Adhesive bonding and miscellaneous chemical manufacture – Methods – Surface bonding and/or assembly therefor
Reexamination Certificate
2000-08-09
2004-12-21
Copenheaver, Blaine (Department: 1733)
Adhesive bonding and miscellaneous chemical manufacture
Methods
Surface bonding and/or assembly therefor
C525S285000, C525S301000, C525S303000
Reexamination Certificate
active
06833045
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a resin dispersion useful as a coating or an adhesive, and more particularly to a resin dispersion having excellent low-temperature heat-sealing properties.
BACKGROUND ART
A resin dispersion of modified polypropylene has been proposed as an adhesive between slightly adherent polypropylene and a metal such as aluminum (see Japanese Patent Laid-Open Publication No. 12651/1988). In order to lower the heat-sealing temperature of the resin dispersion in the adhesion process, the present inventors have made studies of polypropylene that is a starting resin and have proposed a resin dispersion of modified polypropylene capable of being heat sealed at a lower temperature than the invented product mentioned above (see Japanese Patent Laid-Open Publication No. 91514/1991).
In the market, however, there are strong demands for simplification of production line and reduction of cost, so that uses of not only polypropylene but also polyethylene as adherends have been studied. On this account, a resin dispersion capable of being heat sealed to polyethylene at a lower temperature has been desired. The present inventors have studied to develop a resin dispersion which exhibits excellent heat-sealing properties when polyethylene is used as an adherend. As a result, they have found that a resin dispersion comprising a specific modified ethylene/&agr;-olefin random copolymer obtained by grafting a polar monomer on an ethylene/&agr;-olefin random copolymer comprising ethylene and an &agr;-olefin of 6 to 20 carbon atoms which is dispersed in an organic solvent, satisfies the above demands. Based on the finding, the present invention has been accomplished.
The present invention has been made to solve such problems associated with the prior art as described above, and it is an object of the invention to provide a resin dispersion, which has excellent low-temperature heat-sealing properties and can be used as an adhesive for polyolefins, particularly polyethylene, and to provide a process for preparing the dispersion and uses of the dispersion.
DISCLOSURE OF THE INVENTION
The resin dispersion according to the invention is a resin dispersion comprising solid particles of a graft modified ethylene/&agr;-olefin random copolymer dispersed in an organic solvent, wherein the graft-modified ethylene/&agr;-olefin random copolymer has the following properties:
(a) the copolymer contains components derived from ethylene and an &agr;-olefin of 6 to 20 carbon atoms, the content of the ethylene component is in the range of 75 to 97% by mol, and the content of the &agr;-olefln component is in the range of 3 to 25% by mol, each content being based on 100% by mol of the total of both components,
(b) the intrinsic viscosity (&eegr;) as measured in decalin at 135° C. is in the range of 0.2 to 5.0 dl/g, and
(h) the copolymer contains a graft component derived from a polar monomer, and the content of the polar monomer graft component is in the range of 0.1 to 15% by weight.
The graft modified ethylene/&agr;-olefin random copolymer preferably further has the following properties:
(c) the glass transition temperature (Tg) is not higher than −40° C.,
(d) the crystallinity as measured by X-ray diffractometry is less than 30%, and
(e) the molecular weight distribution (Mw/Mn) as measured by GPC is not more than 3.
The graft modified ethylene/&agr;-olefin random copolymer preferably further has, in addition to the above properties, the following properties:
(f) the B value as calculated from the following equation is in the range of 1.0 to 1.4:
B
value=
POE
/(2
PO·PE
)
wherein POE, 2PO and PE are each a parameter determined from the
13
C-NMR spectrum, PE and PO are a molar fraction of ethylene and a molar fraction of the &agr;-olefin, respectively, to the total number of moles of the ethylene component and the &agr;-olefin contained in the modified ethylene/&agr;olefin random copolymer, and POE is a proportion of the number of ethylene/&agr;-olefin alternating sequences to the number of all dyad sequences.
The process for preparing a resin dispersion according to the present invention comprises grafting a polar monomer on an unmodified ethylene/&agr;-olefin random copolymer having the following properties:
(a′) the copolymer contains components derived from ethylene and an &agr;-olefin of 6 to 20 carbon atoms, the content of the ethylene component is in the range of 75 to 97% by mol, and the content of the &agr;-olefin component is in the range of 3 to 25% by mol, each content being based on 100% by mol of the total of both components, and
(b′) the intrinsic viscosity (&eegr;) as measured in decalin at 135° C. is in the range of 0.2 to 5.0 dl/g,
to prepare a graft modified ethylene/&agr;-olefin random copolymer containing 0.1 to 15% by weight of a graft component derived from the polar monomer, and then dispersing solid particles of the graft modified copolymer in an organic solvent.
In the process for preparing a resin dispersion according to the invention, the unmodified ethylene/&agr;-olefin random copolymer preferably further has the following properties:
(c′) the glass transition temperature (Tg) is not higher than −40° C.,
(d′) the crystallinity as measured by X-ray diffractometry is less than 30%, and
(e′) the molecular weight distribution (Mw/Mn) as measured by GPC is not more than 3.
In the above process, the unmodified ethylene/&agr;-olefin random copolymer preferably furthermore has the following properties:
(f′) the B value as calculated from the following equation is in the range of 1.0 to 1.4:
B
value=
POE
/(2
PO·PE
)
wherein POE, 2PO and PE are each a parameter determined from the
13
C-NMR spectrum, PE and PO are a molar fraction of ethylene and a molar fraction of the &agr;-olefin, respectively, to the total number of moles of the ethylene component and the &agr;-olefin contained in the modified ethylene/&agr;-olefin random copolymer, and POE is a proportion of the number of ethylene/&agr;-olefin alternating sequences to the number of all dyad sequences.
In the above process, the unmodified ethylene/&agr;-olefin random copolymer preferably is a linear ethylene/&agr;-olefin random copolymer having the following properties:
(g′) the ratio (g&eegr;* (=(&eegr;)/(&eegr;)blank) of the intrinsic viscosity (&eegr;) measured as the property (b′) to the intrinsic viscosity (&eegr;)blank of a linear ethylene/propylene copolymer having the same weight-average molecular weight (by light scattering method) as that of the unmodified ethylene/&agr;-olefin random copolymer and having an ethylene content of 70% by mol is a value exceeding 0.95.
The process for producing a resin-coated metal plate according to the present invention comprises applying the above-mentioned resin dispersion to a metal plate to form a coating film.
The process for producing a laminate according to the present invention comprises applying the above-mentioned resin dispersion to a metal plate to form an adhesive layer and laminating a polyolefin sheet or film on the metal plate by means of the adhesive layer.
BEST MODE FOR CARRYING OUT THE INVENTION
The resin dispersion according to the invention is a resin dispersion wherein a solid graft modified ethylene/&agr;-olefin random copolymer obtained by graft modification with a polar monomer is dispersed in an organic solvent. The graft modified ethylene/&agr;-olefin random copolymer has (a) specific contents of ethylene and &agr;-olefin components, (b) a specific intrinsic viscosity (&eegr;) and (h) a specific content of a polar monomer graft component.
In the process for preparing a resin dispersion according to the invention, an unmodified ethylene/&agr;-olefin random copolymer obtained by random copolymerizing ethylene and an &agr;-olefin of 6 to 20 carbon atoms is graft modified with a polar monomer, and then the graft modified copolymer is dispersed in an organic solvent to prepare a resin dispersion.
The present invention is described in more detail hereinafter.
Mod
Saito Tadao
Tokita Suguru
Copenheaver Blaine
Goff John L.
Mitsui Chemicals Inc.
Sherman & Shalloway
LandOfFree
Resin dispersion, method of preparing the same, resin-coated... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Resin dispersion, method of preparing the same, resin-coated..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Resin dispersion, method of preparing the same, resin-coated... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3278773