NO172246B - MIXING THAT ALLOWS AA TO COMPATIBLE AT LEAST TWO INCOMPATIBLE THERMOPLASTIC POLYMERS, A PROCEDURE FOR AA MAKES THE POLYMERS COMPATIBLE AND THERMOPLASTIC POLYMER ALLOYS CONTAINING THE MIXTURES - Google Patents

Abstract

Composition making it possible to render compatible at least two incompatible thermoplastic polymers at least one of which contains carboxylic functional groups in its molecule and at least one of which does not contain these, characterised in that a bisoxazoline or a hydrogenated bisoxazine is used in combination with a maleinised polymer compatible with the polymers containing no carboxylic functional group. By melt-blending the thermoplastic polymers in the presence of the composition it is possible to obtain new thermoplastic alloys such as, for example, polyolefins-PBT.

Description

The present invention relates to a mixture which allows at least two incompatible thermoplastic polymers to be made compatible where at least one polymer in the molecule contains carboxyl functions and at least one does not. The mixtures are formed from a maleized polymer compatible with at least one of the polymers that do not have a carboxyl function and a bisoxazoline (generic name for hydrogenated oxazoles) or a newly hydrogenated bisoxazine.

The invention also relates to a method for making compatible at least two thermoplastic incompatible polymers.

Finally, the invention also relates to thermoplastic polymer alloys.

The general formula for hydrogenated oxazole rings is: while that of hydrogenated bisoxazine is:

It is known to make compatible, in certain types of specific mixtures, two incompatible polymers by connecting them with a third polymer, optionally sequenced or grafted, which is partially compatible with one or another of the polymers. It is also known to force sequencing or grafting in situ during mixing. This is, for example, the case with the mixture polypropylene-polyamide 6, which is made compatible with maleized polypropylene. The advantage of this technique is that no prior sequencing is necessary. However, it has the disadvantage that it is not sufficiently effective in all cases and especially for mixtures of polypropylene-aromatic polyesters.

The mixture according to the invention allows such compatibility agents to be arrived at in an efficient manner.

According to this, the present invention relates to a mixture of the kind mentioned at the outset and this is characterized as consisting of: 1) a copolymer which in the molecule contains the remainder of at least one of the monomers with the following formulas: 2) a compound with the formula: where D is either zero, or an alkyl chain, possibly containing at least one aromatic ring and/or at least one oxygen, nitrogen, sulfur or halogen atom, as the chain is such that the corresponding diacid

has a pKa value of less than 4.5, and preferably less than or equal to 3.5, X^ and X£ are the same or different and mean a hydrocarbon chain which is not reactive with the other components and containing 2 or 3 carbon atoms in the iminoether ring.

As mentioned, the invention also relates to a method for making at least two thermoplastic incompatible polymers as mentioned above compatible, and this method is characterized by incorporating a compound as described above into the mixture.

Finally, as mentioned above, the invention relates to thermoplastic polymer alloys which are characterized by the fact that they contain a mixture as described above.

By a hydrocarbon chain that is not reactive with the other components is meant a hydrocarbon chain that may possibly contain reactive chemical functions, but which cannot react with the other compounds in the mixture and the products obtained.

In cases where none of the polymers to be made compatible contain hydroxyl or amine functions, it is recommended to add a third compound 3 with the formula to the two precursor compounds for the mixture:

Ride - T

there:

T is equal to OH or NE2 and

R 1 is a straight or branched C 1-6 alkyl chain, optionally containing at least one aromatic ring and/or at least one oxygen, nitrogen, sulfur or halogen atom.

It is known that the compounds 2 as described can react with carboxyl or anhydride functions. It is thus known according to US-PS 4 331 800 to use bisoxazolines to increase the degree of polymerization of aromatic polyesters. This increase results in coupling of the two chains via the carboxyl end functions. Furthermore, the reaction between the anhydride functions and oxazolines is used according to US-PS 2,547,495 to prepare bis(phthalimidoesters).

According to the known technique, there are thus two types of reaction: where M is the polymer chain and

is again the polymer chain.

These end-coupling reactions have no effect in making two polymers compatible. Thus, even bisoxazoline does not have inherent emulsifying ability.

The copolymer 1 can be a statistical copolymer containing 300 to 50,000 carbon atoms in the molecule. It arises from the polymerization of a monomer with reactive sites with amines or alcohols with other radical polymerizable monomers such as olefins, for example ethylene, propylene, 1-butene, alkyl (meth)acrylates such as methyl, ethyl or butyl acrylates or methacrylates, dienes such as 1,3-butadiene, isoprene or 1,4-hexadiene, other useful comonomers such as styrene, methyl vinyl ether, acrylonitrile, vinyl acetate or vinyl chloride.

The polymer 1 can also be a graft copolymer comprising 300 to 50,000 carbon atoms. It occurs by grafting a polymer consisting of radical polymerizable monomers as mentioned above with a monomer that has sites that are reactive with amines or alcohols. This grafting can take place by thermal addition of remaining unsaturation in a diene as described in TJS-PS 3 972 961 or by radical grafting in the molten state. This latter preferred method consists in mixing, in an extruder, a polymer to which is added 500 ppm to 3 wt-# of maleic anhydride and a radical initiator of the order of 250 ppm to 4 wt-#. The thermal decomposition of the initiator and the grafting of maleic anhydride takes place in the extruder between 170 and 250°C and preferably 180 to 200°C. Remaining maleic anhydride can be evacuated by degassing the molten material before passing through the nozzle. The average residence time for the material in the extruder is 15 seconds to 3 minutes and preferably 40 to 80 seconds.

The monomers with sites reactive with amines or alcohols correspond to the general formulas described above under a), b) or c). The representative monomers with the general formula a) are, for example, maleic or citraconic anhydride. Representative monomers with the general formula b) are, for example, maleic, citraconic, fumaric, mesaconic acid or monoesters of these acids where W is a straight or branched C^_^Q chain and optionally with a phenyl nucleus. Monomers represented by the general formula c) are, for example, alkenylsuccinic anhydrides such as 3-allyl or 3-isopropenyl.

The compounds of general formula 2 are derivatives of bisoxazoline or bis(5,6-dihydro-1,3-oxazine). These compounds which are formed by cyclization reaction carried out on the corresponding diacid according to known processes as described for example by H. Wanker in the "Journal of the American Chemical Society", vol. 60, p. 2152 (1938) or by R.H. Wiley, "Chem. Rev.", vol. 44, p. 447 (1949). The preferred compounds are 2,2'-bis(2-oxazoline), 2,2'-bis(4,4-dimethyl-2-oxazoline), 2,2'-bis(5,6-dihydro-4H-1 ,3-oxazine), phenyl-2,2'-bis(2-oxazoline), N,N'-ethylene-bis(2-carbamoyl-2-oxazoline) and N,N'-ethylene-bis(2-carbamoyl -5,6-dihydro-4H-1,3-oxazine).

In the case where none of the incompatible polymers contain a hydroxyl or amine function, a third compound can be added to the mixture which is preferably a fatty alcohol or a fatty amine such as lauric, oleic or stearic alcohol or amine.

Although the components of the composition may be premixed prior to introduction into the composition of thermoplastic incompatible polymers of which at least one contains carboxyl functions and of which at least another is compatible with the copolymer, it is preferred, in order to homogeneously combine the two thermoplastic polymers, to introduce them separately. The introduction of the mixture into the thermoplastic polymers usually takes place by homogenization in a mixer of the various components in a molten state. In order to achieve an optimal efficiency of the mixture, it is recommended to introduce the components in the mixture of the thermoplastic polymer mixture in a molten state, with the compounds described under 2 above being introduced after the other constituent(s) in the mixture so that the anhydride functions are in the form of acid esters or the acid amine. In a first step, the polymer is mixed with the copolymer 1 and possibly the compound R^-T. Compound 2 is added to the resulting mixture, preferably well homogenised.

The amount of the copolymer described above under 1 which is introduced into the mixture of incompatible thermoplastic polymers is approx. 0.1 to 10 and preferably 1 to 5 wt-#, calculated on the weight of mixture of thermoplastic polymers. The amount of compound 2 that is added to the mixture is such that the molar ratio between the oxazoline or 4,5-dihydro-1,3-oxazine functions and the active functions of copolymer 1 or its active functions after the reaction with compound 3 such as anhydrides, acid esters, acids or acid amides, is between 0.1 and 10 and preferably between 1 and 3.

In the case where compound 3 is introduced, the amount incorporated is such that the molar ratio between alcohol or amine functions and the active functions in copolymer 1 is between 0.1 and 10 and preferably between 1 and 3.

The intended compatibility with the mixture according to the invention is shown by electron microscopy of the product obtained by mixing the incompatible thermoplastic polymers.

The morphology of a mixture of incompatible thermoplastic polymers without a compatibilizer appears by electron microscopy in the form of nodules of one of the polymers included in the matrix constituting the other polymer. There is no adhesion between the nodules and the matrix. The addition of the polymers in the mixture according to the invention forces a significant reduction of the nodule diameter. One further observes an increase in the adhesion between the phases which manifests itself in a covering of the nodules by the matrix. Under these conditions, what can be called an alloy is formed by comparison with metallurgical structures as opposed to mixtures. This expression will therefore be used below.

It is known that an improvement of the dispersion and especially the nodule-matrix adhesion improves the mechanical properties, see for this G. Maglio, R. Palumbo, "Polymer Blends", vol. 2, p. 41, ed. Plenum 1984. Furthermore, incorporation of the mixture gives a better pulling of the polymers during extrusion, a reduction of swelling at the outlet of the die and delamination of the extrudate which has been observed during granulation.

In a non-limiting way, the thermoplastic polymers with carboxyl functions can be selected from polyesters such as polybutylene and polyethylene terephthalate, polyamides such as polyamides 6, 11 or 12, statistical copolymers with acrylic or methacrylic acids such as ethylene acrylic acid copolymers.

The thermoplastic polymers which enter the alloy composition and which do not have carboxylic functions can be selected from copolymers of ethylenically unsaturated monomers such as styrene, propylene, ethylene, possibly copolymerized with other monomers such as an α-olefin such as octene, hexene, butene or as vinyl acetate , ethyl or methyl acrylate.

Thanks to the mixture according to the invention, incorporated in the quantities given above, in mixtures of incompatible thermoplastic polymers, it is possible to realize new thermoplastic polymer alloys as alloys of at least one of the following resins: polypropylene, polystyrene, acrylonitrile-butadiene-styrene copolymer, styrene- acrylonitrile copolymer, polyphenyl oxide, polyethylene, ethylene vinyl acetate copolymer, vinylidene polyfluoride, methyl polymethacrylate, EPM, EPDM copolymer, polymethylpentene, phenylidene polysulfide (PPS), with at least one of the following incompatible resins: polyamide or copolyamide 6, 11, 12, 6-10, 6- 6 or 6-9, polyether ester amide, polybutylene or polyethylene terephthalate, ethylene acrylic acid copolymer, semiaromatic amorphous polyamides such as the two described for example in FR-PS 1 588 130 and 2 324 672, EP-PS 53 876 as well as JP- PS 60.217237, aromatic polyesters based on hydroxybenzoic acid, aromatic diacids and diphenols as described in US-PS 4,067,852 and BE-PS

4,184,996, polyacrylates or polycarbonate.

The following examples illustrate the invention without limiting it.

Initially, under the conditions given below, 2,2'-bis(2-oxazoline), 1,4-bis(5',6'-dihydro-4'H-1',3'-oxazin-2'yl )benzene and maleized propylene.

Production of 2 . 2,- bis( 2- oxazoline

146 g of ethyl oxalate and 200 cm<5> of dichloromethane are introduced into a 2 liter flask, with stirring and nitrogen flushing. At room temperature, 122 g of ethanolamine are added and the whole is reacted for one hour. The obtained diethanol oxamide is isolated by filtration and dried. 160 g of the product are dissolved in 900 cm<5>toluene, added to 250 m<5> SOC12 and heated to 70°C for 9 hours. The resulting mixture is filtered, washed with ethanol and then with boiling water and recrystallized from ethoxy-2-ethanol. 127 g of this product and 78.5 g of a solution of 85 µg of potassium are dissolved in 1.2 l of methanol which is then refluxed for 2 hours. After filtration, the organic phase is evaporated to dryness and the product recrystallized from toluene. The product obtained is 2,2'-bis(2-oxazoline). The pKa value for the diacid corresponding to this bisoxazoline, i.e. oxalic acid, is 1.2.

Preparation of 1,4-bis(5'.6'-dihydro-4'H-1',3'-oxazin-2'yl)benzene

The synthesis of this product takes place according to what is described in DE-PS 2 153 513 from dimethyl terephthalate and 3-aminopropanol. After reaction, a white crystalline product whose melting point is 221°C is obtained. Microanalysis of the amount of carbon, hydrogen and nitrogen gives 66.77$, 6.59$ and 11.05$ respectively. The pKa value for the acid corresponding to this hydrogenated bisoxazine, i.e. terephthalic acid, is 3.5.

Grafting of the polypropylene with maleic anhydride in solution XAl

5 l of chlorobenzene, 1200 g of polypropylene of commercial type "3020 GN3" and 200 g of maleic anhydride are added to a 25 l flask. The whole is brought to 125°C, after which 216 g of commercial peroxide ("Lucidol CH 50") are added over the course of 2 hours.

At the end of this addition, the whole is kept at 125°C for 30 minutes, then cooled to 90°C and 10 1 of acetone injected over the course of 30 minutes. The precipitated product is washed with acetone before extraction with free maleic anhydride, then dried under reduced pressure at 80°C for 6 hours. A polypropylene is obtained which is grafted with 6.6% maleic anhydride by weight.

Grafting of polypropylene with maleic anhydride in a molten state (Bl

A mixture of 100 parts "3050 MN4" polypropylene, 1.5 parts maleic anhydride and 1.7 parts 2,5-dimethyl-2,5-diterbutyl peroxide hexane dissolved in 1 part chlorobenzene is successively added to a commercial ZSK30 extruder.

The temperature of the mixture is 200°C and the speed of rotation of the extruder screw is 100 rpm. Volatilization after the nozzle continues until the end before extracting unreacted chlorobenzene and maleic anhydride. In this way, a polypropylene grafted with 1 wt # is obtained maleic anhydride.

EXAMPLE 1 - Polypropylene Polybutylene Terephthalate (PBT)—

alloy

a) Comparative example

50 parts "3050 MN1" polypropylene and 50 parts "Orgater

TMN0"-PBT is mixed at 250°C for 30 minutes in a plastograph container "Haake" (sample 1).

Morphological examination by flushing electron microscopy on a cryogenic fracture indicates the presence of PBT nodules of 14 pm and a poor adhesion between the nodules and the polypropylene matrix.

b) Mixture made compatible by maleized polypropylene.

To the blank mixture specified above, add 0.4,

0.6, 1.2, respectively 3 parts of samples 2, 3, 4, 5 and 6 of the grafted polypropylene (A) for sample 4 and (B) for the other samples and mixed under the conditions stated above. The morphology of these mixtures consists of PBT nodules with a diameter of 4 to 6 pm.

c) Mixture obtained in the presence of bisoxazoline. The blank mixture above from (a) is added to 0.6 parts

2,2'-bis(2-oxazoline) and mixed under the stated conditions, this gives sample 7. The product obtained consists of PBT nodules with a diameter of 17 to 18 pm. Comparison of this sample with samples 1 and 4 shows that 2,2'-bis(2-oxazoline) does not have the inherent compatibility.

d) Alloys obtained according to the invention.

Add 1 part of the blank mixture (a) specified above

maleized polypropylene (A) and mixed at 250°C. After 15 minutes of mixing, 0.2 parts of 2,2'-bis(2-oxazoline) are added and mixed for a further 15 minutes, giving sample 8. The morphology of this alloy consists of PBT nodules with a diameter of 2.5 µm whose adhesion with the matrix is excellent. One can judge the adhesion quality between the nodules and the matrix by comparing the percentage of nodules that can be extracted during cryogenic fracturing before morphological examination. The percentage is 48 in the case of test 4 and 38 in the case of test 8.

The reduction of the nodule diameter and the improvement of the matrix-nodule adhesion reflect the improved efficiency of the blend to make propylene and PBT compatible.

The following diagram shows the nodule diameter for PBT, measured by morphological examination of the samples as a function of the amount of grafted polypropylene added to the mixture. The numbers in brackets correspond to the sample number.

EXAMPLE 2

At 250°C and for 30 minutes and in a "Haake" plastograph container, with a rotation speed of the blades of 50 rpm, the following mixtures are mixed: a) 50 parts of "3050 MN1" polypropylene and 50 parts of commercial polyamide 6 : sample 9; b) The above-mentioned components to which 1 part of grafted polypropylene (A) is added: sample 10; c) The components in mixture a) to which 1 part grafted polypropylene (A) is added and, after 15 minutes of mixing, 0.6

parts 2,2'-bis(2-oxazoline): sample 11.

These three alloys are examined by scanning electron microscopy. The morphology shows polypropylene nodules dispersed in a polyamide matrix and characterized by their diameter and their adhesion to the matrix. The observations are summarized in the following table:

EXAMPLE 3

In a plastograph container of the type indicated above, the following prepared mixtures are mixed at 260°C for 30 minutes, the rotation speed of the paddles being 50 rpm: a) 50 parts "Lacqréne 1160c" polystyrene and 50 parts "Orgater TMN0 "-polybutylene terephthalate: sample 12; b) The above-mentioned components to which 1 part of a styrene-maleic anhydride copolymer is added which has 8 weight-#

maleic anhydride ("Dylark 700"): sample 13; and

c) The samples from mixture b) to which, after 15 minutes of mixing, 0.5 parts of 2,2'-bis(2-oxazoline) are mixed: sample 14.

The morphology of the three alloys is characterized by the nodules of polypropylene dispersed in a matrix of polybutylene terephthalate. The diameters of these nodules and the quality of their adhesion to the matrix are summarized in the following table:

EXAMPLE 4

In a plastograph container of the above-mentioned type, the following mixtures are mixed at 200°C for 30 minutes, the rotation speed being 50 rpm. a) 50 parts of a high-density polyethylene with a melt index of 7, "PEHD 2070 MN60" and 50 parts of "Orgater TMNO" polybutylene terephthalate: sample 15; b) The above-mentioned ingredients to which are added 5 parts of ethylene-vinyl acetate-maleic acid terpolymer whose vinyl acetate amount and maleic anhydride amount are 14 and 0.385$ respectively, "Orevac 9307": sample 16; and c) The components obtained from mixture b) to which, after mixing for 15 minutes, 0.5 parts of 2,2'-bis(2-oxazoline) are added: sample 17.

These three samples are observed under scanning electron microscopy. The nodule diameter of these PBT and their adhesion to the PE matrix are summarized in the table below:

EXAMPLE 5

In a container as above, the following mixtures are mixed at 270°G for 30 minutes, the speed of rotation of the paddles being 50 rpm. a) 50 parts "PP 3050 MNI" polypropylene and 50 parts polybutylene terephthalate: sample 18; b) The above-mentioned components from mixture a) to which 1 part grafted polypropylene (A) is added: sample 19; and c) The above-mentioned ingredients from mixture b) to which, after mixing for 15 minutes, 0.5 parts are incorporated

2,2'-bis(2-oxazoline): sample 20.

The morphology of these alloys shows the nodules of PET, dispersed in a PP matrix. The nodule diameter and the quality of the nodule-matrix adhesion are indicated in the following table:

EXAMPLE 6

In the same way as above, one mixes at 220° C and for 30 minutes: a) 60 parts of "PP 3050 MNI" polypropylene and 40 parts of EAC ethylene-acrylic acid copolymer whose amount of acrylic acid is 8 wt-$ and melt index is 5.5, the whole at 190° C., under 2.16 kg "Dow 499": sample 21;

b) The above stated components from mixture a) to which

one puts 1 part grafted polypropylene (A): sample 22; and

c) The components from mixture b) to which 0.5 parts of 2,2'-bis(2-oxazoline) are added during 15 minutes under

mixture: sample 23;

d) The mixtures from mixture a) to which 0.889 parts grafted polypropylene (A), 0.111 parts dodecanol and, after 15

minute mixture, 0.5 parts 2,2'-bis(2-oxazoline): sample 24.

The morphology of these samples shows nodules of EAC dispersed in a polypropylene matrix.

The diameters of these nodules and their adhesion to the matrix are indicated in the following table:

EXAMPLE 7

A blank mixture is provided under the conditions given in example la): sample 25.

1 part grafted polypropylene (A) is added to this mixture and mixed at 250°C for 30 minutes in a plastograph container: sample 26;

The blank mixture is then added to 1 part maleized polypropylene (A) and mixed at 250°C in the plastograph container. After 15 minutes of mixing, 0.6 parts of 1,4-bis(5',6'-dihydro-4'H-1'3'-oxazin-2'-yl)benzene are added and the mixing is continued for 15 minutes: sample 27 .

The morphology of these samples is examined by scanning electron microscopy.

Sample 25 exhibits PBT nodules in which the diameter is 14 pm and the adhesion is zero with the polypropylene matrix;

Sample 26 shows nodule diameters of 5 µm and with a good nodule-matrix adhesion;

Sample 27 shows nodules with a diameter of 3.2 pm and a good nodule-matrix adhesion.

Incorporation of hydrogenated bisoxazoline results in a reduction of the nodular diameter.

1. Mixture which allows at least two incompatible thermoplastic polymers to be made compatible where at least one polymer in the molecule contains carboxyl functions and at least one does not, characterized in that the mixture consists of 1) a copolymer which in the molecule contains the remainder of at least one of the monomers with the following formulas: where X and Y are either a proton or a C-i_q chain, provided that one of the two is proton where W is either a proton or a straight or too branched C^_^g-alkyl chain where W is as defined above and V is straight or branched co-12~ hydrocarbon group and containing an ethylenic unsaturation; 2) a compound with the formula:

where D is either zero, or an alkyl chain, optionally containing at least one aromatic ring and/or at least one oxygen, nitrogen, sulfur or halogen atom,

Claims (10)

the chain is such that the corresponding diacid has a pKa value of less than 4.5, and preferably less than or equal to 3.5, Xi and X2 are the same or different and mean a hydrocarbon chain that is not reactive with the other components and containing 2 or 3 carbon atoms in the iminoether ring. 2. Mixture according to claim 1, characterized in that, in the case that none of the polymers to be made compatible contains a hydroxyl or amine function, the mixture also contains a compound (3) of formula Ri - T, in which: T = OH or NH2, and Ri is a straight or branched C 1 -g Q alkyl chain, possibly containing at least one aromatic ring and/or an oxygen, nitrogen, sulfur or halogen atom. 3. Mixture according to claim 2, characterized in that the compound Ri~T is selected from among fatty amines or -alcohols. 4. Mixture according to claims 1 to 3, characterized in that the amount of compound (2) which is combined with the mixture is such that the molar ratio between oxazoline or 4,5-dihydro-2,3-oxazine compounds were the active compounds of the copolymer ( 1) or its active functions after reaction with compound (3), is between 0.1 and 10. 5. Mixture according to claims 1 to 4, characterized in that the amount of compound (3) R^-T introduced is such that the molar ratio between alcohol or amine functions and the active functions of the copolymer (1) is between 0.1 and 10. 6. Method for making compatible at least two thermoplastic incompatible polymers, where at least one polymer in the molecule contains carboxyl functions and at least one does not contain such, by carrying out a mixture in the molten state, characterized by incorporating a compound in the mixture according to the requirements 1 to 5. 7. Method according to claim 6, characterized in that the copolymer (1) and optionally the compound with the formula R^-T is incorporated into the mixture of the polymers in the molten state in advance before compound (2) is introduced into the mixture. 8. Method according to claim 6 or 7, characterized in that the amount of copolymer (1) which is introduced into the mixture of incompatible thermoplastic polymers is kept at 0.1 to 10% by weight in relation to the mixture of the polymers. 9. Thermoplastic polymer alloys, characterized in that they contain the mixture according to any one of claims 1 to 5. 10. Alloy according to claim 9 of at least one of the following resins: polypropylene, polyethylene, EPR, EVA, polystyrene, ABS, PVD or PMMA with at least one of the following incompatible resins polyamide-6, -11 -12; copolyamide-6-10, -6-6, -6-9, semi-aromatic amorphous polyamide, PBT, PET or polyether ester resin.