Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Reexamination Certificate
2001-04-16
2003-01-14
Nutter, Nathan M. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
C525S192000, C525S194000, C525S199000, C525S203000, C525S209000, C525S210000, C525S216000, C525S217000, C525S221000, C525S222000, C525S227000, C525S230000, C525S231000, C525S232000, C525S233000, C525S238000, C525S239000, C525S240000, C525S241000
Reexamination Certificate
active
06506840
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for producing a succinimide resin composition of high quality with high production efficiency. The succinimide resin compositions produced according to the process of the present invention have excellent heat resistance and high rigidity, and are useful in many applications such as optical parts, electric and electronic parts, illuminator parts, automobile parts, medical parts, food containers, sundries, and building materials.
2. Description of the Related Art
Copolymers having succinimide units, which have high heat resistance, have been investigated for many years. For example, processes for copolymerizing methyl methacrylate and an N-aromatic-substituted maleimide are disclosed in JP-B-43-9753, JP-A-61-141715, JP-A-61-171708, and JP-A-62-109811. (“JP-A” herein means an “unexamined published Japanese patent application”; “JP-B” herein means an “examined Japanese patent publication”) Processes for copolymerizing a styrene type monomer and an N-aromatic-substituted maleimide are disclosed in JP-A-47-6891, JP-A-61-76512, and JP-A-61-276807.
British Patent 815,821 discloses a process for producing a succinimide copolymer in which process a copolymer constituted of maleic anhydride and an olefin is reacted with methylamine. In this process, the maleic anhydride copolymer is amidated by methylamine in benzene, the solvent is removed, and the remaining matter is heated in an oven for imide formation to obtain a yellow tough resin. This Patent discloses also a process of the imide formation reaction conducted in an extruder.
The aforementioned copolymer of methyl methacrylate or styrene with the N-aromatic-substituted maleimide has disadvantages of brittleness, poor processability, and discoloration of the resin, although the resin has higher heat resistance with increase of the content of the N-substituted maleimide.
The above British Patent 815,821 produces a polymer which becomes yellow and, when the imide-forming reaction is allowed to proceed in an extruder, requires a high extrusion torque, resulting in lower productivity, disadvantageously. To obtain a resin composition composed of the succinimide resin and a second polymer, the produced succinimide resin is kneaded with the second polymer by melt-kneading or a like complicated step, which may cause deterioration of the quality of the product.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a succinimide resin composition of high quality with high production efficiency.
The inventors of the present invention, after comprehensive investigation in view of the above problems, have found that a succinimide resin composition of high quality can be produced with high production efficiency by conducting the imide-forming reaction between a maleic anhydride-olefin type copolymer and an amine in the presence of a second polymer, and completed the present invention.
The process for producing a succinimide resin composition of the present invention is characterized in that a maleic anhydride-olefin type copolymer constituted of 40-60 mol % of maleic anhydride units, 60-40 mol % of olefin units, and 0-20 mol % of another copolymerizable monomer units is reacted for imide formation with one or more amine compounds in the presence of a second polymer other than the succinimide resin to produce a succinimide resin containing the units represented by General Formulas (1) and (2) as essential components:
where R1, R2, and R3 denote independently hydrogen, an alkyl group of 1-6 carbons, or a cycloalkyl group.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is described below in detail.
The present invention relates to a process for producing a succinimide resin composition comprising reacting a maleic anhydride-olefin type copolymer having the units represented by the above General Formulas (1) and (2) as essential components with one or more amines for imide formation.
The maleic anhydride-olefin type copolymer employed in the present invention is constituted of 40-60 mol % of maleic anhydride units, 60-40 mol % of olefin units, and 0-20 mol % of another copolymerizable monomer units. The maleic anhydride-olefin type copolymer can be obtained by radical copolymerization of maleic anhydride, an olefin, and another monomer copolymerizable therewith.
The olefin for introducing the olefin unit includes those which give the unit represented by General Formula (2), in which R2, and R3 denote independently hydrogen, an alkyl group of 1-6 carbons, or a cycloalkyl group. The olefin includes specifically ethylene, propylene, 1-butene, 1-hexene, isobutene, 2-methyl-1-butene, 2-methyl-1-pentene, 2-methyl-1-hexene, 2-methyl-1-heptene, 2,2,4-trimethyl-1-pentene, 2-methyl-1-octene, 2-ethyl-1-pentene, 2-methyl-2-butene, and 2-methyl-2-hexene. Of these olefins, isobutene is particularly preferred since it gives a succinimide resin composition having high heat resistance and excellent mechanical properties. The olefin may be used singly or in combination of two or more thereof. The succinimide resin may contain two or more different types of units represented by General Formula (2) having different R2, or R3.
The maleic anhydride-olefin type copolymer employed in the present invention may be a copolymer which contains units of another copolymerizable monomer, provided that it does not impair the object of the present invention. The additional copolymerizable monomer includes styrene, styrene derivatives such as &agr;-methylstyrene, and methylstyrene; dienes such as 1,3-butadiene, and isoprene; methacrylate esters such as methyl methacrylate, ethyl methacrylate, and glycidyl methacrylate; acrylate esters such as methyl acrylate, ethyl acrylate, butyl acrylate, and 2-hydroxyethyl acrylate; vinyl ethers such as methyl vinyl ether, and ethyl vinyl ether; internal olefins such as 2-butene, and norbornene; vinylpyridine; and vinyl acetate. These monomers may be used singly or in combination of two or more thereof. The unit of the copolymerizable monomer is contained preferably at a content of 0-20 mol %, more preferably not more than 5 mol %, still more preferably not more than 1 mol %.
The content of the residual maleic anhydride monomer in the maleic anhydride-olefin type copolymer employed in the present invention is preferably lower: not higher than 1% by weight, more preferably not higher than 0.1% by weight for particularly reducing the yellowness of the produced succinimide resin composition.
The maleic anhydride-olefin type copolymer employed in the present invention has preferably a number-average molecular weight ranging from 1×10
3
to 1×10
6
, more preferably from 1×10
4
to 5×10
5
according to measurement by gel permeation chromatography (GPC) at 35° C in N,N-dimethylformamide solvent to obtain a succinimide resin composition excellent in moldability and mechanical properties.
The maleic anhydride-olefin type copolymer may be produced by any method without limitation, a commercial one being useful. Preferably the maleic anhydride-olefin type copolymer is produced by radical precipitation polymerization to produce the anhydride-olefin type copolymer in a particle shape, containing a reduced amount of the residual maleic acid which causes discoloration, and to obtain a succinimide resin composition of high quality with high production efficiency.
The solvent for the radical precipitation polymerization includes known precipitation polymerization solvents: acetate esters such as ethyl acetate, propeyl acetate, and butyl acetate; aromatic solvents such as benzene, toluene, and xylene; and mixed solvents such as an acetate ester or an aromatic solvent with an alcohol. A dispersion stabilizer of a cellulose type, a vinyl alcohol type, or the like may be used for the radical precipitation polymerization.
The polymerization initiator for the radical precipitation polymerization includes organic peroxides such as benzoyl peroxide, lauroyl peroxide octanoyl peroxide, acetyl peroxide, di-t-bu
Doi Toru
Harunari Takeshi
Uchida Yoshiki
Nutter Nathan M.
Sughrue & Mion, PLLC
Tosoh Corporation
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