DD275160A3 - PROCESS FOR PREPARING POLAR-MODIFIED POLYPROPYLENE - Google Patents

Abstract

The invention relates to a process for the preparation of polarmodifiziertem polypropylene. By radical Copfropfpolymerisation of maleic anhydride (MSA) containing monomer mixtures with mass ratios between 1 kg MSA / 1 kg comonomer (s) and 1 kg MSA / 10 kg of comonomers (s) as well as on the presented isotactic PP backbone polymers (Mw between 25 000 and 250 000) MSA mass fraction between 0.2 and 10%, wherein the comonomers of the general formula CH2CHR1 or CH2C (CH3) R1, with R1: COOR2 (R2: H or CnH2n1 with n from 1 to 8), C6H5, OOCCH3 or Cl, genuegen and preferably are styrene, acrylic acid, n-butyl acrylate, methacrylic acid and methyl methacrylate, are in the temperature range between 60 and 100C while maintaining a powdery and / or koyigen and / or flaky, flaky or Blaettchenfoermigen consistency of the reaction medium Copfropfpolymerisationsprodukte with a total monomer mass conversion between 60 and 98% obtained for use as a chemical coupler in thermoplastic-glass fiber composites or as sel Bsthaftendes polymer coating material are determined.

Description

where R _{1 is} COOR ₂ (R ₂ : H or C _n H _2n + , where η is from 1 to 8), C ₆ H ₅ , OOC-CH ₃ or Cl, in a mass ratio between 1 kg MSA / 1 kg comonomers ( s) and 1 kg of MSA / 10 kg of comonomers (s) and a PP based MSA mass fraction of between 0.2 and 10% added to the graft polymerization and - after dispersion together with the initiator or initiator mixture - up to a total monomer mass conversion between 60 and 98% polymerized.

2. The method according to claim 1, characterized in that are used as comonomers styrene, acrylic acid, n-butyl acrylate, methacrylic acid and methyl methacrylate.

Field of application of the invention

The invention relates to a process for the preparation of polarmodifiziertem polypropylene based on the radical (^ graftpolymerization of maleic anhydride (MSA) containing monomer mixtures on isotactic polypropylene (PP) having a viscometrically determined average molecular weight M _w between 25,000 and 250,000 using organic peroxidic and / or diazo-containing initiators in the temperature range between 60 and 100 ⁰ C for use as a chemical coupler in thermoplastic-glass fiber composites or as a self-adhesive polymer coating material on Metallioberflächen.

Characteristic of the known technical soundings Known is the modification of polyolefins, in particular polypropylene (PP) and propylene-ethylene copolymers, by Grafting of maleic anhydride (MSA) in solution using various organic solvents

(EP 0187659, EP 0187660) or in aqueous suspension (DD 203553, EP 0001313) analogous to the different

Acrylic monomers optionally blended with styrene to swell the crystalline PP backbone polymer. "

(DE 2640059) or to which a swelling organic solvent is added (EP 0041214).

The grafted MSA-modified PP products can be used either as a coupling component in thermoplastic G> fiber (GF) bonded or as a well-adhering coating material, including as a primer component on Metal surfaces are used (FR 2572417). The above-mentioned grafting methods require due to the high-grade dilution of the reaction phase thereby

conditional low space-time yields and the costly product isolation - separation of the solvent and / or water, including drying and recovery of the solvent and the residual monomers - a high technological and therefore economic effort.

These disadvantages include grafting processes to the exclusion of a liquid phase, i. H. Water in suspension grafting,

organic solvent in the solution grafting or the backbone polymer melt itself, as in the

Melt grafting in the extruder (US 4147740), the work in the range between about 180 and 26O ⁰ C special consuming Do not need devices or ancillary equipment made of corrosion-resistant materials, not on. Accordingly, in the as Gas phase polymerization referred grafting of unsaturated polar liquid gases, such as vinyl chloride (VC) on PP

(DD 137112) or pre-oxidized PP (It 867340) obtained polar modified PP products.

The graft modification of isotactic PP by means of monomer, in particular VC and butadiene, below their Saturation vapor pressures (Pegafaro, M., and Beatl, E., Chim et al. (Milano) 66 (1974) 9, pp. 695-599) lead to an impact strength

PP products, but for use as a chemical coupler to improve the strength between

Glasf asermatorial and the thermoplastic matrix within the composite or as a self-adhesive polymer coating material

on metallic or other surfaces are not suitable.

Object of the invention

The object of the invention is to economically produce polar modified isotactic PP, which by its use ensures a high mechanical strength of the processed products.

-2- 275 160 Outline of the Essence of the Invention

The invention is based on the object, while avoiding a high technical and technological effort, a process for the preparation of polarmodifiziertem PP based on the radical Copfropfung of MSA-containing monomer mixtures on isotactic PP having a viscometrically determined average molecular weight M _w between 25,000 and 250000 using organic Peroxide and / or diazo-containing initiators in the temperature range between 60 and 100 "C, which leads to Spritzgießerzougniesen with a total improved mechanical characteristic level or when direct use as a coating material to polymer topcoats on metal surfaces with increased adhesion when used in glass fiber reinforced thermoplastic molding compositions to develop.

According to the invention mixtures of MSA and comonomers of the general formula CH ₂ = CH-Ri or CH ₂ = C (CH ₃ I-Ri, wherein Ri: COOR ₂ (Rj: H or C _n H _2n +1 with η from 1 to 8 ), C (H ₆ , 0OC-CH ₃ or Cl, in a mass ratio between 1 kg MSA / 1 kg comonomer (s) and 1 kg MSA / 10kg comonomer (s) and an MSA Masscnanteil related to the submitted PP between 0 , 2 and 10% of the graft polymerization and - after dispersion together with the initiator or initiator mixture - while maintaining a powdery and / or granular and / or flaky, flaky or flake-like consistency of the reaction medium to a total monomer mass conversion between 60 and 98% polymerized ,

Preferred comonomers are styrene (St), acrylic acid (AS), n-butyl acrylate (BA), methacrylic acid (MAS) and methyl methacrylate (MMA).

In addition to isotactic propylene homopolymers, the term PP-backbone polymers also includes isotactic propylene copolymers having a small mass fraction of from 0.5 to 5.0% of a copolymerized comonomer, in particular ethylene and butene units.

The backbone polymers have M _w -wait between 2.5 × 10 ⁴ and 2.5-10 ^s , preferably between 1.0 × 10 ⁸ and 2.0 × 10 ⁶ .

They are based on the relationship

[η] - 1,1 · 10- 'I'.? *

by measurements of the viscosity viscosity (η) in decalin at 135 "C determined.

The PP-ROckgratpolymeren be in powder form within a particle size range between 20 and 1000 \ xm (mass fraction of 95 to 100%), preferably 63-800 pm (mass fraction of 85 to 100%), and having an average particle diameter (C-value) between 200 and 450 μm and / or as granules with a particle diameter between 1.0 and 5.0 mm, preferably between 1.5 and 4.0 mm, and / or as flakes, with flakes a length dimension between 0.1 and 0.8 mm (mass fraction of 75 to 100%), preferably between 0.2 and 0.7 mm (mass fraction of 70 to 100%) used.

The criterion for the PP backbone polymer chains, which are composed of predominantly isotactic structural units, is that in boiling heptane it is used twice after 30 minutes. remaining solution residue, which is referred to hereinafter as Isotaxieindex. The isotacticity indices for the PP backbone polymers used are between 50 and 100%, preferably between 90 and 99%.

The backbone polymers are generally prepared by known antitoxydants and / or UV stabilizers, such as. B.

Substituted phenenes or benzene and / or Bonzotriazenderivate pre-stabilized before use.

As peroxidic initiators it is possible to use the known diacyl peroxides, such as dilauroyl and dibenzoyl peroxide (DLPO, DBPO) and dialkyl peroxydicarbonates, such as diisopropyl peroxide borate (DIPP!), And also diazo compounds, such as 2,2'azobis (isobutyronitrile) (AIBN) ,

The dispersion of the monomers and initiators on the PP is generally carried out in the polymerization reactor by means of simple stirring below the polymerization temperature, preferably at room temperature, with stirring time and speed depending on the reactor size and the degree of filling.

Over the entire polymerization section, the reaction medium remains in a dry powdery, granular or flaky to flaky or flaky state.

The polymerization of the monomer mixture is carried out to a total mass conversion of between 50 and 95%, wherein the polar functional group-containing comonomers, in particular AS, BA, MSA and MMA, bring an additional contribution to the polar modification of the PP and styrene as a comonomer swelling of the crystalline backbone polymer at the same time improved distribution of the MSA and the initiator or initiator mixture on the PP and a strong repression of the corrosive effect of MSA on the metallic inner walls and reactor parts causes.

The composition of the Copfropfpolymerisationsprodukte is determined using an extraction procedure (separation of the unreacted monomers and the MSA copolymers using methanol, separation of ungepf rapped PP using a solution in xylene).

exemplary

A temperature-controlled stainless steel reactor equipped with a RHR is equipped with 100 parts by mass (MT) PP with the following characteristics (PP-1):

density 0.91 g / cm ³ M " 159000 C-value 288 μπι Mass fraction of particle sizes between 200 and 800 μπι 92.0% between 20 and 63μΓΠ 5.3% isotactic index 92.2% Melt index MFI ¹ Sn ⁰ s, 6g / 10min. (TGL25244) Mass fraction of antioxidant 0.005%

Octadecyl-S-O.ö-di-tert-butyM-hydroxyphenyDpropionat

and a mixture of 10MT MSA and 10MT styrene and 1.2MT DPP / 0.5MT DLPO added and stirred at room temperature over a period of 90min. on the PP '. Afterwards the reactor will be within 180min. heated to aine Polymerisationsterrperatur of 90 ⁰ C and kept constant J _rm for another 60 min. polymerized. Subsequently, the reactor is cooled, purged with nitrogen several times and discharged at room temperature, a product amount of 118,8MT from the wall-free reactor. The obtained flowable product has a melt index

of 0.5 g / 10 min. von12,2g / 10min.

The analytical characteristics are obtained below:

unreacted monomer mass (based on the total monomer mass used)

Grafting yield PA (mass fraction of the grafted MSA / St mixture of total polymerized MSA / St amount)

- degree of grafting PG (mass fraction of the grafted MSA / quantity for the amount of PP submitted)

4.2%

77.5% 12.3%

In addition to the use of PP-1, two further backbone polymers (PP-2, PP-3) are used as initiators besides DLPO and DIPP, DBPO and AIBN and as further comonomers AS, MAS and BA and MMA and with variation of the polymerisation regime (T. _Pm / polymer! Time) a series of cograft polymerization products are prepared, the production and analytical parameters of which are shown in Table 1.

Table 1: Parameters for the preparation and analytical characterization of the polymodified PP products

polymerization parameters Monomial. Init. tpm Pm-time Copfropfprodukt characteristic values PG MrI Hu Ser. Backbone- (MT) (MT) ( ⁰ o (H) PA (%) (g / 10 min) No. PP (%) 100MT 10 MSA 1,2DIPP 90 3.1 12.3 0.5 1 PP-I 10st 0,5DLPO 77.5 2MSA 0,45DBPO 85 2.2 8.4 0.2 2 PP-1 1CAS 86.5 1MSA 0,3DBPO 80 2.2 7.9 1.2 3 PP-1 10AS 0,3AIBN 88.6 0,62MSA 1,0DBPO 85 3.2 4.7 6.7 4 PP-2 5,6AS 91.2 2MSA 0,5DIPP 90 2.2 6.7 0.2 5 PP-2 10 MAS 70.6 1MSA 0,5DLPO 90 3.2 6.3 4.5 β PP-1 8AS 0,5DIPP 88.5 granules 1,3MSA 0,5DLPO 85 3.2 5.5 3.2 7 PP-1 6,5AS 0,5DIPP 85.2 granules

polymerization parameters Monomial. Init. T, " Pm-time Copfropfprodukt characteristic values PG MFI'S |; ^C Ser. RQckgiM- (MT) (MT) ( ⁰ C) (H) PA (%) (g / 10 min) No. PP (%) 100MT 2MSA 0,5DLPO 80-65 2.5 / 3 8.8 0.25 8th PP-3 10AS 0,5DIPP 91.5 5MSA 0,6DLPO 90 2.2 6.2 4.8 9 PP-3 5MMA 0,5DIPP 76.5 2MSA 1.0 DBPO 85 2.5 / 2 6.7 0.6 10 PP-3 8AS 84.6 IMSA 0,3DLPO 85 3.2 3.1 6.5 11 PP-3 4RA 0,5DIPP 75.6 2MSA 0,5DBPO 90 2.5 / 2 5.8 6.2 12 PP-3 8MMA 0.8 DIP 72.3

The PP-2 and PP-3 backbone polymers present as "flakes" have the following characteristics of density

C-value

Mass fraction of the particles

extension between 0.2

and 0.8 mm

isotactic index Mass fraction of antioxidant

0.915 g / cm ³ 1480Oo 289 \ i, T, 91%

95.4%

5.8 g / 10 min.

0.01%

0.912 g / cm ² 126000 439 pm 96%

94.9%

5.2 g / 10 min.

0.05%

In addition, PP-1 is also used in granular form - average particle diameter of 1.8 mm boi a very small mass fraction between 0.5 and 1.0% of below 0.8 mm diameter - used as Rückgratpoly meres.

Claims (1)

A process for the preparation of polar modified polypropylene based on the radical grafting of MSA-containing monomeric gums onto isotactic polypropylene (PP) having a viscosimetrically determined average molecular weight M _w between 25,000 and 250,000 using organic peroxidic and / or diazo-containing initiators in the temperature range between 60 and 100 ^° C while maintaining a powdery and / or granular and / or flaky, flaky or flake-like consistency of the reaction medium during the polymerization for use as a chemical coupler in thermoplastic-glass fiber composites or as a self-adhesive polymer coating material on metal surfaces, characterized characterized that mixtures of MSA and comonomers of the general formula CH ₂ = CH-R ₁ OdBrCH ₂ = C (CHa) -R ₁ ,