DD266364A1 - GLASS FIBER AMPLIFIED POLYPROPYLENE MOLDING - Google Patents

Abstract

Glasfaserverstaerkte polypropylene molding compositions with improved strength Zaehigkeits-level and as a construction material processed and used are obtained on the basis of mixtures in the mass composition: - 20 to 40% of a equipped with known sizing combinations glass fiber material (reinforcing material), - 40 to 75% of isotactic polypropylene (PP) having a molecular weight Mw between 50,000 and 500,000 (polymer matrix) and 2 to 40% of a by radical (co) grafting of acrylic acid (AS), optionally in admixture with 2 to 50% of a comonomer, with a mass fraction between 1 and 20% AS on isotactic PP (Mw between 25,000 and 250,000) produced carboxylated polypropylene having a carboxyl group mass content between 0.3 and 10.0% ("chemical" coupler), which while maintaining a dry powdery and / or spherical and / or flaky, flaky or blätchenfoermigen consistency of the Pfropfreakt have produced couplers having a gel mass fraction between 25 and 90%.

Description

Field of application of the invention

The invention relates to glass fiber reinforced polypropylene molding compositions having improved strength toughness levels for use as a construction material based on a mixture with the bulk composition:

20 to 40% of a glass silk equipped with known sizing combinations (Verstörkungsmntorlal),

40 to 75% of an isotactic polypropylene (PP) having a molecular weight M _w between 50,000 and 500,000 (polymer matrix) as well as

2 to 40% of a by radical (co-) grafting of acrylic acid (AS), gogebenenfallsjn mixing with 2 to 50% einos comonamers, with a mass fraction between 1 and 20% AS on isotactic PP (M _w between 25000 and 250000) produced .carboxylatedon polypropylene having a carboxyl group mass content between 0.3 and 10.0% ("chemical" coupler).

Characteristic of the known technical solutions

It is known, in order to improve the mechanical properties of glass-fiber reinforced PP, in particular the increase in flexural and tensile strength, stiffness, impact resistance and dimensional stability, at least a portion of the PP in terms of improved adhesion between the GF reinforcing material and the PP Modify the matrix. A convenient way to modify isoactic PP is by ciio grafting of polar monomers, especially of ethylenically unsaturated cai boxyl group-containing compounds, such as acrylic acid, methacrylic acid and itaconic acid, as well as maleic anhydride (MSA) onto the PP backbone. Different graft polymerization processes can be used for the graft products used as chornic coreaver in PP-GF composites. Besides the technical and economic elaborate radiation grafting (US 3,280,415, US 3,347,682, DE 2,725,477;..... J. Polym Be, Polym Lett Ed 1,911,981], 457) is in a larger scale the grafting at high temperatures (180-230 ⁰ C ), ie in the PP melt, in general directly in the extruder (EP 109532, EP 82704, US 3162697, L ¹ S 3882194, US 3987122, US 4147740, DE 224234, DE 2455594).

This technology, carried out in a separate extruder stage, results in more homogeneous grafting of a molten backbone polymer over processes conducted at tematic temperatures (50-1CO ⁰ C) to more homogeneous graft modified PP products.

In spite of the high risk of corrosion of the relevant extruder parts at high temperatures and the sensitivity with regard to regulation or control of this modification stage, taking into account the subsequent PP-GF overall pretreatment in the extruder, VerfahrPii is the grafting of AS and MSA in the PP melt. In this case, larger PP molecular weight decreases are allowed, since diose when using the products as chemical couplers in the usual Massoantoilon between 5 and 20% in PP-GF Vorbundon no dominier end meaning. In addition, processes are used that do not rely on the technical and technological conditions (grafting in the extruder) bacieron, which is necessary for PP-Schmolzo! based on dor i; ommerziollon suspension polymerization at Polymorisationstomporaturen of 60-100 ° C, usually with the addition of swelling agents for the isotactic PP, such as organic (usually aromatischp) solvents or nonpolar comonomers (usually Styron) carried out (EP 0041214, DE 2640059). For these ancestors, there is no need for a technical-technological classification of the coupler within the oinos speci alextrudors operating regime, so that the coupler component can be generated separately in a suspension polymerization reactor, independently of the extrusion process of the PP-GF pretreatment.

On the other hand, the suspension technology, especially when using the necessary for a sufficient swelling of the PP backbone chains solvent or comonomers in excess, requires a very audi technical effort for the workup dor Pfropfproduk'isusponsion, including product purification and solvent or Conomerenrückgowinnung, and There are significantly fewer space-time excursions. Furthermore, sirli distinguish the "suspension" graft products from those in the PP-molten salted couplers

Degradation reactions, which lead to a reduction in the average PP molecular weight, although lower, but the products beritzon - u.a. because of the z.T. significant water solubility of the polar monomer - lower levels of polaron functional groups, i. they are "coupling-inactive".

The polarmodified PP products obtained by means of jarboxyl-containing graft monomers, if appropriate also in the gomic with other monomer components (comonomers), are generally admissible in amounts of 6 to 20%, corresponding to the total proportion of carboxyl or other (additional) polar functional groups fiberglass-reinforced molding compound of conventional mass aggregation of 30% GF / 70% isotactic PP di '<"chemical coupling" between polymer matrix and the surface coated with functional polyol groups) of the fiberglass material Known sizing compositions for glass fibers contain at least one binder each ( so-called Schlichtobindor), ie, an aqueous polymordisporsion, and an adhesive, in particular one or more silane compounds Immediately after dom pulling the glass thread from the melt (Düsenzieh- or Düsenblasverfahren), the sizing is applied to the Glasfiliamento.

For the reinforcement of PP, in analogy to other plastics, generally carbonized Eloktroisolationsglas (Ε-glass) of the composition: 54.5% SiO? 14.5% Al ₂ O ₃ , 7.5% B ₂ O ₃ , 17.0% CaO and 4.5% MgO, which is drawn into the composite as a roving in an olnem extruder.

The abovementioned proportions of a chemical coupler in PP-GF composite clay cause average increases in the most important mechanical characteristics, taking into account a typical variation range corresponding to the carboxyl group massonantoil of between about 0.35 and 0.55% in the molding composition

the tensile strength σ _Μ to about 90-100%,

the Grenzbiegefestipkeit c _{b) i6} to about 20-30% and

Impact resistance is about 20-30%.

Characteristic of the known couplers produced in various ways is their high homogeneity, as it is indicated by a low gel mass fraction, generally between 1 and 5%.

Object of the invention

The object of the invention is to use a chemical coupler based on carboxyliortem PP fiberglass-reinforced PP molding compositions for a wide Verarboitungs- and field of application to economical Woise horzustellon.

Explanation of the nature of the final statement

It is an object of the present invention to provide glass fiber reinforced PP molded articles having improved strength toughness level for use as a construction material based on a precursor mixture having the composition of masson:

20 to 40% of a glassoido (reinforcing material) equipped by means of a known sizing combination,

40 to 75% of an isotactic polypropylene (PP) having a molecular weight M _w between 50,000 and 500,000 (polymer matrix) and

2 to 40% of a by radical (co) grafting of acrylic acid (AS), optionally in admixture with 2 to 50% of a comonomer, with a mass fraction between 1 and 20% AS on isotactic PP (M _w between 25,000 and 250,000) Elongated Carboxyliorton Polypropylene Having a Carboxyl Group Mass between 0.3 and 10.0% ("Chemical" Coupler)

to create. '

According to the invention, the couplers used are those which, while maintaining a dry powdery and / or granular and / or flaky, flaky or platelet-shaped consistency, of the reaction medium (Co-1) graft polymerization products having a gel mass fraction of between 25 and 90%.

An improved toughness strength level is especially ·. ' Base of (Co-1) grafted polymerization product obtained as a coupler having a gel mass fraction of between 35 and 75%.

As Gol mass fraction - in principle, a structure size that expresses an "inhomogeneity" level, the solution residue of a definiorton product sample in oinor fixed amount oinos certain solvent is understood after a fixed treatment, in the present case, the following specific conditions have been established are:

2 g product (coupler)

iniOOmlXylon

1 hour under reflux.

The required for the (co) grafting PP backbone polymers, either dio pure Propylenhomopolymoro or Propylencopolymore with oinpolymorisiorton olefin units, such as ethylene or butene units, with mass fraction of between 0.5 and 5%, dio dio same or different physical-chemical characteristics wio for dio as unmodifiziortes PP in dio molding compound incorporated component

 The PP used for both components has the following basic passwords: ·

Mean molecular weight M ^

(viscometric in decalin at 135 ° C) Density

isotactic index

(Solution residue in boiling heptane) Lard index MFI 19O ⁰ C 49 N (according to TGL 25244)

Gel mass fraction

(Solution residue in xylon / under reflux) Particle form

average particle diameter (C value) for powder

maximum length expansion for flakes, flakes, leaflets particle diameter for granules

25,000 to 500,000, preferably 100,000 to 200,000 from 0.90 to 0.93 g / cm ³ 50-99%, preferably

80-98%

4 ~ 40 g / 10 min.

0.5-20% powder; Flockon, Schuppon, Blättchon; granules

200-450 μηι

100-800 μηι 1.0-5.0 mm

As the main graft monomer for dio production of the carboxylated PP in a separate process step - radical grafting using organic peroxidic and / or diazo-containing initiators, optionally via a hydroperoxidized PP produced in a pre-stored stage - acrylic acid (AS) is prepared according to a carboxyl group to be set in the graft product. Mass fraction (I-COOHI-Antoil) between 0.3 and 10%, based on the graft product used.

Either AS is used alone or in admixture with 2 to 50% of a comonomer from the range of polar ethylenically unsaturated compounds such as maleic anhydride (MSA), methyl methacrylate (MMA), etc., and / or a nonpolar vinyl compound, preferably styrene.

The GF material used in the present case is a roving produced from an E-glassoid of known composition, which is provided with an usual sizing composition consisting essentially of an aqueous polyolefin and / or polyurethane and / or polyacrylate dispersion as sizing binder and a substituted trialkoxysilane and / or or a Viny'silanverbindung as an adhesive and beyond even a small proportion of a known lubricant containing can, used, the so-called adhesives in the sizing composition due to their variety and ability to combine with influenced greater processing and application technology effect the greatest importance in the size composition.

Typical representatives of substituted substituted trialkoxysilanes are, in particular, γ-aminopropyltriothoxysilane and Jf-glycidoxypropyltriethoxysilane, and of vinylsilanone, especially vinyltris (2-methoxyethoxy) silane, vinyltrisethoxysilane and bromovinyltrisethoxysilane. Furthermore, analogs of these Vorbindungsklassen, such as. Ethyl tris- (2-methoxyothoxy) silane and methacrylic acid tris-methoxy-silylpropyldoster. usable.

embodiment

In a twin-screw extruder, molding compounds are based on

30 parts by weight of a sized E-glass silk roving (using an aminosilane / vinylsilane combination as an adhesive and a PU / polyolefin binder as a size binder)

70 pigs (all PP material, of which 11.4-21.4% coupler, manufactured and compared with molding compounds;

Without coupler component (Vergloichs-Formmasse Nr. 1),

- with a total mass of 10% coupler-Vgl. No. 2, d. H. a grafted product with about 6% of PP polymerized on PP-1 under melt conditions (compare molding composition no. 2 with a total of 0.375% carboxyl groupantell),

- With a total mass fraction of 15% coupler-Vgl. No.3, i. a grafted product with about 6% of PP polymerized in the melt in the melt (comparative molding composition no. 3 with a total of 0.543% carboxyl group component),

- with a total mass fraction of 10% coupler-Vgl. No. 4, i. a graft with about 8.3% on PP-3indor melt polymerized AS (Comp. No. 4 with a total mass fraction of 0.475% carboxyl groups).

These coupons are prepared using couplers prepared according to the conditions given in Table 1 by (co) grafting of AS, AS / St and AS / MSA mixtures

- powdery PP-1

(M _w = 159000, isotacty = 0.92, gel content = 13.8%)

- Pf-1 granules

(M _w = 167300, isotacticity = 0.96, gel content = 20.4%)

- flaky PP-2

(M _w = 148,000, isotacty = 0.91, goigehalt = 0.9%)

- sheet-shaped PP-3

(M _w = 126000, isotacticity = 0.96, gel content = 1.0%)

under Verwerduiiy of dibenzoyl peroxide (DBPO) or diisopropyl peroxydicarbonate (DIPP) as initiators, obtained orfindungs'jemäßen molding compositions (Nos. 1-8) with their most important mechanical and two woitoren characteristic values in Table 2 compared.

The main difference is the significantly higher Gol content of the carboxylated PP products (couplers) to be incorporated for the molding materials, which differs even more than one order of magnitude (from 36.5 to 71.6% compared to 1.57-3 , 25%) and, in a certain sense, indicates a drastically higher "heterogeneity" of these couplers The use of couplers with a high gel content leads to a basic mechanical level, based on the characteristics tested in Table 2

Tensile strength σ _Η (50mm / min., ISO rod) and elongation at break C _n (TGL 14070), limit bending strength a _bhi and flexural elasticity modulus Ei, (TGL 14067), impact strength and impact strength a _n and a _k (TGL 14068) and ball hardness KDH (TGL 20924)

including an increased heat resistance (WFB) η I Vicat (TGL 172 74) and a sufficient color stability (according to visual assessment), which corresponds to comparable or equipped by known coupler GF / PP molding compounds or in the upper mechanical Boreich.

Table 1: Preparation of chemical couplers

Polymorisationsbodmgungon graft Init. tpm 80 85 Time (Co) Graft-Could words plug • 85.6 GoI- Ser. Backbone- mon. [COOH) - yield gohalt No. PP (%) (%) ( ⁰ o 80 (H) Gohalt (%) ² ' 87.5 (%) " 100MT (3.5 AS 0,3DCP 180-220 0.1-0.2 (%) " 92.3 3.25 See 2 PP-1 0,5AS 0.1 DMBPH 180-220 85 0.1-0.2 3.75 89.2 84.6 1.57 See 3 PP-2 ! 1AS 0,2DMBPH 185-225 0.15-0.25 3.62 87.5 1.72 See 4 PP-3 OAS 1,5DIPP 30-80) 85 3 4.75 86.0 90.5 36.5 1 PP-2 80) 1 3.22 9AS 0.7 DBPO 80 3.2 90.0 90.5 36.9 2 PP-1 EAST 4.96 OAS 0,5DBPO 30-80) 3.2 91.2 6;, 5 3 PP-1 Gr. 4st 80) 2.93 OAS 0,5DBPO 2.2 40.5 4 PP-3 4st 3.14 BAS 1,0DBPO 2.5 / 2 55.3 5 PP-3 2MSA 5.06 9AS 0,5DBPO 3.2 56.2 6 PP-3 6st 4.63 10AS 1,0DIPP 4 71.6 7 PP-I 1 5.26 5,6AS 1,0DBPO 3.2 53.1 8th PP-2 0,62MSA 3.71

DCP - dicumylpoxide / DMBPH - 2,5-dimethyl-2,5-bis (tert-butylperoxy) hexane

1) percentages based on (co) graft product mass. 2) Exception: graftout as grafted portion to total polymorisiorton monomer mass.

Table 2: Testing of the glass-fiber-reinforced PP molding compositions of the composition 30% GF / 70% PP- with different Coupler proportions (55 to 62% PP-1/8 to 15% coupler, where in PP4 and No.6 anstdlle PP-1 used as matrix material PP-3)

proportion of [COOH] - Mechanical characteristics Om Whether 1.6 E _b a " ak KDH further characteristic values opt. Eig. Ser. Kopplor proportion of ISO 30 soc Vicat (Appearance) , No. inFormm. inFormm. Rod WFB (%) (%) (MPa) (MPa) (GPa) (kJ / m ² ) U / m ² ) (MPa) - (%) 41.5 82.2 3.43 28.5 5.3 80.3 CC) woiß See 1 10 0,375 6.2 76.2 105.5 4.43 35.2 6.8 81.5 134 White See 2 15 0.543 8.9 82.0 107.5 4.70 30.6 5.9 78.6 152 yellowish See 3 10 0,475 9.2 78.5 107.0 4.62 32.5 6.8 82.5 150 yellowish Vgl.4 12 0,386 8.5 69.1 108.2 4.66 37.1 8.2 84.2 153 white-yellowish 1 10 0.469 7.7 80.0 106.8 4.22 50.5 8.8 91.7 152 White 2 13 0,381 9.2 80.9 114.8 4.94 50.5 9.3 88.9 155 white-yellowish 3 10 0,314 8.1 7b, 1 111.7 4.78 39.8 7.6 83.1 156 White 4 10 0.506 8.6 82.4 114.0 4.75 46.8 9.2 83.5 15J yellowish 5 8th 0.370 7.3 82.2 114.7 4.95 53.6 10.1 85.7 150 woiß 6 10 0.526 7.5 78.7 109.4 4.21 35.3 7.0 92.9 152 white-yellowish 7 10 0.37 8.0 78.4 113.1 9.4 50.6 10.3 98.7 157 woiß yellowish 8th 9.6 152

Claims (2)

Glass fiber reinforced polypropyl- ond molding compositions having improved strength toughness level for use as engineering materials based on a blend with the bulk composition: 20 to 40% of a glass silk (reinforcing material) equipped with known sizing combinations, 40 to 75% of an isotactic polypropylene (PP) having a molecular weight M _{w of} between 50,000 and 500,000 (polymer matrix) and - 2 to 40% of a by radical (co) grafting of acrylic acid (AS), optionally in admixture with 2 to 50% of a comonomer, with a mass fraction between 1 and 20% AS on isotactic PP (Μ _Λ between 25000 and 250000) generated carboxylated polypropylene having a carboxyl group mass content between 0.3 and 10.0% ("chemical" coupler), characterized in that as a coupler the (co) graft polymerization products produced while maintaining a dry powdery and / or granular and / or flaky, flaky or flake-like consistency of the reaction medium with a gel mass fraction between 25 and 90%.