Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Patent
1985-03-08
1986-11-11
Lilling, Herbert J.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
524271, 524274, 524505, 525 5444, C09J 312, C08L 906
Patent
active
046223576
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to novel pressure-sensitive adhesive compositions, and more particularly to hot-melt or high solid solvent-type pressure-sensitive adhesive compositions containing a specific type of stabilized rosin ester as a tackifying resin.
BACKGROUND ART
Common pressure-sensitive adhesives heretofore known include those comprising a rubber-type high-molecular-weight substance as a base polymer, tackifying resin, plasticizer and when required, stabilizer, antioxidant, filler, coloring agent and the like. These pressure-sensitive adhesives are applied in the form of a solution or emulsion or in a molten state to a substrate of cellophane, paper, cloth, plastics film, metal foil or the like, and dried to produce an adhesive tape, adhesive sheet or adhesive label. Generally natural rubber, styrene-butadiene rubber, acrylic resin and the like have been used as the rubber-type high-molecular-weight substance in the foregoing solvent-type pressure-sensitive adhesive. However, in light of environmental protection, saving of resources, increase of productivity, etc., recently hot-melt or high solid (solvent-type but high in solids content) pressure-sensitive adhesives containing the so-called block rubber as a base polymer have been increasingly used in place of the solvent-type pressure sensitive adhesives incorporating the rubber-type high molecular-weight substance. These resource-saving pressure sensitive adhesives such as hot-melt type, etc. generally contain a block rubber, tackifying resin and plasticizer (mainly oil) as major components in a weight ratio of 100:70-150:20-30. However, these pressure sensitive adhesives are yet unsatisfactory in cold resistance (tack at low temperatures), preparation of compounds, handle-ability during application and economy as compared with conventional solvent-type pressure sensitive adhesives containing a natural rubber or the like as a base material. Studies are under way to overcome these problems and particularly to improve the cold resistance by using an increased amount of the plasticizer component. More specifically, if the amount of the plasticizer component generally used in the above ratio relative to the block rubber is increased to about 50 to about 100 by weight, the pressure-sensitive adhesive is given a higher degree of cold resistance. On the other hand, the increase of the plasticizer amount to such level causes other drawbacks that packaging tapes are imparted a lower adhesive property (adhesion to corrugated boards) and that labels are made unfit for use because the plasticizer penetrates the surface of labels. Presumably these drawbacks are all caused mainly by the transfer of plasticizer. Accordingly, it is desired in industries to develop a novel tackifying resin which can overcome the drawbacks without the transfer of plasticizer.
We conducted extensive research to eliminate the foregoing drawbacks of hot-melt or high solid pressure-sensitive adhesives and particularly to explore tackifying resins to be used for the adhesives. Generally tackifying resins for pressure-sensitive adhesives must fulfil the following major requirements for properties; (1) to be outstanding in three adhesive characteristics (tack, adhesion and cohesion) in a normal state, (2) to keep the plasticizer from bleeding (to give packaging adhesives a high adhesion to corrugated boards and to provide lables with the surface free from the bleeding of plasticizer), (3) to exhibit high aging resistance and good thermostability. Among the tackifying resins heretofore used are terpene resin, aliphatic petroleum resin, hydrogenated petroleum resin, disproportionated rosin ester and the like. It has been found that these resins are insufficient to fulfil the foregoing requirements and remain to be improved in respect of the aforesaid problems and especially cold resistance. When tested in use for adhesives, aliphatic petroleum resin (usually having a softening point of about 100.degree. C.) was found to allow the transfer of plasticizer in the adhes
REFERENCES:
patent: 3211683 (1965-10-01), Arakana et al.
patent: 3427269 (1969-02-01), Davis et al.
patent: 3519585 (1970-07-01), Miller
patent: 3632540 (1972-01-01), Unmuth et al.
patent: 3658740 (1972-04-01), Marrs et al.
patent: 3686107 (1972-08-01), Russell
patent: 3736281 (1973-05-01), Russell
patent: 4248770 (1981-02-01), Matsuo et al.
patent: 4284541 (1981-08-01), Takeda et al.
patent: 4302371 (1981-11-01), Matsuo et al.
patent: 4325770 (1982-04-01), Korpman
Derwent Abst. 28019e/14 (SU-834062) 5-1981.
Derwent Abst. 30115c/17 (J55035633) 3-1980.
Derwent Abst. 03379x/02 (SU453269) 5-1975.
Derwent Abst. 16931e/09 (J57014675) 1-1982.
Derwent Abst. 26936k/11 (SU-925976) 5-1982.
Hara Hiroari
Kodama Yoshihiro
Tsuchida Seiichi
Arakawa Kagaku Kogyo Kabushiki Kaisha
Lilling Herbert J.
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