DE102004019180A1 - Molding composition useful as e.g. wash liquor vessel and liquor pump casing comprises olefinic polymer containing glass fibers bonded to the olefin polymer by a compatibilizer, and phthalocyanine pigment as a nucleating agent - Google Patents

Abstract

A molding composition comprises an olefinic polymer containing glass fibers (5 - 50 wt.%) bonded to the olefin polymer by a compatibilizer, and phthalocyanine pigment (10 -> 4> - 1 wt.%, preferably 10 -> 3> - 10 -> 1>) as a nucleating agent. An independent claim is included for preparation of the composition involving mixing the propylene polymer (initially melted) and the nucleating agent in a mixing apparatus at 180 - 320[deg]C; followed by mixing the glass fibers with the melt.

Description

The invention relates to a molding composition of an olefin polymer, in particular a propylene polymer containing 5-50 wt .-% glass fibers which are bound by means of a compatibilizer to the olefin polymer, and 10 ⁴ to 1 wt .-% of a phthalocyanine pigment as a nucleating agent.

The reinforcement of olefin polymers by means of glass fibers has been known for a long time. In the EP 663 418 A1 for example, a polypropylene molding composition is described, which is reinforced with glass fibers. However, in order to obtain good mechanical properties, it is necessary to use compatibilizers or coupling agents which ensure good bonding of the glass fibers to the polyolefin matrix. The compatibilizers often contain, on the one hand, a reactively modified polymer which is compatible with the matrix polymer as coupler and, on the other hand, a compound with reactive polar groups which, on the one hand, can bind to the glass fiber and, on the other hand, to the coupler.

The Nucleating unreinforced Propylene polymers to improve stiffness and strength but also the transparency of the molded body produced therefrom also common practice. For this In addition to sodium benzoate, fine talc, phosphate ester salts, sorbitols, Quinacridone pigments and others also phthalocyanine pigments as Nucleating agent used. The nucleation generally leads to a Improvement in tensile strength and rigidity, but not to a significant improvement in impact resistance and often to one reduced elongation at break and elongation at break.

In Polymer 34, 4747 (1993) and European Polymer Journal 32, 1425 (1996), the influence of nucleation on polypropylene-glass fiber composites studied using sodium benzoate as a nucleating agent. It was for the nucleated fiber composites increased by 10% elastic modulus and increased by 10% Tensile strength over found the non-nucleated Connected.

The Sodium benzoate as well as many other nucleating agents have due their nucleating improving polar character has the disadvantage that they react with the coupler of the compatibilizer can and so interfere with the binding of the glass fibers or because of their high Price are economically not very attractive.

One particular disadvantage of nucleating agents such as sodium benzoate the only moderate hot water and steam resistance the polyolefin molding compositions in particular in long-term contact over several Weeks or months.

Of the It is an object of the present invention to provide a polyolefin molding composition available too provide an improved matrix connection of the glass fibers and thus shows better mechanical properties and is available at low cost and the improved hot water resistance, especially in the presence of Dertgentien has.

It has now surprisingly been found that a particularly good matrix connection of the glass fibers in the matrix polymer, in particular propylene polymer, can be achieved by the combination of glass fibers which are bound to the olefin polymer by means of a compatibilizer and a phthalocyanine pigment. Accordingly, the molding compositions according to the invention have an olefin polymer containing 5-50 wt .-% glass fibers and 10 ⁴ to 1 wt .-%, preferably 10 ^-3 to 10 ¹ wt .-%, of a phthalocyanine pigment as nucleating agent. Due to the low cost of the phthalocyanine pigment and the fact that even a very small proportion of the phthalocyanine pigment in the polymer leads to a sufficient nucleation, an extremely low-cost production is ensured. In addition, the polyolefin molding compound is characterized by excellent hot water resistance.

Essential for the Inventive polyolefin molding composition On the one hand, the content of 5 to 50 wt .-% glass fibers is based on the total mass. The glass fibers may be both about cut glass fibers with a length of about 3 to 6 mm as also about long glass fibers act, with the use of cut glass fibers is preferred. Further preferred are 10 to 40 wt .-%, especially preferably 20 to 40 wt .-% glass fibers used.

Preference is given to the use of cut glass fibers, also called chopped strands. Due to the nucleation, the stiffness of molding compositions with long glass fibers can be achieved at a significantly lower price when using the cut glass fibers. The glass fibers used have preferably a length of 3 to 6 mm, more preferably 3 to 4.5 mm and a diameter of 10 to 20 microns, preferably 12 to 14 microns. Depending on the compounding and injection molding conditions, the length of the glass fibers in the molding compound (granules or injection-molded finished part) is 50 μm to 3000 μm, preferably 50 to 1000 μm.

to Connection of the glass fibers to the polyolefin matrix becomes a polar functionalized compatibilizer used. For one thing low molecular weight compounds are used exclusively serve, the glass fibers less hydrophilic and thus compatible with to make the polymer. Suitable compounds are, for example Silanes such as aminosilanes, epoxysilanes, amidosilanes or acrylsilanes. Prefers contains the compatibilizer however, a functionalized polymer and a low molecular weight Compound with reactive polar groups. In the functionalized Polymer is preferably graft or block copolymers, which are compatible with the matrix polymer. For a propylene homopolymer as For example, matrix component is preferred, a graft or block copolymer of propylene as a functionalized polymer.

in this connection preference is given to those polymers which, as reactive groups, are acid anhydrides, Carboxylic acids, carboxylic acid derivatives, primary and secondary Amines, hydroxyl compounds, oxazolines and epoxides and ionic Contain connections. Particularly preferred is the use of a maleic anhydride grafted propylene polymer as a functionalized polymer. The low molecular weight compound serves to the glass fiber to couple the functionalized polymer and thus firmly to the polyolefin matrix to bind. These are mostly bifunctional compounds, where the one functional group is a binding interaction can enter with the glass fibers and the second functional Group a binding interaction with the functionalized polymer can go down. As low molecular weight compound are preferred Amino and epoxy silanes, more preferably aminosilanes used. The aminosilanes bind with the silane-hydroxy groups to the glass fiber, while the amino groups, for example, with maleic anhydride grafted polypropylene form a stable amide bond.

The compatibilizers can be used prefabricated or prepared in situ. Especially It is advantageous, the low molecular weight component on the Glasspainnfasern apply before they are incorporated into the polyolefin matrix becomes. The functionalized polymer can be easily by reactive extrusion of the matrix polymer, for example with maleic anhydride generate in situ. Also the use of a masterbatch containing the Glass fibers and compatibilizers contains premixed is possible.

Furthermore, it is essential for the present invention that the glass-fiber-reinforced polypropylene molding composition is nucleated with a phthalocyanine pigment. The phthalocyanine pigments themselves are generally known and are derived from the main body of phthalocyanine by incorporation of a central metal ion and by substitution of the phthalocyanine ring. In practice, copper, nickel and cobalt are used as central atoms in the pigments, copper being preferred as the central atom. The phthalocyanine base may optionally be substituted, in particular with chlorine or bromine atoms. Substitution with organic radicals can also be carried out to tune the nucleating properties. As the phthalocyanine pigments, for example, the unsubstituted copper phthalocyanine (phthalocyanine blue), polychlorinated copper phthalocyanine (pthalocyanine green, C ₃₂ H ₂ N ₈ Cl ₁₄ Cu), cobalt phthalocyanine (C ₃₂ H ₁₆ N ₈ Co), nickel phthalocyanine (C ₃₂ H ₁₆ N ₈ Ni). Particularly preferred is the unsubstituted copper phthalocyanine.

The unsubstituted copper phthalocyanine and the polychlorinated copper phthalocyanine For example, the company Clariant, Frankfurt, DE under the designations PV Echtblau or PV Echtgrün sold.

The proportion of nucleating agent is between 10 ⁴ and 1 wt.% Based on the total mass. Preferably, the use of 10 ³ to 10 ¹ wt .-%, particularly preferably 5.10 ³ to 5.10 ² wt .-% of the nucleating agent.

The combination of glass fiber reinforcement and nucleation with phthalocyanine pigments gives a comparison with the prior art in terms of stiffness and toughness improved molding composition. Furthermore, surprisingly, with the same compatibilizer, the adhesion of the glass spinning fiber to the polyolefin matrix is markedly improved, resulting in improved crack propagation in the molding composition. Furthermore, surprisingly, the nucleation with phthalocyanine pigments results in markedly improved long-term stability of the tensile strengths and impact strengths in hot water and hot detergents, eg over test times of 1000 hours at 95 ° C., compared to non-nucleated glass fiber-reinforced comparative samples. Advantages in the long-term stability of the molding compositions according to the invention are, for example, too Detect in the long-term tests in aqueous detergents according to the UL standards 2157 and 749 testing for 138 days at 82 ° C.

special Advantage of the Phthalocyaninpigments is that this with the usual compatibilizers is largely compatible, i. Nucleating agents and compatibilizers in their effect not or hardly disturb each other.

The molding compositions according to the invention are available by melting and mixing the Olefinpolymerisats with the Phthalocyanine pigment and the glass fibers, the mixing in a mixing apparatus at temperatures of 180 to 320 ° C, preferably from 200 to 280 ° C, particularly preferably from 220 to 260 ° C. As mixing equipment can in particular extruders or kneaders are used, wherein Twin-screw extruders are particularly preferred. In powdered form present polymers is suitably a premix of the polymer with the nucleating agent and optionally further additives at room temperature in a mixing apparatus. The mixing of the olefin polymer with the nucleating agent and the glass fibers can be done in one step but also in several steps. It is preferred, in the mixing apparatus, first the olefin polymer melt with the nucleating agent and other additives and to mix and then To mix the glass fibers with the melt to the abrasion in the blender and to reduce the fiber breakage.

When Matrix component of the molding composition according to the invention are homopolymers and copolymers of alpha-olefins having 2 to 12 carbon atoms in question, for example, ethylene, propene, 1-butene, 1-hexene or 1-octene. Also suitable are copolymers and terpolymers which in addition to these monomers contain other monomers, in particular dienes, such as ethylidenenorbornene, cyclopentadiene or butadiene.

preferred Matrix components are polyethylene, polypropylene, polybutylene and / or Copolymers of ethene with propene, 1-butene, 1-hexene or 1-octene. in principle Any of these can be commercially available Type can be used. For example: linear High, medium or low density polyethylene, LDPE, ethylene copolymers with smaller amounts (up to a maximum of about 40% by weight) of comonomers such as propene, 1-butene, 1-hexene, 1-octene, n-butyl acrylate, methyl methacrylate, maleic anhydride, Styrene, vinyl alcohol, acrylic acid, Glycidyl methacrylate or the like, isotactic or atactic homopolypropylene, random copolymers of propene with ethene and / or 1-butene, ethylene-propylene block copolymers and more. Such polyolefins may also have an impact modifier component such as As EPM or EPDM rubber or SEBS.

at the use of polyethylene as the matrix component should be the comonomer content of the ethylene copolymers 1 mol% of the total amount of monomers used do not exceed. Preferred comonomers are 1-olefins, particularly preferred comonomers are 1-butene, 4-methyl-1-pentene, 1-hexene and 1-octene. Furthermore, it may be in the polyethylene also a blend of two or more polyethylene components act.

Particularly preferred is the use of a propylene polymer as the matrix component. In particular, a propylene homopolymer or a propylene copolymer having up to 30% by weight of copolymerized other olefins having up to 10 carbon atoms can be used as the propylene polymer. Such other olefins are especially C ₂ -C ₁₀ -1-alkenes such as ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene or 1-octene, with ethylene, 1-butene or ethylene and 1-butene being preferred be used. Particularly preferred is the use of propylene homopolymers.

The copolymers of propylene are in this case block or impact copolymers or preferably random copolymers. If the copolymers of propylene have a random structure, they generally contain up to 15% by weight, preferably up to 6% by weight, particularly preferably up to 2% by weight, of other olefins having up to 10 carbon atoms, in particular Ethylene, 1-butene or a mixture of ethylene and 1-butene as comonomers. The block or impact copolymers of propylene are polymers in which in the first stage a propylene homopolymer or a random copolymer of propylene with up to 15 wt .-%, preferably up to 6 wt .-%, particularly preferably up to 2 wt. -%, of other olefins having up manufactures to 10 C-atoms as comonomers, and then in the second stage a propylene-ethylene copolymer with ethylene contents of from 15 to 99 wt .-%, wherein the propylene-ethylene copolymer additionally another C ₄ -C ₁₀ -olefins may be polymerized. As a rule, so much of the propylene-ethylene copolymer is polymerized that the copolymer produced in the second stage in the final product has a content of 3 to 90 wt .-%. The random copolymers of propylene are polymers in which in the first stage, a propylene homopolymer or a random copolymer of propylene with up to 15 wt .-%, preferably up to 6 wt .-%, particularly preferably up to 2 wt .-%, of other olefins having up to 10 carbon atoms as Comonomers and then in the second stage a propylene homopolymer or a random copolymer of propylene with up to 15 wt .-%, preferably up to 6 wt .-% (particularly preferably up to 2% comonomers) of other olefins with up to 10 C. Added added to polymerized. The polymers of the two stages differ in molecular weight and comonomer content. The ethylene content of the blend is 15% by weight or preferably up to 6% by weight and more preferably up to 3% by weight of comonomers.

It Preferably, an isotactic polypropylene with a xylolunlöslichen Proportion of over 95%, preferably from above 97% used. The polyolefin generally has an MFR (230 ° C / 2.16 kg) from 0.2 to 200 g / 10 min to ISO 1133, preferably between 0.5 and 100 g / 10 min and more preferably between 2 and 30 g / 10 min. Preference is furthermore given to polypropylene molding compositions having a monomodal Molecular weight distribution.

The molding compositions according to the invention can still usual Additives and adjuncts, such as Stabilizers against harmful processing effects, antioxidants against heat oxidation and aging, UV influence, neutralizing agents, fillers, organic and inorganic pigments or pigment preparations such as for example, carbon black dispersions in polyolefins, antistatic agents, nonpolar waxes or special low molecular weight Lubricants and lubricants included. UV stabilizers, in particular monomeric and oligomeric HALS, antistatic and polar waxes as well Stearates are for the molding compositions according to the invention less suitable or at best in very low concentrations, since these with the coupler of the compatibilizer also can react and thus reduce the efficiency of coupling, the amount of additives and auxiliaries but should be 10 wt.% Based on the total amount of the material, preferably 5% by weight. From optical establish It may also recommend, by adding appropriate appropriate Color pigments to the molding compositions of this invention in one to color other, preferably darker color.

The in the molding compositions according to the invention used olefin polymers can with all common ones Methods and catalysts are obtained. The polymerization is preferred the corresponding monomers by means of a Ziegler-Natta catalyst, a Phillips catalyst based on chromium oxide or a metallocene catalyst. Among metallocenes here complex compounds of metals of groups 3 to 12 of the Periodic Table with organic ligands be understood, which together with metalloceniumionenbildenden Compounds effective catalyst systems yield.

To prepare the olefin polymers, the usual reactors used for the polymerization of C ₂ -C ₁₀ olefins can be used. Suitable reactors include continuously operated horizontal or vertical stirred tanks, circulation reactors, loop reactors, stage reactors or fluidized bed reactors. The size of the reactors is not essential for the preparation of the molding compositions of the invention. It depends on the output that is to be achieved in or in the individual reaction zones. The polymerization process can be carried out in one or more stages. It may be polymerized in the gas phase, in bulk or suspension or a combination thereof.

The molding composition according to the invention is particularly suitable for the production of automotive parts, the high demands to the stiffness and toughness of the material. Particularly advantageous is the use in dark colored or provided with a decorative layer automotive parts such as Front-ends or dashboard supports, in which the blue color caused by the phthalocyanine pigment is covered becomes. From the molding composition of the invention produced moldings are by their improved rigidity and toughness even in use cut glass fibers for Suitable applications, the previously long fiber reinforced propylene polymers were reserved.

Farther is characterized molding composition of the invention by a very good creep behavior against hot water and detergents. She lets Therefore, use particularly advantageous as a material for moldings, the contact with hot water, Washing and rinsing eyes and other aggressive materials. Another item The present invention is therefore the use of the molding composition according to the invention as a wash tank (preferably not visible) in washing machines and wash tubs manufactured from the molding composition according to the invention, but also the use for water and lye pump housing.

example 1

a) Preparation of the glass-fiber-reinforced polypropylene molding composition:

The the following parts by weight each refer to the total mass the polymer molding composition, unless otherwise specified.

68.19 % By weight of polypropylene homopolymer (Moplen HF500H, Basell Polyolefins, Germany, MFR (230 ° C, 2.18 kg) = 1.2 g / 10 min) were in a twin-screw extruder (ZSK 53) with 30% by weight of a short glass fiber (Chopped strands ECS 03T-T480, NEG) with a length offset by 3mm and a diameter of 13μm. The short glass fibers were in the polymer molding material melt at element 3 or 4 of the 10 schüssigen Two-screw extruders dosed. The polypropylene homopolymer were at the same time still 0.01 wt .-% phthalocyanine blue 15: 3 (PV-Echtblau 2GL SP, Clariant) as nucleating agent, 1.2% by weight Polybond 3200 (Crompton) as a compatibilizer, 0.1 wt .-% of an inorganic acid scavenger and 0.5 wt .-% of a stabilizer combination of a phenolic Antioxidant, distearyl thio-dipropionate and a di-tert-butyphenyl phosphite.

b) Hot water test

The Polypropylene molding compound from Example 1 was in an injection molding machine to test specimens according to DIN EN ISO 527-2 and DIN EN ISO 179/1 processed.

At the test specimens was the breaking stress and tensile modulus according to ISO 527-2 and -1 certainly. Furthermore, the Charpy impact strength according to DIN EN ISO 179 / 1eU measured.

The specimens were demineralized in a temperature-controlled bath at a temperature of 95 ° C Water stored. Depending on the application or requirements can also different detergents with defined concentrations added become.

To in each case at least 5 specimens were taken from the corresponding time and again the breaking stress and the tensile modulus according to DIN EN ISO 527-2 determined as the average of 5-10 individual measurements. On the same Way became the Charpy impact resistance determined according to DIN EN ISO 179 / 1eU.

The test results are shown in Tables 1 to 3 and in the 1 to 3 compiled.

Example 2

example 1 was repeated with a content of 0.05% by weight phthalocyanine Blue 15: 3 (PV-Echtblau 2GL SP, Clariant). The amount of the polypropylene was 100 in total Adjusted wt .-% total mass of the polymer molding composition.

Comparative Example 3

example 1 was repeated at a level of 0.1% by weight of sodium benzoate as a nucleating agent. The amount of polypropylene was increased to total Adjusted 100 wt .-% total mass of the polymer molding composition.

Comparative Example 4

example 1 was repeated with a content of 0.3% by weight of sodium benzoate as a nucleating agent. The amount of polypropylene was increased to total Adjusted 100 wt .-% total mass of the polymer molding composition.

Table 1: Breaking stress as a function of the duration of the hot water contact

Table 2: Tensile modulus as a function of the duration of the hot water contact

Table 3: Charpy impact strength as a function of the duration of the hot water contact

you recognizes that the drop in breaking stress and the tensile modulus of elasticity and the Charpy impact strength surprisingly in the phthalocyanine nucleated glass fiber reinforced polypropylene molding compositions (Symbols ✧ and ☐) is significantly lower than in the sodium benzoate nucleated (symbols ∇ and o).

Claims (12)

Molding compositions comprising an olefin polymer comprising a) from 5 to 50% by weight of glass-fiber fibers bound to the olefin polymer by means of a compatibilizer, and b) from 10 ⁴ to 1% by weight, in particular from 10 ^-3 to 10 ¹ % by weight, a phthalocyanine pigment as nucleating agent. Molding composition according to claim 1, wherein the olefin polymer is a propylene polymer. Molding composition according to claim 1 or 2, wherein it is at the glass fibers are cut fiberglass fibers. Molding composition according to one of claims 1 to 3 containing 10 bis 40, in particular 20 to 40 wt .-% glass fibers. Molding composition according to one of claims 1 to 4, wherein the compatibilizer a polar group functionalized olefin polymer, in particular Propylene polymer. A molding composition according to claim 5, wherein the functionalized compatibilizers one with maleic anhydride grafted olefin polymer and an aminosilane or epoxysilane includes. Molding composition according to one of claims 2 to 6, wherein the propylene polymer is a propylene homopolymer. Molding composition according to one of the preceding claims, wherein the olefin polymer has a melt mass flow rate according to ISO 1133 at 230 ° C and 2.16 kg of 0.5 and 100 g / 10 min, preferably between 2 and 30 g / 10 min having. Process for the preparation of the molding compositions according to a of the preceding claims, wherein in a mixing apparatus initially the propylene polymer melted with the nucleating agent at temperatures of 180 to 320 ° C. and mixed and then the glass fibers are mixed with the melt. Use of the molding compositions according to one of claims 1 to 8 as a shaped body for the Automotive or as a suds tank, water pump and lye pump housing. Wash tub, Water pump and lye pump housings obtained from the molding compositions according to a the claims 1 to 8. Motor vehicle part, in particular trim part a motor vehicle, obtained from the molding compositions according to a the claims 1 to 8.