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
1996-11-01
1999-10-05
Reddick, Judy M.
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...
428460, 428462, 428463, 428514, 523201, 523403, 523404, 523410, 523411, 523412, 524507, 524517, 524520, 524521, 524522, C08F 216
Patent
active
059625716
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a process for the production of certain aqueous crosslinkable polymer compositions useful for coating, to the aqueous compositions so produced, and to their use in coating applications.
There is an ever increasing impetus to replace or supplement solvent-based polymer coating compositions with aqueous-based counterparts due to the environmental toxicity and flammability problems posed by the use of volatile organic solvents. However, even where aqueous-based polymer compositions have been devised, their production has usually entailed the intermediate use of organic solvents, requiring subsequent removal which is costly and time-consuming, or the incorporation of a certain amount of a solvent in the final composition which acts to ensure proper film-formation on coating (known as a coalescing solvent). There is therefore also now increasing pressure to significantly reduce or eliminate the volatile organic contents (VOC's) in aqueous-based polymer composition syntheses both as components in their production (even if subsequently removed) and in the resulting composition as an aid to film coalescence.
Further still, even if one can achieve a solvent-free aqueous polymer coating composition, it has been found difficult to achieve one with a balance of good properties conventionally required in most coating compositions, particularly acceptably high hardness and low minimum film forming temperature (MFFT). It should also have good water and solvent resistance, and good storage stability.
We have now invented a process which enables such compositions to be prepared. In particular, the process of the invention produces in most cases in the resulting composition an exceptionally advantageous combination of MFFT and hardness wherein one obtains in a given composition an exceptionally high hardness opposite the particular MFFT of that composition.
According to the present invention there is provided a process for the production of an organic solvent-free aqueous crosslinkable polymer composition useful for coating, which process is organic solvent-free and comprises: olefinically unsaturated monomers, said oligomer having a number average molecular weight Mn within the range of from 500 to 50,000 (preferably 2000 to 25000), a glass transition temperature Tg within the range of 10 to 125.degree. C. (preferably 50 to 125.degree. C.), said oligomer being formed using an organic solvent-free aqueous emulsion or aqueous solution polymerisation process, and said acid functionality rendering the oligomer water-soluble per se or by neutralization, and said oligomer also having functional groups for imparting crosslinkability when the aqueous polymer composition is subsequently dried, emulsion of a hydrophobic polymer from at least one olefinically unsaturated monomer in the presence of the aqueous solution of the oligomer, said hydrophobic polymer having a Tg which is at least 25.degree. C. lower than the Tg of said oligomer (preferably at least 40.degree. C. lower), and said hydrophobic polymer optionally having functional groups for imparting crosslinkability when the aqueous polymer composition is subsequently dried, and addition of the crosslinking agent after the polymerisation of step b) and/or performing the polymerisation in the presence of the crosslinking agent, said crosslinking agent being reactable with the crosslinker functional groups of the oligomer and (if present) of the hydrophobic polymer on subsequent drying to effect crosslinking, wherein said crosslinking agent is not an agent which effects crosslinking by the formation of ionic bonds, hardness of at least 40 sec (preferably within the range 60 to 200 sec) and said polymer composition has a minimum film forming temperature of .ltoreq.55.degree. C. (preferably within the range 0 to 30.degree. C.).
There is also provided an aqueous polymer composition which is formable by a process as defined supra.
There is further provided the use of an aqueous polymer composition as defined supra in coating applications, and in part
REFERENCES:
patent: 4150005 (1979-04-01), Gehman et al.
patent: 4151143 (1979-04-01), Blank et al.
patent: 4250070 (1981-02-01), Ley et al.
patent: 4325856 (1982-04-01), Ishikawa et al.
patent: 4351875 (1982-09-01), Arkens
patent: 4465803 (1984-08-01), Nakayama
patent: 4628071 (1986-12-01), Morgan
patent: 4786676 (1988-11-01), Blum et al.
patent: 4820762 (1989-04-01), Tsaur
patent: 4845149 (1989-07-01), Frazee
patent: 4876313 (1989-10-01), Lorah
patent: 4894397 (1990-01-01), Morgan et al.
patent: 4904724 (1990-02-01), Auchter et al.
patent: 4916171 (1990-04-01), Brown et al.
patent: 4923919 (1990-05-01), Frazee
patent: 4931494 (1990-06-01), Auchter et al.
patent: 4952623 (1990-08-01), Auchter et al.
patent: 5073591 (1991-12-01), Tsaur
patent: 5306743 (1994-04-01), Klesse et al.
patent: 5403894 (1995-04-01), Tsai et al.
Buckmann Alfred Jean Paul
Overbeek Gerardus Cornelis
Smak Yvonne Wilhelmina
Reddick Judy M.
Zeneca Resins B.V.
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