic amine compound to such formulations.
  • Block copolymer can be obtained by an anionic copolymerization of a conjugated diene compound and an alkenyl arene compound by using an organic alkali metal initiator.
  • Block copolymers have been produced which comprise primarily those having a general structure
  • polymer blocks A comprise thermoplastic polymer blocks of alkenyl arenes such as polystyrene
  • block B is a polymer block of a conjugated diene such as butadiene or isoprene.
  • the proportion of the thermoplastic blocks to the elastomeric polymer block and the relative molecular weights of each of these blocks is balanced to obtain a rubber having unique performance characteristics.
  • the produced block copolymer is a so-called thermoplastic rubber.
  • the blocks A are thermodynamically incompatible with the blocks B resulting in a rubber consisting of two phases--a continuous elastomeric phase (blocks B) and a basically discontinuous hard, glass-like plastic phase (blocks A) called domains. Since the A-B-A block copolymers have two A blocks separated by a B block, domain formation results in effectively locking the B blocks and their inherent entanglements in place by the A blocks and forming a network structure.
  • These domains act as physical crosslinks anchoring the ends of many block copolymer chains.
  • Such a phenomena allows the A-B-A rubber to behave like a conventionally vulcanized rubber in the unvulcanized state and is applicable for various uses.
  • these network forming polymers are applicable for uses such as in adhesive formulations; as moldings of shoe soles, etc.; impact modifier for polystyrene resins and engineering thermoplastics; modification of asphalt; etc.
  • Such polymers are made by coupling with coupling agents as described in U.S. Pat. No. 4,096,203.
  • Such coupling agents may contain halogens and often there is some residual halogen which reacts with residual lithium to form LiX.
  • Other coupling agents such as epoxy resins, are also used.
  • Adhesive formulations containing coupled polymers are known to develop a brown color when aged at high temperatures such as 177° C.
  • Polymers coupled with epoxy resins and sequentially polymerized polymers exhibit this behavior to a lesser degree because the process for making these polymers does not produce a lithium halide salt as a by-product.
  • This is considered a problem for hot melt adhesive manufacturers who sometimes hold adhesives at high temperatures for extended times during hot melt application.
  • the brown color is undesirable for many end uses for such adhesive products such as diaper assembly, clear labels, clear tapes, clear decals, etc. I have found that the use of a specific aromatic amine compound will greatly reduce the color formation in hot melt adhesive formulations which include epoxy resin-coupled polymers.
  • the present invention provides a method of reducing the color of a hot melt adhesive formulation comprising coupled polymers including block copolymers of a conjugated diene and a vinyl aromatic hydrocarbon.
  • the process comprises adding to the formulation an amount of 4,4'-bis(alpha,alpha-dimethylbenzyl)diphenylamine sufficient to reduce color formation.
  • at least about 0.2 parts per hundred of rubber (phr) of the compound should be used (the "rubber” in phr refers to the polymer).
  • the present invention also encompasses a color stabilized product made by the above process.
  • polymers containing both aromatic and ethylenic unsaturation can be prepared by copolymerizing one or more polyolefins, particularly a diolefin, in this case butadiene and isoprene, with one or more alkenyl aromatic hydrocarbon monomers, in this case styrene.
  • diolefins such as 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene and the like, and other vinyl aromatic hydrocarbons such as o-methylstyrene, p-methylstyrene, p-tertbutylstyrene, 1,3-dimethylstyrene, alphamethylstyrene, vinylnapthalene, vinylanthracene and the like may be used.
  • the copolymers may, of course, be random, tapered, block or a combination of these, in this case block.
  • Polymers containing ethylenic unsaturation or both aromatic and ethylenic unsaturation may be prepared using free-radical, cationic and anionic initiators or polymerization catalysts. Such polymers may be prepared using bulk, solution or emulsion techniques. In any case, the polymer containing at least ethylenic unsaturation will, generally, be recovered as a solid such as a crumb, a powder, a pellet or the like. Polymers containing ethylenic unsaturation and polymers containing both aromatic and ethylenic unsaturation are, of course, available commercially from several suppliers.
  • ABA block copolymers Polymers of conjugated diolefins and copolymers of one or more conjugated diolefins and one or more alkenyl aromatic hydrocarbon monomers such as ABA block copolymers are frequently prepared in solution using anionic polymerization techniques.
  • these ABA block copolymers are prepared by contacting the monomers to be polymerized simultaneously or sequentially with an organoalkali metal compound in a suitable solvent at a temperature within the range from about -150° C. to about 300° C., preferably at a temperature within the range from about 0° C. to about 100° C.
  • organoalkali metal compound in a suitable solvent at a temperature within the range from about -150° C. to about 300° C., preferably at a temperature within the range from about 0° C. to about 100° C.
  • Particularly effective anionic polymerization initiators are organolithium compounds having the general formula:
  • R is an aliphatic, cycloaliphatic, aromatic or alkyl-substituted aromatic hydrocarbon radical having from 1 to about 20 carbon atoms; and n is an integer of 1 to 4.
  • any of the solvents known in the prior art to be useful in the preparation of such polymers may be used.
  • Suitable solvents include straight- and branched-chain hydrocarbons such as pentane, hexane, heptane, octane and the like, as well as, alkyl-substituted derivatives thereof; cycloaliphatic hydrocarbons such as cyclopentane, cyclohexane, cycloheptane and the like, as well as, alkyl-substituted derivatives thereof; aromatic and alkyl-substituted aromatic hydrocarbons such as benzene, naphthalene, toluene, xylene and the like; hydrogenated aromatic hydrocarbons such as tetratin, decalin and the like.
  • Block copolymers are prepared only in that an unexpectedly large improvement in color stability is seen with polymers produced so that lithium bromide salt is not produced as a by-product.
  • Polymers not containing LiBr as a by-product include epoxy resin coupled polymers and sequentially polymerized polymers.
  • a coupled A-B-A triblock copolymer a polystyrene block (A) is anionically polymerized and then a short polydiene block (B) is added thereto.
  • a coupling agent is then added to the mixture and, depending upon the functionality available on the coupling agent, two or more of the anionically polymerized A-B "arms" are coupled together through the coupling agent to form the polymer.
  • Coupling agents that are particularly useful in this invention include EPON® 825 resin and methyldimethoxysilane since they do not produce LiBr as a by-product.
  • polymers made with coupling agents that do produce LiBr, such as dibromoethane, can also be improved in color using the aromatic amine compound of the present invention.
  • the invention is also especially useful with sequentially polymerized copolymers.
  • a sequential polymerization of A-B-A triblock copolymer a polystyrene block is anionically polymerized, followed by polymerization of a conjugated diene block, and followed once again by a block of polystyrene. No coupling agent is required and there is no LiBr in the polymer produced.
  • the aromatic amine compound of the present invention has special utility when used in a polymer of the type described herein which has been coupled with an epoxy resin.
  • the epoxy resin component of the composition can be any curable resin having, on the average, more than one vicinal epoxide group per molecule and which has at least one aromatic group, and may bear substituents which do not materially interfere with the curing reaction.
  • Suitable epoxy resins include glycidyl ethers prepared by the reaction of epichlorohydrin with an aromatic compound containing at least one hydroxyl group carried out under alkaline reaction conditions.
  • the epoxy resin products obtained when the hydroxyl group-containing compound is bisphenol-A are represented below by the structure below wherein n is zero or a number greater than 0, commonly in the range of 0 to 10, preferably in the range of 0 to 2, and R is H or an alkyl group, preferably methyl or ethyl.
  • epoxy resins can be prepared by the reaction of epichlorohydrin with mononuclear di- and trihydroxy phenolic compounds such as resorcinol and phloroglucinol, selected polynuclear polyhydroxy phenolic compounds such as bis(p-hydroxyphenyl)methane and 4,4'-dihydroxybiphenyl, or aliphatic polyols such as 1,4-butanediol and glycerol.
  • mononuclear di- and trihydroxy phenolic compounds such as resorcinol and phloroglucinol
  • selected polynuclear polyhydroxy phenolic compounds such as bis(p-hydroxyphenyl)methane and 4,4'-dihydroxybiphenyl
  • aliphatic polyols such as 1,4-butanediol and glycerol.
  • Epoxy resins suitable for the invention compositions have molecular weights generally within the range of 86 to about 10,000, preferably about 200 to about 1500.
  • the commercially-available epoxy resin EPON® Resin 828 a reaction product of epichlorohydrin and 2,2-bis(4-hydroxyphenylpropane) (bisphenol-A) having a molecular weight of about 400, an epoxide equivalent (ASTM D-1652) of about 185-192, and an n value (from the formula above) of about 0.2, is presently the preferred epoxy resin because of its low viscosity and commercial availability.
  • tapered copolymer blocks can be incorporated in the multiblock copolymer by copolymerizing a mixture of conjugated diene and vinyl aromatic hydrocarbon monomers utilizing the difference in their copolymerization reactivity rates.
  • Various patents describe the preparation of multiblock copolymer containing tapered copolymer blocks including U.S. Pat. Nos. 3,251,905; 3,265,765; 3,639,521 and 4,208,356. The disclosures of all of the patents mentioned in this paragraph are herein incorporated by reference.
  • these block copolymers can be hydrogenated. Hydrogenation may be effected selectively as disclosed in U.S. Pat. No. Re.
  • a common tackifying resin is a diene-olefin copolymer of piperylene and 2-methyl-2-butene having a softening point of about 95° C. This resin is available commercially under the tradename Wingtack 95 and is prepared by the cationic polymerization of 60 percent piperylene, 10 percent isoprene, 5 percent cyclopentadiene, 15 percent 2-methyl-2-butene and about 10 percent dimer, as taught in U.S. Pat. No. 3,577,398 which is incorporated by reference.
  • tackifying resins of the same general type may be employed in which the resinous copolymer comprises 20-80 weight percent of piperylene and 80-20 weight percent of 2-methyl-2-butene.
  • the resins normally have softening points (ring and ball) between about 80° C. and about 115° C.
  • adhesion promoting resins which are also useful in the compositions of this invention include hydrogenated rosins, esters of rosins, polyterpenes, terpenephenol resins and polymerized mixed olefins.
  • the tackifying resin be a saturated resin, e.g., a hydrogenated dicyclopentadiene resin such as Escorez® 5000 series resin made by Exxon or a hydrogenated polystyrene or polyalphamethylstyrene resin such as Regalrez® resin made by Hercules.
  • the amount of adhesion promoting resin employed varies from about 20 to about 400 parts by weight per hundred parts rubber (phr), preferably between about 100 to about 350 phr.
  • the selection of the particular tackifying agent is, in large part, dependent upon the specific block copolymer employed in the respective adhesive composition.
  • the adhesive composition of the instant invention may contain plasticizers, such as rubber extending plasticizers, or compounding oils or liquid resins.
  • Plasticizers are well-known in the art and include both high saturates content oils and high aromatics content oils.
  • Preferred plasticizers are highly saturated oils, e.g. Tuffio® 6056 oil made by Arco.
  • the amounts of rubber compounding oil employed in the invention composition can vary from 0 to about 100 phr, and preferably between about 0 to about 60 phr.
  • Optional components of the present invention are stabilizers which inhibit or retard heat degradation, oxidation, and skin formation.
  • Stabilizers are typically added to the commercially available compounds in order to protect the polymers against heat degradation and oxidation during the preparation, use and high temperature storage of the adhesive composition. Additional stabilizers known in the art may also be incorporated into the adhesive composition.
  • This aromatic amine compound also has utility in blends of thermoplastic elastomers and other polymers, especially thermoplastic polymers such as polypropylene, polyethylene, nylon, polycarbonate, polyphenylene ether, etc. This aromatic amine is also advantageous used in blends of thermoplastic elastomers with asphalt.
  • hot melt adhesives were compounded in a Sigma blade mixer.
  • Polymer A was a linear styrene-isoprene-styrene block copolymer coupled with lithium bromide.
  • Polymer B was a similar polymer coupled with an epoxy resin, EPON® 825, a high purity version of EPON® 828 resin, from Shell Oil Company described above.
  • Irganox 565 is a commercial stabilizer from Ciba Geigy with the chemical name 2,4 bis(n-octylthio)-6-(4-hydroxy-3,5-ditertbutylaniline)-2,3,5-triazine.
  • Naugard 445 is an aromatic amine compound available from Uniroyal. This is the compound of the present invention and it is 4,4'-bis(alpha,alpha-dimethylbenzyl)diphenylamine.
  • the formulations utilized are set out below:
  • Phosphite antioxidants are well known as being useful in retarding the formation of color as materials are aged.
  • a well known and widely used phosphite is trisnonylphenylphosphite (TNPP).
  • TNPP trisnonylphenylphosphite
  • Polygard HR trisdinonylphenylphosphite
  • Table 4 compares the utility of Polygard HR against Naugard 445 in combination with the phenolic antioxidant Irganox 565 in the standard adhesive formulation (Table 1). It is obvious that only Naugard 445 provides significantly improved color stability in these systems.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Epoxy Resins (AREA)
  • Adhesives Or Adhesive Processes (AREA)
US08/148,742 1993-11-05 1993-11-05 Process for the reduction of diene polymer hot melt adhesive color (II) Abandoned USH1581H (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US08/148,742 USH1581H (en) 1993-11-05 1993-11-05 Process for the reduction of diene polymer hot melt adhesive color (II)
TW083109553A TW280828B (cs) 1993-11-05 1994-10-14
PCT/EP1994/003650 WO1995012644A1 (en) 1993-11-05 1994-11-02 Process for the reduction of diene polymer hot melt adhesive color

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US08/148,742 USH1581H (en) 1993-11-05 1993-11-05 Process for the reduction of diene polymer hot melt adhesive color (II)

Publications (1)

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USH1581H true USH1581H (en) 1996-08-06

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US (1) USH1581H (cs)
TW (1) TW280828B (cs)
WO (1) WO1995012644A1 (cs)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100241052B1 (ko) * 1997-08-27 2000-02-01 박찬구 블록 공중합체의 제조방법
KR100425243B1 (ko) 2001-11-14 2004-03-30 주식회사 엘지화학 선형의 블록 공중합체의 제조방법

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3452056A (en) * 1966-04-07 1969-06-24 Uniroyal Inc Substituted diphenylamines
US4007230A (en) * 1975-02-24 1977-02-08 The Dow Chemical Company Antioxidant composition for stabilizing polyols
US4117033A (en) * 1976-12-10 1978-09-26 E. I. Du Pont De Nemours And Company Polyoxymethylene/copolyether-ester blends
US4125515A (en) * 1976-03-19 1978-11-14 The Goodyear Tire & Rubber Company Antioxidant combination of esters and amines
US4277391A (en) * 1979-12-27 1981-07-07 Gaf Corporation Durable polyester molding composition and product
US4837259A (en) * 1987-09-25 1989-06-06 Uniroyal Chemical Company, Inc. Polypropylene stabilized against oxidative degradation with mixtures of diarylamine derivatives and sterically hindered phenols
US4925889A (en) * 1987-09-25 1990-05-15 Uniroyal Chemical Company, Inc. Stabilized carbon black loaded polyolefins
US4954548A (en) * 1989-04-27 1990-09-04 Shell Oil Company Ethylene-carbon monoxide copolymer stabilization
US5114998A (en) * 1990-12-06 1992-05-19 Hoechst Celanese Corp. Stabilized talc-filled polyester compositions
US5145896A (en) * 1991-09-09 1992-09-08 Shell Oil Company Process for the reduction of diene polymer hot melt adhesive color
USH1251H (en) * 1992-04-24 1993-11-02 Shell Oil Company Acrylic-containing diene copolymers in adhesives, sealants and coatings

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4096203A (en) * 1976-07-30 1978-06-20 Shell Oil Company Process to control cohesive strength of block copolymer composition
JPS6155134A (ja) * 1984-08-24 1986-03-19 Dainippon Ink & Chem Inc 耐熱劣化性高分子水分散液
JP2893124B2 (ja) * 1990-04-02 1999-05-17 日本エラストマー株式会社 粘着剤組成物

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3452056A (en) * 1966-04-07 1969-06-24 Uniroyal Inc Substituted diphenylamines
US4007230A (en) * 1975-02-24 1977-02-08 The Dow Chemical Company Antioxidant composition for stabilizing polyols
US4125515A (en) * 1976-03-19 1978-11-14 The Goodyear Tire & Rubber Company Antioxidant combination of esters and amines
US4117033A (en) * 1976-12-10 1978-09-26 E. I. Du Pont De Nemours And Company Polyoxymethylene/copolyether-ester blends
US4277391A (en) * 1979-12-27 1981-07-07 Gaf Corporation Durable polyester molding composition and product
US4837259A (en) * 1987-09-25 1989-06-06 Uniroyal Chemical Company, Inc. Polypropylene stabilized against oxidative degradation with mixtures of diarylamine derivatives and sterically hindered phenols
US4925889A (en) * 1987-09-25 1990-05-15 Uniroyal Chemical Company, Inc. Stabilized carbon black loaded polyolefins
US4954548A (en) * 1989-04-27 1990-09-04 Shell Oil Company Ethylene-carbon monoxide copolymer stabilization
US5114998A (en) * 1990-12-06 1992-05-19 Hoechst Celanese Corp. Stabilized talc-filled polyester compositions
US5145896A (en) * 1991-09-09 1992-09-08 Shell Oil Company Process for the reduction of diene polymer hot melt adhesive color
USH1251H (en) * 1992-04-24 1993-11-02 Shell Oil Company Acrylic-containing diene copolymers in adhesives, sealants and coatings

Also Published As

Publication number Publication date
TW280828B (cs) 1996-07-11
WO1995012644A1 (en) 1995-05-11

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