【Suppressing Titanium Hydrolysis】Balancing the Physical Properties and High Whiteness of Polycarbonate | Stabilization Technology Using Surface-Treated Titanium Pigments

Reginocolor Industry Co., Ltd. develops and manufactures the surface-treated titanium dioxide “White DCF-T-17007” and the surface-treated titanium dioxide masterbatch “White PC-TT3045-A” in Japan and throughout Asia, with the aim of suppressing hydrolysis of polycarbonate (hereinafter “PC”) while maintaining high whiteness and mechanical properties.

These products address issues that can arise during high-temperature molding, including reductions in PC molecular weight, deterioration of physical properties, and silver streaks.

Table of Contents

• Suppression of Polycarbonate Hydrolysis and Maintenance of Physical Properties
• Technical Specifications and Product Forms
• Surface Treatment Technology and Suppression of Silver Streaks
• Consultation and Trial Evaluation Process
• Frequently Asked Questions (FAQ)

■　Suppression of Polycarbonate Hydrolysis and Maintenance of Physical Properties

When titanium dioxide is added to PC resin and processed at high temperatures, certain types or surface conditions of titanium dioxide may cause reductions in the molecular weight and mechanical properties of PC.

“White DCF-T-17007” is a surface-treated titanium dioxide designed to reduce its impact on PC by applying a proprietary surface treatment to the titanium dioxide surface. It is designed to suppress reductions in PC molecular weight and hydrolysis during high-temperature processing and to help maintain the material’s physical properties.

By suppressing hydrolysis, PC resin can be made highly white while maintaining mechanical properties such as impact resistance and tensile strength at break.

Color evaluation has demonstrated high whiteness with an L* value of 98 or higher and a low b* value. It is suitable for a wide range of PC molded products, including electrical and electronic components and construction materials, where both strength and appearance quality are required.

■　Technical Specifications and Product Forms

Representative properties of “White DCF-T-17007” and “White PC-TT3045-A”

■　Advantages of the Masterbatch Form and Support System

When powdered pigments such as titanium dioxide are fed directly into a production line, issues may arise including dust dispersion, weighing errors, and contamination around production equipment.

“White PC-TT3045-A” is a masterbatch containing “White DCF-T-17007” pelletized at a high concentration of 50%. Compared with powdered pigments, it is easier to handle and helps improve weighing accuracy and automatic feeding while also contributing to a cleaner production environment.

In addition to supply within Japan, a distribution and support system is available in Thailand through the group company SAKAI TRADING (THAILAND) CO.,LTD., enabling supply to local molding manufacturers.

■　Surface Treatment Technology and Suppression of Silver Streaks

During PC injection molding, moisture and volatile substances contained in colorants and additives can be among the causes of silver streaks, which appear as silver-colored lines on the surface of molded products.

“White DCF-T-17007” uses rutile-type titanium dioxide with a proprietary surface treatment designed to suppress moisture adsorption and gas generation during heating. This helps reduce appearance defects such as silver streaks.

In addition, advanced dispersion technology suppresses pigment agglomeration within the resin and reduces color unevenness and specks. It can therefore be used for applications requiring a uniform and smooth molded-product appearance.

The production plant has obtained ISO 9001 quality management system certification and ISO 14001 environmental management system certification. Reflectance and color are measured using a spectrophotometer, and thermal stability evaluations are also conducted as part of ongoing quality control.

■　Consultation and Trial Evaluation Process

1. Inquiry and Specification Confirmation
We confirm the PC grade to be used, molding conditions, required whiteness and opacity, mechanical properties, and other required specifications.

2. Formulation Review and Grade Selection
We confirm the applicability of “White DCF-T-17007” and “ホワイト PC-TT3045-A” and, when necessary, review a formulation according to the required specifications.

3. Sample Provision and Molding Evaluation
Trial samples are provided so that moldability and appearance can be checked using actual equipment. When necessary, impact resistance, whiteness, and the occurrence of silver streaks are also evaluated.

4. Specification Finalization and Mass-Production Supply
Based on the evaluation results, product specifications and quality control standards are determined before proceeding to mass-production supply.

For details or trial evaluations of “White DCF-T-17007” and “White PC-TT3045-A,” as well as surface-treated titanium dioxide, please download the materials or contact us via the inquiry form.

■　Frequently Asked Questions (FAQ)

Q1 : Why does the type of titanium dioxide affect the physical properties of PC?
A1 : Depending on the surface condition and treatment method of the titanium dioxide, a reduction in PC molecular weight may be accelerated under high-temperature and moisture-containing conditions. As a result, mechanical properties such as impact resistance may decrease.

“White DCF-T-17007” and “White PC-TT3045-A” are designed to suppress these effects by applying an appropriate treatment to the titanium dioxide surface.

Q2 : Can “White PC-TT3045-A” also help improve the working environment?
A2 : Yes. Because it is a pelletized masterbatch containing 50% “White DCF-T-17007,” it makes it easier to suppress dust dispersion compared with directly feeding powdered pigments and can also improve weighing and automatic feeding.

It is also suitable when considering improvements in production-area cleanliness and material handling.

Q3 : Can it be used with engineering plastics other than PC?
A3 : The application of “White DCF-T-17007” to various engineering plastics other than PC resin can also be considered. “White PC-TT3045-A” uses PC resin as the carrier resin and therefore cannot be used with resins other than PC.

However, suitability varies depending on the type of resin, molding temperature, and required properties, so the conditions of use are confirmed before an appropriate formulation or grade is proposed.

For details or trial evaluations of “White DCF-T-17007” and “White PC-TT3045-A,” as well as surface-treated titanium dioxide, please download the materials or contact us via the inquiry form.

※For more details, please download the attached materials or contact us via the form below.