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It’s also used in food products to provide a white color. Candies, cakes and creamers are examples of foods that may contain titanium dioxide for its color enhancing and bleaching properties.
As a result, tariffs for titanium products are remaining similar to the ones in 2016, which will not cause bigger price fluctuations and keep a stable market.
A Lawsuit Claims Skittles Are Unfit for Consumption. Experts Weigh in, by Rachel Rabkin Peachman, The New York Times, July 26, 2022
It's all over the place in our environment, said Dr. Johnson-Arbor.
Pure PVB is non-toxic and harmless to human body. In addition, ethyl acetate or alcohol can be used as solvent, so PVB is widely used in printing ink of food containers and plastic packaging in European and American countries.
Storage safety properties
PVB can be stored for two years without affecting its quality as long as it is not in direct contact with water; PVB shall be stored in a dry and cool place and avoid direct sunlight. Heavy pressure shall be avoided during PVB storage.
Solubility
PVB is soluble in alcohol, ketone, ester and other solvents. The solubility of various solvents changes according to the functional group composition of PVB itself. Generally speaking, alcohol solvents are soluble, but methanol is more insoluble for those with high acetal groups; The higher the acetal group, the easier it is to dissolve in ketone solvents and ester solvents;
PVB is easily soluble in cellosolve solvents; PVB is only partially dissolved in aromatic solvents such as xylene and toluene; PVB is insoluble in hydrocarbon solvents.
Viscosity characteristics of PVB solution
The viscosity of PVB solution is greatly affected by the formula of solvent and the type of solvent; Generally speaking, if alcohol is used as solvent, the higher the molecular weight of alcohol, the higher the viscosity of PVB solution;
Aromatic solvents such as xylene and toluene and hydrocarbon solvents can be used as diluents to reduce the viscosity of PVB solution; The effect of PVB chemical composition on viscosity is summarized as follows: under the same solvent and the same content of each base, the higher the degree of polymerization, the higher the solution viscosity; Under the same solvent and the same degree of polymerization, the higher the acetal group or acetate group, the lower the solution viscosity.
Dissolution method of PVB
Where mixed solvents are used, the dissolution step is to first put aromatic solvents (such as xylene, toluene, etc.) or ester solvents (such as n-butyl acetate, ethyl acetate, etc.) into the mixing, slowly put PVB into the mixing, and then add alcohol solvents (such as n-butanol, ethanol, etc.) after PVB is dispersed and expanded,
At this time, the dissolution time can be shortened by heating; Using this dissolution method, the formation of lumpy PVB can be avoided (because the dissolution time will be several times after the formation of lumpy PVB), so the dissolution speed can be accelerated. Generally, the ratio of aromatic and alcohol solvents is 60 / 40 ~ 40 / 60 (weight ratio), and PVB solution with low viscosity can be prepared.
The solvent composition contains 2 ~ 3wt% water, which can improve the hydrogen bonding strength of alcohol solvents and help the solubility of PVB.
Processing properties
Although PVB resin is a thermoplastic, it has little processability before plasticizer is added. Once plasticizer is added, its processability is very easy.
The purpose of general coatings and adhesives is to change the resin characteristics by adding plasticizers to meet the application requirements, such as film softness, reducing the TG point of the resin, reducing the heat sealing temperature, maintaining low-temperature softness, etc.
Compatibility
PVB can be compatible with a variety of resins, such as phenolic resin, epoxy resin, alkyd resin and MELAMINE resin.
B-08sy, b-06sy and b-05sy with high acetal degree can be mixed with nitrocellulose in any proportion. PVB and alkyd resin are partially compatible. General PVB is compatible with low molecular weight epoxy resin, while high molecular weight epoxy resin needs PVB with high acetal degree to be compatible with each other.
Amount: if too little titanium dioxide is added, the distance between particles is too large and there is not enough opacity, while if the titanium content is too high, the particles interfere with each other and poor efficiency is obtained.
Analyst Insight
JECFA previously assessed titanium dioxide at its 13th meeting, at which time the expert committee assigned a “not specified” ADI for the additive due to an absence of significant absorption and a lack of toxicological effects in the available experimental animal and human studies. Since its original evaluation by JECFA, titanium dioxide has become a public point of contention, with its ban being introduced (and then subsequently withdrawn) in California legislation in 2023, a legal battle playing out in the EU over the additive’s ban and classification as a carcinogen in 2022, and the European Food Safety Authority (EFSA) calling titanium dioxide unsafe. However, supporters of titanium dioxide say that claims about its dangers are founded in unreliable studies, and some recent research has supported its safety as a food additive.
Titanium dioxide, (TiO2), a white, opaque, naturally occurring mineral existing in a number of crystalline forms, the most important of which are rutile and anatase. These naturally occurring oxide forms can be mined and serve as a source for commercial titanium. Titanium dioxide is odourless and absorbent. Its most important function in powder form is as a widely used pigment for lending whiteness and opacity.
The precipitation of titanium dioxide involves the reaction of titanium sulfate with an alkaline solution to form titanium hydroxide, which is then calcined to produce titanium dioxide. The precipitation process is crucial for achieving the desired particle size distribution, crystallinity, and purity of the final product.
Titanium dioxide (TiO2) is by far the most suited white pigment to obtain whiteness and hiding power in coatings, inks and plastics. This is because it has an extremely high refractive index and it does not absorb visible light. TiO2 is also readily available as particles with the right size (d ≈ 280 nm) and the right shape (more or less spherical) as well as with a variety of post-treatments.
However, the pigment is expensive, especially when the volume prices of systems are used. And, there always remains a need to develop a full-proof strategy to obtain the best results in terms of cost/performance ratio, scattering efficiency, dispersion… while using it in coating formulations. Are you searching for the same?
Explore the detailed knowledge of TiO2 pigment, its scattering efficiency, optimization, selection, etc. to achieve the best possible white color strength and hiding power in your formulations.