Abstract: The impact-resistant thermoplastic compositions comprising (A) a rigid thermoplastic methacrylic polymer or copolymer matrix P containing mostly methyl methacrylate units, (B) at least one impact-modifying additive and (C) at least one elastomer copolymer which contains grafting sites, at least on pendant chains, and is obtained from at least one vinylaromatic monomer (C1) and from at one monomer chosen from the monomers (C2): C1-C15 linear or branched alkyl acrylates, C1-C4 alkoxyalkyl acrylates and aralkyl acrylates, dienes (C3) and ethylenically unsaturated monomers (C4) having one or more pendant initiating functional groups, the said copolymer (C) being grafted by thermoplastic polymer groups P and being dispersed in the matrix (A) in the form of nodules, which can be called “particles”, from 10 nm to 500 nm in size and able to have a droplet, capsule-type monoinclusion and/or salami-type multi-inclusion morphology.

Abstract: The invention concerns thermoplastic impact-resistant compositions comprising (A) a thermoplastic methacrylic polymer of copolymer (P) including for the major part methyl methacrylate units, (B) at least an impact resistance enhancing additive and at least a grafted elastomeric polymer (C) bearing thermoplastic methacrylic (co)polymer groups (P) grafted at least in pendant position on an elastomeric copolymer (C°), said elastomeric copolymer (C°) being obtained from (i) at least a vinylaromatic monomer (C1), (ii) at least a monomer (C2) selected among the C1-C15 linear or branched alkyl acrylates, alkoxyalkyl acrylates wherein the alkyl group(s) have 1 to 4 carbon atoms and aralkyl acrylates wherein the alkyl group(s) has/have 1 to 15 carbon atoms and/or at least a diene monomer (C3) and (iii) optionally at least an ethylenically unsaturated monomer (C4) with pendant initiator function(s), said monomer(s) (C4) being necessary in the absence of monomer (C3), said grafted elastomeric copolymer (C) being

Abstract: Living random (meth)acrylic copolymers, facilely converted into random co(meth)acrylates and block copolymers thereof, comprise the anionic copolymerizates of at least one comonomer A with at least one comonomer B selected from among the (meth)acrylates and maleimides, at least one of the comonomers A and B comprising a (meth)acrylate, in the presence of (i) at least one alkali or alkaline earth metal, mono- or difunctional initiator and (ii) at least one ligand, for example a nonnitrogenous macrocyclic complexant, e.g., a crown ether, or an alkali metal alcoholate.

Abstract: Living random (meth)acrylic copolymers, facilely converted into random co(meth)acrylates and block copolymers thereof, comprise the anionic copolymerizates of at least one comonomer A with at least one comonomer B selected from among the (meth)acrylates and maleimides, at least one of the comonomers A and B comprising a (meth)acrylate, in the presence of (i) at least one alkali or alkaline earth metal, mono- or difunctional initiator and (ii) at least one ligand, for example a nonnitrogenous macrocyclic complexant, e.g., a crown ether, or an alkali metal alcoholate.

Abstract: A multifunctional anionic polymerization initiator which is in the form of a star-shaped polymer, and which is soluble in a nonpolar medium and is substantially free of residual double bonds. The initiator is denoted by the general formula (PA).sub.a N.sup.n- nLi.sup.+. PA is a polymer block of a vinylaromatic or diene monomer A. The variable "a" is the number of branches in the block PA. N is a crosslinked core comprising no or practically no residual double bonds and has the formula (PMc)(RLi).sub.p. Mc is a monomer containing at least two polymerizable double bonds per molecule. PMc is a crosslinked core of at least one polymerized monomer Mc, containing 3 to 30% of residual double bonds in relation to the initial double bonds originating from the monomer Mc. R is an alkyl, aryl, arylalkyl, alkylaryl, cycloalkyl, or alkenyl. The variable "p" is the number of residual double bonds in PMc which are neutralized by RLi. The variable "n" is the number of anionic sites present in the crosslinked core N.

Abstract: The invention relates to an adhesive composition for plastics based on (meth)acrylic (co)polymer derived from 80 to 100% by weight of methyl methacrylate and from 0 to 20% by weight of at least one monomer containing ethylenic unsaturation which can be copolymerized with the methyl methacrylate. The adhesive composition comprises 1,3-dioxolane combined with formic acid or a mono-, di- or tetraglyme, dissolved (meth)acrylic (co)polymer, and optionally diluent additives. The invention further relates to articles made of (meth)acrylic (co)polymer obtained by casting, extrusion or injection and comprising a bonding joint formed from the said adhesive composition.

Abstract: The invention relates to compositions for flame-retardant cast panels made of (meth)acrylic polymers.The composition comprises at least one (meth)acrylic ester monomer, (meth)acrylic acid and at least one phosphorus compound which is anhydrous and is chosen from phosphoric acids, phosphoric acid esters or their mixtures, optionally in combination with an optionally halogenated neutral phosphoric ester. The amount of (meth)acrylic acid and of phosphorus compound, by weight with respect to the total mixture constituting the composition, is such that the flame-retardancy coefficient FRC: ##EQU1## is greater than 0.95.

Abstract: A multifunctional anionic polymerization initiator which is in the form of a star-shaped polymer, and which is soluble in a nonpolar medium and is substantially free of residual double bonds. The initiator is denoted by the general formula (PA).sub.a N.sup.n- nLi.sup.+. PA is a polymer block of a vinylaromatic or diene monomer A. The variable "a" is the number of branches in the block PA. N is a crosslinked core comprising no or practically no residual double bonds and has the formula (PMc)(RLi).sub.p. Mc is a monomer containing at least two polymerizable double bonds per molecule. PMc is a crosslinked core of at least one polymerized monomer Mc, containing 3 to 30% of residual double bonds in relation to the initial double bonds originating from the monomer Mc. R is an alkyl, aryl, arylalkyl, alkylaryl, cycloalkyl, or alkenyl. The variable "p" is the number of residual double bonds in PMc which are neutralized by RLi. The variable "n" is the number of anionic sites present in the crosslinked core N.

Abstract: An initiation system for the anionic polymerization of (meth)acrylic monomers and, optionally, nonacrylic vinyl monomers is disclosed. The initiation system comprises (1) a functional initiator and (2) an alkali metal alcoholate having the formula R'OM', in which M' is an alkali metal and R' is a group R.sup.1 (OR.sup.2).sub.m where R.sup.1 is a C.sub.1 -C.sub.6 alkyl or arylalkyl radical, R.sup.2 is a C.sub.2 -C.sub.4 alkylene radical and m is equal to 1, 2 or 3. The initiation system is applied to the formation of (meth)acrylic homopolymers and block copolymers of (meth)acrylic monomers and, optionally, nonacrylic vinyl comonomers.

Abstract: A diblock copolymer obtained by polymerizing acrylic, methacrylic or nonacrylic vinyl monomers in the presence of a polymerization initiating amount of an initiation system including (1) at least one functional initiator and (2) an alkali metal alcoholate. The alcoholate has the formula:R'OM'in which M' is an alkali metal and R' has the formula:R.sup.1 (OR.sup.2).sub.min which R.sup.1 is a linear or branched alkyl radical containing from 1 to 6 carbon atoms or an arylalkyl radical, R.sup.2 is a linear or branched alkylene radical containing from 2 to 4 carbon atoms, and m is the integer 1, 2 or 3.

Abstract: Living random (meth)acrylic copolymers, facilely converted into random co(meth)acrylates and block copolymers thereof, comprise the anionic copolymerizates of at least one comonomer A with at least one comonomer B selected from among the (meth)acrylates and maleimides, at least one of the comonomers A and B comprising a (meth)acrylate, in the presence of (i) at least one alkali or alkaline earth metal, mono- or difunctional initiator and (ii) at least one ligand, for example a nonnitrogenous macrocyclic complexant, e.g., a crown ether, or an alkali metal alcoholate.

Abstract: Mechanically strong; heat-resistant and transparent PMMA polymers having a high content of syndiotactic triads, a number average molecular weight ranging from 5,000 to 500,000 and a polydispersity index ranging from 1.01 to 1.5, are prepared by anionically polymerizing methyl methacrylate, characteristically at a temperature of at least 0.degree. C., in the presence of (a) at least one organolithium or organosodium initiator and (b) at least one AlR.sup.1 R.sup.2 R.sup.3 ligand, for example at least one di- or tri-phenoxy alkyl aluminum compound.

Abstract: A multifunctional anionic polymerization initiator which is in the form of a star-shaped polymer soluble in an apolar medium and substantially free of residual double bonds. The initiator is denoted by the general formula (PA).sub.a N.sup.n- nLi.sup.+. PA is a polymer block of a vinylaromatic or diene monomer A. The variable "a" is the number of branches in the block PA. N is a crosslinked core comprising no or practically no residual double bonds and has the formula (PMc)(RLi).sub.p. Mc is a monomer containing at least two polymerizable double bonds per molecule. PMc is a crosslinked core of at least one polymerized monomer Mc, containing 3 to 30% of residual double bonds in relation to the initial double bonds originating from the monomer Mc. R is an alkyl, aryl, arylalkyl, alkylaryl, cycloalkyl, or alkenyl. The variable "p" is the number of residual double bonds in PMc which are neutralized by RLi. The variable "n" is the number of anionic sites present in the crosslinked core N.

Abstract: Living random (meth)acrylic copolymers, facilely converted into random co(meth)acrylates and block copolymers thereof, comprise the anionic copolymerizates of at least one comonomer A with at least one comonomer B selected from among the (meth)acrylates and maleimides, at least one of the comonomers A and B comprising a (meth)acrylate, in the presence of (i) at least one alkali or alkaline earth metal, mono- or difunctional initiator and (ii) at least one ligand, for example a nonnitrogenous macrocyclic complexant, e.g., a crown ether, or an alkali metal alcoholate.

Abstract: Imidation-modified MMA (co)polymers, characteristically having a Tg from 20.degree. to 30.degree. C. higher than the Tg of the corresponding unmodified MMA (co)polymer, are produced by reacting an amine, e.g., methylamine or cyclohexylamine, with a suspension, in a hydrophobic nonsolvent reaction medium, of beads of such MMA polymer/copolymer.

Abstract: In a first step of this process an elastomer latex is prepared in aqueous emulsion in the presence of at least one ionic surfactant and at least one ethylenically unsaturated monomer; then in a second step at least one vinyl monomer, which is insoluble in water or sparingly soluble in water, is added to the latex thus obtained and the ionic charges introduced by the said latex are neutralised by adding to the mixture of latex and monomer at least one transfer agent carrying ionic charges opposite to those of the surfactant used in the first step, in order to effect the transfer of particles of the latex into the vinyl monomer; then in a third step the aqueous phase is separated from the organic phase comprising the latex and the vinyl monomer; and in a fourth step the bulk polymerisation of the organic phase is carried out in such a way as to obtain the cast sheet after cooling and release from the mould.

Abstract: Thermoplastic, elastomeric, conjugated diene (e.g., butadiene)/methyl methacrylate block copolymers having elevated Tg and improved impact strength, well suited as polymer impact strength-modifiers and for conversion into pressure-sensitive adhesives, are prepared by (a) anionically polymerizing a conjugated diene monomer in an apolar solvent medium to provide a living polydiene, (b) next adding an alkali metal alkoxyalcoholate ligand to the medium comprising the living polydiene thus formed, (c) block copolymerizing the step (b) living polydiene with methyl methacrylate comonomer to provide a living copolymer, and (d) reacting the step (c) living copolymer with at least one protonic compound, e.g., water, alcohol and/or acid, and completing the polymerization thereof, with the proviso that polymerization of the conjugated diene and the methyl methacrylate comonomers is strictly carried out in the apolar solvent medium, in particular in toluene, benzene or ethylbenzene.

Abstract: (Meth)acrylic/glutarimide copolymers, well suited, e.g., for optical applications, having enhanced glass transition temperatures (Tg), are prepared by salifying the acid functions of (meth)acrylic ester/(meth)acrylic acid copolymers, and then imidifying such "intermediate" salified copolymers into the subject (meth)acrylic/glutarimide polymers.

Abstract: A process for preparing a rubber modified thermoplastic resin, in which a latex in aqueous emulsion is prepared in the presence of an ionic surfactant; a vinyl monomer insoluble or substantially insoluble in water is added, and the particles of the latex are transferred to the monomer to form an organic phase using a transfer agent of opposite charge to the surfactant; and a polymerization of the organic phase is performed.

Abstract: Imidation-modified MMA (co)polymers, characteristically having a Tg from 20.degree. to 30.degree. C. higher than the Tg of the corresponding unmodified MMA (co)polymer, are produced by reacting an amine, e.g., methylamine or cyclohexylamine, with a suspension, in a hydrophobic nonsolvent reaction medium, of beads of such MMA polymer/copolymer.