Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Polymers from only ethylenic monomers or processes of...
Reexamination Certificate
2002-09-27
2004-05-04
Pezzuto, Helen L. (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Polymers from only ethylenic monomers or processes of...
C526S264000, C526S320000, C526S328500
Reexamination Certificate
active
06730763
ABSTRACT:
TECHNICAL FIELD
The present invention relates to compositions useful as materials for overprint varnishes (hereinafter called “OPV”), paints, printing inks, adhesives, fillers, molding materials, resists and the like. The compositions of this invention are especially suitable for such applications as OPV and paints.
In this specification, “acrylate and/or methacrylate” is expressed as “(meth)acrylate”, “acrylic acid and/or methacrylic acid”, as “(meth)acrylic acid”, and “acryloyl and/or methacryloyl”, as “(meth)acryloyl”.
BACKGROUND ART
Materials often used for the above-mentioned applications include acrylic polymers. Acrylic polymers are materials that have relatively good weather resistance, but depending on conditions of use, they are still insufficient in weather resistance, and often limited in use for applications that require high weather resistance.
Acrylic polymers obtained by polymerizing a monomer having a maleimide or succinimide group are known (JP-A-62-205108), and copolymers obtained by polymerizing monomers having a maleimide group which contains two substituents at an ethylenically unsaturated group is also known as acrylic polymers that can be crosslinked with the photo dimerization reaction triggered by irradiation with ultraviolet light (JP-A-55-160010). However, these polymers are also still insufficient in weather resistance, depending on conditions of use, and have the problem that they are often limited in use for the applications that require high weather resistance.
As materials that have often been used for the above-mentioned applications other than the acrylic polymers, ultraviolet-curing compounds can be exemplified. Typical examples of them include acryloyl group-containing compounds (hereinafter called “oligoacrylates”) such as trimethylolpropane triacrylate and pentaerythritol tetraacrylate. Since these compounds are usually cured with addition of an ultraviolet polymerization initiator, components derived from the initiator remain in the cured products, and it can happen that the cured products are colored or degraded in weather resistance. So, their use in the applications requiring high weather resistance is restricted.
Ultraviolet light absorbers, light stabilizers, antioxidants, etc. are used in attempts to improve weather resistance, but their effect is still insufficient. Furthermore, ultraviolet-curing compounds also have a problem that they are lowered in ultraviolet curability by the addition of these additives, and cause productivity to be lowered as the case may be.
The present invention provides compositions excellent in weather resistance and useful as materials for paints, printing inks, adhesives, fillers, molding materials, resists and the like, especially compositions suitable for such applications as OPV, paints and the like.
DISCLOSURE OF THE INVENTION
To solve the above problems, the composition of this invention is characterized in that it comprises, as an effective ingredient, a polymer obtained by effecting a continuous polymerization of a polymerizable monomer having a maleimide group and a polymerizable group other than the maleimide group, or a polymerizable monomer having a succinimide group, at high temperature.
Furthermore, in the composition of this invention, it is preferred that the polymer is obtained by effecting the continuous polymerization at a temperature of 150 to 350° C.
Still furthermore, in the composition of this invention, it is preferred that the polymerizable monomer is one which contains a maleimide group bonded to an acryloyl group by way of an oxyalkylene group.
Still furthermore, it is preferred that the composition of this invention also contains a compound having a radical-polymerizable group as an essential ingredient.
This invention also provides an overprint varnish composed of said composition.
Furthermore, this invention provides a paint composed of said composition.
Hereinafter, embodiments of this invention are described in detail.
The composition of this invention comprises,. as an effective ingredient, a polymer obtained by effecting a continuous polymerization of a polymerizable monomer having a maleimide group and a polymerizable group other than the maleimide group (this monomer is hereinafter called “maleimide monomer”), or a polymerizable monomer having a succinimide group (this monomer is hereinafter called “succinimide monomer”) at high temperature. (This polymer is hereinafter simply called “polymer” in some cases).
As the maleimide group of the maleimide monomer, those having a structure represented by the following formula (1) can be exemplified.
In the above formula, R
1
and R
2
each independently denote a hydrogen atom or alkyl group with 1 to 4 carbon atoms, or jointly denote an alkylene group forming a five- or six-membered ring.
The polymerizable group other than the maleimide group of the maleimide monomer can be a radical-polymerizable group such as (meth)acryloyl group, allyl group, methallyl group and vinyl ester group.
The maleimide monomer can be a monomer having a maleimide group and a (meth)acryloyl group, allyl group, methallyl group or vinyl ester group respectively exemplified above. It is preferred that the maleimide monomer has the maleimide group bonded to an acryloyl group by way of an oxyalkylene group, since the monomer has good polymerizability, and since the resultant polymer has good flexibility. It is especially preferred that the maleimide monomer is a monomer represented by the structural formula shown in the following formula (2), since the resultant polymer has the maleimide groups unreacted and are likely to remain curable.
In the above formula, R
3
and R
4
each independently denote an alkyl group with 1 to 4 carbon atoms, or jointly denote an alkylene group forming a five- or six-membered ring. Furthermore, R
5
denotes a straight-chain or branched-chain alkylene group with 1 to 6 carbon atoms; R
6
denotes a hydrogen atom or methyl group; and n denotes an integer of 1 to 6.
Especially preferred examples of the maleimide monomer include the compounds represented by the structural formulae shown in the following formulae (3) and (4).
These maleimide monomers can be produced, for example, by the methods described in the following publicly known documents:
Kiyoshi Kato et al, “Journal of Synthetic Organic Chemistry Association”, 30 (10), 897, (1972).
Javier de Abajo et al, “Polymer”, vol.33 (5), (1992).
JP-A-56-53119
JP-A-1-242569
The succinimide monomer has a succinimide group and a polymerizable group. As the succinimide group of the succinimide monomer, those represented by the structure shown in the following formula (5) can be exemplified.
In the above formula, R
7
and R
8
each independently denote a hydrogen atom or alkyl group with 1 to 4 carbon atoms, or jointly denote an alkylene group forming a five- or six-membered ring.
The polymerizable group of the succinimide monomer can be a radical-polymerizable group such as (meth)acryloyl group, allyl group, methallyl group or vinyl ester group.
The succinimide monomer can be a monomer having a succinimide group and a (meth)acryloyl group, allyl group, methallyl group or vinyl ester group respectively exemplified above.
Especially preferred examples of the succinimide monomer include the compounds represented by the structural formula shown in the following formula (6).
The succinimide monomer can be produced according to the methods described in the publicly known documents listed above, like said maleimide monomer.
The polymer of this invention can be obtained by polymerizing one or more kinds of maleimide monomers or one or more kinds of succinimide monomers, and also may be a copolymer of a maleimide monomer with a succinimide monomer, and furthermore may be those with which another monomer (hereinafter called “comonomer”) than the maleimide monomer and the succinimide monomer, which is copolymerizable with these monomers, is copolymerized.
Examples of the comonomer include styrene, (&agr;-methylstyrene, (meth)acrylonitrile, vinyl acetate, and (meth)acrylates other than said m
Kaai Michihiro
Okazaki Eiichi
Fitch Even Tabin & Flannery
Pezzuto Helen L.
Toagosei Co. Ltd.
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