Titanium-Doped Calcium Carbonate UV Absorption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing filler compositions using surface-reacted calcium carbonate and titanium dioxide face challenges such as potential carcinogenicity of submicron and nanometer-sized titanium dioxide particles, dusting issues due to dry mixing, and particle separation during transport.
Innovation Solution
A process for producing a white UV-absorbing surface-reacted calcium carbonate doped with a titanium species, involving the reaction of a calcium carbonate material with a H3O+ ion donor in an aqueous medium, with the titanium species added before, during, or after the reaction, resulting in a product with a specific surface area of 15 m2/g to 200 m2/g and a weight ratio of calcite to hydroxyapatite from 99:1 to 1:99.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If titanium dioxide particles are used as a white pigment and UV absorber, then UV-absorbing properties and white color are improved, but potential carcinogenicity occurs due to submicron and nanometer-sized particles
Solution Approach 1:
The patent combines titanium dioxide particles with surface-reacted calcium carbonate into a single composite filler material. The titanium dioxide is incorporated during the surface reaction process of the calcium carbonate, creating an integrated structure where the titanium species are embedded within or on the surface of the calcium carbonate particles, rather than being separate mixtures.
Solution Approach 2:
The invention creates a composite material consisting of calcium carbonate particles with incorporated titanium dioxide. This composite structure allows the material to maintain the UV-absorbing and white color properties of titanium dioxide while using the bulkier, less harmful calcium carbonate as the primary matrix, thereby reducing the overall harm from fine titanium particles.
2Ease of manufacture
If surface-reacted calcium carbonate is mixed with titanium dioxide in dry form, then filler composition is achieved, but dusting issues occur during mixing and transport
Solution Approach 1:
The patent merges the mixing process with the surface reaction process. By incorporating the titanium dioxide into the calcium carbonate particles during the surface reaction (which occurs in an aqueous medium), the material is formed as a pre-mixed composite rather than requiring separate dry mixing steps, thereby eliminating dusting issues associated with dry handling and transport.
3Adaptability or versatility
If separate filler particles are used, then functional properties are achieved, but particle separation occurs during transport
Solution Approach 1:
The patent combines multiple functional components (calcium carbonate and titanium dioxide) into a single integrated filler particle structure. The titanium dioxide is incorporated during the surface reaction of the calcium carbonate, creating a unified composite particle that maintains compositional stability during transport and storage, preventing the separation that would occur with separate particles.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The resulting product exhibits excellent UV-absorbing properties, a high surface area, and a white color, making it suitable for various applications without the need for labeling with titanium dioxide particles in the submicron and nanometer size range, thus enhancing consumer acceptance.
Implementation Method 1
surface-reacted calcium carbonate is a reaction product of natural ground or precipitated calcium carbonate with carbon dioxide and at least one acid in an aqueous medium
Implementation Method 2
the titanium species are present in an amount from 0.01 to 20 wt.-% of titanium element, based on the total dry weight of the surface-reacted calcium carbonate... excellent UV-absorbing properties
Implementation Method 3
having a specific surface area of from 15 m2/g to 200 m2/g
Data Source
AI summary
The present invention refers to a white UV-absorbing surface-reacted calcium carbonate doped with a titanium species, comprising calcite and hydroxyapatite in a weight ratio of from 99:1 to 1:99 based on the dry weight of the calcite and the dry weight of the hydroxyapatite and having a specific surface area of from 15 m2/g to 200 m/2g, wherein the titanium species is present in an amount from 0.01 to 20 wt.-% of titanium element, based on the total dry weight of the surface-reacted calcium carbonate. Furthermore, the present invention refers to a process for producing the white UV-absorbing surface-reacted calcium carbonate doped with a titanium species, the use of said white UV-absorbing surface-reacted calcium carbonate doped with a titanium species as well as an article comprising said white UV-absorbing surface-reacted calcium carbonate doped with a titanium species.