Titanium masterbatch of production methods can generally be divided into wet process and dry process. Wet process is with Switzerland CIBA - GEIGY company's craft as a representative, which uses water as medium under the action of surfactant, and rely on the  impact of pebble of the ball mill to crush and refine the pigment, and which uses dispersing agent to clad small pigment particle, making its stability under 1 μ m. In this way, the masterbatch has small size of the pigment particle, even dispersibility, which can meet the requirements of fine denier fibers and ultrathin film. however, the defects in the production are obvious, such as the long production cycle, huge energy consumption, high technical requirements and the production cost. Dry process also can be divided into the mixing method, the banburying method, high-speed mixing method and direct extrusion method, etc. Foreign company also uses continuous mixers of FCM and BUSS for production.

This research chooses different TiO2, using dry process production of titanium masterbatch. By comparing its whiteness, dispersity and relative tinting strength, it confirmes the convenient and feasible methods of production in order to produce different uses, different grades of titanium white masterbatch to meet the need of plastics and chemical fiber industry.

Test part:
The main raw material:
PP, 3702, Yanshan petrochemical.
PE, 1F7B, Yanshan petrochemical.
Titanium pigment: A1, anatase type, Nanjing； A2, anatase type, Hengyang; R1, rutile type, Nanjing; R2, rutile type, imported; R3, rutile type, imported; R4, rutile type, imported.
Dispersant agent, imported.
Ultramarine pigment, Beijing.
Whitening agent KFP, Jiangsu.

The main instrument and equipment:
Name                                                 specification                manufacturers
Banburying machine                               1 L                             German WP company
Double screw extruder                         Φ 25 mm                       Chengdu keQiang
Pressure rise refers to the instrument     Φ25 mm                               Italy
ACS computer color matching instrument CS- 5                                 US
Double roll mixing machine                      M150 x 300                       Italy
Injection machine                                     45 g                        YunNan GuangYu
Spinning machine                                     MK Ⅱ                          Britain
Stamping press                                         P7-34                            US
This test uses three kinds of process routes as follows.
(1) mixing method:
(2) banburying method:
(3) extrusion method:
Testing and characterization:
Whiteness measurement:
Puting contained 50% of titanium masterbatch as 1% of the added amount into PP3702 aggregate, after mixing, injecting into 15 cm x 10 cm x 0.3 cm slices with ACS computer's color blending instrument  to measure whiteness.

Dispersion measurement:
Narrow-band method: putting the masterbatch as 1% of the proportion into PE1F7B, and in spinning machine, extrusing narrow bands, taking narrow-band of 10 cm respectively with the naked eye and microscope to observe titanium pigment of dispersion situation.
Pressure rise of index method: putting titanium masterbatch as 6% of the proportion into PP3702, after blending, extruding 1 h in the pressure rise index instrument with 325 mesh filter, and remembering the pressure in the first 60 min.

The representation of the relative tinting strength:
Plasticating 50.0 g resin in double roll mixing machine evenly, then adding 0.3000 g titanium masterbatch and 1.0000 g standard of phthalein cyanine masterbatch to them, than continuing to plastication 5 mins, and hot pressing with moulding press, after cooling to become samples and comparing the representation tinting strength with the master standard. In this paper, with 50% A1 titanium masterbatch for standard, increasing or decreasing the weight of the sample to be tested, and making the testing sample's and standard sample's color difference within in 1.5, according to the method of converting weight into particle concentration which is equivalent to the standard sample to represent.

Results and discussion:
The influence of titanium pigment type on the white degree of titanium masterbatch.

The masterbatch with 50% of titanium contained produced by extrusion methods, and the influence of titanium pigment type on the white degree of titanium masterbatch is shown in table 1.

Table 1: the influence of titanium pigment type on the white degree of masterbatch.

Titanium pigment type    auxiliary          whiteness %
A1                                                                      75.2
A2                                                                      6.4
R1                                                                     71.1
R2                                                                     76.2
R3                                                                     84.5
R4                                                                    78.0
A1                              KFP                               102.3
R1                              KFP                               5.6
A1                          Ultramarine                     76.1

It can be seen from table 1, masterbatch whiteness containing imported TiO is commonly higher than that of masterbatch containing domestic TiO2. The whiteness of domestic product containing anatase TiO2 (A1, A2) is higher than that of products containing rutile TiO2 (R1) . Adding ultramarine pigment or fluorescent brightening agent can improve titanium masterbatch's whiteness, but the adding amount is not more than 1%, if over, the titanium masterbatch is pale blue with white degree falling rapidly. This is because that the ultramarine uses the blue and yellow lights which are complementary to each other to eliminate the yellow light produced in part of the photochemical reaction, when titanium pigment is in use, stored and so on situations. When the yellow light was eliminated, blue light will appear. Fluorescent whitening agent of whitening is because that it absorbs ultraviolet ray of wavelength of 300 ~ 400 nm in the sunlight, and  transfors its energy into purple or blue fluorescence of 400 ~ 500 nm, which can make up for the absorption of blue light, and make titanium pigment whiteness increase.

The comparison of dispersion of different titanium pigment:
The TiO2 dispersed well can not only eliminate the spot of products, but also can improve the light scattering efficiency, which has the tinting power.
Respectively using six kinds of TiO2 to produce titanium masterbatch, and surveying the dispersion, and the testing result is seen in table 2.

Table 2: the dispersionof titanium pigment dispersion
Titanium pigment type       disperse equipment               dispersion      pressure rise index/MPa
A1, A2, R1          mixing method narrow-band method        poor                                     

A1, A2, R1         extrusion method                                       general
R2                     extrusion method                                         good                        0.001
R3                     extrusion method                                         good                        0.0015
R4                     extrusion method                                         good                        0.001

FromTable 2 , it canbe seen, imported TiO2's dispersion is obviously better than the domestic. The experiment can also found that all domestic samples containing particles of more than 25 μ m which can't dye chemical fiber. Using narrow band method to observe the imported TiO2 masterbatch, it did not find visible pigment particle, which means it easy to disperse. The measurement result of pressure rise of index method also shows that it has good spinnability, and can be used for chemical fiber colouring.

The comparison of relative tinting strength of titanium pigment:
Pigment's color force is that the pigment volume needed by a particular color product. This paper uses the percentage of tinting strength of standard sample to show. The relative tinting strength of different types of TiO2 is seen in table 3.

Table 3: the relative tinting strength of several titanium dixoide.
Titanium pigment type      relative tinting strength
A1                                         0.50
A2                                         0.48
R1                                         0.51
R2                                         0.61
R3                                         0.55
R4                                         0.52