| WO/2018/092716 | METHOD FOR PRODUCING CONJUGATED-DIENE-BASED RUBBER |
| WO/2010/112750 | METHOD FOR PREPARING A SUPERPLASTICIZER |
KOTLAR HANS KRISTIAN (NO)
BOERVE KJETIL L (NO)
KOTLAR HANS KRISTIAN (NO)
| WO1990012054A1 | 1990-10-18 | |||
| WO1991014248A1 | 1991-09-19 |
| EP0577208A1 | 1994-01-05 |
| 1. | A graft copolymer of a functionalized polypropylene polymer and a novolak polymer, characterized in that it con¬ sists essentially of a reaction product of: (1) a functionalized polypropylene polymer having functional groups capable of reacting with hydroxyl groups, and having a melt index MI in the range of 0.1450 g/10 min at 230°C/2.16 kg, especially 5200 g/10 min at 230 "C/2.16 kg, and a functionality of 0.110 wt%, especially 0.44.0 wt%, and (2) a novolak polymer having a weight average molecu¬ lar weight M.. of 75040.000 g/mole, especially 100025.000 g/mole, formed by reacting (a) phenol and/or one or more phenol derivatives with (b) for¬ maldehyde or acetone, and that it contains 175 wt%, especially 140 wt%, of blocks of the novolak polymer and has a melt index in the range of 0.1400 g/10 min at 230 "C/2.16 kg, especially 3100 g/10 min at 230 "C/2.16 kg. |
| 2. | A graft copolymer according to claim 1, characterized by there being used a novolak polymer wherein the molar ratio of phenol compound to formaldehyde, or of phenol compound to acetone, is in the range of 1:0.5 to 1:0.95. |
| 3. | A graft polymer according to claim 1 or 2, charac¬ terized in that the functionalized polypropylene polymer has been produced from a polypropylene homopolymer or a copolymer of propylene with ethylene and/or butadiene. |
| 4. | A graft copolymer according to any of claims 1 to 3, characterized by there being used as functionalized polypro pylene polymer a polypropylene polymer grafted with a compound selected from maleic anhydride, glycidyl alkyl acrylates, acrylic acid, vinyl silanes and other vinyl monomers. |
| 5. | A graft copolymer according to any of claims 1 to 4, characterized by there being used as novolak polymer a polymer produced by reaction of (a) one or more phenol compounds having the general formula: wherein Rl r R2, R3, R4 and R5 are identical or nonidentical and are selected from hydrogen, alkyl having 1 to 3 carbon atoms, and hydroxyl, with (b) a compound selected from formaldehyde and acetone. |
| 6. | A process for producing a graft copolymer of a func¬ tionalized polypropylene polymer and a novolak polymer, which graft copolymer contains 175 wt%, especially 140 wt%, of blocks of the novolak polymer and has a melt index in the range of 0.1400 g/10 min at 230 "C/2.16 kg, especially 3100 g/10 min at 230 "C/2.16 kg, characterized in that: (i) 9925 parts by weight, especially 9560 parts by weight, of a functionalized polypropylene polymer having functional groups capable of reacting with hydroxyl groups, and having a melt index MI in the range of 0,1450 g/10 min at 230 "C/2.16 kg, espe¬ cially 5200 g/10 min at 230 "C/2.16 kg, and a func¬ tionality of 0.110 wt%, especially 0.44.0 wt%, and 175 parts by weight, especially 140 parts by weight, of a novolak polymer having a weight average molecular weight M, of 75040.000 g/mole, especially 100025.000 g/mole, formed by reacting (a) phenol and/or one or more phenol derivatives with (b) for maldehyde or acetone, are mixed and molten together under an inert atmosphere, pre¬ ferably with simultaneous kneading, (ii) the molten mixture is kneaded under an inert atmosphere until the functionalized polypropylene polymer has reacted with the novolak polymer to the desired degree of con¬ version, and (iii) the kneaded product is cooled and optionally granulated. |
| 7. | A process according to claim 6, characterized by the steps of: (i) reacting the functionalized polypropylene polymer in a molten state with the novolak polymer under an inert ιo atmosphere in an extruder, by either (a) introducing the func¬ tionalized polypropylene polymer and the novolak polymer into the extruder through the hopper, in the form of a premixture or separately, or (b) introducing the functionalized polypro¬ pylene polymer into the extruder through the hopper and intro i5 ducing the novolak polymer into the extruder through an aper¬ ture in the cylinder wall of the extruder at a position down¬ stream of the hopper, where the polypropylene polymer is in a molten state, (ii) processing the mixture in the extruder until the 20 novolak polymer has reacted with the functionalized polypropy¬ lene polymer to the desired degree of conversion, and (iii) extruding, cooling and optionally granulating the mix¬ ture. 25 8. A process according to claim 6 or 7, characterized by there being used a functionalized polypropylene polymer having been produced from a polypropylene homopolymer or a copolymer of propylene with ethylene and/or butadiene. 30 9. A process according to any of claims 6 to 8, charac¬ terized by there being used as functionalized polypropylene polymer a polypropylene polymer grafted with a compound selec¬ ted from maleic anhydride, glycidyl alkyl acrylates, acrylic acid, vinyl silanes and other vinyl monomers. *& 35. |
| 8. | A process according to any of claims 6 to 9, charac¬ terized by there being used as novolak polymer a polymer pro¬ duced by reaction of (a) one or more phenol compounds having the general formula: wherein Rl r R2, R3, R4 and R5 are identical or nonidentical and 10 are selected from hydrogen, alkyl having 1 to 3 carbon atoms, and hydroxyl, with (b) a compound selected from formaldehyde and acetone. |
| 9. | 11 A process according to any of claims 6 to 10, charac i5 terized in that the functionalized polypropylene polymer is reacted with the novolak polymer in the presence of a catalyst selected from: (a) compounds having the general formulae: 25 wherein Rfi, R7, R8, R9 and R 10 are identical or nonidentical and are selected from hydrogen and alkyl having 1 to 3 carbon atoms, and R1X is alkyl having 1 to 3 carbon atoms, (b) hydroxides and oxides of mono, di and trivalent so cations, and (c) organic and inorganic mono and diprotic acids, such as formic acid, oxalic acid and sulphuric acid. |
| 10. | 12 A process according to any of claims 6 to 10, charac 35 terized in that the functionalized polypropylene polymer is reacted with the novolak polymer in the presence of a catalyst selected from hydroxides and oxides of mono , di and triva¬ lent cations. |
| 11. | 13 A process according to any of claims 6 to 12, charac¬ terized in that it is carried out under an inert atmosphere of nitrogen. |
| 12. | 14 A use of a graft copolymer according to any of claims 1 to 5 as a compatibilizer in the production of polymer alloys of polypropylene polymer materials with an alloying partner selected from polymers containing aromatic monomeric units as repeating unit(s) in the polymer chain and/or functionality which is complementary to hydroxyl. |
The invention relates to novel graft copolymers of a function¬ alized polypropylene polymer and a novolak polymer as well as a process for producing said graft copolymers.
The new graft copolymers are useful as compatibilizers, espe¬ cially in the production of polymer alloys of a polypropylene polymer with an alloying partner selected from polymers con¬ taining aromatic monomeric units as the repeating unit(s) in the polymer chain and/or having a functionality which is com¬ plementary to hydroxyl, including functionality allowing for secondary chemical bonds.
Although the polypropylene polymers exhibit a number of good properties which make them useful for many applications, there is a great demand for polymer materials combining the proper¬ ties of the polypropylene materials with the properties of other types of polymer materials. Thus, it is often desirable to produce a blend or an alloy of a polypropylene polymer with such other type of polymer so as to obtain a product having an optimal balance between the properties of the two components. However, to produce such blends or alloys wherein one of the components is a polypropylene polymer often presents problems, because the polypropylene polymer will often be incompatible with the other type of polymer which it is desired to use. A compatibilization can be especially difficult in cases where the other type of polymer contains repeating aromatic monome¬ ric units in the polymer chain and is selected e.g. from poly- phenylene ethers (PPE), polyphenylene oxides (PPO), polybuty- lene terephthalates (PBT), polyethylene terephthalates (PET), polystyrenes (PS), polycarbonates (PC), and phenol-formalde¬ hyde thermoplastics and copolymers thereof (PF).
It has been usual in such cases to use compatibilizers, which increase the compatibility between the dissimilar polymers by directly participating in reactions with the polymers, or by entering into physical/chemical interactions with them. For instance, it is well known to use as compatibilizers polyole-
fins grafted with maleic anhydride, acrylic acid, allyl-2,3- epoxyalkyl ether, vinyl silanes and other vinyl monomers. With such compatibilizers, a certain degree of compatibility has been achieved between polypropylene polymers and polymers of 5 the above-mentioned type. However, it has been difficult to achieve an acceptable degree of compatibility in cases where the other type of polymer material has been lacking a suffi¬ ciently good complementary chemistry.
o However, previously known compatibilizers for polyolefin mate¬ rials have not been produced by using any phenol-formaldehyde novolak or any polymer related therewith.
GB 1463452 (UBE Ind. Ltd., 1971) teaches polyolefins modified s with γ-metacryloyloxy-propyl-trimethoxy silane and glycidyl methacrylates and their use in the production of curable poly¬ mer compositions and as adhesives for use in the coating of metals, paper, glass, ceramics and plastics. These previously known modified polyolefins are not being used for compatibili- o zing polyoleifins with other polymers in a molten phase, and the patent is silent on blends or alloys of polypropylene polymers and polymers of the phenol-formaldehyde type (the novolak type) .
5 GB 1567375 (Du Pont, 1980) teaches blends of thermosetting resins with flexible copolymers of ethylene with various co- monomers. The aim is to produce a blend having a low thermal deformation, and being useful especially for casting. Polypro¬ pylene is not mentioned in the patent and polymer alloying 0 technology is not utilized.
EP 416526 (Takeda Chem. Ind., 1989) discloses an addition of phenol-formaldehyde resols to thermoplastic resins to reduce the occurrence of cure shrinkage in the casting of sheets. No 5 mention is made of polypropylene and compatibilization tech¬ nology.
SE 387355 (Dart Ind. Inc., 1976) teaches composites of poly¬ olefin and glass. Phenol-formaldehyde polymers and alloying
technology are not mentioned.
It has now been shown that graft polymers of certain function¬ alized polypropylene polymers and certain novolak polymers are 5 very useful as compatibilizers in the production of polymer alloys of polypropylene polymers and alloying partners selec¬ ted from polymers containing aromatic monomeric units as the repeating unit(s) in the polymer chain and/or having a func¬ tionality which is complementary to hydroxyl. Said graft copo- o lymers are also useful as binders for the purpose of increa¬ sing the ability of polymers to adhere to metals. Also, the graft copolymers are useful to increase the capacity of poly¬ mers to provide adhesion for varnishes and adhesives as a con¬ sequence of the increased functionality and polarity of the s graft copolymers compared to the starting polymer.
Thus, the invention provides a graft copolymer of a functiona¬ lized polypropylene polymer and a novolak polymer, which graft copolymer is characterized in that: o it consists essentially of a reaction product of:
(1) a functionalized polypropylene polymer having functional groups capable of reacting with hydroxyl groups, and having a melt index MI in the range of 0.1-450 g/10 min at 230°C/2.16 kg, especially 5-200 5 g/10 min at 230 °C/2.16 kg, and a functionality of
0.1-10 wt%, especially 0.4-4.0 wt%, and
(2) a novolak polymer having a weight average mole¬ cular weight M„ of 750-40.000 g/mole, especially 1000-25.000 g/mole, formed by reacting (a) phenol 0 and/or one or more phenol derivatives with (b) for¬ maldehyde or acetone, and it contains 1-75 wt%, especially 1-40 wt%, of blocks of the novolak polymer and has a melt index in the range of 0.1-400 g/10 min at 230 °C/2.16 kg, especially 3-100 g/10 min 5 at 230 °C/2.16 kg.
The chemical structure of the graft copolymer of the invention can be illustrated by the formula:
5 wherein X is a group derived from e.g. maleic anhydride (MAH), glycidyl methacrylate (GMA), or acrylic acid, and Z is hydro¬ gen, Ci-Cs alkyl, hydroxyl, or C^-Cg alkoxy. Instead of -CH 2 -0-CH 2 - groups between the benzene nuclei, -CH-- groups may be present. The balance between -CH 2 -0-CH 2 - groups and -CH 2 - o groups depends on the synthesis conditions.
The functionalized polypropylene polymer which is capable of reacting with hydroxyl groups is preferably produced from a polypropylene homopolymer or a copolymer of propylene with 5 ethylene and/or butadiene. These preferred neat polypropylene polymers have a melt index MI in the range of 0.1-100 g/10 min at 230 °C/2.16 kg, especially in the range of 0.35-10 g/10 min at 230 "C/2.16 kg, and a weight average molecular weight in the range of 10.000-500.000 g/mole. The functionalization of
the polypropylene polymer may be obtained by grafting with a compound selected from e.g. maleic anhydride, glycidylalkyl acrylates, acrylic acid, vinyl silanes and other vinyl mono¬ mers. The functionalized polypropylene polymer may advantage¬ ously be selected from the following materials: (1) Polypropylene polymers grafted with an epoxyalkyl acrylate compound using an organic peroxide as a radical former, and having a melt index MI in the range of 1-250 g/10 min at 230 °C/2.16 kg, especially in the range of 3-40 g/10 min at 230 °C/2.16 kg, and a graft ratio of 0.2-10 wt%, especially 0.8-2.5 wt%, and having been produced by:
(i) said polypropylene polymer having been mixed with the organic peroxide and the mixture having been mol- ten under an inert atmosphere, preferably with knea¬ ding of the mixture, (ii) an epoxyalkyl acrylate com¬ pound having the general formula:
H 2 C=C i-C-0-(CH 2 ) n -C AH-CH 2 (I)
wherein R is H or C . 4 alkyl, and n is an integer of 1 to 6, having been introduced into the molten mixture, (iii) said mixture having been kneaded until the epoxyalkyl acrylate compound has reacted with the polypropylene polymer to a desired graft ratio, and (iv) the kneaded product having been cooled and gra¬ nulated.
For a more detailed description of this graft polypropylene polymer and the production thereof, a reference is made to
Norwegian Patent Application No. 924746.
(2) Polypropylene polymers containing 0.1-6 wt%, espe¬ cially 0.4-1.2 wt%, of maleic anhydride, and having a melt index MI of 3-450 g/10 min at 230 °C/2.16 kg, especially 5-250 g/10 min at 230 °C/2.16 kg. Such maleic anhydride-functionalized polypropylene poly¬ mers are sold by several polymer producers.
(3) Polypropylene polymers containing 0.1-10 wt% acrylic acid grafted thereon.
(4) Polypropylene polymers containing 0.1-10 wt% allyl- 2,3-epoxyalkyl ether grafted thereon.
The novolak polymers used in the production of the graft copo¬ lymers of the invention have a molar ratio between phenol com¬ pound and formaldehyde in the range of 1:0.5 to 1:0.95, and a similar ratio when acetone is used in substitution of formal- dehyde. Preferably, a novolak polymer is used, which novolak polymer is a polymer produced by reaction of (a) one or more phenol compounds having the general formula:
wherein R-_, R 2 , R 3 , R 4 and R 5 are identical or non-identical and are selected from hydrogen, alkyl having 1 to 3 carbon atoms, and hydroxyl, with (b) a compound selected from formaldehyde and acetone. 5
The novolak polymers and the production thereof are described i.a. in L.H. Baekeland, "The Synthesis, Constitution and Uses of Bakelite", J. Ind. Eng. Chem. 1 (1909), p.p. 149-161; E. Manegold & W. Petzold, Kolloid-Z, 94 (1941), p. 284; and D.N. o Khana, D.L. Durham, F. Seyedi, P.H. Lu & T. Perera, "Novolak Resins With High Thermal Stability, High Resolution, Improved Photospeed and Etch Characteristics for Advanced Photoresist Applications", Polymer Engineering and Science 32 (1992), p.p. 1500-1508. 5
The invention also provides a process for producing a graft copolymer of a functionalized polypropylene polymer and a novolak polymer, which graft copolymer contains 1-75 wt%, especially 1-40 wt%, of blocks of the novolak polymer, and has
a melt index in the range of 0.1-400 g/10 min at 230 °C/2.16 kg, especially 3-100 g/10 min at 230 °C/2.16 kg. The process is characterized in that:
(i) 99-25 parts by weight, especially 95-60 parts by weight, of a functionalized polypropylene polymer having functional groups capable of reacting with hydroxyl groups, and having a melt index MI in the range of 3-450 g/10 min at 230 °C/2.16 kg, especially 5-200 g/10 min at 230 °C/2.16 kg, and a functionality of 0.1-10 wt%, especially 0.4-4.0 wt%, and 1-75 parts by weight, especially 5-40 parts by weight, of a novolak polymer having a weight average molecular weight M„ of 740-40.000 g/mole, especially 1000-25.000 g/mole, formed by reacting (a) phenol and/or one or more phenol derivatives and (b) formal¬ dehyde or acetone, are mixed and molten together under an inert atmosphere, pre¬ ferably with simultaneous kneading,
(ii) the molten mixture is kneaded under an inert atmosphere until the functionalized polypropylene polymer has reacted with the novolak polymer to the desired degree of con¬ version, and
(iii) the kneaded product is cooled and optionally granulated.
Preferably, the graft copolymer is produced by the steps of (i) reacting the functionalized polypropylene polymer in a molten state with the novolak polymer under an inert atmos¬ phere in an extruder, by either (a) introducing the functiona- lized polypropylene polymer and the novolak polymer into the extruder through the hopper, in the form of a premixture or separately, or (b) introducing the functionalized polypropy¬ lene polymer into the extruder through the hopper and intro¬ ducing the novolak polymer into the extruder through an aper- ture in the cylinder wall of the extruder at a position down¬ stream of the hopper, where the polypropylene polymer is in a molten state, (ii) processing the mixture in the extruder un¬ til the novolak polymer has reacted with the functionalized polypropylene polymer to the desired degree of conversion, and
(iii) extruding, cooling and optionally granulating the mix¬ ture.
The graft copolymer of the invention is produced at melt tem¬ peratures in the range of 160-275 C C, especially in the range of 180-240 °C. Catalyst is added as required. Usually, 0.01-2.5 wt%, especially 0.1-0.5 wt%, of catalyst is added, and the catalyst may be selected e.g. from:
(a) compounds having tl-e general formulae:
wherein R 6 , R 7 , R 8 , R 9 and R 10 are identical or non-identical and are selected from hydrogen and alkyl having 1 to 3 carbon atoms, and R is alkyl having 1 to 3 carbon atoms,
(b) hydroxides and oxides of mono-, di- and trivalent cations, and
(c) organic and inorganic mono- and diprotic acids, such as formic acid, oxalic acid and sulphuric acid.
The produced graft copolymer of the invention exhibits the following product characteristics:
E module: 1000-3500 MPa.
Elongation at break: 0.5-600%. Impact strength; total energy in drop test: 0.5-30 J (0 'O Content of novolak polymer: 1-75 wt%.
By means of the new compatibilizers consisting of graft copo¬ lymers of a functionalized polypropylene polymer and a novolak polymer it is possible - through an appropriate selection of alloying partners and alloying conditions, to produce polymer alloys exhibiting a reproducible broad range of desired pro-
perties, especially alloys having improved E module and impact strength, thus making the alloys useful for many applications.
The above polymer alloys are produced essentially from: s - a Polymer 1 consisting of a polypropylene polymer,
- a Polymer 2, used in an amount of 0.5-95 wt% of the amount of Polymer 1, and containing aromatic monome- ric units as repeating unit(s) in the polymer chain and/or having a functionality which is complementary o to hydroxyl, including a functionality allowing for secondary chemical bonds, and a compatibilizer consisting of a graft copolymer of the present invention. 5
The new polymer alloys, having a melt index in the range of 0.1-400 g/10 min at 230 °C/2.16 kg, especially 3-100 g/10 min at 230 °C/2.16 kg, are produced by mixing Polymer 1, Polymer 2 and the compatibilizer with one another in a molten state o under an inert atmosphere, e.g. in a nitrogen atmosphere, in a batch blender or an extruder, using melt temperatures of 160 to 340 °C, especially from 180 to 280 °C.
The polypropylene polymer which is used as Polymer 1 in the 5 polymer alloy may advantageously consist of a propylene homo¬ polymer or a copolymer of propylene with ethylene and/or buta¬ diene. These preferred polypropylene polymers have a melt index MI in the range of 0.1-100 g/10 min at 230 "C/2.16 kg, especially in the range of 0.35-50 g/10 min at 230 "C/2.16 kg, o and a weight average molecular weight in the range of 10.000-500.000 g/mole.
The polymer containing aromatic monomeric units as repeating unit(s) in the polymer chain, and which is used as Polymer 2 5 in the polymer alloy, may advantageously be selected from polyphenylene ethers (PPE), polyphenylene oxides (PPO), poly- butylene terephthalates (PB ), polyethylene terephthalates (PET), polystyrenes (PS), polycarbonates (PC), and phenol-for¬ maldehyde thermoplastics and copolymers thereof (PF) . The
selected Polymer 2 should have viscosity properties such that its viscosity under the extrusion conditions is in the range of 0.1 to 10 times the viscosity of the polypropylene polymer used as Polymer 1.
5
Useful types of Polymer 2 having "a functionality which is complementary to hydroxyl", are e.g. polybutylene terephtha- late having free terminal carboxyl groups, polyamide having free terminal carboxyl groups, and polyethylene terephthalate o having free terminal carboxyl groups.
As already mentioned, the amount of Polymer 2 in relation to the amount of Polymer 1 is from 0.5 to 95 wt%. Especially, the amount of Polymer 2 is from 1 to 75 wt%. The compatibilizer is s used in an amount of 1-40 wt%, preferably 5-20 wt%, of the total composition.
For a more detailed description of the new polymer alloys and their production using the graft copolymer of the present o invention e/3 a compatibilizer, a reference is made to Nor¬ wegian Patent Application No. 941559.
The invention is further illustrated in the following examples and comparison examples. After examples 1-9, which illustrate 5 the production of the new graft copolymers of the invention for use as compatibilizers, two examples follow which illu¬ strate the production of polymer alloys using two of the new graft copolymers as compatibilizers.
o Examples 1 - 4.
A maleic acid-grafted polypropylene (PP) containing 0.4 wt% of MAH (maleic anhydride) and having a melt index MI of 50 g/10 min at 230 "C/2.16 kg was reacted in an extruder with a novo¬ lak polymer consisting of a phenol-formaldehyde polymer (PF) 5 having a molar ratio of formaldehyde to phenol of 0.9 and a molecular weight of 7500 g/mole, with no catalyst present. In the four examples, the novolak polymer was introduced in amounts of 10, 25, 40 and 20 wt%, respectively, based on the total mixture. The extruder was a twin screw extruder of the
type "Clextral BC 21" having 25 mm co-rotating screws. In all the runs, the hopper was flushed with nitrogen gas in order that the runs should be carried out in an essentially inert atmosphere. The screw speed was 200 r.p.m. and the extrusion speed was 3 kg/h. All raw materials were introduced gravimet- rically into hopper 1. The temperature profile of the extruder was maintained in the range of 195 to 210 °C. The components added, the amounts thereof, and the results are given in Table 1 below.
Example 5.
The procedure was as described in Examples 1 to 4, except that the maleic acid-grafted polypropylene was replaced by a gly¬ cidyl methacrylate-grafted polypropylene having a content of grafted GMA of 1.25 wt%, and having a melt index MI of 28 g/10 min at 230 "C/2.16 kg, produced in accordance with Norwegian Patent Application No. 924746. The novolak polymer was added in an amount of 20 wt%, based on the total mixture. The com¬ ponents added, the amounts thereof, and the results are given in Table 1 below.
Example 6.
A maleic acid-grafted polypropylene (PP) having a content of grafted MAH of 0.15 wt%, and having a melt index MI of 7 g/10 min at 230 "C/2.16 kg was reacted with a novolak polymer consisting of a phenol-formaldehyde polymer having a molar ratio of formaldehyde to phenol of 0.9, and having a molecular weight of 7500 g/mole, in the extruder used in Exam¬ ples 1 to 4. The novolak polymer was added in an amount of 20 wt% of the total mixture. No catalyst was added. Otherwise, the conditions were as indicated in Examples 1 to 4. The com¬ ponents added, the amounts thereof, and the results are given in Table 1 below.
Example 7 (Comparison Example) .
A polypropylene (PP) with no content of grafted MAH, and with a melt index MI of 7 g/10 min at 230 "C/2.16 kg was reacted with a novolak polymer consisting of a phenol-formaldehyde polymer having a molar ratio of formaldehyde to phenol of 0.9,
and having a molecular weight of 7500 g/mole, in the extruder used in Examples 1 to 4. The novolak polymer was added in an amount of 20 wt% of the total mixture. No catalyst was added. Otherwisw, the conditions were as indicated in Examples 1 to 4. In this comparison example, no reaction was expected. The components added, the amounts thereof, and the results are given in Table 1 below.
Example 8. A maleic acid-grafted polypropylene (PP) having a content of grafted MAH of 0.4 wt%, and having a melt index MI of 50 g/10 min at 230 "C/2.16 kg was reacted with a novolak polymer con¬ sisting of a phenol-formaldehyde polymer having a molar ratio of formaldehyde to phenol of 0.9, and having a molecular weight of 7500 g/mole, in the extruder used in Examples 1 to 4, in the presence of a catalyst. As catalyst 0.5 wt% of oxalic acid dihydrate was used. The novolak polymer was added in an amount of 40 wt%, based on the total mixture. Otherwise, the reaction conditions were otherwise as stated in Examples 1 to 4. The components added, the amounts thereof, and the re¬ sults are given in Table 1 below.
Example 9.
The process of Example 5 was repeated, except that the reac- tion was carried out in the presence of 0.5 wt% of triethyl- amine (TEA) as a catalyst, based on the total mixture. The components added, the amounts thereof, and the results are given in Table 1 below.
Table 1
PF
Degree grafted
Graft Cata¬ of conv. on the
Example PP PF lyst of PF graft (wt%) (wt%) (wt%) (%) PP (wt%)
1 90 1 ' 10 0 7.4 0.7
2 75 1 ' 25 0 13.1 3.3
3 60 x) 40 0 17.4 7.0
4 80 1 ' 20 0 15.5 3.0
5 80 3) 20 0 44.1 8.8
6 80 4) 20 0 4.8 1.0
7 (comp. ) 80 5) 20 0 0 0
8 60 1 ' 40 0,5 2) 18.8 7.5
9 80 3) 20 0,5 6) 45.8 9.2
PP grafted with maleic acid; high maleic acid content (0.4 wt%).
Catalyst of the oxalic acid dihydrate type.
PP grafted with glycidyl methacrylate (GMA) .
PP grafted with maleic acid; low maleic acid content (0.15 wt%).
5) Non-grafted PP having a viscosity similar to that of the maleic acid-grafted PP with a low (0.15 wt%) maleic acid content.
Catalyst of the triethylamine type.
It can be seen from the above Table 1 that an increase in the amount of novolak polymer (PF) from 10 to 40 wt% conveys to the graft copolymer an increased content of grafted PF.
It can also be seen from Table 1 that with an addition of 20 wt% of novolak polymer (PF), a GMA-functionalized PP provides a higher content of grafted PF (8.8 wt%) than a MAH-functio-
nalized PP having a high MAH content (3 wt%) and/or a MAH- functionalized PP having a low MAH content (1.0 wt%) .
As expected, no reaction occurred, i.e. no PF was grafted on the polymer in Example 7 (comparison example), wherein a non- functionalized PP was used.
A comparison between Example 3 and Example 8, where the only difference consisted in a catalyst being used in Example 8, shows that the degree of conversion of the novolak polymer (PF) increased, and that the amount of PF grafted on the poly¬ mer increased from 7.0 wt% to 7.5 wt%.
A comparison of Example 5 with Example 9, in which Example 9 a catalyst was used, shows that the degree of conversion of PF increased from 44.1% to 45.8%, and that the amount of grafted PF increased from 8.8 wt% to 9.2 weigh%.
Examples on the production of polymer alloys. Procedure.
In a twin screw extruder of the type "Clextral BC 21" having 25 mm co-rotating screws a polypropylene polymer (Polymer 1) is reacted/mixed with an alloying partner (Polymer 2), with or without addition of compatibilizer. Polymer 1 is introduced into hopper 1, whereas Polymer 2 is introduced into hopper 2 (downstream of hopper 1) . The hoppers are flushed with nitro¬ gen gas in order that the mixing and kneading should take place in an essentially inert atmosphere. All raw materials are introduced gravimetrically into the respective hoppers. The screw speed of the extruder is 200 r.p.m. and the extru¬ sion speed is 3 kg/h.
Example 10.
The above described procedure was followed. A polypropylene copolymer of the type Statoil P 401 having a melt index MI of 0.35 g/10 min at 230 "C/2.16 kg was used as Polymer 1, pre- mixed with standard stabilizers. A polyphenylene ether having a viscosity of 1000 Pa.s at 1000 s _1 /265 "C was used as Polymer 2. Polymer 1 and Polymer 2 were added in amounts of 69.4 wt%
and 23.1 wt%, respectively, based on the total mixture. A com¬ patibilizer similiar to the one described in Example 4 above, but having a content of grafted novolak polymer (PF) of 2.5 wt% instead of 3.0 wt%, was introduced into hopper 1 in an s amount of 7.5 wt%, together with the polypropylene copolymer. The temperature profile of the extruder was maintained in the range of 225 to 275 °C. A polymer alloy was obtained, the pro¬ perties of which are compared in Table 2 below with the prope¬ rties of the corresponding binary polymer blend containing o 75 wt% of Polymer 1 and 25 wt% of Polymer 2, i.e. a polymer blend having the same weight ratio between the two Polymers 1 and 2.
Table 2
Example 11. 5 The above described procedure was followed. A polypropylene copolymer of the type Statoil P 401 having a melt index MI of 0.35 g/10 min at 230 "C/2.16 kg was used as Polymer 1, pre- mixed with standard stabilizers. As Polymer 2 there was used a polybutylene terephthalate having a melt index MI of 34 g/10 0 min at 250 "C/21.2 N. Polymer 1 and Polymer 2 were added in amounts of 69.4 wt% and 23.1 wt%, respectively, based on the total mixture. A compatibilizer similiar to the one described in Example 4 above, but having a content of grafted novolak polymer (PF) of 2.5 wt% instead of 3.0 wt%, was introduced 5 into hopper 1 in an amount of 7.5 wt%, together with the poly¬ propylene copolymer. The temperature profile of the extruder was maintained in the range of 225 to 265 °C. A polymer alloy was obtained, the properties of which are compared in Table 2
below with the properties of the corresponding binary polymer blend containing 75 wt% of Polymer 1 and 25 wt% of Polymer 2, i.e. a polymer blend having the same weight ratio between the two Polymers 1 and 2.
Table 3