Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K9/00—Use of pretreated ingredients
  • C08K9/04—Ingredients treated with organic substances

Definitions

• the invention relates to a method for adding inorganic additives to finished polymer melts.
• Different functional inorganic additives are used to modify polymers, especially polyester, polyamide 6 and polyamide 6.6. These additives can be used to change the corresponding polymers in terms of processing, optical and application properties.
• matting agents are used in the synthetic fiber industry in order to avoid the greasy sheen and the transparency of the polymers, which is particularly undesirable for textile fibers.
• microcrystals made of titanium dioxide TiO 2 or zinc sulfide ZnS are used. The use of these microcrystals also creates a surface structure on the synthetic fibers, which have a positive influence on the processing properties with regard to the friction of the thread on thread guide elements and the thread running during spinning and stretching.
• microcrystals made from aftertreated barium sulfate BaSO 4 which do not lead to matting of the polymers compared to TiO 2 and ZnS.
• nanocrystals made of titanium dioxide to produce polymers with UV-protective properties.
• Option 3 (adding the additives to the finished polymer melt, also called melt modification process or melt matting process) is e.g. described in DE 4039857 C2 and can be divided into 3 variants.
• the end product (additive-containing polymer) is produced directly by incorporating the additives into the polymer.
• a so-called masterbatch is created by incorporating the additives into the polymer (e.g. through extruders or kneaders)
• the end product is produced by incorporating a masterbatch into the polymer.
• melt modification process has the following disadvantages:
• the additives are incorporated as powder into the finished polymer melt.
• the powders based on TiO 2 , BaSO 4 and ZnS all show poor flowability and can lead to undesirable bridging and shaft formation in the powder feed system. It was found (measurements with a ring shear device) that these powders can be classified as very cohesive to non-flowing. Therefore, when dosing this powder with considerable Dosing fluctuations to be expected, which would lead to considerable quantities of non-specification products due to the associated deviations in the solids concentration.
• the powder is dispersed in the various melt modification processes and in the production of masterbatches in specially designed extruders.
• the dispersibility of the powders used must be so good that the shear forces in these extruders are sufficient to achieve the required particle size distribution in the polymer.
• the powders based on TiO 2 , BaSO 4 and ZnS used according to the state of the art are in the delivery form in agglomerated form, ie strong shear forces have to be applied in order to break up and optimally distribute these agglomerates.
• melt modification processes described result in poorer quality polymer products in terms of particle distribution because the shear forces for dispersing the additive suspensions are higher than in extruders or kneaders by suitable choice of the dispersing machines.
• the proportion of coarse additive particles plays a quality-relevant role in the further processing of the polymers produced. These particles lead, for example, to an increased number of undesirable thread breaks in the production of synthetic fibers by spinning and drawing. At the same time, the service life of Pplymer filters and Spinpack filters is reduced.
• additive suspensions for addition during the polymer formation process (addition option 2), these coarse particles which have not been broken up by dispersion can be removed from the low-viscosity suspension by centrifugation, sedimentation and / or filtration. After the dispersion in the extruder (option 3), the remaining coarse particles can no longer be removed separate, since the required filter fineness cannot be achieved in these highly viscous polymer melts. This means that the powders based on TiO 2 , BaSO 4 and ZnS used according to the prior art have an undesirable coarse fraction even after dispersion in the extruder, which has a negative influence on the quality of the polymer end products.
• the melt modification process has so far hardly been successful in practice and the addition of the additives is still carried out in most cases during the polymer formation process, even if in some cases.
• Considerable technical and personnel expenditure for the preparation of the additive particles must be carried out before the addition into the mass flow during the polymer formation. This includes dispersing the additive particles in the suspension medium, separating the coarse grain fraction and avoiding refiockulation in the suspension. It is also important to ensure that when the prepared suspension is added to the mass flow, there are no flocculation effects, e.g. due to interaction with other additives or due to temperature influences.
• the object of the invention is to eliminate the disadvantages of the prior art and, in particular, to provide a process for modifying polymer melt by means of finely divided inorganic solid particles (melt modification process) which allows a sufficiently precise metering of the additives to be added and which permits homogeneous distribution of the additives without undesired ones Grobanteii guaranteed in the polymer melt.
• the object is achieved by a process for modifying polymer melts by means of finely divided inorganic solid particles (melt modification process),
• the. organic substance contains one or more of the substances polyols, polyglycols, polyether, dicarboxylic acids and their derivatives, AH salt (nylon salt, adipic acid hexamethylene diamine or hexamethylene ammonium adipate), caprolactam, paraffins, phosphoric acid esters, hydroxycarboxylic acid esters and cellulose,
• the production of the powdery additives is described in WO 00/14165 or also in WO 00/14153.
• the preparation agents (matting additives, powder additives) for further processing in synthetic polymers consisting of finely divided inorganic solids, selected from pigments and / or fillers, are in a carrier material, selected from at least one of the organic substances polyols, polyglycols, polyethers, dicarboxylic acids and the like Derivatives, AH salt, caprolactam, paraffins, phosphoric acid esters, hydroxycarboxylic acid esters and cellulose. embedded finely divided. Finely divided means that the solid particles are in an agglomerated form in an organic matrix.
• an aqueous premix containing the organic substance in such an amount that the proportion of the organic substance is 0.2 to 50% by weight (based on the inorganic solids content of the finished powdery additive) , 20 to 60 wt .-% (based on the total batch of the aqueous premix) of the inorganic solids dispersed then the dispersion is an average grain size d as 0.2 microns wet milled to 0.5, the supernatant coma portion of> 1 micron from the suspension removed and the suspension dried.
• the powdery additives obtained have an average particle size of up to 100 ⁇ m.
• the inorganic solid particles preferably contain TiO 2 and / or BaSO 4 and / or ZnS, and the solid particles can also be after-treated.
• the organic substance preferably contains antioxidants (for example butylated hydroxyanisole or hydroxyanisole) in an amount of up to 0.5% by weight (based on the amount of organic substance).
• the organic substance can contain other customary auxiliaries and additives.
• the organic substance preferably contains at least 98% by weight of polyethylene glycol or AH salt or caprolactam, particularly preferably the organic substance consists of polyethylene glycol or AH salt or caprolactam and up to 0.5% by weight of an antioxidant. Polyester or polyamide 6 or polyamide 6.6 is preferably used as the polymer.
• powdery additive compositions are preferably used for the process according to the invention:
• Powdery additives with 75 to 85% by weight of inorganic solid and 15 to 25% by weight are particularly preferred.
• a preferred average grain size d 5 o of the inorganic solid, which is embedded in the organic substance is 0.25 to 0.45 microns.
• the powdery additive is preferably incorporated into the polymer by means of an extruder or a kneader.
• a polyester or polyamide containing inorganic solid particles can be used to produce polyester fibers and polyester films, or polyamide fibers and polyamide films, which likewise contain the inorganic solid particles.
• Example 1 Production of a masterbatch according to the invention
• the 10% masterbatch obtained was examined by means of a pressure filter test. A DF value of 0.5 cm 2 -bar / g was determined.
• the DF value (measure of the quality of masterbatches) was determined as follows: the masterbatch obtained with a TiO 2 content of 10% by weight was continuously melted in a Plasti-Corder measuring extruder and a spinning pump using a spinning pump 40 ⁇ m sieve mesh fed. The temperature in all heating zones was kept constant at 285 ° C. The pressure built up in front of the filter package was plotted against time. The end of the measurement is reached when the pressure has either reached 190 bar or 60 minutes have passed.
• the yardstick for masterbatch quality is the pressure test value (DF value), which can be calculated using the following formula:
• the DF value of this masterbatch was determined to be 12.4 cm 2 bar / g.

Landscapes

• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Processes Of Treating Macromolecular Substances (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Artificial Filaments (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=7659756

Family Applications (1)

Country Status (7)

Families Citing this family (6)

Family Cites Families (13)

• 2000
  • 2000-10-13 DE DE10050913A patent/DE10050913A1/de not_active Ceased
• 2001
  • 2001-09-27 TW TW090123911A patent/TWI288152B/zh not_active IP Right Cessation
  • 2001-10-05 JP JP2002534418A patent/JP2004511602A/ja active Pending
  • 2001-10-05 AU AU2002221654A patent/AU2002221654A1/en not_active Abandoned
  • 2001-10-05 EP EP01986705A patent/EP1328578A2/de not_active Withdrawn
  • 2001-10-05 WO PCT/EP2001/011496 patent/WO2002031042A2/de active Application Filing
  • 2001-10-05 US US10/398,790 patent/US7008978B2/en not_active Expired - Lifetime

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events