Carrier resin

A dramatic improvement in the performance of PMDA in chain extension of PET is possible if the PMDA is added to the extruder in a concentrate using a polycarbonate (PC) carrier [10]. The reason being that if PMDA is compounded in a PET carrier resin then a premature reaction results leading to ultra-high MW PET and gel problems. Alternatively, if PMDA is compounded in a polyolefin carrier then degradation of the polyolefin occurs whereas, when PMDA is compounded in a polycarbonate carrier there is no premature reaction because PC contains no acid end groups (rather, -OH end groups instead). Furthermore, PC is quite miscible with PET. 

The MFR for the PP resin and the masterbatch colorant were measured to see if the masterbatch material met the criteria defined by Benkreira and Britton [28] and as discussed in Section 8.6. The MFRs were 20 and 116 dg/min (230 °C, 2.16 kg) for the natural PP resin and the masterbatch colorant, respectively. Obviously, the color concentrate masterbatch was not well matched for the natural PP resin according to the guidelines developed by Benkreira and Britton. That is, the carrier resin used to make the masterbatch was too low in viscosity to break up pigment... 

Wang, Q., Chen, Y.H., Liu, Y., Yin, H., Nico, A., and Kierkels, R. 2004. Performance of an intumescent-flame-retardant master batch synthesized by twin-screw reactive extrusion Effect of the polypropylene carrier resin. Polym. Int. 53 439 148. 

A typical masterbatch for extrusion, injection, or blow molding would consist of an appropriate carrier resin for the polymer being processed, a fluorescent pigment, and a wax additive. The following example illustrates a 25% color concentrate formula for injection molding which should be let down at 4% to yield a final color loading of 1% ... 

Low Density Polyethylene Carrier Resin 25% Fluorescent Pigment (ZQ, K-7000)... 

Selection of a carrier resin is much more complex than one would naturally suspect. Some of the considerations seem obvious for instance one cannot use a carrier that is incompatible with the letdown resin. For example, low-density polyethylene (LDPE) is incompatible with ABS. It leads to delimitation in parts, poor impact, and low tensile strength. However, small amounts of LDPE are not a problem in ABS. It simply disappears in the matrix and has no measurable effect. Would the writer recommend using LDPE as a carrier for ABS concentrates Certainly not. However, pigments weighed in polyethylene bags are thrown bag and all into batch mixers with ABS everyday. The point is that questionable contaminants in polymers can be acceptable as long as the amounts are small and they are well distributed in the matrix. 

Companies will custom formulate colorant and additive products designed to be used by plastic molders, who will, in turn, produce the final consumer products. The raw materials for colorant and additive products may be in powder, liquid, or solid form. The products formulated from them may also be in powder, liquid, or solid form. Dry color formulations (powder form) currently comprise less than 5% of the total colorant and additive products being produced today. Liquid formulations account for another 5% however, this form of product is increasing in popularity and is expected to capture a larger share of the colorant and additives market in the near future. The solid form, known as concentrates or masterbatch products, are concentrated ingredients encapsulated in a carrier resin that is usually in pellet form. This type of product comprises the overwhelming majority of the formulated products used by molders and compounders today. A discussion of the basic production processes associated with the production of the various colorant and additive product types is presented below. 

Caibodilite E is a masterbatch of 10wt% carbodiimide in a PET carrier resin. 

Exxon LL5202.09 LLDPE, a barefoot 12 melt index, 0.924 density polyethylene was used as the carrier resin for preparation of all concentrate formulations. Exxon LL1001.09 LLDPE, a barefoot 1.0 melt index, 0.918 density film resin was selected as the matrix material for the preparation of all letdown compounds. Additive-lree resins were used throughout this trial to minimize potential interactions with additive packages and to simplify the analysis task. 

A representative selection of commercial color concentrates (Colortech Inc, Brampton, ON) were used for this study. Each pelletized sample consisted of a blend of organic and inorganic pigments dispersed in Linear Low Density Polyethylene (LLDPE) carrier resin. Pigment loading varied between 3,6 and 50.0 wt,% and some formulations contained up to 33.1 wt.% calcium carbonate filler. All were prepared on a production-scale 40 Liter Gelimat-style... 

In general, the plateout material from a fluorescent color concentrate is composed of lower molecular weight fluorescent pigment carrier resin fractions, color concentrate carrier resin, and other additives and materials that are present during the molding process. This mixture of plateout normally appears as colored deposits on the mold face, or condenses on the blow pin assembly of blow molding equipment. 

Pigments used to color polypropylene, as used also in other polymers, are organic or inorganic compounds. They are usually employed as concentrated master batches dispersed in a carrier resin. The carrier resin may be based on polypropylene or another polymer. The final pigment concentration, in the end product is in the range of 0.1-2.0% depending on the color sought. 

Unlike titanium dioxide, most other pigments need to be hnely predispersed in a carrier resin, or medium , by grinding equipment, before adding to gelcoats. Such dispersions are known as pigment pastes and the... 

Chem. Descrip. Ethylene-methacrylic acid carrier resin with 10% slip agent and 5% silica antiblock... 

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