JP5820393B2 - Cross-linked and branched polymer formation process - Google Patents

Description

  The present invention relates to a process of forming a crosslinked and / or branched polymer and a polymer composition that can react to form a crosslinked and / or branched polymer.

  British Patent No. GB95717 discloses that a polymer of an ethylenically unsaturated monomer is a free radical source, a filler, and R is an alkyl or aryl group, X is a carboxyl group, an aldehyde group, an acid chloride group, an acid amide group, Alternatively, it is described that a polymer having an unsaturated compound of the general formula R—CH═CH—CH═CH—X, which is an ester group, is vulcanized by heating.

  U.S. Pat. No. 4,303,763 describes unsaturated ethylene polymers characterized by a process comprising the step of reacting saturated linear polyethylene directly with a diene monomer in the melt phase, and Canadian Patent No. CA1109840 describes conjugated olefins. A method of cross-linking an elastomer containing randomly distributed sites of saturation with a monomer adsorbed on a particulate adsorbent and dispersed in the elastomer, wherein the weight ratio of monomer to adsorbent is about 100: 1 to 1 1 is described.

  Cross-linking of polymers such as polyolefins and diene elastomers with multifunctional acrylates is described, for example, in the literature “Crosslinking and degradation of polypropylene by the hydrogen and radicals in the production of Hensogen's Hundredogenous,” physics and chemistry; 2004, vol. 69, n3, pp. 239-244: “Cross-Linking of Polypropylene by Peroxide and Multifunctional Monomers DURING REACTIVE EXTRUSION”, B.C. K. Kim, K .; J. et al. Kim, Advances in Polymer Technology; Volume 12 Issue 3, Pages 263-269 (Mar 2003); “Branching of Polypropylene with A PolymermonTorporation. W. Yu, S .; K. Day, F.M. Pinggosusanto and M.M. Xanthos, ANTEC 2000 conference processings, by Society of Plastics Engineers; “Efficiency of Chemical Cross-Linking of Polypropylene”, E. Borsig; Fidelov; Lazr, Journal of Macromolecular Science, Part A, Volume 16, Issue 2 July 1981, pages 513-528; and “Application of co-agents for peroxide crossing.” C. Endstra, Kautschuk und Gummi, Kunststoffe; 1990, vol. 43, n9, pp. 790-793. They describe a process of grafting a polyfunctional acrylate onto a polyolefin in the presence of means capable of generating free radical sites in the polyolefin, for example by heating in the presence of a peroxide.

  When trying to modify polypropylene using the above technique, grafting is accomplished by breaking the polymer at the β-position, or by so-called β-cleavage. Such degradation results in a decrease in the viscosity of the material being processed. Although the use of crosslinking aids such as styrene in combination with multifunctional acrylates inhibits polymer degradation, there is still a need for increased crosslinking without polymer degradation.

  The process according to one aspect of the present invention for forming a crosslinked or branched polyolefin comprises the polyolefin in the presence of means capable of generating free radical sites in the polyolefin, respectively, with olefin-C = C-bonds or acetylene-C. Reacting with an unsaturated compound (B) having three or more groups having a ≡C-bond, wherein the olefin-C = C-bond or acetylene-C = C-bond in the unsaturated compound (A) Each group having an aromatic ring or further olefinic double bond or acetylenic unsaturation, where the aromatic ring or further olefinic double bond or acetylenic unsaturation is olefin-C = C- or acetylene-C≡C-unsaturated. Saturated and conjugate.

  In accordance with another aspect of the present invention, the process of forming a crosslinked or branched diene elastomer comprises a diene elastomer having three or more groups having olefin-C = C-bonds or acetylene-C≡C-bonds, respectively. Reacting with compound (A), wherein each group having an olefin-C = C- bond or acetylene-C = C- bond in unsaturated compound (A) is an aromatic ring or a further olefinic double bond or It contains acetylenic unsaturation, characterized in that the aromatic ring or further olefinic double bond or acetylenic unsaturation is conjugated with the olefin-C = C- or acetylene-C≡C-unsaturation.

  The polymer composition according to the invention comprises a polyolefin or diene elastomer and an unsaturated compound (A) having at least two groups each having an olefin-C = C-bond or acetylene-C≡C-bond, Each group having an olefin-C = C- bond or acetylene-C = C- bond in (A) contains an aromatic ring or a further olefin double bond or acetylenic unsaturation, and The heavy bond or acetylene unsaturation is characterized in that it is conjugated with olefin-C = C- or acetylene-C≡C-unsaturation. When the polymer is a polyolefin, such compositions form a crosslinked or branched polyolefin when subjected to means to create free radical sites in the polyolefin. When the polymer is a diene elastomer, the composition forms a crosslinked or branched elastomer upon heating without any specific means of creating free radical sites in the elastomer.

  The present invention relates to olefin-C = C-bond or acetylene-C≡C-bond, respectively, in the crosslinking of polyolefins with less degradation of the polyolefin compared to crosslinking with polyunsaturated compounds containing no conjugated unsaturation. In the use of unsaturated compounds (A) having three or more groups having the olefin-C = C-bond or acetylene-C = C-bond, each group having an aromatic ring or a further olefinic double bond or It contains acetylenic unsaturation, characterized in that the aromatic ring or further olefinic double bond or acetylenic unsaturation is conjugated with the olefin-C = C- or acetylene-C≡C-unsaturation.

  We have according to the invention an aromatic ring or a further olefin which is conjugated with the olefin-C = C- or acetylene-C≡C-unsaturation of the polyfunctional unsaturated compound in carrying out a crosslinking reaction on the polyolefin. Increased cross-linking and / or branching of the polymer compared to cross-linking with polyfunctional unsaturated compounds that do not contain aromatic rings or additional olefinic bonds, as the use of polyfunctional unsaturated compounds containing bonds (A) Has been found to result in the production of and / or less degradation. The use of a crosslinking aid, such as styrene, has some limitations because a competitive reaction occurs between the grafting with the crosslinking aid and the grafting with the polyfunctional unsaturated compound. Styrene crosslinking aids cannot provide crosslinking or branching. The process of the present invention provides high cross-linking and / or branching efficiency while preventing chain scission with a single molecule. There is no competitive reaction between the cross-linking monomer and the monomer that inhibits degradation, thus the present invention provides a more efficient reaction.

Polyolefin starting materials are, for example, olefins having 2 to 18 carbon atoms, in particular α-olefins of the formula CH ₂ ═CHQ, in which Q is hydrogen or a linear or branched alkyl group having 1 to 8 carbon atoms. It can be a polymer. Polyolefins can be polyethylene or ethylene copolymers, but polymers composed of polyethylene and predominantly ethylene units usually do not decompose when free radical sites are generated in the polyethylene. Many polymers of olefins having 3 or more carbon atoms, such as polypropylene, undergo polymer degradation by chain β-breaking when free radical sites are generated in the polyolefin. The process of the present invention is particularly useful for such polyolefins because it achieves grafting while inhibiting degradation of the polyolefin.

The polyolefin can be, for example, a polymer of ethene (ethylene), propene (propylene), butene, 2-methyl-propene-1 (isobutylene), hexene, heptene, octene, or styrene. Propylene and ethylene polymers are an important class of polymers, especially polypropylene and polyethylene. Polypropylene is a widely available low cost product polymer. It has a low density, is easily processed and is versatile. The most commercially available polypropylene is isotactic polypropylene, but the process of the present invention is applicable to atactic and syndiotactic polypropylene and to isotactic polypropylene. Isotactic polypropylene is prepared, for example, by propene polymerization using a Ziegler-Natta catalyst or a metallocene catalyst. The present invention can result in cross-linked polypropylene having improved properties from product polypropylene. Polyethylene, for example, high density polyethylene having a density of 0.955～0.97G / cm ^3, a density 0.935～0.955G / density polyethylene (MDPE) Among cm ³ or ultra low density polyethylene, high pressure low density polyethylene and Low-density low-density polyethylene or low-density polyethylene (LDPE) having a density of 0.918 to 0.935 g / cm ³ containing microporous polyethylene can be used. Polyethylene can be produced using, for example, a Ziegler-Natta catalyst, a chromium catalyst or a metallocene catalyst. Polyolefins are copolymers or terpolymers such as copolymers of propylene with ethylene, propylene or copolymers of ethylene with alpha olefins having 4 to 18 carbon atoms, ethylene or propylene acrylic acid, methacrylic acid, acrylonitrile, methacrylonitrile, Or an ester of acrylic or methacrylic acid and an alkyl or substituted alkyl group having 1 to 16 carbon atoms, for example a copolymer with an acrylic monomer such as ethyl acrylate, methyl acrylate or butyl acrylate, or a copolymer with vinyl acetate Can do. The polyolefin can be a heterophase, such as a propylene ethylene block copolymer.

Mixtures of different polyolefins can be used. The polyfunctional unsaturated compound (A) can be mixed with one type of polyolefin to form a masterbatch, which can then be mixed with a different type of polyolefin. For example, microporous polypropylene is very effective in mixing with liquid additives to form a masterbatch, which can be mixed with the bulk polymer. Microporous polyethylene or ethylene vinyl acetate copolymer is also very effective in mixing with liquid additives to form a masterbatch, which can be mixed with a polymer such as polypropylene.

  The diene elastomer can be natural rubber. The diene elastomer can alternatively be a synthetic polymer that is a homopolymer or copolymer of a diene monomer (a monomer having two double carbon-carbon bonds with or without conjugation). Preferably, the elastomer is a diene elastomer that is derived at least in part from a conjugated diene monomer and has a content of diene source (conjugated diene) members or units greater than 15 mol%, “essentially unsaturated. Is a diene elastomer. More preferred are “highly unsaturated” diene elastomers, which are diene elastomers having a content of units of diene source (conjugated diene) greater than 50 mol%. Of an ethylene-propylene diene monomer (EPDM) type which can be expressed as a diene elastomer such as butyl rubber or a diene and a low (less than 15 mol%) diene source unit content Copolymers of alpha olefins can also be used.

Diene elastomers are for example:
(A) any homopolymer obtained by polymerization of a conjugated diene monomer having 4 to 12 carbon atoms;
(B) any copolymer obtained by copolymerization with one or more conjugated dienes or one or more vinyl aromatic compounds having 8 to 20 carbon atoms;
(C) ternary copolymers obtained by copolymerization of α-olefins having 3 to 6 carbon atoms with non-conjugated diene monomers having 6 to 12 carbon atoms of ethylene, for example from ethylene, from propylene, Elastomers obtained with non-conjugated diene monomers of the aforementioned type, such as in particular 1,4-hexadiene, ethylidene norbornene or dicyclopentadiene;
(D) Copolymers of isobutene and isoprene (butyl rubber), and also halogenated, in particular chlorinated or brominated versions of this type of copolymer.

Suitable conjugated dienes are in particular 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-di (C ₁ -C ₅ alkyl) -1,3-butadiene, such as 2,3- Dimethyl-1,3-butadiene, 2,3-diethyl-1,3-butadiene, 2-methyl-3-ethyl-1,3-butadiene, 2-methyl-3-isopropyl-1,3-butadiene, aryl- 1,3-butadiene, 1,3-pentadiene and 2,4-hexadiene. Suitable vinyl-aromatic compounds are, for example, styrene, ortho-, meta-, and para-methylstyrene, the commercially available mixture “vinyltoluene”, para-tert-butylstyrene, methoxystyrene, chlorostyrene, vinylmesitylene, divinyl. Benzene and vinyl naphthalene.

  The diene elastomeric copolymer can contain 99-20% by weight diene units and 1-80% by weight vinyl aromatic units. Elastomers can have any microstructure that is a function of the polymerization conditions used, in particular the presence or absence of modifying and / or randomizing agents, and the amount of modifying and / or randomizing agents used. Elastomers can be, for example, block, statistical, sequential or micro sequential elastomers and can be prepared in dispersions or in solution; they can be combined and / or starred or combined with functionalizing agents and / or Alternatively, it can be star-shaped or alternatively functionalized. Examples of suitable block copolymers are styrene-butadiene-styrene (SBS) block copolymers and styrene-ethylene / butadiene-styrene (SEBS) block copolymers.

  Preference is given to polybutadienes, in particular those having a content of 1,2-units of 4% to 80% by weight, or those having a content of cis-1,4 of greater than 80% by weight, polyisoprene, butadiene -Styrene copolymers, in particular 5% to 50% by weight, in particular 20% to 40% by weight styrene content, 4% to 65% by weight butadiene fraction 1,2-bond content, 20% by weight Those having a trans-1,4 bond content of -80 wt%, butadiene-isoprene copolymers, and especially those having an isoprene content of 5 wt% to 90 wt%. In the case of butadiene-styrene-isoprene copolymers, suitable ones are in particular 5% to 50% by weight, in particular 10% to 40% by weight of styrene, 15% to 60% by weight, in particular 20% to 50%. % By weight isoprene content, 5% by weight to 50% by weight, especially 20% by weight to 40% by weight butadiene content, 4% by weight to 85% by weight 1,2-unit content of butadiene fraction, 6% by weight The content of trans-1,4 units in the butadiene fraction from 5% to 80% by weight, the content of 1,2-plus 3,4-units in the isoprene fraction from 5% to 70% by weight, and 10% by weight It has a content of trans-1,4 units of isoprene fraction of ˜50% by weight.

  The elastomer may be an epoxidized rubber, such as an epoxidized natural rubber (ENR). Epoxidized rubber is obtained by modifying rubber, such as natural rubber, where some of the saturation is replaced by epoxy groups by chemical modification. Useful epoxidized rubbers are from about 5 to about 95 mole percent, preferably as defined as the mole percent of olefinic unsaturation sites originally present in the rubber whose degree of epoxidation has been converted to oxirane, hydroxyl, or ester groups. Has a degree of epoxidation of from about 15 to about 80 mole percent, more preferably from about 20 to about 50 mole percent.

  The epoxidation reaction can be effected by reacting an unsaturated rubber with an epoxidizing agent. Useful epoxidizing agents include peracids such as m-chloroperbenzoic acid and peracetic acid. Other examples include carboxylic acids such as acetic acid and formic acid, or carboxylic acid anhydrides such as acetic anhydride, along with hydrogen peroxide. A catalyst such as cation exchange resin such as sulfuric acid, p-toluenesulfonic acid, or sulfonated polystyrene can optionally be used.

  Epoxidation is preferably performed at a temperature of about 0 ° C to about 150 ° C, preferably about 25 ° C to about 80 ° C. The time required to effect the epoxidation reaction is generally about 0.25 to about 10 hours, preferably about 0.5 to about 3 hours.

  The epoxidation reaction is preferably carried out in a solvent capable of substantially dissolving the rubber both at its original conditions and after epoxidation. Suitable solvents include aromatic solvents such as benzene, toluene, xylene, and chlorobenzene, and alicyclic solvents such as cyclohexane, cycloheptane, and mixtures thereof.

  After epoxidation, the epoxidized rubber is preferably removed or separated from an acidic environment that may include an epoxidizing agent and an acidic catalyst. This separation can be achieved by filtration or by adding a dilute aqueous base solution to neutralize the acid and then substantially coagulating the polymer. The polymer can be coagulated by using an alcohol such as methanol, ethanol, or propanol. Antioxidants are generally added after the separation procedure and the final product may be dried using techniques such as vacuum distillation. Alternatively, other known methods for removing polymers from hydrocarbon solvents and the like, including steam distillation and drum drying, may be used.

  Other diene elastomers can also be used in epoxidized forms such as, but not limited to, rubbers derived from polymerization of conjugated dienes alone or in combination with vinyl aromatic monomers.

  The elastomer can be an alkoxysilane-terminated diene polymer or a copolymer of diene and alkoxy-containing molecules prepared by tin-bonded solution polymerization.

  In the unsaturated compound (A), each group having an olefin-C═C— bond or acetylene-C≡C— bond in the unsaturated compound (A) is an aromatic ring or an additional olefinic double bond or acetylene-free group. Contains saturation, the aromatic ring or further olefinic double bond or acetylenic unsaturation is conjugated with the olefin —C═C— or acetylene-C≡C-unsaturation. According to one embodiment of the present invention, each group having an olefin-C═C— bond or acetylene-C≡C— bond in the unsaturated compound (A) is an olefin-C═C— or acetylene-C≡. It also contains an electron withdrawing moiety for the C-bond.

The electron withdrawing moiety is a chemical group that withdraws electrons from the reaction center. The electron withdrawing bond X is generally Michael B. et al. Smith and Jerry March; March's Advanced Organic Chemistry, 5 th edition, John Wiley & Sons, may be either of the groups listed as dienophiles in New York 2001, at Chapter 15-58 ( page 1062). The bond X can in particular be a C (═O) R ^* , C (═O) OR ^* , OC (═O) R ^* , C (═O) Ar bond, Ar represents arylene, R ^* is Represents a divalent hydrocarbon moiety. X can also be a C (═O) —NH—R ^* bond.

  Each group having an olefin-C═C— bond or an acetylene-C≡C— bond in the unsaturated compound (A) can have, for example, the formula R—CH═CH—CH═CH—Y—, In the formula, R represents hydrogen or a hydrocarbyl group having 1 to 12 carbon atoms, and Y represents an organic bond having an electron withdrawing effect on the adjacent —CH═CH— bond. Alternatively, the unsaturated compound (A) can have the formula Ar—CH═CH—Y—. The bond Y having an electron withdrawing effect can be, for example, a carboxyl bond, and the unsaturated compound (A) can be an ester of a polyhydric alcohol.

  The unsaturated compound (A) has at least two groups each having an olefin-C═C— bond or acetylene-C≡C— bond. Grafting of compound (A) onto a polyolefin or diene elastomer by one of these reactions allows further reaction of the second olefin-C = C-bond or acetylene-C≡C-bond to result in branching or crosslinking To. Unsaturated compounds (A) having an average of three or more groups each having one olefin-C = C-bond or acetylene-C≡C-bond per molecule, for example 3-6 unsaturated groups having such groups It may be preferred for compound (A) to increase the density of crosslinking.

  The unsaturated compound (A) is, for example, an ester of any polyhydric alcohol having 2 to 6 or more —OH groups, such as 3- (hydroxymethyl) pentane-1,5-diol (trimethylolpropane or TMP). , Pentaerythritol, propane-1,3-diol, propane-1,2-diol (propylene glycol), ethylene glycol, glycerol or sorbitol. Polyhydric alcohols having 3 or more -OH groups can be fully or partially esterified.

The unsaturated compound (A) is, for example,
Pentaerythritol trisorbate,

Pentaerythritol tetrasorbate,

Trimethylolpropane trisorbate,

Propane-1,2-diol disorbate or propane-1,3-diol disorbate,

Or a solvate of a polyhydric alcohol such as trimethylolpropane tricinnamate. The preparation of pentaerythritol tetrasorbate by acid-catalyzed esterification is described in Example 4 of US Pat. No. 3,458,460. Other polyhydric alcohol sorbates can be prepared by the same technique.

Grafting of unsaturated compounds (A) to polyolefins to the extent that results in sufficient crosslinking and / or branching of the polyolefin and improves the stability and / or physical properties of the polyolefin is generally free radicals in the polyolefin. Although a means capable of generating sites is required, the diene elastomer is optional (preferably not required). The means for generating free radical sites in the polyolefin preferably includes a compound capable of generating free radicals and thus generating free radical sites in the polyolefin. Other means include application of irradiation such as shearing, heating or electron beam radiation. The high temperature and high shear rate provided by the melt extrusion process can create free radical sites in the polyolefin.

  The compound capable of generating free radical sites in the polyolefin is preferably an organic peroxide, but other free radical initiators such as azo compounds can be used. Preferably, the group formed by decomposition of the free radical initiator is an oxygen-based free radical. It is more preferred to use hydroperoxides, carboxyl peroxyesters, peroxyketals, dialkyl peroxides and diacyl peroxides, ketone peroxides, diaryl peroxides, aryl-alkyl peroxides, peroxydicarbonates, peroxyacids, acylalkylsulfonyl peroxides and monoperoxydicarbonates. Examples of suitable peroxides include dicumyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, di-tert-butyl peroxide, 2,5-dimethyl-2,5. -Di- (tert-butylperoxy) hexyne-3,3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxonane, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butylperoxyacetate, tert-butylperoxybenzoate, tert-amylperoxy-2-ethylhexyl carbonate, tert-butylperoxy-3,5,5-trimethylhexanoate, 2,2-di (tert-butylperoxy) butane Tert-butylperoxyisopropylcar Tert-butylperoxy-2-ethylhexyl carbonate, butyl 4,4-di (tert-butylperoxy) valerate, di-tert-amyl peroxide, tert-butylperoxypivalate, tert-butyl-peroxy-2-ethylhexa Noate, di (tertbutylperoxy) cyclohexane, tertbutylperoxy-3,5,5-trimethylhexanoate, di (tertbutylperoxyisopropyl) benzene, cumene hydroperoxide, tert-butylperoctoate, methyl ethyl ketone peroxide, tert -Butyl α-cumyl peroxide, 2,5-dimethyl-2,5-di (peroxybenzoate) hexyne-3, 1,3- or 1,4-bis (t-butylperoxyiso Propyl) benzene, lauroyl peroxide, tert-butyl peracetate, and tert-butyl perbenzoate. Examples of azo compounds are azobisisobutyronitrile and dimethylazodiisobutyrate. The above radical initiators can be used alone or in combination of at least two of them.

  The temperature at which the polyolefin and the unsaturated compound (A) react in the presence of a compound capable of generating free radical sites in the polyolefin is generally higher than 120 ° C., usually higher than 140 ° C., and melts the polyolefin. And high enough to decompose free radical initiators. For polypropylene and polyethylene, temperatures in the range of 170 ° C to 220 ° C are usually preferred. Other compounds capable of generating free radical sites in the peroxide or polyolefin have a decomposition temperature in the range of 120-220 ° C, most preferably 160-190 ° C. In one suitable procedure, the polyolefin, the unsaturated compound (A) and the compound capable of generating free radical sites in the polyolefin are mixed at a temperature above 120 ° C. in a twin screw extruder and the unsaturated compound (A ) To the polymer, thereby resulting in cross-linking and / or branching of the polyolefin.

  Compounds capable of generating free radical sites in the polyolefin are generally present in an amount of at least 0.01% by weight of the total composition and can be present in an amount of up to 5 or 10% by weight. The organic peroxide is, for example, preferably present at 0.01 to 2% by weight with respect to the polyolefin during the grafting reaction. Most preferably, the organic peroxide is present at 0.01% to 0.5% by weight of the total composition.

  The means for generating free radical sites in the polyolefin can alternatively be an electron beam. When using electron beams, there is no need for compounds such as peroxides that can generate free radicals. The polyolefin is irradiated with an electron beam having an energy of at least 5 MeV in the presence of unsaturated silane (I) or (II). Preferably, the acceleration potential or energy of the electron beam is 5 MeV to 100 MeV, more preferably 10 to 25 MeV. The power of the electron beam generator is preferably 50 to 500 kW, more preferably 120 to 250 kW. The radiation dose applied to the polyolefin / graft agent mixture is preferably 0.5 to 10 Mrad. The mixture of polyolefin and unsaturated compound (A) can be deposited on a continuously moving conveyor, such as an endless belt, passing under an electron beam generator that irradiates the mixture. The conveyor speed is adjusted to achieve the desired irradiation dose.

  Grafting of unsaturated compounds (A) to diene elastomers to the extent that sufficient crosslinking and / or branching of the polyolefin is achieved and the stability and / or physical properties of the diene is improved is generally by ene reaction. Going forward, no means is needed that can generate free radical sites in the polyolefin. The elastomer and the unsaturated compound (A) can be reacted by various procedures. Although some reactions occur at ambient temperature, the elastomer and unsaturated compound (A) are preferably both at a temperature of at least 80 ° C, more preferably 90 ° C to 200 ° C, most preferably 120 ° C to 180 ° C. To a temperature of Although the elastomer and the unsaturated compound (A) can be mixed by pure mechanical mixing, separate heating steps can be performed as desired, but mixing and heating are preferably performed simultaneously, with the elastomer being heated and mechanically Processing is applied. The unsaturated compound (A) grafted to the diene elastomer functions as an anti-reversion agent in rubber production.

  The elastomer and unsaturated compound (A) may be reacted in the presence of a catalyst that accelerates the ene addition reaction between the unsaturated compound (A) and a diene-containing rubber polymer, for example, a Lewis acid such as boron triacetate. it can. The use of such a catalyst can reduce the temperature of the thermomechanical treatment necessary to effect a reaction between the elastomer and the unsaturated compound (A). The catalyst can control the number of bonds produced during the mixing stage and optimize the torque. However, it may be desirable for the diene elastomer and unsaturated compound (A) to react readily at temperatures conventionally used for rubber thermomechanical kneading to avoid catalyst residues in the crosslinked or branched elastomer.

A diene elastomer composition that is cured into a molded rubber product typically has two consecutive preparation stages: high temperature, thermomechanical mixing or kneading first stage (“non-manufacturing”) at a maximum temperature (T _max ) of 110 ° C. to 190 ° C. After the second stage of mechanical mixing at a temperature generally below 110 ° C. (sometimes referred to as the “manufacturing stage”), between which the crosslinking and vulcanization system is incorporated. There is also. Catalysts such as Lewis acids can also be added during the manufacturing stage in order to accelerate the curing behavior under the heating of the semi-finished product.

  The diene elastomer compositions according to the invention which are cured into molded rubber products generally contain a filler, in particular a reinforcing filler such as silica or carbon black. The filler is usually mixed with the elastomer in a non-manufactured thermomechanical mixing or kneading stage, and the unsaturated compound (A) is also mixed with the elastomer and filler in this stage.

  The polyolefin composition according to the present invention may contain a filler. The filler can be conveniently mixed into the polyolefin along with the unsaturated compound (A) and the organic peroxide during the graft / crosslinking reaction. Alternatively, the unsaturated compound (A) can be deposited on the filler prior to reacting with the polyolefin or diene elastomer.

  The filler is preferably a reinforcing filler such as a silica or silicate filler, such as used in white tire compositions, an alumina type mineral oxide such as alumina trihydrate or aluminum hydroxide oxide. Metal oxides, carbon blacks pretreated with alkoxysilanes such as tetraethylorthosilicate, silicates such as aluminosilicate, or mixtures of these different fillers.

The reinforcing filler can be any common siliceous filler used in rubber compounding applications, including, for example, calcined or precipitated siliceous pigments or aluminosilicates. Preference is given to precipitated silicas such as those obtained by acidification of soluble silicates such as sodium silicate. Precipitated silica preferably has a BET surface area in the range of about 20 to about 600, more typically about 40 or 50 to about 300 square meters per gram, as measured using nitrogen gas. The BET method for measuring surface area is described in Journal of the American Chemical Society, Volume 60, Page 304 (1930). Silica is generally measured as described in ASTM D2414, of about 100 to about 350, more typically have a dibutylphthalate (DBP) value in a range of about 150 to about 300 cm ^3/100 g Then it can be characterized. Silica, and if used, alumina or aluminosilicate preferably has a CTAB surface area in the range of about 100 to about 220 m ² / g (ASTM D3849). The CTAB surface area is the external surface area as assessed by cetyltrimethylammonium bromide having a 9 pH. The method is described in ASTM D3849.

  Silica commercially available from Rhodia, for example under the designation Zeosil® 1165MP, 1115MP, or HRS 1200MP; under the Hi-Sil trademark from PPG Industries, representations of Hi-Sil® EZ150G, 210, 243, etc. 200 MP premium, 80 GR or equivalent silica commercially available from Degussa AG, for example, the silica sold commercially under the designation VN3, Ultrasil® 7000 and Ultrasil® 7005; and from Huber, for example Hubersil® ) Various commercially available silicas, such as silica sold under the designation 8745 and Hubersil® 8715, can be considered for use in elastomer compositions according to the present invention. That. Treated precipitated silicas such as the aluminum doped silica described in EP-A-735088 can be used.

When alumina is used for the elastomer composition of the present invention, for example, synthetic aluminum oxide (Al ₂ O ₃ ) prepared by controlled precipitation of natural aluminum oxide or aluminum hydroxide can be used. The reinforced alumina preferably has a BET surface area of 30 to 400 m ² / g, more preferably 60 to 250 m ² / g, and an average particle size of up to 500 nm, more preferably up to 200 nm. Examples of such reinforced alumina are neutral, acidic, or basic Al ₂ O ₃ available from Baikowski's alumina A125, CR125, D65CR or Aldrich Chemical Company. Neutral alumina is preferred.

  Examples of aluminosilicates that can be used in the elastomeric composition of the present invention include Tolsa S., Toledo, Spain. A. A synthetic aluminosilicate from Degussa GmbH, a natural aluminosilicate sepiolite available as PANSIL®.

  Examples of mineral fillers or pigments that can be incorporated into the polyolefin or diene elastomer compositions of the present invention include titanium dioxide, aluminum trihydroxide, magnesium dihydroxide, mica, kaolin, calcium carbonate; sodium, potassium, magnesium, Non-hydrous, partially hydrous or hydrous fluoride, chloride, bromide, iodide, chromate, carbonate, hydroxide, phosphate, hydrogen phosphate, nitrate, oxide, and sulfate of calcium and barium Zinc oxide, antimony pentoxide, antimony trioxide, beryllium oxide, chromium oxide, iron oxide, lithopone, boric acid or borate such as zinc borate, barium metaborate or aluminum borate, vermiculite, quartz, sand, Silica gel; rice husk ash, ceramic and glass beads, zeolite, Minium flakes or powder, bronze powder, copper, gold, molybdenum, nickel, silver powder or flakes, stainless steel powder, metals such as tungsten, hydrous calcium silicate, barium titanate, silica-carbon black composite, functionalized carbon Nanotubes, cement, fly ash, slate powder, bentonite, clay, talc, anthracite, apatite, attapulgite, boron nitride, cristobalite, diatomite, dolomite, ferrous iron, feldspar, graphite, calcined kaolin, molybdenum disulfide, pearlite, pumice , Pyrophyllite, sepiolite, zinc stannate or wollastonite.

  Examples of fiber fillers that can be incorporated into the polyolefin or diene elastomer compositions of the present invention include natural fibers such as wood flour, wood fibers, cotton fibers, cellulose fibers, or wheat straw, hemp, flax, kenaf, kapok, jute , Agricultural fibers such as ramie, sisal, henecken, corn fiber, coir, nut shell or rice husk, or synthetic fibers such as polyester fiber, aramid fiber, nylon fiber, or glass fiber. Examples of organic fillers include lignin, starch or cellulose and cellulose-containing products, or plastic microspheres of polytetrafluoroethylene or polyethylene. The filler can be a solid organic pigment such as one incorporating an azo, indigoid, triphenylmethane, anthraquinone, hydroquinone or xanthine dye.

  The concentration of filler or pigment in such filler compositions can vary widely; for example, the filler can form from 1 or 2% up to 70% by weight of the total composition.

  The reaction between the polyolefin or diene elastomer and the unsaturated compound (A) can be carried out as a batch process or as a continuous process using any suitable apparatus. The batch process can be performed, for example, in an internal mixer such as a Banbury mixer or a Brabender Plasgraph ™ 350S mixer with roller blades. An external mixer such as a roll mill can be used for either batch or continuous processing.

  Continuous processing can be carried out in an extruder such as a single or twin screw extruder. An extruder, for example a twin screw extruder, is preferably used for mechanical processing, ie kneading or compounding while passing the material. One example of a suitable extruder is that commercially available from Coperion Werner Pfeiderer under the trademark ZSK. The extruder is preferably equipped with a vacuum port immediately in front of the extrusion die to remove any unreacted unsaturated compound (A).

  The diene elastomer compositions according to the present invention are preferably machined or thermomechanically mixed or kneaded (“non-manufacturing” stage) at elevated temperatures, during which the vulcanization system is incorporated, followed by lower temperatures, generally less than 110 ° C. For example, using two conventional continuous preparation stages of the second stage (“manufacturing” stage) of mechanical mixing at 40 ° C. to 100 ° C. The non-manufacturing stage can be performed as described above as a batch or continuous process. In a batch process, the elastomer and the unsaturated compound (A) are generally mixed for at least 1 minute at temperatures above 100 ° C. and can be mixed for up to 20 minutes, although the mixing time at high temperatures is generally 2 to 10 minutes. The residence time of the diene elastomer and unsaturated compound (A) in the extruder or other continuous reactor at temperatures higher than 100 ° C. is generally at least 0.5 minutes, preferably at least 1 minute. Can be up to 15 minutes. More preferably, the residence time is 1 to 5 minutes.

  Compositions containing cross-linked or branched elastomers produced according to the present invention can be cured by various mechanisms and provide further cross-linking as needed. The curing agent for the modified elastomer can be a conventional rubber curing agent such as a sulfur vulcanizing agent. Alternatively, the modified elastomer can be cured with a radical initiator such as a peroxide.

  Examples of suitable sulfur vulcanizing agents include, for example, elemental sulfur (free sulfur) or sulfur donating vulcanizing agents such as amine disulfides, polymer polysulfides or sulfur olefin additions conventionally added in the final manufacturing rubber composition mixing step. Compounds. Suitably, in most cases, the sulfur vulcanizing agent is elemental sulfur. The sulfur vulcanizing agent is used in an amount in the range of about 0.4 to about 8% by weight, preferably 1.5 to about 3% by weight, especially 2 to 2.5% by weight, based on the elastomer.

  Accelerators are generally used to control the time and / or temperature required for vulcanization and to improve the properties of the vulcanized elastomer composition. In one embodiment, a single accelerator system may be used, i.e., primary accelerator. More preferably, the primary accelerator is used in a total amount in the range of about 0.5 to about 4 weight percent, preferably about 0.8 to about 1.5 weight percent, based on the elastomer. In another embodiment, a combination of primary and secondary accelerators can be used, but secondary accelerators are used in small amounts of about 0.05 to about 3% by weight to activate and improve the properties of the vulcanizate. Used in Delayed action accelerators can be used and are not affected by normal processing temperatures, but provide sufficient cure at normal vulcanization temperatures. Vulcanization retarders such as phthalic anhydride, benzoic acid or cyclohexylthiophthalimide can also be used. Suitable types of accelerators that can be used in the present invention are amines, disulfides, guanidines, thioureas, thiazoles such as mercaptobenzothiazole, thiuram, sulfenamide, dithiocarbamates, thiocarbonates, and xanthates. Preferably, the primary accelerator is sulfenamide. When a secondary accelerator is used, the secondary accelerator is preferably a guanidine, dithiocarbamate or thiuram compound.

  When the curing system is composed of sulfur, the vulcanization or curing of rubber products such as tires or tire treads is a known method, preferably at a temperature of 130 ° C. to 200 ° C., for a sufficiently long time under pressure. Done. The time required for vulcanization can vary, for example, between 2 and 30 minutes.

  Filling compositions according to the invention comprise binders having 1 to 20 carbon atoms in the alkyl group and 1 to 6 carbon atoms in the alkoxy group, such as trialkoxy, dialkoxy or monoalkoxysilane binders, in particular It may contain sulfide silane, mercaptosilane, azosilane, acrylamide silane, block mercaptosilane, aminosilane, alkylsilane or alkenylsilane. Examples of suitable binders include bis (trialkoxysilylpropyl) described in US Pat. No. 5,684,171 such as bis (triethoxysilylpropyl) tetrasulfane or bis (triethoxysilylpropyl) disulfane. ) Bis (dialkoxymethylsilylpropyl) disulfane such as disulfane or tetrasulfane, bis (methyldiethoxysilylpropyl) tetrasulfane or bis (methyldiethoxysilylpropyl) disulfane, tetrasulfane, bis (dimethylethoxysilyl) Bis (dimethylethoxysilylpropyl) oligosulfan, such as propyl) tetrasulfane or bis (dimethylethoxysilylpropyl) disulfane, US Pat. No. 1,671,742 Bis (dimethylhydroxysilylpropyl) polysulfane described in No. 5, dimethylhydroxysilylpropyldimethylalkoxysilylpropyl oligosulfane described in International Publication No. WO-A-2007 / 061550, or triethoxysilylpropyl mercapto Examples include mercaptosilane such as silane. Such binders promote the bonding of the filler to the elastomer or polyolefin and thus improve the physical properties of the filled elastomer or polyolefin. The filler can be pretreated with the binder, or the binder can be added to the mixer along with the elastomer or polyolefin, the filler and the unsaturated compound (A) according to the invention.

  For many applications, the polymer composition of the present invention preferably contains at least one antioxidant. Examples of suitable antioxidants are tris (2,4-di-tert-butylphenyl) phosphite marketed under the trademark Ciba Irgafos® 168, marketed under the trademark Ciba Irganox® 1010 Tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl-propionate)] methane treatment stabilizer and 1,3,5-trimethyl-commercially available under the trademark Ciba Irganox® 1330 2,4,6-Tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, N-1,3-dimethylbutyl-N commercially available from Flexsys as “Santoflex 6-PPD” ™ -Phenyl-para-phenylenediamine, diphenyl-p-phenylenedia Emissions, etc., for example, The Vanderbilt Rubber Handbook (1978), include those disclosed in Pages 344-346. The polymer composition is a stabilizer against ultraviolet radiation and light radiation, for example hindered amine light stabilizers such as 4-substituted-1,2,2,6,6-pentamethylpiperidine, such as the trademark Tinuvin® 770, Tinuvin ( It may also be desirable to include those marketed under registered trademark 622, Uvasil® 299, Chimassorb® 944 and Chimassorb® 119. Antioxidants and / or hindered amine light stabilizers can be conveniently incorporated with the unsaturated compound (A) and, if used, organic peroxides in the polyolefin or diene elastomers during the crosslinking and / or branching reactions. The total concentration of antioxidants and light stabilizers in the crosslinked polyolefin is generally in the range of 0.02 to 0.15% by weight of the total composition. The total concentration of antioxidants and light stabilizers in the crosslinked diene elastomer is generally in the range of 0.1 to 5% by weight.

  The elastomer composition according to the invention comprises processing additives such as oils, resins containing tackifying resins, plasticizers, fatty acids, zinc oxide, waxes, antiozonants, heat stabilizers, UV stabilizers, dyes, pigments, weight gains. It can be blended with various common additive substances such as additives and peptizers. When used, typical amounts of tackifying resin include about 0.5 to about 10% by weight, preferably 1 to 5% by weight, based on the elastomer. Typical amounts of processing aids include about 1 to about 50 weight percent based on the elastomer. Such processing aids can include, for example, aromatic, naphthene, and / or paraffin processing oils. When used, common amounts of fatty acids that can include stearic acid or zinc stearate include from about 0.1 to about 3 weight percent based on the elastomer. Typical amounts of zinc oxide include from about 0 to about 5 weight percent, or from 0.1 to 5 weight percent, based on the elastomer. Typical amounts of wax include about 1 to about 5 weight percent based on the elastomer. Microcrystalline and / or crystalline waxes can be used. Typical amounts of peptizers include about 0.1 to about 1% by weight with respect to the elastomer. Common peptizers can be, for example, pentachlorothiophenol or dibenzamide diphenyl disulfide.

  The polyolefin composition according to the invention may also contain other additives such as dyes or processing aids.

  The crosslinked and / or branched polyolefin compositions produced according to the present invention can be used in a wide variety of products. Blowing or rotational molding of crosslinked and / or branched polyolefin compositions, bottles, cans or other liquid containers, liquid supply sections, ventilation sections, tanks including fuel tanks, corrugated bellows, covers, cases, tubes, tubes, tubes A joint or transport trunk can be formed. Cross-linked and / or branched polyolefin compositions can be blow extruded to form films, profiles, flooring, tubes, conduits or sleeves, including tubes, corrugated tubes, sheets, fibers, plates, coatings, shrink wrap films, or It can be extruded onto a wire or cable as an electrical insulation layer. Crosslinked and / or branched polyolefin compositions can be injection molded to form tubes and fittings, packaging, gaskets and panels. Crosslinked and / or branched polyolefin compositions can also be foamed or thermoformed.

  Crosslinked and / or branched diene elastomer compositions containing curing agents such as vulcanization systems are formed and cured into products. An elastomer composition can be used to produce a tire that includes any part thereof such as a bead, apex, sidewall, innerliner, tread or carcass. The elastomeric composition may alternatively be used to produce any other engineering rubber product, such as bridge cushioning elements, hoses, belts, shoe soles, seismic vibrators, and damping elements. The elastomeric composition can be cured by contact with a cord, for example an organic polymer cord such as polyester, nylon, rayon or cellulose cord or a reinforcing element such as a steel cord, fiber layer or metal or organic sheet.

  Products formed from crosslinked and / or branched polyolefins have improved physical / mechanical properties and / or improved heat resistance, scratch resistance and flame resistance compared to products formed from the same polyolefin without crosslinking or branching Have Vulcanized products formed from crosslinked and / or branched diene elastomers have improved physical / mechanical properties and improved heat resistance, scratch resistance and difficulty compared to products formed from the same diene elastomer without crosslinking or branching. Has flammability.

The present invention relates to a polymer composition comprising a polyolefin or a diene elastomer and an unsaturated compound (A) having at least two groups each having an olefin-C = C-bond or acetylene-C≡C-bond. Each group having an olefin-C = C-bond or acetylene-C≡C-bond in (A) contains an aromatic ring or a further olefin double bond or acetylenic unsaturation, Provided is a composition characterized in that the heavy bond or acetylenic unsaturation is conjugated with olefin-C = C- or acetylene-C≡C-unsaturation.
Preferably, the polyolefin comprises alpha olefins having 3 to 8 carbon atoms of at least 50% by weight units.
-Preferably, the polyolefin is polypropylene.
-Preferably, each group having an olefin-C = C- bond or acetylene-C≡C- bond in the unsaturated compound (A) is relative to the olefin-C = C- or acetylene-C≡C- bond. Contains an electron withdrawing moiety.
Preferably, each group having an olefin —C═C— bond or acetylene-C≡C— bond in the unsaturated compound (A) has the formula R—CH═CH—CH═CH—Y—. In the formula, R represents hydrogen or a hydrocarbyl group having 1 to 12 carbon atoms, and Y represents an organic bond having an electron withdrawing effect on the adjacent —CH═CH— bond.
-Preferably, the unsaturated compound (A) is a sorbate ester of a polyhydric alcohol.
Preferably, the sorbate ester is pentaerythritol trisorbate, pentaerythritol tetrasorbate, trimethylolpropane trisorbate, propane-1,2-diol disorbate or propane-1,3-diol disorbate is there.

The present invention relates to an unsaturated compound having three or more groups each having an olefin-C = C-bond or an acetylene-C≡C-bond in the presence of means capable of generating free radical sites in the polyolefin. In the process of forming a crosslinked or branched polyolefin comprising reacting with compound (A), each group having an olefin-C = C-bond or acetylene-C≡C-bond in the unsaturated compound (A) is aromatic. An aromatic ring or further olefinic double bond or acetylenic unsaturation, wherein the aromatic ring or further olefinic double bond or acetylenic unsaturation is conjugated with olefin-C = C- or acetylene-C≡C-unsaturation A process characterized by
Preferably, the organic peroxide compound capable of generating free radical sites in the polyolefin is present in the composition in an amount of 0.01 to 5% by weight relative to the total composition.
Preferably, the process of forming the crosslinked or branched diene elastomer comprises the step of diene elastomer with an unsaturated compound (A) having three or more groups having olefin-C = C-bond or acetylene-C≡C-bond, respectively. Each step having an olefin-C = C-bond or acetylene-C≡C-bond in the unsaturated compound (A) contains an aromatic ring or a further olefinic double bond or acetylenic unsaturation And the aromatic ring or further olefinic double bond or acetylenic unsaturation is conjugated with the olefin-C = C- or acetylene-C≡C-unsaturation.
Preferably, 85 to 100 parts by weight of polyolefin or diene elastomer is reacted with 0.01 to 10 parts by weight of unsaturated compound (A).
Preferably, the unsaturated compound (A) is deposited on the filler prior to reacting with the polyolefin or diene elastomer.
Preferably, the unsaturated compound (A), filler and polyolefin or diene elastomer are reacted in situ.

  The present invention provides olefin-C = C-bond or acetylene-C≡C-bond, respectively, in cross-linking of polyolefins with less degradation than polyolefins compared to cross-linking with polyunsaturated compounds containing no conjugated unsaturation. In the use of an unsaturated compound (A) having more than two groups, each group having an olefin-C = C-bond or acetylene-C≡C-bond is an aromatic ring or a further olefinic double bond or acetylene Uses containing unsaturation are provided wherein the aromatic ring or further olefinic double bond or acetylenic unsaturation is conjugated with the olefin-C = C- or acetylene-C≡C-unsaturation.

  The invention is illustrated by the following examples.

Polymers used as raw materials :
PP = isotactic polypropylene homopolymer supplied as Borealis® HB205TF (melt flow index MFR 1 g / 10 min at 230 ° C./2.16 kg as measured by ISO 1133);
-Porous PP = microporous polypropylene supplied by Membrana as Accurel (R) XP100. This microporous polymer was used to absorb the liquid component. The characteristics of Accurel® XP100 are MFR (2.16 kg / 230 ° C.) 2.1 g / 10 min (ISO 1133 method) and melting temperature (DSC) 156 ° C.

Peroxide used:
DHBP = 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane peroxide supplied as Arkema Luperox® 101 peroxide.

Antioxidants used:
Irgafos® 168 = Tris- (2,4-di-tert-butylphenyl) phosphite antioxidant supplied as Irgafos® 168 from Ciba Irganox® 1010 = Irganox from Ciba Tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl-propionate)] methanephenol antioxidant supplied as ® 1010

Crosslinking aid:
Styrene (99% purity, Reagent Plus® (ref. S4972) supplied by Sigma-Aldrich)
Ethyl sorbate (Purity ≧ 98%, Reagent Plus® (ref. 177687) supplied by Sigma-Aldrich)

Pentaerythritol tetraacrylate (PETA) is Reagent Plus® (ref. 408263) supplied by Sigma-Aldrich, and trimethylolpropane triacrylate (TMPTA) was supplied by Cray Valley (ref. SARTOMER 351). .

  Pentaerythritol tetrasorbate (PETS), trimethylolpropane trisorbate (TMPTS) and propane-1,3-diol disorbate ("disorbate") are the corresponding multivalents according to Example 4 of US Pat. No. 3,458,460. Prepared by acid-catalyzed esterification of alcohol.

Example 1
Ten parts by weight of the porous PP pellets were tumbled until 1.87 parts by weight of PETS and 0.2 parts of DHBP and the liquid reagent were absorbed by the polypropylene to form a multifunctional sorbate masterbatch.

  100 parts by weight of Borealis® HB205TF polypropylene pellets were placed in a Brabender® Plastograph 350E mixer equipped with a roller blade and compounded. The filling ratio was set to 0.7. The rotation speed was 50 rpm and the chamber temperature was maintained at 190 ° C. The melt torque and temperature were observed to control the reaction process of the components. PP was divided into 3 parts and fused / mixed for 1 minute after each addition. The multifunctional sorbate masterbatch was then added and mixed for 4 minutes to initiate the grafting reaction. 0.5 parts Irganox 1010 and 0.5 parts Irgafos 168 antioxidant were then added and mixed for an additional 1 minute while grafting was continued. The melt was then dripped from the mixer and cooled to ambient temperature. The resulting grafted polypropylene was molded into 2 mm thick sheets by further pressing at 210 ° C. for 5 minutes on an Agila® PE 30 press before cooling to ambient temperature at 15 ° C./min.

Examples 2 and 3
As shown in Table 1, Example 1 was repeated, replacing PETS with either the corresponding amount of TMPTS or disorbate required to match the molar amount of sorbyloxy functionality.

Comparative Examples C1 and C2
In Comparative Example C1, Example 1 was repeated with PETS omitted. In Comparative Example 2, PETS and peroxide were omitted.

Comparative examples C3 and C4
As shown in Table 1, PETS and TMPTS were replaced with the corresponding amounts of PETA and TMPTA, respectively, necessary to match the molar amount of acrylate functional groups to the molar amount of sorbyloxy functional groups, and Examples 1 and 2 were repeated. .

Comparative Example C5
As shown in Table 1, 1.6 parts of styrene was added as a crosslinking aid, and Comparative Example C4 was repeated.

  For each example, the torque and elastic shear modulus G 'during blending of the crosslinked polypropylene was measured. These are recorded in Table 1.

  Process torque is a measurement of torque in Newton meters (Nm) applied by the motor of a Plasgraph 350E mixer to maintain a mixing speed of 50 rpm. The value reported is one of the torque level plateaus at the end of mixing.

  The lower the torque, the lower the polymer viscosity. The torque level after the mixing stage thus represents polymer degradation during mixing.

  Elastic shear modulus (G ') measurement was performed on an Advanced Polymer Analyzer APA2000 (registered trademark). A 3.5 g sample was analyzed at a temperature of 210 ° C. above its melting point. Elastic shear modulus (G ') was recorded for strain sweeps under constant vibration conditions (0.5 Hz). The recording of elastic shear modulus (G ′), viscosity (G ″), and TanD for the strain range of 1-610% takes about 8 minutes. From various plots of G ′ as a function of strain percent, strain 12 All values in% were in the linear viscoelastic region, so G ′ values at 12% strain were chosen according to the change in elastic shear rate as a function of sample degradation and crosslinking as described in the examples.

The gel content of the polypropylene sheet was measured and recorded in Table 1. The gel content was measured using the ISO 10147 method “Pipes and fittings made of crossed polyethylene (PE-X) -Estimation of the degree of crosslinking by dent.” The principle of the test consists of measuring the mass of the specimen taken from the molded part before and after immersion in the solvent of the specimen (8 hours in refluxing xylene). The degree of crosslinking is expressed as a weight percent of insoluble material.

  Comparing Examples 1 to 3 with Comparative Examples C1 and 2, we found that the formulation of our invention is more pronounced compared to the formulation made with peroxide in the absence of additives (Comparative Example C1). The effect of preventing polypropylene decomposition was observed. Examples 1-3 showed higher torque values than Comparative Example C1, which were close to or even higher than those of PP without peroxide (Comparative Example C2). Examples 1-3 also showed substantial cross-linking as shown by the high G ′ and gel content values obtained from good grafting efficiency of unsaturated compounds to polypropylene resin while preventing its degradation. . This showed the polypropylene crosslinking efficiency of our inventive formulation.

  Compared Examples 1-3 with Comparative Examples C3 and C4, we observed significant polypropylene degradation prevention and polypropylene cross-linking effects of our inventive formulations compared to formulations made with acrylate compounds. Examples 1-3 showed higher torque, G 'and gel content values than Comparative Examples C3 and C4 where polypropylene degradation occurred during grafting.

The use of crosslinking aids such as styrene in combination with multifunctional acrylates is known to inhibit polymer degradation. A comparison of Examples 1-3 with Comparative Example C5 shows that our formulation achieves the same performance as a formulation using an acrylate compound and styrene as a crosslinking aid at the same time without the need for such a crosslinking aid. Showed that it is possible to do.

Claims (10)

In a polymer composition comprising a polyolefin or a diene elastomer and an unsaturated compound (A) having at least two groups each having an olefin-C═C-bond or acetylene-C≡C-bond,
The unsaturated compound (A) is pentaerythritol trisorbate, pentaerythritol tetrasorbate, trimethylolpropane trisorbate, propane-1,2-diol disorbate or propane-1,3-diol disorbate. A polymer composition characterized by being a sorbate ester of a polyhydric alcohol.   2. Polymer composition according to claim 1, characterized in that the polyolefin comprises alpha olefins having 3 to 8 carbon atoms in units of at least 50% by weight.   The polymer composition according to claim 2, wherein the polyolefin is polypropylene. In the presence of means capable of generating free radical sites in the polyolefin, the polyolefin is converted to an unsaturated compound having at least two groups each having an olefin-C = C-bond or acetylene-C≡C-bond ( In the process of forming a crosslinked or branched polyolefin comprising the step of reacting with A)
The unsaturated compound (A) is pentaerythritol trisorbate, pentaerythritol tetrasorbate, trimethylolpropane trisorbate, propane-1,2-diol disorbate or propane-1,3-diol disorbate. A process characterized by being a sorbate ester of a polyhydric alcohol.   The organic peroxide compound capable of generating free radical sites in the polyolefin is present in the composition in an amount of 0.01 to 5% by weight based on the total composition. 4. Process according to 4. In the process of forming a crosslinked or branched diene elastomer comprising reacting a diene elastomer with an unsaturated compound (A) having at least two groups each having an olefin-C = C-bond or an acetylene-C≡C-bond The unsaturated compound (A) is pentaerythritol trisorbate, pentaerythritol tetrasorbate, trimethylolpropane trisorbate, propane-1,2-diol disorbate or propane-1,3-diol disorbate A process characterized in that it is a sorbate ester of a polyhydric alcohol consisting of   Process according to claim 6, characterized in that 85 to 100 parts by weight of polyolefin or diene elastomer are reacted with 0.01 to 10 parts by weight of the unsaturated compound (A).   Process according to any of claims 4 to 7, characterized in that the unsaturated compound (A) is deposited on a filler before reacting with the polyolefin or diene elastomer.   The process according to claim 4, wherein the unsaturated compound (A), the filler and the polyolefin or diene elastomer are reacted in situ. At least each having an olefin-C = C-bond or an acetylene-C≡C-bond in crosslinking of the polyolefin with less degradation of the polyolefin compared to crosslinking with a polyunsaturated compound containing no conjugated unsaturation In the use of an unsaturated compound (A) having two groups,
The unsaturated compound (A) is pentaerythritol trisorbate, pentaerythritol tetrasorbate, trimethylolpropane trisorbate, propane-1,2-diol disorbate or propane-1,3-diol disorbate. Use characterized by being a sorbate ester of a polyhydric alcohol.