Method for producing functionalized thermoplastic elastomers

Abstract

A method for producing functionalized thermoplastic elastomers on the basis of grafting substrates, selected from olefine-block copolymers of composition 80 to 98 mass-% ethylene-/2 to 20 mass-% C.sub.3- to C.sub.12-olefine units or partially crystalline propylene/ethylene and/or C.sub.4- to C.sub.12-olefine and/or C.sub.4- to C.sub.12-diene-copolymers of composition 50 to 98 mass-% propylene-/2 to 50 mass-% C.sub.2- and/or C.sub.4- to C.sub.12-olefine and/or C.sub.4- to C.sub.12-diene units or cross-linked styrene/olefine/styrene or styrene/olefine-block copolymers, wherein, in a liquid mixing reactor per 100 mass parts of particular grafting substrate0.1 to 15 mass parts of at least one functional monomer from the series of functional groups comprising ,-ethylenic unsaturated compounds or 0.1 to 15 mass parts of a monomer mixture comprising at least one of said functional monomers and0.01 to 10 mass parts of at least one initiator forming free radicals having a 1-hour half-life temperature (T.sub.Hwz/1h) between 50 and 200 C. are added and, at reaction temperatures between 40 C. and the melting or softening temperature of the grafting substrate, are polymerized over a reaction period between 10 and 200 min to solid-fluid phase, wherein a grafting product having a grafted functional monomer is produced by such a solid phase functionalization which is used as an input component for further processing. Functionalized thermoplastic elastomers having a degree of functionalization between 0.1 and 5 mass-% can be obtained using the method. Said elastomers are suitable for use as a bonding agent and/or adhesive agent for various substrates or multi-layer composites.

Claims

1. A process for preparing a functionalized thermoplastic elastomer based on particulate graft substrates selected from the group consisting of: (i) olefin block copolymers comprising 80 to 98 mass-% of ethylene- and 2 to 20 mass-% of C.sub.3- to C.sub.12-olefin units; (ii) semi-crystalline copolymers of the composition 50 to 98 mass-% of propylene- and 2 to 50 mass-% of ethylene and/or C.sub.4- to C.sub.12-olefin and/or C.sub.4- to C.sub.12-diene units, and (iii) cross-linked styrene/olefin/styrene block copolymers or cross-linked styrene/olefin block copolymers, wherein in a fluid mixing reactor, is added: 0.1 to 15 mass parts of ,-ethylenically unsaturated compounds containing at least one functional monomer or a monomer mixture containing the at least one functional monomer, wherein the at least one functional monomer contains functional groups, 0.01 to 10 mass parts of at least one initiator forming free radicals with a 1-hour half-life temperature (T.sub.HWZ/1h) between 50 and 200, and 100 mass parts of the particulate graft substrate; wherein the unsaturated compounds, the at least one initiator and particulate graft substrate are polymerized at reaction temperatures between 40 C. and the melting or softening temperature of the particulate graft substrate for a reaction time between 10 and 200 min in a solid-fluid phase, wherein a graft product having a grafted functional monomer is produced by such a solid state functionalization, which is used as a starting component for further processing, wherein during further processing: 100 mass parts of the graft product is mixed with: (i) between 0.1 and 60 mass parts of at least one other functional monomer; or (ii) between 0.1 and 60 mass parts of another monomer mixture containing the at least one other functional monomer and between 0.01 and 20 mass parts of at least one other initiator forming free radicals with a 1-hour half-life temperature (T.sub.HWZ/1h) 80-240 C. producing a mixture; the mixture together with 100 to 4000 mass parts of an unmodified olefin elastomer, are continuously fed into an intake area of a reaction extruder via metering devices, reactive extrusion from the reactor extruder is carried out at temperatures above melting or softening point of the unmodified olefin elastomer, and the functionalized thermoplastic elastomer is continuously discharged from the reaction extruder.

2. The process according to claim 1, wherein the at least one functional monomer is ,-ethylenically unsaturated compounds containing carboxyl groups and/or derivatives selected from their anhydrides and/or mono- or diesters and/or mono- or diamides.

3. The process according to claim 1, wherein the functional groups comprise hydroxyl, epoxy-, amino-, imido- or silane groups.

4. The process according to claim 2, wherein the functional monomers are maleic anhydride (MA) and/or acrylic acid (AS) alone or as a mixture with a co-monomer from a group of vinyl aromatics.

5. The process according to claim 2, wherein the functional monomers are C.sub.1- to C.sub.12-alkyl esters of acrylic or methacrylic acid alone or as a mixture with a co-monomer from a group of vinyl aromatics.

6. The process according to claim 4, wherein compositions of 99 to 20 mass-% of the functional monomer and 1 to 80 mass-% of the co-monomer are used.

7. The process according to claim 1, wherein the radical-initiated grafting using a radical former or a mixture consisting of at least two different free-radical formers is performed using organic peroxides with 1-hour half-life temperature (T.sub.HWZ/1h) between 50 and 200 C. or a 1-minute half-life temperature (T.sub.HWZ/1min) between 85 and 250 C. in a concentration between 0.001 and 5 mass-% in relation to an entire quantity of the graft substrate.

8. The process according to claim 7, wherein dialkyl peroxydicarbonates with a 1-hour half-life temperature (T.sub.HWZ/1h) between 60 and 70 C., dilauroylperoxide (DLPO) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 80 C., dibenzoyl peroxide (DBPO) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 91 C., tert-butyl peroxy-2-ethylhexanoate (TBPEH) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 91 C., tert-butyl peroxy-isobutyrate (TBPIB) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 98 C., 1,1-di-(tert-butylperoxy) cyclohexane (DTBPC) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 113 C., tert-butyl perbenzoate (TBPB) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 122 C., dicumyl peroxide (DCP) having a 1-hour half-life temperature (T.sub.HWZ/1h) of 132 C., 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane (DHBP) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 134 C., 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3 (DYBP) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 141 C., di-tert-butyl peroxide (TBP) having a one-hour half-life temperature (T.sub.HWZ/1h) of 141 C., cumene hydroperoxide (CHP) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 166 C. and tert-butyl hydroperoxide (TBHP) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 185 C. are used as the radical formers.

9. The process according to claim 1, further comprising the step of adding to the functionalized thermoplastic elastomer at least one additive selected from antioxidants and/or processing stabilizers, fillers, reinforcement agents, flame retardants, lubricants, extender oils, and at least one polymer and/or elastomer component with a proportion of 1 to 90 mass-% based on the entire elastomeric extruded mass.

10. The process according to claim 9, further comprising the step of adding as processing stabilizers primary antioxidants which are sterically hindered phenol compounds with a proportion of 0.01 to 5 mass parts in relation to an elastomeric olefin copolymer or olefin block copolymer functionalized to 100 mass parts.

11. The process according to claim 10, wherein the processing stabilizers are a combination of at least one primary and at least one secondary antioxidant.

12. The method according to claim 1, wherein the fluid mixing reactor is a temperature-controllable mixer for fine-grained materials.

13. A process for preparing a functionalized thermoplastic elastomer based on particulate graft substrates selected from the group consisting of: (i) olefin block copolymers comprising 80 to 98 mass-% of ethylene- and 2 to 20 mass-% of C.sub.3- to C.sub.12-olefin units; (ii) semi-crystalline copolymers of the composition 50 to 98 mass-% of propylene- and 2 to 50 mass-% of ethylene and/or C.sub.4- to C.sub.12-olefin and/or C.sub.4- to C.sub.12-diene units, and (iii) cross-linked styrene/olefin/styrene block copolymers or cross-linked styrene/olefin block copolymers, wherein in a fluid mixing reactor is added: 0.1 to 15 mass parts of ,-ethylenically unsaturated compounds containing at least one functional monomer or a monomer mixture containing the at least one functional monomer, wherein the at least one functional monomer contains functional groups, 0.01 to 10 mass parts of at least one initiator forming free radicals with a 1-hour half-life temperature (T.sub.HWZ/1h) between 50 and 200 C. are added to, and 100 mass parts of the particulate graft substrate; wherein the unsaturated compounds, the at least one initiator and the particulate graft substrate are polymerized at reaction temperatures between 40 C. and the melting or softening temperature of the particulate graft substrate for a reaction time between 10 and 200 min in a solid-fluid phase, wherein a graft product having a grafted functional monomer is produced by such a solid state functionalization, which is used as a starting component for further processing, wherein during further processing: 100 mass parts of the graft product is mixed with: (i) between 0.5 to 50 mass parts of at least one other functional monomer; or (ii) between 0.5 to 50 mass parts of another monomer mixture containing the at least one other functional monomer and between 0.02 and 12 mass parts containing at least one initiator forming free radicals with a 1-hour half-life temperature (T.sub.HWZ/1h) 80-240 C. producing a mixture; the mixture together with 200 to 2000 mass parts of an unmodified olefin elastomer, are continuously fed into an intake area of a reaction extruder via metering devices, reactive extrusion from the reactor extruder is carried out at reaction temperatures between 160 and 300 C., the functionalized thermoplastic elastomer is continuously discharged from the reaction extruder.

Description

DETAILS OF THE INVENTION

(1) According to the invention, from 0.1 to 15 mass parts of ,-ethylenically unsaturated compounds containing at least one functional monomer from the series of functional groups or from 0.1 to 15 mass parts (MT) of a monomer mixture containing at least one of these functional monomers, and from 0.01 to 10 mass parts of at least one initiator forming free radicals with a 1-hour half-life temperature (T.sub.HWZ/1h) between 50 and 200 C.
are added in the process to 100 mass parts of particulate graft substrate in a fluid mixing reactor, i.e. in a temperature-controlled mixer for fine-grained materials, which ensures a free flowing powder bed, and polymerized at reaction temperatures between 40 C. and the melting or softening temperature of the graft substrate for a reaction time between 10 and 200 min in a solid-fluid phase, wherein a graft product having a grafted functional monomer is produced by such a solid phase functionalization, which is used as starting component for further processing.

(2) In further processing of the graft product, which advantageously contains a proportion between 0.05 and 12 mass-% of grafted functional monomer, 100 mass parts of the solid phase graft product, to which between 0.1 and 60 mass parts of at least one functional monomer or a monomer mixture containing between 0.1 and 60 mass parts of at least one functional monomer and between 0.01 and 20 mass parts containing at least one initiator forming free radicals with a 1-hour half-life temperature T.sub.HWZ/1h between 80 and 240 C. are mixed in, together with 100 to 4000 mass parts of an unmodified olefin elastomer, are fed continuously by way of metering devices into the intake area of an extruder. The reactive extrusion is performed at temperatures above the melting or softening point of the olefin elastomer. A functionalized elastomer advantageously having a degree of functionalization between 0.1 and 5 mass-% is continuously discharged at the end of the reactor.

(3) As a specific embodiment of the invention, a process variant has been found advantageous wherein the solid phase functionalization of 100 mass parts of particulate graft substrate with between 0.5 and 15 mass parts of at least one functional monomer or with between 0.5 to 15 mass parts of a monomer mixture containing at least one functional monomer and 0.05 to 10 mass parts of at least one initiator forming free radicals with a 1 hour half-life temperature T.sub.HWZ/1h at between 50 and 200 C. takes place at reaction temperatures between 50 C. and the melting or softening temperature of the graft substrate for a reaction time between 10 and 100 min, and wherein thereafter a graft product containing a proportion of between 0.1 and 10 mass-% grafted functional monomer is used as starting component. Here, 100 mass parts solid-phase graft product, to which between 0.5 and 50 mass parts of at least one functional monomer or between 0.5 and 50 mass parts of at least one monomer mixture containing a functional monomer and between 0.02 to 15 mass parts of at least one initiator forming free radicals with a 1-hour half-life temperature T.sub.HWZ/1h between 80 and 240 C. are admixed, are continuously fed together with 200 to 2000 mass parts of an unmodified olefin elastomer, preferably of the graft substrate used for solid phase functionalization, via metering devices into the intake section of a reaction extruder. The reactive extrusion is performed at temperatures between 160 and 300 C. An elastomer, advantageously with a degree of functionalization between 0.2 and 4 mass-% is continuously discharged at the end of the reactor.

(4) ,-ethylenically unsaturated compounds containing carboxyl groups and/or derivatives selected from their anhydrides, mono- or di-esters, or mono- or di-amides are used as preferred functional monomers. Likewise, the functional monomers can advantageously also be selected from hydroxyl-, epoxy-, amino-, imido-, silane- or other ,-ethylenically unsaturated compounds containing functional groups.

(5) Of the carboxyl- and anhydride monomers usable as functionalizing agents, the so-called carboxylic monomers, maleic anhydride (MSA) and/or acrylic acid (AS) are particularly preferred. They are used alone or as a mixture with a co-monomer from the group of vinyl aromatics, preferably styrene. Other compounds preferably used as functional monomers are C.sub.1- to C.sub.12-alkyl esters of acrylic or methacrylic acid, preferably methyl or ethyl or butyl acrylate or methyl methacrylate, which are used also either alone or as a mixture with a co-monomer from the group of vinyl aromatics, preferably styrene.

(6) According to one embodiment of the aforedescribed process variant, compositions of from 99 to 20 mass-% functional monomer and from 1 to 80 mass-% of co-monomer are employed, preferably 95 to 50 mass-% of maleic anhydride (MSA) and/or acrylic acid (AA) and from 5 to 50 mass-% styrene.

(7) The grafting initiated by radicals is, in order to achieve adequate degrees of functionalization and uniform grafting, advantageously performed by using a radical former or optionally a mixture of at least two different radical formers by using organic peroxides with 1-hour half-life temperatures (T.sub.HWZ/1h) between 50 and 200 C. or 1-minute half-life temperatures (T.sub.HWZ/1h) between 85 and 250 C., measured in 0.1 molar monochlorobenzene solution, with a concentration in relation to the entire graft substrate quantity between 0.001 and 5 mass-%, preferably between 0.02 and 2 mass-%.

(8) Selected examples of useful radical initiators are dialkyl peroxy-dicarbonates with a 1-hour half-life temperature (T.sub.HWZ/1h) between 60 and 70 C., such as dibutyl peroxy-dicarbonate (DBPOC) and dicetyl peroxy-dicarbonate (DCPOC) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 65 C., diauroyl peroxide (DLPO) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 80 C., dibenzoyl peroxide (DBPO) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 91 C., tert-butyl peroxy-2-ethylhexanoate (TBPEH) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 91 C., tert-butyl peroxy-isobutyrate (TBPIB) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 98 C., 1,1-di-(tert-butylperoxy) cyclohexane (DTBPC) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 113 C., tert-butyl perbenzoate (TBPB) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 122 C., dicumyl peroxide (DCP) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 132 C., 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane (DHBP) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 134 C., 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3 (DYBP) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 141 C., di-tert-butyl peroxide (TBP) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 141 C., cumene hydroperoxide (CHP) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 166 C. and tert-butyl-hydroperoxide (TBHP) with a 1-hour half-life temperature (T.sub.HWZ/1h) of 185 C.

(9) Taking into account the particular use, at least one additive selected from among known antioxidants and/or processing stabilizers, known fillers, reinforcing agents, fire-retardants and lubricant materials, extender oils and other additives can be added prior to further processing to the olefin elastomer functionalized according to the invention in the first stage, in the concentrations customary for the respective additives, as well as at least one polymer and/or elastomer component with a proportion of 1 to 90 mass-% in relation to the entire elastomeric molding material content.

(10) Particularly advantageous is the use of processing stabilizers, wherein generally primary antioxidants are added based on sterically hindered phenol compounds with a proportion of 0.01 to 5 mass parts, preferably 0.1 to 2 mass parts, in relation to a elastomeric olefin copolymer or olefin block copolymer functionalized to 100 mass parts. Frequently, processing stabilizers are also used in the form of a combination of at least one primary and at least one secondary antioxidant, preferably a mixture consisting of 20 to 67 mass-% of a sterically hindered phenol and 80 to 33% mass-% of a phosphite compound.

(11) The types IRGANOX 1010 (pentaerythrityl tetrakis-[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate]), IRGANOX 1330, IRGANOX 1425 WL and IRGANOX 3114 offered commercially by Ciba, as well as synergistic IRGANOX mixtures of 20 to 50 mass-% of one of these primary antioxidants and 50 to 80 mass-% of the secondary antioxidant IRGAFOS 168 (tris-(2,4-di-tert-butyl phenyl) phosphite), such as the type IRGANOX B561 prepared from 20 mass-% IRGANOX 1010 and 80 mass-% IRGAFOS 168, can be used as particularly suitable primary antioxidants.

(12) Preferably, the functionalized thermoplastic elastomers according to the invention with a degree of functionalization between 0.1 and 5 mass-%, preferably with a degree of carboxylation between 0.2 and 4 mass-%, can be used as an adhesion promoter and/or adhesive for various substrates or multi-layer composites, preferably on and between plastic and/or metal surfaces.

(13) Further details, features and advantages of the invention will become apparent from the following description of exemplary embodiments.

(14) In the exemplary embodiments, the abbreviation MT is used for the unit mass parts. Accordingly, the unit mass parts per hour is abbreviated as MT/h.

Solid Phase Grafting

Example 1

(15) In a temperature-controllable fluid mixing reactor equipped with an continuously variable stirrer from the company Reimelt Henschel, 100 MT powdery ethylene/-olefin block co-elastomer of the type Infuse D 9007.15 with a density of 0.866 g/cm.sup.3, a melt flow rate (MFR) (190 C./2.16 kg) of 0.5 g/10 min, a Shore hardness A of 64 and an average particle diameter of 0.36 mm, hereinafter referred to as OBC 0.5, together with 1 MT dilauroyl peroxide, in the following designated by the abbreviation DLPO, and 2.8 MT maleic anhydride, hereinafter abbreviated as MSA, are fed at an internal reactor temperature of 20 C. Thereafter, the reaction mixture is dispersed in a nitrogen atmosphere at an agitation speed of 650 revolutions per minute [RPM] while simultaneously increasing the temperature with a heating rate of 2 C./min, and upon reaching the final reaction temperature T.sub.R1 of 90 C. maintained at T.sub.R1 over a time t.sub.R1 of 60 min.

(16) The solid phase reaction is terminated by discharging the reaction product into the cooling mixer at a temperature of 20 C., from which it is taken out for determining the characteristic values shown in Table 1.

Examples 2 to 13

(17) In the following examples, the term melt flow rate is abbreviated as MFR and the term melt volume rate is abbreviated with MVR.

(18) Other graft-functionalized olefin copolymers or olefin block copolymers are prepared according to the process flow described in Example 1 by using the following components:

(19) Particulate Elastomeric Graft Substrates:

(20) Infuse D 9007.15: density=0.866 g/cm.sup.3, MFR (190 C./2.16 kg)=0.5 g/10 min, Shore A=64, with the designation description OBC-0.5,

(21) Infuse D 9817.15: density=0.877 g/cm.sup.3, MFR (190 C./2.16 kg)=15 g/10 min, Shore A=75, with the designation OBC-15,

(22) Versify 4000.01: density=0.888 g/cm.sup.3, MFR (230 C./2.16)=25 g/10 min, Shore A: 96

(23) Notio PN-3560: density=0.866 g/cm.sup.3, MFR (230 C./2.16 kg)=6 g/10 min, Shore A: 70

(24) Septon V 9461: density 0.863 g/cm.sup.3, MVR (320 C./21.6 kg)=7.2 cm.sup.3/10 minutes

(25) Septon V 9461-compound (for 100 MT Septon V 100 MT process oil and 27 MT PP): MFR (230 C./10 kg)=7 g/10 min, Shore A hardness=61.

(26) All of the aforementioned graft substrates with the designation Infuse belong to the group of olefin block copolymers (OBC) having the composition 80 to 98 mass-% ethylene-/2 to 20 mass-% of C.sub.3- to C.sub.12-olefin units. The OBC are generally materials that are characterized by alternating HDPE and POE blocks. All of the aforementioned graft substrates with the designations Versify and Notio belong to the group of semi-crystalline propylene/ethylene- and/or C.sub.4- to C.sub.12-olefin copolymers and/or C.sub.4- to C.sub.12-diene copolymers having the composition 50 to 98 mass-% propylene-/2 to 50 mass-% of C.sub.2- and/or C.sub.4- to C.sub.12-olefin units and/or C.sub.4- to C.sub.12-diene units. All of the aforementioned graft substrates with the designation Septon belong to the group of cross-linked styrene/olefin/styrene- or styrene/olefin block copolymers.

(27) Graft Monomers:

(28) Maleic anhydride with the abbreviation MSA and acrylic acid with the abbreviation AS, hydroxyethyl acrylate with the abbreviation HEA, methyl methacrylate with the abbreviation MMA, and butyl acrylate with the abbreviation BA as well as styrene as co-monomer addition to the aforementioned functional monomers;
Peroxide Initiators:

(29) Dilauroyl with the abbreviation DLPO, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane with the abbreviation DHBP, and dicetyl peroxidicarbonate with the abbreviation DCPOC, wherein these abbreviations are primarily used below.

(30) While maintaining the charging and heating regime used in the Example 1, the reaction end temperature T.sub.R1, at a reaction time t.sub.R1 of 50 to 60 min and an agitation speed between 400 and 700 RPM and the monomer/initiator proportions introduced for 100 MT olefin elastomer are varied as essential parameters in accordance with the examples given in Table 1.

(31) Table 1 lists the key process parameters for solid phase grafting: Column 1: example number (Ex. No.) Column 2: employed olefin-graft substrate, 100 MT Column 3: type and concentration of the employed initiator in [MT] Column 4: monomer(s) with concentration specified in [MT] Column 5: final reaction temperature T.sub.R1 in [ C.] Column 6: volume melt rates, abbreviated as MVR, in [cm.sup.3/10 min] Column 7: grafted monomer content, expressed as a degree of functionalization FG in mass-%.

(32) TABLE-US-00001 TABLE 1 Elastomer Initiator Monomer T.sub.R1 MVR Ex. No. 100 MT [MT] [MT] [ C.] [cm.sup.3/10 min] FG [wt.-%] 1 OBC 0.5 1.0 2.8 MSA 92 2.2 1.31 DLPO 1.0 styrene (190 C./21.6 kg) 2 OBC-15 1.0 4.0 HEA 90 18 2.51 DLPO 1.0 styrene (190 C./2.16 kg) 3 OBC-15 1.0 6.0 MMA 90 19 3.3 DLPO 0.5 BA (190 C./2.16 kg) 4 OBC-15 1.0 2.8 MSA 88 7.5 1.62 DLPO 0.5 styrene (190 C./21.6 kg) 5 OBC-15 1.0 5.0 BA 90 13 3.7 DLPO (190 C./2.16 kg) 6 Versify 0.5 5.0 AS 90 18 2.75 DLPO 1.0 styrene (230 C./2.16 kg) 7 Versify 0.3 4.5 AS 90 13 3.27 DCPOC 1.0 MSA (230 C./2.16 kg) 0.5 styrene 8 Notio 1.0 1.9 MSA 90 0.9 0.94 DLPO 0.2 styrene (230 C./2.16 kg) 9 Notio 0.7 1.5 MSA 90 1.0 0.77 DLPO 0.5 styrene (230 C./2.16 kg) 10 Notio 1.2 1.5 MSA 85 5.6 0.84 DCPOC 0.5 Styrene (230 C./5 kg) 11 Septon V 1.0 2.1 MSA 100 18 1.20 DLPO (320 C./21 kg) 12 Septon V 0.14 2.4 MSA 160 23 1.51 DHBP (320 C./21 kg) 13 Septon V- 0.5 2.4 MSA 80 16 0.64 Compound DCPOC (320 C./21 kg)
Melt Grafting and Melt Compounding

(33) As an advantageous embodiment of the inventive solution while using a particular concentration of solid phase functionalized product and after the addition of a further proportion of a functional monomer, an initiator and usually also a stabilizer, unmodified olefin elastomer is graft-functionalized in the molten statein addition to the direct use of the elastomers functionalized in accordance with the inventive examples 1 to 13.

(34) Preferably, the reactive extrusion, in particular the carboxylation or maleation, is performed in a twin-screw extruder.

Example 14

(35) The powdery solid phase product obtained in the first stage according to Example No. 1, which is included in the total mixture with 81.8 mass-% and to which 16 mass-% MSA and 1.2 mass-% DHBP and as a stabilizer 1.0 mass-% IRGANOX B561, and mixture of 20 mass-% of the primary antioxidant, IRGANOX 1010 and 80 mass-% of the secondary antioxidant IRGAFOS 168 (manufacturer: Ciba) were added and dispersed, is fed via a metering scale at a feed rate of 5 MT/h to a twin screw kneader of the type ZSK 25 (L=42 D, temperatures ranging from 160 to 240 C., screw speed: 300 RPM) from the company Werner & Pfleiderer, equipped with an underwater granulator, abbreviation UWG. Simultaneously, granular OBC D 9000.00 with the characteristic value MVR (230 C./5 kg)=4 cm.sup.3/10 min, hereinafter referred to as OBC-4, are metered on a second scale 95 MT/h and added.

(36) In accordance with the above-mentioned mass ratio of the solid phase graft product-mixture and OBC-4, the reactive extrusion is carried out at an average throughput of 100 MT/h. The melt temperature T.sub.M is measured as 256 C. The smooth product strand emerging from the extruder nozzle is cut off by UWG. After drying the granules, the following parameters listed in Example 14 are determined:

(37) MVR (230 C./5 kg)=5.3 cm.sup.3/10 min and degree of maleation CS.sub.ex=0.84 mass-%.

Examples 15 to 20

(38) By varying the recipe for melt grafting and melt compounding, i.e. the type of the components and their proportions, further melt grafting was carried out with the extrusion conditions described in Example 14, i.e. temperature, screw rotation speed and throughput, with the results being shown in Table 2.

(39) In Table 2 are Listed:

(40) Column 1 contains the numbers of the examples. Column 2 contains the concentration of used solid phase graft product with the corresponding example number from Table 1, indicated in mass parts per hour [MT/h]. Column 3 contains the type and concentration of added unmodified olefin elastomer, expressed in [MT/h]. In column 4, the average melt temperature T.sub.M measured on the ZSK-nozzle is listed in [ C.]. In columns 5 to 7, the determined characteristic values are given, with column 5 containing the melt volume rate (MVR) (230 C./5 kg) in [cm.sup.3/10 min] and the qualitative strand assessment, selected from the assessments smooth, almost smooth and rough. Column 6 includes an indication of the respective degree of functionalization (CS.sub.ex), given in mass-%, also abbreviated as [wt.-%]. Column 7 contains information relating to the adhesive or peel strength (peel strength), specified in [N/mm].

(41) The grafted portion CS.sub.ex of MSA or AS, i.e. the degree of functionalization, also referred to as carboxylation or for MSA-grafting as degree of maleation CS.sub.ex designated, was determined by way of reverse titration of the potassium hydroxide solution that was not neutralized by the proportion of carboxylic acid, i.e. MSA or AS, as follows: After treatment of the residue contained in the boiling methanol of a 2 g graft product sample over more than 6 h at 80 C. with a mixture composed of 100 ml of water-saturated xylene and 20 ml of 0.1 molar methanolic potassium hydroxide solution, titration is carried out with 0.1 molar hydrochloric acid following the adding of a few drops of a 1% methanolic phenolphthalein solution.

(42) The grafted amount of HEA, BA and MMAalso shown as CS.sub.ex values in Table 2was determined by Near Infrared (NIR) analysis.

(43) The melt volume rates, abbreviation MVR, just like the melt flow rates, abbreviation MFR, were determined according to ISO 1133.

(44) Moreover, Table 2 also indicates a characteristic value for the adhesive strength in the form of the modified peel strength (peel strength) as a key property for the evaluation of the inventively functionalized olefin thermoplastic elastomers.

(45) Table 2 also lists for comparison in the Examples 14A, 17A, 18A and 20A four graft-carboxylated olefin elastomers in the melt that were produced exclusively in the meltwithout supplying an olefin elastomer grafted in the solid phase, wherein in contrast to the examples according to the invention, the MSA, the initiator DHBP and also the stabilizer IRGANOX B561 are fed not in the form of a mixture with the solid phase graft product, but instead are fed via the scale 2 into the extruder intake premixed in a portion of the respective unmodified olefin elastomer. According to the Example 14A, 95 MT/h of pure OBC D9000.00 was here fed via the first scale and a mixture consisting of 4 MT/h of pure OBC D9000.00, 0.9 MT/h MSA, 0.05 MT/h DHBP and 0.05 MT/h IRGANOX B561 was fed via the second scale. A corresponding process occurred in the other comparative examples 17A, 18A and 20A.

(46) 0.05 mass-% of Irganox B561 were used in the examples for which no stabilizer concentrations are listed in the Table 2.

(47) TABLE-US-00002 TABLE 2 Extruder operation Characteristic values Olefin Solid phase Monomer/ MVR Peeling elastomer Prod Table 1 Initiator T.sub.M (230/5) CS.sub.ex strength Ex. No. [MT/h] [MT/h] [MT/h] [ C.] [cm.sup.3/10] [wt.-%] [N/mm] 14 95 OBC-4 4.09 No. 1 0.8 MSA 256 5.3 0.84 6.2 0.05 smooth DHBP 14A 99 OBC-4 0.9 MSA 258 2.3 0.65 4.1 0.05 almost DHBP smooth 15 92 OBC- 6.544 no. 1 1.28 MSA 262 14 0.92 7.0 15 0.096 smooth DHBP 0.08 stab. 16 95 OBC-4 4.01 No. 4 0.8 MSA 252 4.6 0.71 6.6 0.04 smooth DHBP 0.15 stab 17 95 Versify 4.09 No. 6 0.8 MSA 235 29 0.87 6.3 0.05 smooth DHBP 17A 99 Versify 0.9 MSA 235 12 0.67 4.5 0.05 almost DHBP smooth 18 95 Notio 4.1 No. 8 0.8 MSA 238 6.7 0.73 6.0 0.05 smooth DHBP 18A 99 Notio 0.9 MSA 240 2.3 0.65 4.1 0.05 rough DHBP 19 95 OBC-4 4.1 No. 2 0.8 HEA 261 1.6 0.91 5.3 0.05 smooth DHBP 20 90 OBC-4 8.2 No. 5 1.6 BA 258 1.2 1.25 6.5 0.1 DHBP almost 0.1 stab smooth 20A 98 OBC-4 1.8 BA 260 0.5 0.95 4.8 0.1 DHBP rough 0.1 stab.

(48) As adhesion strength parameter is the peel strength determined in a material testing machine TC-FR010TH.A5V from the company Zwick GmbH & Co. on clamped samples composed of aluminum sheet strip/0.3 mm adhesive film/aluminum sheet strip composites (Al/HV/Al) with a pulling speed of 100 mm/min.

(49) The granules obtained by UWG are extruded after drying into 0.3 mm thick sheets, cut into strips having a length of 80 mm and a width of 40 mm, and placed between two aluminum sheet strips with the same dimensions. The Al/HV/Al composites are then heat-treated in an oven at 180 C., and are afterwards measured after different storage times in the oven without application of additional weight and pressure.

(50) The measurement is performed after a storage time of 8 min on the respective Al/HV/Al sample stripes that were cut into three pieces of 13.3 min80 mm each. The peel strengths listed in Table 2 are the average values obtained from four Al/HV/Al composites and hence from a total of 12 single values for the test strips of a tested sample.

(51) As the comparison of the characteristic values of graft products with the pure melt-functionalized products from the Examples 14A, 17A, 18A and 20A of Table 2 shows, the functionalized olefin elastomers produced according to the invention are characterized by high adhesive strengths with peel strengths a 5 N/mm and by concurrent melt viscosities according MVR values (230 C./5 kg) between 1 and 30 cm.sup.3/10 min well and are thus well suited for many applications. In addition, it should be particularly emphasized that the high peel strengths of these new adhesion promoters are retained even after prolonged heat treatment.

LIST OF ABBREVIATIONS USED

(52) AS Acrylic acid BA Butyl acrylate CHP Cumene hydroperoxide CS.sub.ex Degree of maleation, carboxylation, grafted proportion DBPO Dibenzoylperoxide DBPOC Dibutyl peroxidicarbonate DCP Dicumylperoxide DCPOC Dicetyl peroxidicarbonate DHBP 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane DLPO Diauroylperoxide DTBPC 1,1-di-(tert-butylperoxy)-cyclohexane DYBP 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne (3) EOC Ethylene/octene (C.sub.8) copolymers EPM Ethylene/propylene rubber FG Degree of functionalization HDPE High density polyethylene HEA Hydroxyethyl acrylate HV Adhesion promoter LDPE Low density polyethylene LLDPE Linear ethylene copolymers with a low C.sub.3- to C.sub.12-olefin co-monomer fraction below 15 mass-% MFR Melt flow rates MMA Methyl methacrylate MSA Maleic anhydride MT Mass parts MT/h Mass parts per hour MVR Melt volume rate NIR Near Infrared OBC Olefin block copolymer POE Linear ethylene copolymers with a higher C.sub.3- to C.sub.12-olefin co-monomer fraction above 15 mass-% TBHP tert-butyl hydroperoxide TBP Di-tert-butyl TBPB tert-butyl perbenzoate TBPEH tert-butyl peroxy-2-ethylhexanoate TBPIB tert-butyl peroxy-isobutyrate T.sub.HWZ/1h 1-hour half-life temperature T.sub.HWZ/1min 1 minute half-life temperature T.sub.M Melt temperature TPE-S Styrene/diene segment/styrene or styrene/diene segmentblock copolymers TPES-V Styrene/olefin/styreneblock copolymers T.sub.R1 Reaction end temperature t.sub.R1 Time (for holding the reaction end temperature T.sub.R1) RPM Revolutions per minute UWG Underwater granulation