Abrasive silica particles

Abstract

Abrasive silica particles suitable for use in a dentifrice composition, comprising particles of a first abrasive silica in an amount of at least 90% by weight based on the total weight of the abrasive silica particles, and particles of a second abrasive silica in an amount of up to 10% by weight based on the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle diameter (d 50 ) and 15% to 70% of the d50 value of the particles of the first abrasive silica. Dentifrice compositions containing such particles, and methods of making such particles are also described.

Description

[Technical Field]

[0001] The present invention relates to abrasive silica particles for use in toothpaste applications, and more particularly to a silica composition comprising first abrasive silica particles and second abrasive silica particles. The first abrasive silica and the second abrasive silica are distinct. When incorporated into toothpaste compositions such as toothpaste, the abrasive silica particles described herein provide desirable cleaning and polishing properties. [Background technology]

[0002] Toothpaste is used for oral hygiene, particularly for cleaning teeth. Abrasive silica has been provided in toothpaste formulations, especially toothpaste, as a primary cleaning agent to provide cleaning to the tooth surface. Cleaning may include the complete or partial removal of food debris, plaque, stains, bacteria / biofilm, etc., from the tooth surface. Thickening agents, which may be non-abrasive silica, may also be provided in toothpaste formulations.

[0003] The abrasive properties and cleaning capabilities of silica are related. Generally speaking, highly abrasive silica tends to provide a higher degree of cleaning than less abrasive silica. However, highly abrasive silica may also be more likely to damage the tooth surface than less abrasive silica. Therefore, those skilled in the art of toothpaste must strike a balance between abrasiveness and cleaning power so that toothpaste products, including toothpaste, gel, or powder, provide effective cleaning of the user's tooth surface while minimizing tooth damage caused by the abrasive.

[0004] Toothpaste compositions (e.g., toothpaste) containing a first "bulk" abrasive silica along with a relatively small amount of a second abrasive silica are known. Typically, the two silicas are used to modify the properties of the toothpaste composition containing the silica combination, such as the cleaning properties. Commercial toothpastes have conventionally provided abrasive silica particles containing approximately 20% by weight or more of the second abrasive silica and usually up to approximately 80% by weight of the first "bulk" abrasive silica to achieve an acceptable combination of cleaning and abrasive properties. Typically, such second silica may include finely ground / highly ground silica particles. Such second silica is also typically more abrasive than the first "bulk" silica. As a result, abrasive silica particles (containing the first "bulk" silica and a smaller amount of the second silica) are conventionally incorporated into toothpastes in amounts of approximately 10% to 20% by weight relative to the total weight of the toothpaste.

[0005] Abrasive silica compositions containing silica gel abrasives and / or precipitated silica for use in toothpastes are described in Patent Documents 1, 2, 3, and 4. Patent Document 5 describes an abrasive system comprising crystalline aluminosilicate and at least one (optionally two) abrasive amorphous silica. These documents describe abrasive systems containing abrasive silica particles / abrasive silica particles, wherein the second silica is preferably provided in the abrasive silica particles in an amount exceeding 10% by weight of the total abrasive silica composition. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] U.S. Patent No. 6896876 [Patent Document 2] U.S. Patent Application Publication No. 2001 / 0055572 [Patent Document 3] U.S. Patent No. 5651958 [Patent Document 4] U.S. Patent No. 5,658,553 [Patent Document 5] International Publication No. 2005 / 065634 [Overview of the project]

[0007] The present invention is particularly applicable to toothpaste compositions comprising a first "bulk" abrasive silica and a second abrasive silica, wherein the second abrasive silica is used to improve the performance of the toothpaste compared to a toothpaste containing the first silica alone.

[0008] Abrasive silica particles and abrasive silica compositions are described, which provide desirable cleaning performance acceptable for use in toothpastes. The inventors have found that by carefully controlling the specific characteristic properties of each first “bulk” abrasive silica relative to the second abrasive silica, it is possible to provide abrasive silica particles or abrasive silica compositions that exhibit desirable cleaning and polishing properties compared to comparative mixed silica toothpaste compositions, even when using a considerably smaller amount of the second abrasive silica than conventionally proposed in the art. As described in the example, the silica and toothpaste compositions of the present invention provide remarkably effective cleaning and polishing properties even when containing only a small amount of the second abrasive silica (often much less than 10% by weight, for example, as little as 1% by weight in some cases) compared to the first “bulk” abrasive silica. In other words, the inventors have found that by carefully controlling the specific parameters of each first “bulk” abrasive silica and the second abrasive silica, it is possible to provide the second abrasive silica in a considerably smaller amount than conventionally considered effective, without the expected adverse effects on the cleaning properties of silica.

[0009] This unexpected advantage presents a clear technical and commercial benefit in industrial toothpaste applications, as the second abrasive silica in such commercial applications is generally desirable to have higher abrasiveness and a smaller average particle size compared to the first "bulk" abrasive silica. Therefore, it tends to be more difficult, energy-intensive, and time-consuming to manufacture compared to typical bulk toothpaste silica. Thus, because producing such silica from ordinary silica raw materials requires larger-scale grinding and processing, the second abrasive silica is usually a more valuable silica component in combination. Consequently, the embodiments described herein can provide desirable cleaning / polishing performance while advantageously reducing the amount of precious and energy-intensive silica raw materials required. Ultimately, this means that the method for manufacturing the compositions herein consumes less energy compared to conventional multi-silica particles used in toothpaste applications. Furthermore, a smaller amount of second abrasive silica required can have a beneficial effect in reducing polishing without significantly impacting cleaning performance.

[0010] In particular, by carefully controlling the relative particle size ratio between the second abrasive silica and the first "bulk" abrasive silica (and optionally further controlling the abrasiveness of the second abrasive silica relative to the first "bulk" abrasive silica), and / or by carefully controlling the oil absorption values ​​of the second abrasive silica and the first "bulk" abrasive silica, the above-mentioned beneficial cleaning performance can be provided.

[0011] In a first aspect of the present invention, abrasive silica particles suitable for use in toothpaste compositions are provided. The particles comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles. The weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50The value is between 15% and 70%.

[0012] As is evident from the data disclosed herein, by controlling the respective parameters of the second abrasive silica relative to the first silica, it was surprisingly found that a relatively small amount of the second abrasive silica could be used without compromising cleaning performance.

[0013] In a second aspect of the present invention, a composition for use in toothpaste is provided, comprising abrasive silica particles according to the first aspect of the present invention and optionally a carrier.

[0014] In a third aspect of the present invention, a toothpaste is provided that comprises abrasive silica particles according to the first aspect of the present invention, or a composition according to the second aspect of the present invention.

[0015] A fourth aspect of the present invention provides a method for producing abrasive silica particles suitable for use in a toothpaste composition, comprising combining first abrasive silica particles and second abrasive silica particles to provide abrasive silica particles. The first abrasive silica particles are present in an amount of at least 90% by weight of the total weight of the abrasive silica particles. The second abrasive silica particles are present in an amount of up to 10% by weight of the total weight of the abrasive silica particles. The weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica. 50 ) is smaller than the d of the first silica particle 50 The value is between 15% and 70%.

[0016] In a fifth aspect of the present invention, abrasive silica particles prepared according to the method of the fourth aspect of the present invention are provided. The abrasive silica particles may be those described in the first aspect of the present invention.

[0017] Herein, the present invention will be described with reference to the accompanying drawings, although this is merely an example. [Brief explanation of the drawing]

[0018] [Figure 1] This graph shows the cleaning performance of Examples 1 to 31 described herein, as determined by a ferric tannate cleaning test (FT100) with 100 brush strokes. [Figure 2] The graphs shown here illustrate the cleaning performance of the FT100 against the Plastic Abrasion Value (PAV) for Examples 1 to 31 described herein. [Modes for carrying out the invention]

[0019] The abrasive silica particles according to the present invention are very suitable for use in toothpaste compositions.

[0020] Unless otherwise stated herein, references to “abrasive silica particles” according to the present invention and the characteristics of such particles (e.g., PAV or RDA parameters, or oil absorption characteristics, or FT) refer to “abrasive silica particles” according to the present invention and the characteristics of such particles (e.g., PAV or RDA parameters, or oil absorption characteristics, or FT). 100 References to polishing properties (as described by cleaning values) are intended to refer to the entire set of polishing silica particles described. When it is intended to refer to a specific subgroup of polishing particles and the properties of particles within such subgroup, for example, when the text refers to a first, second, and / or further polishing silica, this specification will describe it accordingly.

[0021] In this specification, the phrases “first (or second, or third, or further) abrasive silica,” “first (or second, or third, or further) silica,” and “first (or second, or third, or further) silica particles” are used interchangeably. Those skilled in the art will understand that these terms refer to first or second (and optionally third or further) silica particles included within (i.e., as a subgroup) a group of abrasive silica particles according to the present invention. The “further” abrasive silica particles may be fourth, fifth, sixth, and so on abrasive silica.

[0022] It is understood that the first (or second, or third, or further) abrasive silica particles described herein may contain an appropriate amount of water. In a typical embodiment, each abrasive silica (first / second / third abrasive silica) may independently contain up to 8% by weight of water, and optionally up to 6% by weight of water. Unless otherwise specified, weight percentages referred to herein mean on a gross weight basis. Alternatively, it is understood that weight percentages may be calculated on a dry weight basis of the abrasive silica (first / second / third abrasive silica).

[0023] In this disclosure, references to the first, second, and optionally third (and optionally another further, e.g., fourth) abrasive silicas are intended to refer to different abrasive silicas contained within the population of abrasive silica particles of the present invention. Those skilled in the art will understand that different silicas may have different characteristics (e.g., chemical or physical characteristics) and will readily be able to suggest silicas suitable for use in the present invention. Silicas may differ, for example, in pore properties, surface area, hardness, and / or acidity. Different silicas may be prepared, for example, by different synthesis methods. Those skilled in the art will readily be able to select first, second, optionally third, and optionally another further (e.g., fourth) abrasive silicas that are very suitable for use in the present invention from, for example, commercially available silicas. Those skilled in the art will also be able to prepare the first, second, optionally third, and optionally another further (e.g., fourth) abrasive silicas used in the present invention using routine methods known to those skilled in the art.

[0024] The first and second (and optionally third, and optionally further, e.g., fourth) silica particles can be selected from any suitable type of abrasive silica, provided that such silica has particle properties as defined herein. In embodiments, the first and second (and optionally third, and optionally further, e.g., fourth) abrasive silicas can be selected from precipitated silica and silica gel. Typically, at least the first silica is precipitated silica, and in embodiments, the first and second (and optionally third, and optionally further) silicas are selected from precipitated silica. Precipitated silica is understood to be typically amorphous. The first silica may be abrasive silica gel, and in embodiments, the second (and optionally third, and optionally further) silicas are selected from abrasive silica gel and precipitated silica.

[0025] Substantively, this claim describes abrasive silica particles (i.e., a collection of abrasive silica particles) comprising a combination of two (or optionally three, or optionally more, e.g., four, five, etc.) different subgroups of abrasive silica, and the specific relative particle properties (e.g., weight median particle size d) of the first and second (and optionally a third, optionally another further, e.g., fourth) abrasive silicas. 50 It has been confirmed that controlling ) yields the benefits described herein.

[0026] According to the present invention, the first abrasive silica particles are provided in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and therefore may be referred to herein as the first “bulk” silica, or the first “bulk” silica particles, or the first “bulk” abrasive silica, or the first “bulk” abrasive silica particles. The second abrasive silica particles are a trace component relative to the total weight of the abrasive silica particles and are provided in an amount of up to 10% by weight, for example, up to 7% by weight relative to the total weight of the abrasive silica particles.

[0027] In one embodiment, the abrasive silica particles according to the present invention may contain second silica particles in an amount of 0.05% to 10% by weight, for example, 1% to 10% by weight, relative to the total weight of the abrasive silica particles. The abrasive silica particles may contain second silica particles in an amount of 2% to 7% by weight, optionally, 3% to 5% by weight (for example, about 4% by weight), relative to the total weight of the abrasive silica particles.

[0028] In one embodiment, the abrasive silica particles according to the present invention further comprise third abrasive silica particles, wherein the total weight of the second and third abrasive silica particles does not exceed 10% by weight of the total weight of the abrasive silica particles. Therefore, the second and third abrasive silica particles are trace components relative to the total weight of the abrasive silica particles and are provided in an amount of up to 10% by weight of the total weight of the abrasive silica particles.

[0029] In one embodiment, the abrasive silica particles according to the present invention may contain second and third silica particles in a total amount of 0.05% to 10% by weight, for example, 1% to 10% by weight, relative to the total weight of the abrasive silica particles. The abrasive silica particles may contain second and third silica particles in a total amount of 1% to 10% by weight, optionally 2% to 7% by weight, or optionally 3% to 5% by weight relative to the total weight of the abrasive silica particles.

[0030] In this embodiment, the first abrasive silica is amorphous precipitated silica, and / or the second abrasive silica is amorphous precipitated silica, and / or any third and / or any further (e.g., fourth) abrasive silica is amorphous precipitated silica. The first abrasive silica may be amorphous precipitated silica. The second abrasive silica may be amorphous precipitated silica. Any third abrasive silica may be amorphous precipitated silica. In this embodiment, each (e.g., the first, second and third) abrasive silica may be amorphous precipitated silica.

[0031] In an embodiment, the abrasive silica particles according to the present invention consist substantially of only the first silica particles, the second silica particles, and optionally the third silica particles. As used herein, the phrase "consist substantially of only" means that other components are not substantially included. For example, in an embodiment, the abrasive silica particles may comprise the first silica particles and the second silica particles in an amount of at least 95% by weight, optionally at least 98% by weight, optionally even at least 99% by weight, based on the total weight of the abrasive silica particles, and optionally third (and optionally further, for example fourth) silica particles. In an embodiment, the abrasive silica particles according to the present invention consist of only the first silica particles, the second silica particles, and optionally third (and optionally further, for example fourth) silica particles, and for example, such particles may account for 100% by weight of the abrasive silica particles.

[0032] In an embodiment, the abrasive silica particles according to the present invention comprise first abrasive silica particles in an amount of at least 90% by weight based on the total weight of the abrasive silica particles, and second abrasive silica particles in an amount of 1% by weight to 10% by weight based on the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) of the second abrasive silica particles is the weight median particle diameter (d 50 ) of the first abrasive silica particles, and is d 50 of the first abrasive silica particles is 15% to 70% of the value.

[0033] In an embodiment, the abrasive silica particles according to the present invention comprise first abrasive silica particles in an amount of at least 90% by weight based on the total weight of the abrasive silica particles, and second abrasive silica particles in an amount of 2% by weight to 7% by weight based on the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) of the second abrasive silica particles is the weight median particle diameter (d 50 ) of the first abrasive silica particles, and is d 50 of the first abrasive silica particles is 15% to 70% of the value.

[0034] In one embodiment, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of 3% to 5% by weight (for example, about 4% by weight) relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than and the d of the first abrasive silica particles 50 The value is between 15% and 70%.

[0035] particle size The particle size is the weight median particle diameter (d 50 This can be characterized by the fact that 50% by weight of the particles contained in the particle population (e.g., abrasive silica such as particles of the first abrasive silica) is d 50 This refers to particles having a diameter less than or equal to a certain value. By defining the proportion of particles having a diameter less than or equal to a specific value, it is possible to provide further characterization of the particle size distribution of a given population of particles. For example, d 90 This means that 90% by weight of the particles contained in the particle group (for example, abrasive silica such as the first abrasive silica particles) is d 90 This refers to having a particle diameter less than or equal to the value. For example, d 10 This means that 10% by weight of the particles contained in the particle group (for example, abrasive silica such as the first abrasive silica particles) is d 10 This refers to having a diameter less than or equal to a certain value.

[0036] In the embodiment, the abrasive silica particles according to the present invention have a weight median particle size (d) of 5 μm or more, preferably 9 μm or more. 50 The abrasive silica particles have a d value of 15 μm or less, preferably 12 μm or less. 50 The abrasive silica particles according to the present invention have a weight median particle size (d) of 5 μm to 15 μm, and optionally 9 μm to 12 μm (for example, about 10 μm, about 11 μm). 50 It has a value.

[0037] Abrasive silica particles are d25μm or larger.90 It may have a value (in this case, 90% by weight of the particles contained in the abrasive silica particles is d 90 (Having a diameter less than the specified value). Abrasive silica particles have a diameter of 35 μm or less. 90 The abrasive silica particles according to the present invention have a diameter of 25 μm to 35 μm, and optionally 30 μm to 34 μm (for example, about 31 μm, about 32 μm). 50 It has a value.

[0038] Abrasive silica particles are d of 2 μm or larger. 10 It may have a value (in this case, 10% by weight of the particles contained in the abrasive silica particles is d 10 (Having a diameter less than the specified value). Abrasive silica particles have a diameter of 4 μm or less. 10 It may have a value. The abrasive silica particles according to the present invention have a d of 2 μm to 4 μm (for example, about 3 μm). 10 It has a value.

[0039] In one embodiment, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the d of the first silica particle 50 15% to 65% of the first silica particles, optionally d 50 The value is 15% to 55%. In the embodiment, the weight median particle diameter (d) of the second silica particle is 50 ) is the d of the first silica particle 50 15% to 50% of the first silica particles, optionally d 50 It is between 20% and 50% of the value.

[0040] In one embodiment, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the d of the first silica particle 5015% to 25% of the first silica particles, optionally d 50 The value is between 18% and 23% (for example, around 20%, 21%, or 22%).

[0041] In one embodiment, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the d of the first silica particle 50 25% to 40% (for example, around 35%, around 36%) of the first silica particles, optionally d 50 This is 30% to 35% of the value (for example, around 31%, 32%, or 33%).

[0042] In one embodiment, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the d of the first silica particle 50 40% to 55% of the first silica particles, optionally d 50 This is 40% to 50% of the value (for example, around 44%, 45%, 46%, or 47%).

[0043] In this embodiment, the d of the first abrasive silica particles 50 The particle size of the first abrasive silica particle is less than 15 μm, optionally less than 13 μm, and optionally even less than 12 μm. 50 The particle size of the first abrasive silica is generally 5 μm or larger, optionally 7 μm or larger, and optionally even 9 μm or larger. 50 For example, the particle size can be 5 μm to 15 μm, optionally 7 μm to 14 μm, optionally 8 μm to 13 μm, and optionally 9 μm to 12 μm. In the embodiment, the d of the first abrasive silica particles 50 The size is 10 μm to 12 μm (for example, approximately 10 μm, approximately 11 μm, and approximately 12 μm).

[0044] The first abrasive silica particles are d 35 μm or smaller. 90 It may have a value, in which case 90% by weight of the particles contained in the first silica particle is d 90 The first abrasive silica particles have a diameter less than the value d 90 The particle size of the first abrasive silica is generally 20 μm or larger, optionally 23 μm or larger, and optionally even larger than 25 μm. 90 The size can be 25 μm to 35 μm, arbitrarily 27 μm to 33 μm, and arbitrarily even further 28 μm to 32 μm.

[0045] The first abrasive silica particles are d 4 μm or smaller. 10 It may have a value, in which case 10% by weight of the particles contained in the first silica particle is d 10 The first abrasive silica particles have a diameter less than the value d 10 The particle size of the first abrasive silica is generally 1 μm or larger, and optionally 2 μm or larger. 10 The particle size can be 1 μm to 4 μm, arbitrarily 1.5 μm to 3.5 μm, arbitrarily further 2 μm to 3.5 μm, or 2 μm to 4 μm.

[0046] In this embodiment, the d of the second abrasive silica particles 50 The particle size of the second abrasive silica is 9 μm or less, optionally 8.5 μm or less, and optionally even more than 8 μm or less. 50 The particle size of the second abrasive silica particle is 0.5 μm or larger, optionally 1 μm or larger, optionally 1.5 μm or larger, and optionally 2 μm or larger. In the embodiment, the particle size of the second abrasive silica is d 50 The particle size is 1 μm to 9 μm, arbitrarily 1.5 μm to 8.5 μm, arbitrarily 2 μm to 8 μm, and even more arbitrarily 2 μm to 7 μm. In the embodiment, the d of the second abrasive silica particles 50 The particle size is 2 μm to 6 μm, and arbitrarily 2 μm to 5 μm.

[0047] The second abrasive silica particles are 25 μm or less, optionally 20 μm or less. 90It may have a value, in which case 90% by weight of the particles contained in the second abrasive silica particles is d 90 The second abrasive silica particle has a diameter less than the value d 90 The particle size of the second abrasive silica particle is 2 μm or larger, optionally 2.5 μm or larger, optionally 3 μm or larger, and optionally 3.5 μm or larger. 90 The particle size can be 3 μm to 25 μm, arbitrarily 3 μm to 20 μm, arbitrarily 3 μm to 15 μm, and even arbitrarily 3 μm to 13 μm.

[0048] The second abrasive silica particles are 5 μm or less, optionally 4 μm or less, optionally 3 μm, and optionally 2.5 μm or less. 10 It may have a value, in which case 10% by weight of the particles contained in the second abrasive silica particles is d 10 The second abrasive silica particle has a diameter less than the value d 10 The particle size of the second abrasive silica particle is 0.5 μm or larger, and optionally 1 μm or larger. 10 The particle size can be 0.5 μm to 5 μm, arbitrarily 0.5 μm to 4 μm, arbitrarily 1 μm to 3 μm, and even arbitrarily 1 μm to 2.5 μm.

[0049] In this embodiment, the abrasive silica particles are d 50 Values ​​and d from 25 μm to 35 μm 90 The value is (in this case, 90% by weight of the particles contained in the first silica is d 90 First silica particles (having a diameter less than the specified value) and d 50 Values ​​and d from 3μm to 25μm 90 It includes a second silica particle having a value.

[0050] In embodiments, the abrasive silica particles of the present invention optionally further comprise a third, optionally further (e.g., fourth, fifth, etc.) abrasive silica particles. Any third abrasive silica particle is as outlined above with respect to the second abrasive silica. 10 d 50 and d 90 d according to the value 10 d 50and d 90 may be included. Arbitrary third abrasive silica particles may have a d relationship with the first abrasive silica that follows the d relationship between the second abrasive silica and the first abrasive silica described above 50 that follows the aforementioned relationship between the second abrasive silica and the first abrasive silica, for the d with the first abrasive silica 50 may have the relationship.

[0051] In an embodiment, the abrasive silica particles of the present invention further comprise third abrasive silica particles, and the weight median particle diameter of the third silica particles (d 50 ) is smaller than the d of the first silica particles 50 and is 15% to 70% of the d of the first silica particles 50 , and the total weight of the second abrasive silica particles and the third abrasive silica particles does not exceed 10% by weight relative to the total weight of the abrasive silica particles.

[0052] In some embodiments, the abrasive silica particles according to the present invention comprise first abrasive silica particles in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and second abrasive silica particles in an amount of at most 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter of the second abrasive silica particles (d 50 ) is smaller than the weight median particle diameter of the first abrasive silica particles (d 50 ) and is 15% to 70% of the d value of the first abrasive silica particles 50 , the first silica particles have a d value of 5 μm to 15 μm 50 , and the second silica particles have a d value of 1 μm to 9 μm 50 .

[0053] In some embodiments, the abrasive silica particles according to the present invention comprise first abrasive silica particles in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and second abrasive silica particles in an amount of at most 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter of the second abrasive silica particles (d 50 ) is smaller than the weight median particle diameter of the first abrasive silica particles (d 50 ) and is smaller than the d of the first abrasive silica particles 50The value is 15% to 25% (for example, about 20% or 21%), and the first silica particles are 10 μm to 12 μm (preferably about 11 μm) d 50 The second silica particle has a value of 1 μm to 3 μm (preferably about 2 μm) 50 It has a value.

[0054] In some embodiments, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50 The value is 25% to 40% (for example, about 33%, 34%, 35%, or 36%), and the first silica particles are 10 μm to 12 μm (preferably about 11 μm) d 50 The second silica particle has a value of 3 μm to 5 μm (preferably about 4 μm) d 50 It has a value.

[0055] In some embodiments, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50 The value is 40% to 55% (for example, about 44%, 45%, 46%, 47%, 48%, 49%, and 50%), and the first silica particles are 10 μm to 12 μm (preferably about 11 μm) d 50 The second silica particle has a value of 4 μm to 6 μm (preferably about 5 μm) 50 It has a value.

[0056] In some embodiments, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50 The value is 15% to 70%, and the first silica particles are 5 μm to 15 μm in size. 50 Values ​​and d from 25 μm to 35 μm 90 The second silica particle has a value of 1 μm to 9 μm. 50 Values ​​and d from 3μm to 25μm 90 It has a value.

[0057] In some embodiments, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50 The value is 15% to 25% (for example, about 20% or 21%), and the first silica particles are 10 μm to 12 μm (preferably about 11 μm) d 50 The value and d of 30 μm to 32 μm (preferably about 31 μm) 90 The second silica particle has a value of 1 μm to 3 μm (preferably about 2 μm) 50 The value and d of 3μm to 5μm (preferably about 4μm) 90 It has a value.

[0058] In some embodiments, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50 The value is 25% to 35% (for example, about 32%, 33%, or 34%), and the first silica particles are 10 μm to 12 μm (preferably about 11 μm) d 50 The value and d of 30 μm to 32 μm (preferably about 31 μm) 90 The second silica particle has a value of 3 μm to 5 μm (preferably about 4 μm) d 50 The value and d of 6 μm to 8 μm (preferably about 7 μm) 90 It has a value.

[0059] In some embodiments, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50 The value is 40% to 50% (for example, about 43%, 44%, or 45%), and the first silica particles are 10 μm to 12 μm (preferably about 11 μm) d 50 The value and d of 30 μm to 32 μm (preferably about 31 μm) 90 The second silica particle has a value of 4 μm to 6 μm (preferably about 5 μm) 50 The value and d of 12 μm to 14 μm (preferably about 13 μm) 90 It has a value.

[0060] In some embodiments, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50 The value is 15% to 25% (for example, about 21% or 22%), and the first silica particles are 10 μm to 12 μm (preferably about 11 μm) d 50 The value and d of 28 μm to 30 μm (preferably around 29 μm) 90 The second silica particle has a value of 1 μm to 3 μm (preferably about 2 μm) 50 The value and d of 3μm to 5μm (preferably about 4μm) 90 It has a value.

[0061] In some embodiments, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50 The value is 30% to 40% (for example, about 35%, 36%, or 37%), and the first silica particles are 10 μm to 12 μm (preferably about 11 μm) d 50 The value and d of 28 μm to 30 μm (preferably around 29 μm) 90 The second silica particle has a value of 3 μm to 5 μm (preferably about 4 μm) d 50 The value and d of 6 μm to 8 μm (preferably about 7 μm) 90 It has a value.

[0062] In some embodiments, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50 The value is 40% to 55% (for example, about 47%, 48%, 49%, or 50%), and the first silica particles are 10 μm to 12 μm (preferably about 11 μm) d 50 The value and d of 28 μm to 30 μm (preferably around 29 μm) 90 The second silica particle has a value of 4 μm to 6 μm (preferably about 5 μm) 50 The value and d of 12 μm to 14 μm (preferably about 13 μm) 90 It has a value.

[0063] In some embodiments, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50 The value is 15% to 70%, and the first silica particles are 5 μm to 15 μm in size. 50 The value, and d from 25 μm to 35 μm 90 The second silica particle has an oil absorption value of 75g / 100g to 150g / 100g, and the second silica particle is d, 1μm to 9μm in size. 50 The value, and d from 3μm to 25μm 90 It has a value and an oil absorption value of 30g / 100g to 120g / 100g.

[0064] Abrasiveness Abrasive silica particles suitable for use in toothpaste compositions according to embodiments of the invention disclosed herein (i.e., a group of abrasive silica particles as a whole) may have a relative dentine abrasion (RDA) value of 150 or less, optionally 120 or less, and optionally further 100 or less. Abrasive silica particles may have an RDA value of 30 or more, optionally 40 or more, preferably 45 or more. In embodiments, abrasive silica particles according to the present invention may have an RDA of 30 to 150, optionally 30 to 120, optionally further 40 to 100, for example 45 to 80.

[0065] The RDA of the first silica particle is typically smaller than that of the second silica particle. In other words, the second silica particle typically has a larger RDA than the first silica particle. Any third silica particle, and any further (e.g., fourth) silica particle, also typically have a larger RDA than the first silica particle.

[0066] In this embodiment, the abrasive silica particles include first abrasive silica particles in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and second abrasive silica particles in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than and the d of the first abrasive silica particles 50 The values ​​range from 15% to 70%, and the second silica particle has a larger RDA than the first silica particle.

[0067] In this embodiment, the first silica particles have a relative dentin abrasion (RDA) value that is 10% to 70%, optionally 10% to 50%, optionally further 15% to 40%, for example 15% to 35%, of the RDA value of the second silica particles.

[0068] In one embodiment, the first silica particles have an RDA value of 110 or less, and optionally 105 or less. In another embodiment, the first silica particles have an RDA value of 30 or more, optionally 40 or more, and optionally 50 or more. In yet another embodiment, the first silica particles have an RDA value of 30 to 110, optionally 40 to 80, and optionally 50 to 60 (for example, 50 to 55).

[0069] In the embodiment, the second silica particles have an RDA value of 350 or less, preferably 300 or less, and more preferably 250 or less. In the embodiment, the second silica particles have an RDA value of 200 or less. The second silica particles may have an RDA value of 120 or more, optionally 130 or more, preferably 140 or more. In the embodiment, the second silica particles have an RDA value of 120 to 300, optionally 130 to 290, and optionally even further 140 to 280. The second silica particles may have an RDA of, for example, 150 to 180.

[0070] If present in the composition, the third abrasive silica, and any additional (e.g., fourth) abrasive silica particles may have RDA values ​​according to the RDA values ​​outlined above with respect to the second abrasive silica.

[0071] In this embodiment, the abrasive silica particles include first abrasive silica particles in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and second abrasive silica particles in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than and the d of the first abrasive silica particles 50 The values ​​range from 15% to 70%, with the first abrasive silica particles having an RDA of 30 to 110, and the second abrasive silica particles having an RDA of 120 to 300.

[0072] In this embodiment, the abrasive silica particles include first abrasive silica particles in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and second abrasive silica particles in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than and the d of the first abrasive silica particles 50 The values ​​are 15% to 70%, and the first abrasive silica particles have an RDA of 30 to 60, optionally 45 to 55 (e.g., around 51, 52, 53, 54), while the second abrasive silica particles have an RDA of 120 to 300. The RDA of the second abrasive silica may optionally be 130 to 170, optionally further 140 to 160, for example 145 to 155 (e.g., around 153, 154). The RDA of the second abrasive silica may optionally be 150 to 190, optionally further 160 to 180, for example 165 to 175 (e.g., around 170, 171, 172, 173). The RDA of the second abrasive silica can be any 250-290, and possibly even more 260-280, for example 265-275 (for example around 270, 271, 272, or 273).

[0073] In this embodiment, the abrasive silica particles include first abrasive silica particles in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and second abrasive silica particles in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than and the d of the first abrasive silica particles 50The values ​​are 15% to 70%, and the first abrasive silica particles have an RDA of 90 to 120, optionally 100 to 110 (e.g., around 104, 105, 106), and the second abrasive silica particles have an RDA of 120 to 300. The RDA of the second abrasive silica may optionally be 130 to 170, optionally further 140 to 160, for example 145 to 155 (e.g., around 153, 154). The RDA of the second abrasive silica may optionally be 150 to 190, optionally further 160 to 180, for example 165 to 175 (e.g., around 170, 171, 172, 173). The RDA of the second abrasive silica can be any 250-290, and possibly even more 260-280, for example 265-275 (for example around 270, 271, 272, or 273).

[0074] In one embodiment, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50 The value is 15% to 70%, and the first silica particles are 5 μm to 15 μm in size. 50 The value, and d from 25 μm to 35 μm 90 The second silica particle has an oil absorption value of 75g / 100g to 150g / 100g and an RDA value of 30 to 110, and the second silica particle has a d size of 1μm to 9μm. 50 The value, and d from 3μm to 25μm 90 It has a value, an oil absorption value of 30g / 100g to 120g / 100g, and an RDA value of 120 to 300.

[0075] The abrasive silica particles according to the present invention may have a Plastic Abrasion Value (PAV) of 15 or less, and optionally 10 or less. The abrasive silica particles may have a PAV of 3 or more, and optionally 4 or more. The abrasive silica particles may have a PAV of 3 to 15, optionally 3 to 10, and optionally even further 4 to 15 (for example, 4 to 10).

[0076] In the embodiment, the abrasive silica particles according to the present invention have 2 to 6, optionally 3 to 5 (for example, about 4) PAVs.

[0077] In one embodiment, the abrasive silica particles according to the present invention have 4 to 10, optionally 5 to 10 (for example, about 7 or about 8) PAVs.

[0078] In one embodiment, the abrasive silica particles according to the present invention have 6 to 15, optionally 7 to 14 (for example, about 10) PAVs.

[0079] In one embodiment, the abrasive silica particles according to the present invention have 6 to 15, optionally 7 to 14 (for example, about 10, about 12, or about 14) PAVs.

[0080] In this embodiment, the abrasive silica particles include first abrasive silica particles in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and second abrasive silica particles in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than and the d of the first abrasive silica particles 50 The values ​​range from 15% to 70%, and the second silica particle has a larger PAV than the first silica particle.

[0081] The PAV of the first silica particle is generally smaller than that of the second silica particle. In other words, the second silica particle generally has a larger PAV than that of the first silica particle. Any third silica particle, and any further (e.g., a fourth) silica particle, generally have a larger PAV than that of the first silica particle.

[0082] In this embodiment, the first silica particles have a plastic abrasion value (PAV) that is 5% to 80%, optionally 7% to 50%, for example 9% to 45%, of the PAV value of the second silica particles.

[0083] In one embodiment, the first silica particles have a PAV of 8 or less, optionally 7 or less, and optionally further 5 or less. In another embodiment, the first silica particles have a PAV of 2 or more, optionally 3 or more. In yet another embodiment, the first silica particles have a PAV of 2 to 8, optionally 3 to 7, and optionally further 3 to 5, for example 3 to 4, and the PAV of the first silica particles is smaller than the PAV of the second silica particles.

[0084] In one embodiment, the second silica particles have a PAV of 50 or less, and optionally 40 or less. In another embodiment, the second silica particles have a PAV of 7 or more, and optionally 8 or more. In yet another embodiment, the second silica particles have a PAV of 7 to 50, and optionally 8 to 40, and the PAV of the second silica particles is greater than the PAV of the first silica particles.

[0085] Any particles of the third abrasive silica, and optionally any further (e.g., a fourth) abrasive silica, may have PAV values ​​that conform to the PAV values ​​outlined above with respect to the second abrasive silica.

[0086] In this embodiment, the abrasive silica particles include first abrasive silica particles in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and second abrasive silica particles in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles.50 ) is smaller than and the d of the first abrasive silica particles 50 The values ​​are 15% to 70%, and the first abrasive silica particles have a PAV of 2 to 5, optionally 3 to 5 (e.g., about 4), while the second abrasive silica particles have a PAV of 7 to 50. The PAV of the second abrasive silica can optionally be 7 to 10, optionally even further 8 to 9. The PAV of the second abrasive silica can optionally be 15 to 25, optionally even further 18 to 23 (e.g., about 19, about 20, about 21, about 22). The PAV of the second abrasive silica can optionally be 25 to 50, optionally even further 35 to 40 (e.g., about 35, about 36, about 37).

[0087] In this embodiment, the abrasive silica particles include first abrasive silica particles in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and second abrasive silica particles in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than and the d of the first abrasive silica particles 50 The values ​​are 15% to 70%, and the first abrasive silica particles have a PAV of 4 to 8, optionally 5 to 7 (e.g., about 6), and the second abrasive silica particles have a PAV of 7 to 50. The PAV of the second abrasive silica can optionally be 7 to 10, optionally further 8 to 9. The PAV of the second abrasive silica can optionally be 15 to 25, optionally further 18 to 23 (e.g., about 19, about 20, about 21, about 22). The PAV of the second abrasive silica can optionally be 25 to 50, optionally further 35 to 40 (e.g., about 35, about 36, about 37).

[0088] In one embodiment, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50 The value is 15% to 70%, and the first silica particles are 5 μm to 15 μm in size. 50 The value, and d from 25 μm to 35 μm 90 The second silica particle has an oil absorption value of 75g / 100g to 150g / 100g and a PAV value of 2 to 8, and the second silica particle has a d of 1μm to 9μm. 50 The value, and d from 3μm to 25μm 90 The second silica particle has an oil absorption value of 30g / 100g to 120g / 100g and a PAV value of 7 to 50, with the PAV of the second silica particle being greater than that of the first silica particle.

[0089] Oil absorption value / porosity The oil absorption value of abrasive silica particles correlates with the porosity of a given abrasive silica. Typically, the abrasive silica according to the present invention is porous silica, such as precipitated silica.

[0090] In an embodiment, the abrasive silica particles according to the present invention (i.e., a group of abrasive silica particles) have an oil absorption value of 150 g / 100 g or less, and optionally 140 g / 100 g or less. The abrasive silica particles according to the first aspect of the present invention may have an oil absorption value of 75 g / 100 g or more, optionally 80 g / 100 g or more, and optionally 100 g / 100 g or more. For example, the abrasive silica particles according to the first aspect of the present invention may have an oil absorption value of 75 g / 100 g to 150 g / 100 g, optionally 80 g / 100 g to 145 g / 100 g, and optionally even further 90 g / 100 g to 140 g / 100 g. In a particular manner, the oil absorption value of the abrasive silica particles may be 90g / 100g to 150g / 100g, optionally 110g / 100g to 135g / 100g, and optionally even 120g / 100g to 140g / 100g (for example, about 130g / 100g, about 135g / 100g). In a particular manner, the oil absorption value of the abrasive silica may be 80g / 100g to 120g / 100g, optionally 90g / 100g to 110g / 100g (for example, about 100g / 100g, about 101g / 100g, about 102g / 100g).

[0091] In this embodiment, the abrasive silica particles include first abrasive silica particles in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and second abrasive silica particles in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than and the d of the first abrasive silica particles 50 The value is 15% to 70%, and the second silica particle has a lower oil absorption value than the second silica particle.

[0092] In a typical embodiment of the present invention, the oil absorption value of the first silica particles is greater than that of the second silica particles. In other words, the second silica particles typically have a lower oil absorption value than that of the first silica particles. Any third silica particles, if present, and any further (e.g., fourth) silica particles may also each have a lower oil absorption value than that of the first silica particles.

[0093] In preferred embodiments of the invention described herein (for example, in the first aspect of the present invention), the oil absorption value of the second abrasive silica particles is smaller than that of the first abrasive silica particles, and is 30% to 70% of the oil absorption value of the first abrasive silica particles.

[0094] In this embodiment, the abrasive silica particles include first abrasive silica particles in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and second abrasive silica particles in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles. 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50 The oil absorption value of the second abrasive silica particles is smaller than that of the first abrasive silica particles, being 30% to 70% of the first abrasive silica particle's oil absorption value.

[0095] In this embodiment, the second silica particles have an oil absorption value of 35% to 65%, optionally 40% to 60%, for example 44% to 55%, of the oil absorption value of the first silica particles.

[0096] In an embodiment, the first silica particles have an oil absorption value of 150 g / 100 g or less. The first silica particles may have an oil absorption value of 75 g / 100 g or more, optionally 80 g / 100 g or more, and optionally 100 g / 100 g or more. In an embodiment, the first silica particles have an oil absorption value of 75 g / 100 g to 150 g / 100 g, optionally 80 g / 100 g to 145 g / 100 g, and optionally even further 90 g / 100 g to 140 g / 100 g. In an example, the oil absorption value of the first abrasive silica may be 90g / 100g to 150g / 100g, optionally 110g / 100g to 135g / 100g, and optionally even further 120g / 100g to 140g / 100g (for example, about 130g / 100g, about 135g / 100g). In an example, the oil absorption value of the first abrasive silica may be 80g / 100g to 120g / 100g, optionally 90g / 100g to 110g / 100g (for example, about 100g / 100g, about 101g / 100g, about 102g / 100g).

[0097] In one embodiment, the second silica particles have an oil absorption value of 120 g / 100 g or less, optionally 110 g / 100 g or less, optionally further 100 g / 100 g or less, for example 85 g / 100 g or less. In another embodiment, the second silica particles have an oil absorption value of 30 or more, optionally 40 or more. In yet another embodiment, the second silica particles have an oil absorption value of 30 to 120, optionally 40 to 115, optionally further 45 to 110.

[0098] In an embodiment, the second silica particles have an oil absorption value of 50g / 100g to 100g / 100g, optionally 50g / 100g to 85g / 100g, and optionally even further 50g / 100g to 80g / 100g. In an embodiment, the oil absorption value of the second abrasive silica may be 50g / 100g to 70g / 100g, optionally 55g / 100g to 65g / 100g (for example, about 60g / 100g).

[0099] In an embodiment, the oil absorption value of the second abrasive silica may be 30g / 100g to 70g / 100g, optionally 40g / 100g to 60g / 100g, and optionally even further 45g / 100g to 55g / 100g (for example, about 46g / 100g, about 47g / 100g, about 48g / 100g).

[0100] The third abrasive silica, and any particles of any further (e.g., a fourth) abrasive silica, may have oil absorption values ​​that conform to the oil absorption values ​​outlined above with respect to the second abrasive silica.

[0101] In an embodiment, the abrasive silica particles according to the present invention include first silica particles having an oil absorption value of 75 g / 100 g to 150 g / 100 g, and second silica particles having an oil absorption value of 30 g / 100 g to 120 g / 100 g.

[0102] In the embodiment, the abrasive silica particles of the present invention further comprise third abrasive silica particles, the third abrasive silica particles having an oil absorption value as outlined above with respect to the oil absorption value of the second abrasive silica.

[0103] In this embodiment, the abrasive silica particles include first abrasive silica particles in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and second abrasive silica particles in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than and the d of the first abrasive silica particles 50The oil absorption values ​​are 15% to 70% of the original value, and the second silica particles have a lower oil absorption value than the second silica particles. The oil absorption of the first abrasive silica is 75g / 100g to 150g / 100g, and the oil absorption of the second abrasive silica is 30g / 100g to 120g / 100g.

[0104] In one embodiment, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than and the d of the first abrasive silica particles 50 The oil absorption value of the second abrasive silica particles is 15% to 70% of the value, and the oil absorption value of the second abrasive silica particles is smaller than that of the first abrasive silica particles, being 30% to 70% of the oil absorption value of the first abrasive silica particles, and the oil absorption amount of the first abrasive silica is 75g / 100g to 150g / 100g, while the oil absorption amount of the second abrasive silica is 30g / 100g to 120g / 100g.

[0105] In one embodiment, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than and the d of the first abrasive silica particles 50The oil absorption value of the second abrasive silica particles is 15% to 70% of the first abrasive silica particle's value, and is smaller than that of the first abrasive silica particle, being 30% to 70% of the first abrasive silica particle's value. The oil absorption value of the first abrasive silica is 90g / 100g to 150g / 100g, arbitrarily 110g / 100g to 135g / 100g, and arbitrarily even further 120g / 100g to 140g / 100g (for example, around 130g / 100g or 135g / 100g). In this case, the oil absorption value of the second abrasive silica is 30g / 100g to 120g / 100g. The oil absorption value of the second abrasive silica can be 30g / 100g to 70g / 100g, arbitrarily 40g / 100g to 60g / 100g, and arbitrarily even further 45g / 100g to 55g / 100g (for example, around 46g / 100g, around 47g / 100g, around 48g / 100g). The oil absorption value of the second abrasive silica can be 50g / 100g to 80g / 100g, and arbitrarily even further 55g / 100g to 65g / 100g (for example, around 60g / 100g).

[0106] In one embodiment, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than and the d of the first abrasive silica particles 50The oil absorption value of the second abrasive silica particles is 15% to 70% of the value of the first abrasive silica particles, and is smaller than that of the first abrasive silica particles, being 30% to 70% of the value of the first abrasive silica particles. The oil absorption value of the first abrasive silica is 80g / 100g to 120g / 100g, or arbitrarily 90g / 100g to 110g / 100g (for example, around 100g / 100g, around 101g / 100g, around 102g / 100g). In this case, the oil absorption value of the second abrasive silica is 30g / 100g to 120g / 100g. The oil absorption value of the second abrasive silica can be 30g / 100g to 70g / 100g, arbitrarily 40g / 100g to 60g / 100g, and arbitrarily even further 45g / 100g to 55g / 100g (for example, around 46g / 100g, around 47g / 100g, around 48g / 100g). The oil absorption value of the second abrasive silica can be 50g / 100g to 80g / 100g, arbitrarily 50g / 100g to 70g / 100g, and arbitrarily even further 55g / 100g to 65g / 100g (for example, around 60g / 100g).

[0107] In some embodiments, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight, optionally 2% to 7% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50 The value is 15% to 25% (for example, about 20% or 21%), and the first silica particles are 10 μm to 12 μm (preferably about 11 μm) d 50 The value, and d of 30 μm to 32 μm (preferably about 31 μm) 90 The second silica particles have an oil absorption value of 125g / 100g to 135g / 100g (preferably 130g / 100g to 135g / 100g, for example 134g / 100g), and the second silica particles are d, 1μm to 3μm (preferably about 2μm) 50 The value, and d of 3μm to 5μm (preferably about 4μm) 90It has a value and an oil absorption value of 55g / 100g to 65g / 100g (preferably around 60g / 100g).

[0108] In some embodiments, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight, optionally 2% to 7% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50 The value is 25% to 35% (for example, about 32%, 33%, or 34%), and the first silica particles are 10 μm to 12 μm (preferably about 11 μm) d 50 The value, and d of 30 μm to 32 μm (preferably about 31 μm) 90 The second silica particles have an oil absorption value of 125g / 100g to 135g / 100g (preferably 130g / 100g to 135g / 100g, for example 134g / 100g), and the second silica particles are 3μm to 5μm (preferably about 4μm) in size. 50 The value, and d of 6 μm to 8 μm (preferably about 7 μm) 90 It has a value and an oil absorption value of 60g / 100g to 70g / 100g (preferably around 65g / 100g).

[0109] In some embodiments, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight, optionally 2% to 7% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50The value is 40% to 50% (for example, about 43%, 44%, or 45%), and the first silica particles are 10 μm to 12 μm (preferably about 11 μm) d 50 The value, and d of 30 μm to 32 μm (preferably about 31 μm) 90 The second silica particles have an oil absorption value of 125g / 100g to 135g / 100g (preferably 130g / 100g to 135g / 100g, for example 134g / 100g), and the second silica particles are d, 4μm to 6μm (preferably about 5μm) 50 The value, and d of 12 μm to 14 μm (preferably about 13 μm) 90 It has a value and an oil absorption value of 40g / 100g to 50g / 100g (preferably around 45g / 100g).

[0110] In some embodiments, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight, optionally 2% to 7% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50 The value is 15% to 25% (for example, about 21% or 22%), and the first silica particles are 10 μm to 12 μm (preferably about 11 μm) d 50 The value, and d of 28 μm to 30 μm (preferably around 29 μm) 90 The second silica particle has an oil absorption value of 90g / 100g to 100g / 100g (preferably around 95g / 100g), and the second silica particle has a d size of 1μm to 3μm (preferably around 2μm). 50 The value, and d of 3μm to 5μm (preferably about 4μm) 90 It has a value and an oil absorption value of 55g / 100g to 65g / 100g (preferably around 60g / 100g).

[0111] In some embodiments, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight, optionally 2% to 7% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50 The value is 30% to 40% (for example, about 35%, 36%, or 37%), and the first silica particles are 10 μm to 12 μm (preferably about 11 μm) d 50 The value, and d of 28 μm to 30 μm (preferably around 29 μm) 90 The second silica particle has an oil absorption value of 90g / 100g to 100g / 100g (preferably around 95g / 100g), and the second silica particle is d 3μm to 5μm (preferably around 4μm) 50 The value, and d of 6 μm to 8 μm (preferably about 7 μm) 90 It has a value and an oil absorption value of 60g / 100g to 70g / 100g (preferably around 65g / 100g).

[0112] In some embodiments, the abrasive silica particles according to the present invention comprise a first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and a second abrasive silica particle in an amount of up to 10% by weight, optionally 2% to 7% by weight relative to the total weight of the abrasive silica particles, wherein the weight median particle diameter (d 50 ) is the weight median particle size (d) of the first abrasive silica particles. 50 ) is smaller than the d of the first abrasive silica particles 50 The value is 40% to 55% (for example, about 47%, 48%, 49%, or 50%), and the first silica particles are 10 μm to 12 μm (preferably about 11 μm) d 50 The value, and d of 28 μm to 30 μm (preferably around 29 μm) 90The second silica particle has an oil absorption value of 90g / 100g to 100g / 100g (preferably around 95g / 100g), and the second silica particle is d 4μm to 6μm (preferably around 5μm) 50 The value, and d of 12 μm to 14 μm (preferably about 13 μm) 90 It has a value and an oil absorption value of 40g / 100g to 50g / 100g (preferably around 45g / 100g).

[0113] Cleaning performance (FT 100 ) The abrasive silica particles according to the present invention (i.e., a collection of abrasive silica particles as a whole) have a ferric tannate cleaning value (FT) of 40-100, for example 50-95, optionally 60-95, and optionally even 65-90 per 100 strokes. 100 ) may have. The abrasive silica particles have 60-80, optionally 60-70 FT 100 It may have. The abrasive silica particles have a hardness of 70-90, optionally 70-80 FT. 100 It may have the following properties. The abrasive silica particles have a hardness of 75-95, optionally 80-90 FT. 100 It may have. FT 100 The values ​​are obtained from a slurry of abrasive silica particles prepared according to the ferric tannate (FT) cleaning protocol described herein.

[0114] Composition containing silica particles of the present invention The present invention further provides a composition for use in toothpaste, comprising abrasive silica particles according to the present invention (for example, a first aspect of the present invention). The composition may contain 1% to 99% by weight of abrasive silica particles, optionally 20% to 80% by weight, and optionally even further 40% to 60% by weight of abrasive silica particles.

[0115] The composition may further comprise a carrier, such as a liquid carrier or a fluid carrier such as a powder. A powder composition containing the abrasive silica of the present invention as a powder component is envisioned in the first aspect of the present invention. The carrier may comprise one or more of the following: water, solvent, sugars / sweeteners (e.g., sorbitol, glycerol, xylitol, and combinations thereof), surfactants (e.g., sodium lauryl sulfate), humectants (e.g., polyethylene glycol), titanium dioxide, gum (e.g., xanthan gum), salts (e.g., fluoride salts such as sodium fluoride), thickeners, and combinations thereof. The carrier may be present in the composition in an amount of 0.1% to 90% by weight, optionally 10% to 80% by weight, and optionally further 20% to 70% by weight.

[0116] In embodiments, the composition may contain silica particles not present in the abrasive silica particles of the present invention (i.e., silica particles that are not defined for the first, second, third, or further (e.g., fourth) abrasive silica). Such silica particles may be, for example, non-abrasive silica particles. Such silica particles may have an RDA of less than 30, typically less than 20, and optionally less than 10 (e.g., about 8). Such silica particles may be thickeners, such as SORBOSIL® TC15, commercially available from PQ Silicas UK Limited. If silica particles not from the first, second, third, or further (e.g., fourth) abrasive silica of the present invention are present in the composition, they may be present in the composition in amounts typically 5% to 30% by weight, and optionally 10% to 20% by weight (e.g., 11%, 15%, 19%).

[0117] In embodiments, the composition according to the present invention further comprises one or more surfactants. The surfactant may include a water-soluble salt. Suitable surfactants can be selected from anionic surfactants (e.g., sodium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium lauryl sulfoacetate, 1,2-dihydroxypropanesulfonic acid, etc.), cationic surfactants (e.g., betaine), and combinations thereof. The surfactant may be present in the composition in an amount of 0.1% to 10% by weight, optionally 1% to 5% by weight, and optionally further 2% to 3% by weight.

[0118] The resulting composition may contain one or more polyols. Suitable polyols can be selected from sorbitol, glycol, propylene glycol, polyethylene glycol (PEG), and combinations thereof.

[0119] The compositions according to the present invention may include additional excipients, colorants, fragrances, carrageenan (rich oss), sodium carboxymethylcellulose, starch, polyvinylpyrrolidone, hydroxyethylpropylcellulose, hydroxybutylmethylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, and combinations thereof.

[0120] Toothpaste The present invention provides a toothpaste comprising abrasive silica particles according to the present invention, or a composition according to the present invention. The toothpaste may be a powder, paste, or gel. Preferably, the toothpaste is a paste.

[0121] In one embodiment, the toothpaste contains 0.1% to 50% by weight, optionally 1% to 30% by weight, and optionally further 10% to 25% by weight (e.g., 20% by weight) of abrasive silica particles according to the present invention.

[0122] In this embodiment, the RDA of the toothpaste is 250 or less, optionally 200 or less. The RDA of the toothpaste may be 5 or more. The RDA of the toothpaste may be 5 to 200, optionally 40 to 150, and optionally even more optionally 70 to 120.

[0123] Toothpaste can be prepared by combining silica particles according to the first aspect of the present invention, or a composition according to the second aspect of the present invention, with one or more excipients suitable for toothpaste applications.

[0124] Method for producing abrasive silica particles The present invention further provides a method for producing abrasive silica particles for use in toothpaste compositions. This method includes providing abrasive silica particles by combining first abrasive silica particles and second abrasive silica particles. The first abrasive silica particles are present in an amount of at least 90% by weight of the total weight of the abrasive silica particles, and the second abrasive silica particles are present in an amount of up to 10% by weight of the total weight of the abrasive silica particles. The weight median particle diameter (d 50 ) is smaller than the first silica particle, and the d of the first silica particle 50 The value is between 15% and 70%.

[0125] In this embodiment, the combining step includes combining first abrasive silica particles, second abrasive silica particles, and third abrasive silica particles to provide abrasive silica particles. This step may optionally include combining further abrasive silica particles (e.g., fourth abrasive silica particles). The weight median particle diameter d of the third silica particle. 50 It is smaller than the first silica particle, and the weight median particle diameter d of the first silica particle 50 This is between 15% and 70%. The combined weight of the second and third silica particles does not exceed 10% by weight of the total weight of the abrasive silica particles.

[0126] In the embodiment, combining involves mixing silica particles, and optionally, the mixing provides a homogeneous mixture of silica particles.

[0127] Those skilled in the art are familiar with methods for mixing a first "bulk" abrasive silica with a second abrasive silica. Suitable apparatus for mixing includes a powder blender mixer (e.g., a Turbula® mixer). The first abrasive silica and the second abrasive silica may be mixed simultaneously (i.e., added to the mixture in equal amounts until completely mixed), or added sequentially in any order. The first abrasive silica may be added to the second abrasive silica (e.g., gradually), and the second abrasive silica may be added to the first abrasive silica (e.g., gradually).

[0128] In one embodiment, the above method is a method for producing abrasive silica particles as defined in the present invention.

[0129] The above method may further include an additional step of contacting the abrasive silica particles obtained by the above method step with one or more excipients suitable for toothpaste applications to form a toothpaste. The toothpaste thus prepared is as defined according to a third aspect of the present invention and may be, for example, any toothpaste as defined herein.

[0130] The present invention further provides abrasive silica particles, which are produced according to a method for producing abrasive silica particles as defined herein, for use in toothpaste compositions. Such particles may be as defined herein in relation to a first aspect of the present invention.

[0131] General method Polishable silica Those skilled in the art will be able to easily select from the wide variety of commercially available silicas suitable for use as the first, second, or third (or further) abrasive silica particles described herein. Methods for preparing suitable particles of the first, second, or third (or further) abrasive silica used in the present invention are also well known to those skilled in the art. For example, a method for preparing abrasive silica is described in "The Chemistry of Silica" by Ralph K. Iler (ISBN: 9780471024040). Precipitated abrasive silica particles suitable for use in the present invention can be prepared by preparing an alkali metal silicate solution, mixing the solution with an acid and optionally an electrolyte, stirring, and filtering off the precipitated silica. The resulting precipitate filter cake is then washed, dried, and ground to the desired particle size.

[0132] European Patent No. 1976482 describes the preparation of silica suitable for use according to the present invention. Examples 1C, 1D, 1E, and 4A described in European Patent No. 1976482 are particularly suitable for use according to the present invention, especially as second (or third, or further) abrasive silica particles.

[0133] The abrasive silica described in U.S. Patent No. 5,098,695, European Patent No. 0835,223, and European Patent No. 0785,169 is particularly suitable for use in the present invention as particles of the first "bulk" abrasive silica.

[0134] Specific examples of suitable particles of the first “bulk” abrasive silica include SORBOSIL® AC39 and SORBOSIL® AC36, commercially available from PQ Silicas UK Limited. Other suitable commercially available first (i.e., “bulk”) abrasive silicas that can be used in accordance with the present invention include Tixosil® 123, commercially available from Solvay, Zeodent® 113 and Zeodent® 116, commercially available from Evonik, and Sylodent® VP5, commercially available from Grace.

[0135] A general method for producing silica used in accordance with the present invention is outlined below with reference to U.S. Patent No. 5,447,704 and European Patent No. 0308165.

[0136] U.S. Patent No. 5,447,704 describes a preferred method for preparing preferred amorphous precipitated silica produced by the reaction of sodium silicate with a mineral acid having a silica:Na2O ratio in the range of 1.8:1 to 3.5:1, in the presence of a water-soluble electrolyte containing a cation selected from the group including aluminum, magnesium, calcium, sodium, and potassium, along with an associated anion selected from the group including bromides, carbonates, chlorides, nitrates, acetates, and sulfates, with the concentration and volume of the reactants controlled to set the pH in the range of about 10 to about 10.5, the electrolyte:silica weight ratio being about 0.1:1 to about 2:1, and the precipitation reaction being carried out at a temperature range of about 95°C to about 100°C.

[0137] European Patent No. 0308165 describes a method for preparing suitable amorphous abrasive silica produced by the reaction of sodium silicate with a silica:Na2O ratio in the range of 3.2:1 to 3.4:1, wherein the reaction is carried out at a temperature range of approximately 45°C to approximately 55°C, the concentration and volume of the reactants are controlled to set the pH in the range of approximately 10 to approximately 10.5, the weight ratio of electrolyte:silica is approximately 0.4:1 to approximately 1.2:1, the precipitation reaction is carried out at a temperature range of approximately 45°C to approximately 55°C, the pH of the reaction solution is made acidic by adding a mineral acid, and the resulting silica product is separated and washed.

[0138] Once the silica is prepared (for example, according to the method outlined above in U.S. Patent No. 5,447,704 or European Patent No. 0308,165), the abrasive silica may be finely ground to the desired particle size using a mechanical mill (e.g., a hammer mill). In mechanical milling, a median particle size (d) of 7 μm to 20 μm is generally achieved. 50This yields finer particles. For even smaller particle sizes, high-energy grinding processes, such as micronization, may be used. Micronization can be achieved using, for example, one or more of the following: jet, fluid energy mill, pancake micronizer, fluidized bed micronizer, and counter-jet micronizer.

[0139] Optionally, the material may be subjected to classification, screening, or sieving at any stage of the process to optimize the process and remove excess large particles so that a desirable particle size distribution of abrasive silica is obtained. [Examples]

[0140] Preparation of abrasive silica particles according to the present invention A mixture was prepared by combining (for example, in the amounts (wt%) shown in Table 2 below) a first "bulk" abrasive silica particle (silica A1, A2, A3), a second abrasive silica particle (silica B1, B2, B3, B4), and optionally a third abrasive silica particle (from silica B1, B2, B3, B4). The abrasive silica was weighed at atmospheric pressure and room temperature. This mixture was blended to provide a homogeneous mixture of abrasive silica particles.

[0141] Preparation of a composition containing abrasive silica particles A batch of abrasive silica particles, prepared as described above, was added to one or more additional components (generally carriers) and mixed to provide the composition.

[0142] Preparation of toothpaste containing abrasive silica particles A toothpaste containing abrasive silica particles (as in the example or reference example of the present invention) and having the following general components was prepared.

[0143] [Table 1]

[0144] Water and sorbitol were combined, then sodium fluoride and sodium saccharin were added. The resulting composition was mixed at ambient temperature for 30 minutes, then SLS powder was added and mixed for a further 30 minutes. Flavor oil was then added and mixed for a further 30 minutes, followed by the addition of TiO2 and mixing for another 30 minutes. Separate mixtures of SCMC and PEG400 were added to the resulting mixture and mixed for 30 minutes. Next, abrasive silica particles (i.e., those of the present invention, or abrasive reference silica) were added to the resulting mixture and mixed for 30 minutes. The thickening agent silica TC15 was added to the resulting mixture and stirred for 30 minutes to obtain a toothpaste. A toothpaste is provided in which the abrasive silica particle component is either a) according to an embodiment of the present invention (to provide a toothpaste according to the present invention), or b) reference abrasive silica not according to the present invention (typically containing only a single silica corresponding to one of the silicas used in the composition of the present invention).

[0145] Particle size measurement With respect to any given batch of silica particles described herein, for example, the abrasive silica particles of the present invention as a whole, or the first or second silica used as a subgroup within the abrasive silica particles of the present invention, the weight median particle diameter (d 50 The particle size distribution was determined by laser diffraction using a Malvern Mastersizer 2000 and a Hydro 2000 AG dispersion unit. Mie theory was used to calculate the particle size distribution. A real refractive index of 1.46 was assigned to silica, an imaginary refractive index of 1.0 was assigned to the particles, and the aqueous dispersion medium had a real refractive index of 1.33. Abrasive silica particles were ultrasonically dispersed in deionized water at 50% power for 5 minutes using a Hydro 2000 AG dispersion unit to form an aqueous suspension. Laser light was passed through a flow cell containing the particles dispersed in deionized water. The scattered light intensity was measured as a function of angle, and the particle size distribution was calculated using this data. Assuming that the particle density was constant, weight-based particle size measurements were used.

[0146] Oil absorption value For any given batch of silica particles described herein, for example, the abrasive silica particles of the present invention as a whole, or the first or second silica used as a subgroup within the abrasive silica particles of the present invention, the oil absorption (O / A) value was determined by the ASTM spatula rub-out method (American Society for Testing and Materials standard D281). Linseed oil and abrasive silica particles were mixed on a smooth surface by rubbing with a spatula until a hard, putty-like paste was formed. The volume of absorbed oil was measured per 100 g of silica in cm³. 3 Expressed as a number, followed by the oil absorption value = (cm 3 The calculation is (oil absorption × 100) / (weight of silica (grams)). This amount is based on the assumed density of linseed oil, which is 0.93 g / cm³. 3 By multiplying by a factor, the amount can also be expressed as the number of grams of oil per 100g of silica (g / 100g). All oil absorption results presented herein are calculated using this method and are expressed as the number of grams of oil per 100g of silica.

[0147] Plastic wear value (PAV) The abrasiveness of the silica particles described herein, for example, the abrasive silica particles of the present invention as a whole, or any predetermined batch of the first or second silica used as a subgroup within the abrasive silica particles of the present invention, was measured using the Plastic Abrasion Value (PAV) test. Perspex® has a hardness close to that of dentin. The sample was prepared as a slurry by mixing the following components to form a suspension. Abrasive silica particles, 2.5 grams 10.0 grams of glycerol Sorbitol syrup (70% sorbitol and 30% water by weight) 23.0 grams

[0148] A standard transparent Perspex® sheet (Grade 000, manufactured by Lucite International UK Ltd) was used. A Sheen Instruments Wet Paint Scrub Tester was modified to accommodate a toothbrush (instead of a paintbrush) in the holder. A 400g weight was attached to the brush assembly (weighing 145g), and the brush was pressed against the Perspex® sheet. The toothbrush used was multi-tufted, nylon-headed, and medium-textured (e.g., Professional Mentadent® P gum health design, or equivalent toothbrush). A Byk Microgloss 45° detector was calibrated using a standard (56.8% gloss) reflector. The gloss of a new Perspex® sheet was then measured and fitted into the holder. 2 mL of sample was placed on the sheet and brought into contact with the brush head in 300 strokes. The Perspex® sheet was removed from the holder, cleaned, dried, and measured again. The abrasion value was determined as the difference between the gloss measurement before and after abrasion. Based on the example provided, the following results were obtained.

[0149] [Table 2]

[0150] Relative dentin wear The abrasiveness of the abrasive silica particles according to the present invention was measured using a relative dentin abrasion test (RDA, also known as radioactive dentin abrasion) for any given batch of silica particles described herein, for example, the abrasive silica particles of the present invention as a whole, or the first or second silica used as a subgroup within the abrasive silica particles of the present invention. The procedure used was that of the American Dental Association (Journal of Dental Research 55 (4) page 563-573, 1976). This involves irradiating extracted human teeth with a neutron flux and performing standard brushing. Radioactive phosphorus-32 removed from the dentin in the tooth root is used as an indicator of the abrasion of the tested powder or oral composition. 50 cm³ of a 0.5% aqueous solution of sodium carboxymethylcellulose was used. 3 A reference slurry containing 10 g of calcium pyrophosphate was defined as RDA 100. A slurry sample containing abrasive silica particles according to the present invention was prepared at the same weight % concentration as the calcium pyrophosphate in the reference slurry. A slurry sample containing toothpaste according to the present invention was prepared by mixing 25 g of toothpaste with 40 cm³ of water. 3 A slurry with the required concentration was prepared by mixing the ingredients. The RDA test was conducted at the Institute of Oral Health, Indiana University School of Dentistry, USA. The RDA of a comparative toothpaste prepared using the above method was determined using the same method.

[0151] Ferric tannate (FT) cleaning test The ferric tannate cleaning test was performed according to the method described in "Dental stain prevention by abrasive toothpastes: A new in vitro test and its correlation with clinical observations", PL Dawson et al., J. Cosmet. Sci., 49, 275-283 (1998). The test substrate was a pure hydroxyapatite (HAP) disc, which was polished using a Buehler rotary grinder and P600 wet paper, followed by P1200 lapping paper. The whiteness of the disc before cleaning (using the CIE 1976 L*a*b* system) L* (clean) was then measured using a Minolta Chroma-meter CR200 calibrated against a standard calibration tile. The substrate was repeatedly stained with a staining solution (50 g of 0.5 wt% tannic acid solution and 50 g of 0.5 wt% ammonium ferric sulfate solution to form a fresh colloidal iron(III) tannate complex ("ferric tannate")) using a Minolta Chroma-meter CR200 until the darkness measurement L* reached 50 ± 5. This value was defined as L* (stained). The stained substrate was placed in a container with the sample FT slurry, and a Mentadent® P Professional soft nylon flat trim toothbrush head (weight 263 g) was vibrated (150 cycles / min) on the surface of the stained substrate using a mechanical scrubbing machine (modified Martindale Mk111 abrasion tester). Stain removal after desired vibration frequencies (e.g., 50, 100, 150, 300) was measured using a Minolta Chroma-meter CR200, and the FT value was determined. XX The results of the removal test were matched (where XX is the desired vibration frequency). The whiteness of the substrate after cleaning at the desired vibration frequency is defined as L* (cleaned). The comparative polishing performance is defined as the percentage of material cleaned or removed after XX vibrations (e.g., 100 vibrations).

[0152] For example, FT 100is %FT 100 Defined as removal: %FT 100 Removal = (L * (Cleaned) - L * (Stained)) / (L * (Cleaned) - L * (Stained)) × 100

[0153] A sample FT slurry (containing abrasive silica particles or toothpaste according to the present invention) was prepared as follows.

[0154] Preparation of FT slurry containing toothpaste preparations - 25 g of toothpaste prepared according to the above method (containing 20% ​​by weight of abrasive silica particles according to the present invention) was combined with 50 g of desalinated water, and the resulting mixture was mixed to provide a homogeneous slurry. A comparative FT slurry containing a comparative toothpaste prepared according to the above method was prepared using the same method.

[0155] Preparation of FT slurry containing abrasive silica particles - Abrasive silica particles were added to diluents (0.35 wt% xanthan gum, 0.5 wt% sodium lauryl sulfate, 99.15 wt% demineralized water) and mixed to obtain a homogeneous mixture. The weight % of abrasive silica particles was 3.3 wt% of the final total weight of the slurry. While 3.3 wt% was used in the example described herein, those skilled in the art will understand that other weight % loading rates may be preferable. Using the same method, comparative FT slurries were prepared containing only single silica particles (i.e., single silica corresponding to one of the particles contained in the abrasive silica particles according to the present invention [i.e., the first, second, or third abrasive silica particles]).

[0156] Pellicle Cleaning Ratio (PCR) The pellicle cleaning rate (PCR) method is known to those skilled in the art. For example, a preferred method is described in J. Dent. Res., 61:1236, 1982. Enamel surfaces (10 mm × 10 mm) cleaned according to the above method were stained with a solution containing PYG (peptone yeast glucose) broth, tea, coffee, mucin, FeCl3, and Micrococcus luteus until a uniform staining film was obtained on the enamel surface. The stain film was photometrically evaluated using a spectrophotometer (Minolta CM2600d), and stained enamel surfaces with a stain film score of 30-42 were selected for PCR testing.

[0157] A reference slurry was prepared by mixing 10 g of Ca2P2O7 with 50 mL of a glycerin aqueous solution (10 wt%) containing 0.5% carboxymethylcellulose (CMC) (density: 1.03 g / L). Each slurry sample to be tested was mounted on a mechanical V-8 cross-brushing machine equipped with a soft nylon filament (Oral-B 40) toothbrush. The enamel surface tension was adjusted to 150 g. The test specimens were brushed for 800 strokes (approximately 4.5 minutes), which is a typical number of strokes for PCR. Slurry samples were also brushed for specified modified brush stroke counts (mPCR) (e.g., 60, 120, 360, 1200). The specified brush stroke counts (e.g., 60, 120, 360, 800, 1200) represent the number of brush strokes before scoring. After each slurry sample was stroked 60 times, it was removed, scored, and then replaced. Scoring involved measuring the difference between the pre-brushing staining score and the post-brushing staining score before and after 60 brushing strokes. Then, another 60 strokes were performed, for a total of 120 strokes. After this, the slurry sample was removed, scored in the same manner, and replaced. This method was continued until the cumulative number of strokes reached 1200, after which the sample was removed and scored for the final time. The results are shown in Table 5 below.

[0158] A slurry sample containing abrasive silica particles was prepared by mixing 10 g of abrasive silica particles with 50 mL of a glycerin (10 wt%) aqueous solution containing 0.5 wt% CMC (density: 1.03 g / L) to obtain a slurry. Using the same method, a comparative slurry sample was prepared containing only a single silica particle (i.e., a single silica corresponding to one of the particles contained in the abrasive silica particles according to the present invention [i.e., the first, second, or third abrasive silica particle]).

[0159] A slurry sample containing a toothpaste with abrasive silica particles according to the present invention was prepared by mixing 25 g of toothpaste with 40 mL of deionized water (1.00 g / mL) to provide a toothpaste slurry. A comparative slurry sample containing a comparative toothpaste prepared according to the method outlined above was prepared using the same method.

[0160] example Table 1 below describes the abrasive silica particles A1, A2, A3, B1, B2, B3, and B4 used in this example. Silica A1, A2, and A3 were used as the first "bulk" abrasive silica, respectively. Silica A1 and Silica A2 are commercially available from PQ Silicas UK Limited as SORBOSIL® AC39. Silica A3 is commercially available from PQ Silicas UK Limited as SORBOSIL® AC36. Other suitable commercially available first "bulk" abrasive silicas that can be used in accordance with the present invention include Tixosil® 123 from Solvay, Zeodent® 113 and Zeodent® 116 from Evonik, and Sylodent® VP5 from Grace.

[0161] Silica B1, B2, B3, and B4 were used as particles for the second abrasive silica (optionally a third abrasive silica). Silica B1 was prepared according to the methodology of Example 1D of European Patent No. 1976482. Silica B2 was prepared according to the methodology of Example 1C of European Patent No. 1976482. Silica B3 was prepared according to Example 1E of European Patent No. 1976482. Silica B4 was prepared according to Example 6 of European Patent No. 0535943. The water content (H2O [wt%]) of the particles of abrasive silica A1, A2, A3, B1, B2, B3, and B4 was calculated based on the weight loss after heating in an oven at 105°C for 2 hours.

[0162] [Table 3]

[0163] Polishable silica particles were prepared according to the method outlined above, and Examples 1 to 31 (Table 2) of polishable silica particles are provided. Examples 4R, 10R, 11R, 16R, 20R, 21R, 22R, 23R, 24R, and 29R are reference examples. Example 21R is provided as a reference example containing two “first” polishable silicas, A1 and A3. Example 25 contains a third polishable silica. The notation “nd” means “undetermined”.

[0164] [Table 4] TIFF0007927719000005.tif94170

[0165] Cleaning performance - Abrasive silica microparticles Ferric tannate (FT) cleaning test Table 3 provides data from FT cleaning tests performed on each of the abrasive silicas A1, A2, A3, B1, B2, B3, and B4, as well as on each of the abrasive silica particle examples 1 to 31. The FT cleaning tests were performed for 100 strokes according to the method described above (Table 3). The change in cleaning performance of each example relative to the first "bulk" abrasive silica (A1, A2, A3) is provided as "% increase relative to the first silica". The cleaning performance of each example relative to a reference example containing 20 wt% of the second abrasive silica is provided as "% cleaning performance relative to a 20 wt% loading rate". From these data, it became clear that by combining specific silicas with specific properties, the amount of the second abrasive silica contained in the abrasive silica particles can be significantly reduced without impairing cleaning performance.

[0166] [Table 5]

[0167] These data demonstrate that examples of the present invention can exhibit excellent cleaning performance similar to the reference example containing 20% ​​by weight of the second silica, even when the amount of the second silica is reduced to one-tenth. Examples 17-19 (B2+A1) provided 90%-99% of the cleaning performance of reference example 20R containing 20% ​​by weight of the second abrasive silica, despite having up to one-tenth the amount of the second silica component, and were found to have significantly reduced wear. Similarly, Examples 26-28 (B3 in A3) were found to have 85%-98% of the cleaning performance of reference example 29R containing 20% ​​by weight of the second abrasive silica. Similar results were observed for Examples 13-15 compared to reference example 16R, Examples 5-9 compared to reference example 12R, and Reference Examples 1-3 compared to reference example 4R.

[0168] These data also demonstrate that examples of the present invention provide significantly improved cleaning performance compared to the first abrasive silica alone, using relatively small amounts of the second silica (less than 10% by weight, e.g., 2%, 3%, 4%, 5%, or 7%). Examples 17-19 (including 2%, 3%, and 4% by weight of B2, respectively) show the cleaning performance (FT) compared to the first abrasive silica (A1 alone). 100 The improvement in ) was found to be 84% to 99%, which was similar to the improvement provided by Reference Example 20R (20 wt% B2; 99.5%). Similarly, Examples 27 and 28 showed an improvement in cleaning performance of 25% to 28% compared to the first abrasive silica, which was similar to the improvement provided by Reference Example 29R (20 wt% second silica, 29.7%). Similar results were observed for Examples 13 to 15 compared to Reference Example 16R, Examples 5 to 9 compared to Reference Example 12R, and Reference Examples 1 to 3 compared to Reference Example 4R.

[0169] These data further demonstrate that by controlling the particle size of the second silica relative to the first silica, excellent cleaning is possible with a relatively small amount of the second silica. Reference Examples 23R and 24R deviate from the claimed invention because the relative particle sizes of the first and second silica are not in accordance with the present invention. These data show that, unlike the abrasive silica of the present invention, the improvement in cleaning performance when 20% by weight of the second silica is supported is not maintained when the amount of second silica supported decreases. Comparing Example 23R (4% by weight of B4) and Example 24R (20% by weight of B4), the improvement in cleaning performance compared to the first silica (A1 alone) is 24.5% for Example 24R, compared to only 7.7% for Example 23R. Therefore, even when 4% by weight of B4 is supplied, the cleaning performance only increases slightly (7.7%, Example 23R) compared to the improvement with 20% by weight of B4 (24.5%, Example 24R). These data support the need to carefully control the relative properties of the first and second silica layers in order to achieve good cleaning performance.

[0170] Example 25 is provided to show that good cleaning performance can also be achieved (86% relative to the first silica A2 alone) when the second silica (B2) and the third silica (B3) are provided in a total amount of 4% by weight relative to the total weight of the abrasive silica particles.

[0171] Figure 1 is a diagram showing the performance of the FT cleaning test (100) of Examples 1 to 31. Examples of abrasive silica particles having a specific combination of a first "bulk" abrasive silica and a second abrasive silica provide good cleaning properties even when the amount of the second abrasive silica (B1, B2, B3, B4) is very small, as described above.

[0172] Cleaning performance versus abrasiveness FT of Examples 1 to 31 versus PAV for each example 100 are shown in Table 4 below (FT 100 / PAV; cleaning-to-abrasiveness ratio). Further, FT of abrasive silicas A1 to A3 and B1 to B4 100 / PAV are also provided. FT 100 / PAV data are shown in Figure 2.

[0173] As mentioned above, it is considered desirable to provide abrasive silica particles that have good cleaning properties but are not so abrasive as to cause undesirable damage to tooth surfaces. Accordingly, it is desirable to provide abrasive silica particles that exhibit excellent cleaning performance (high FT 100 ) while exhibiting low abrasiveness (e.g., low PAV). In other words, a higher FT 100 / PAV ratio is more desirable than a lower one.

[0174]

Table 6

[0175] Referring to Table 4 and Figure 2, Examples 1 to 3 (2% by weight, 3% by weight and 4% by weight of B1 in A1, respectively) exhibit higher FT than Reference Example 4R (20% by weight of B1 in A1)100 / PAV. Examples 6 to 9 (each containing 3% by weight, 5% by weight, 7% by weight, and 10% by weight of B1 in A2, respectively) have a higher FT than Reference Example 12R (containing 20% by weight of B1 in A1) 100 / PAV. Examples 13 to 15 (each containing 2% by weight, 3% by weight, and 4% by weight of B3 in A1, respectively) have a higher FT than Reference Example 16R (containing 20% by weight of B3 in A1) 100 / PAV. In particular, the FT of Example 13 (containing 2% by weight of B3 in A1) 100 / PAV is approximately three times greater than that of Example 16R, and the FT of Examples 14 and 15 (containing 3% by weight and 4% by weight of B3 in A1, respectively) 100 / PAV is approximately two times greater than that of Example 16R. Examples 17 to 19 (containing 2% by weight, 3% by weight, and 4% by weight of B2 in A1, respectively) have a higher FT than Example 20R 100 / PAV. In particular, the FT of Example 17 100 / PAV is approximately two times greater than that of Example 20R. Examples 26 to 28 (containing 2% by weight, 3% by weight, and 4% by weight of B3 in A3, respectively) have a higher FT than Example 29R 100 / PAV. In particular, the FT of Example 26 100 / PAV is approximately four times greater than that of Example 29R, and the FT of Examples 26 to 28 100 / PAV is approximately two times greater than that of Example 29R.

[0176] All of these data surprisingly show that, in general, the examples exemplified herein according to the present invention provide more cleaning with less abrasion (indicated by a lower PAV), as compared to examples containing a conventional amount of a second silica (i.e., about 20% by weight). In other words, it has become clear from the data that a relatively good cleaning performance to abrasion ratio for these examples is generally provided when the amount of the second abrasive silica in the abrasive silica particles according to the present invention is less than 10%.

[0177] PCR The cleaning performance of each of Example 1 and Example 3 (containing 2% by weight and 4% by weight of B1, respectively, in first abrasive silica A1) was evaluated using the PCR method outlined above. Similarly, the cleaning performance of Example 30 (containing 4% by weight of B1 in A3) in first abrasive silica A3 was also compared. The results are shown in Table 5 below.

[0178] [Table 7]

[0179] Sample slurries containing abrasive silica particles with 2% by weight and 4% by weight of the second abrasive silica B1 (Examples 1 and 3, respectively) showed improved cleaning performance compared to the first "bulk" abrasive silica A1. Surprisingly, the improvement in cleaning was greatest at low brush strokes (e.g., 60, 120, 360), and the improvement in cleaning performance was found to be more than twice that of A1 alone (see, e.g., mPCR60 in Example 3). Similarly, Example 30 (containing 4% by weight of B1 in A3) showed improved cleaning performance compared to the first "bulk" abrasive silica A3 at all brush strokes investigated. Likewise, the improvement in cleaning for Example 30 appeared to be more pronounced (i.e., greater) at low brush strokes (e.g., 60, 120, 360) compared to sample A3 alone, compared to high brush strokes (e.g., 800, 1200).

[0180] Cleaning performance - Toothpaste containing abrasive silica particles PCR Furthermore, the PCR cleaning performance of toothpastes P1, P2, P3, and P4 containing abrasive silica particles was also investigated. Toothpastes P1 to P4, shown in Table 6, were prepared according to the method described above. The results are shown in Table 6.

[0181] [Table 8]

[0182] As can be seen from Table 6, toothpastes P2 and P4 were found to have improved cleaning properties (higher mPCR values) compared to toothpastes P1 and P3, which contain only the first "bulk" abrasive silica. The greatest improvement in cleaning performance compared to the first "bulk" abrasive silica was observed with low brush strokes (e.g., the mPCR60 of P2 was 12 greater than the mPCR60 of P1). These data again demonstrate that abrasive silica particles containing certain combinations of abrasive silica with less than 10 wt% of the second abrasive silica provide good cleaning properties with low brush strokes.

[0183] FT Furthermore, the cleaning performance of each toothpaste (P1, P2, P3, and P4) was evaluated using the FT cleaning test outlined above. The results are shown in Table 7.

[0184] [Table 9]

[0185] As can be seen from Table 7, P2 demonstrated more than twice the cleaning performance of P1 at 100 strokes, and nearly twice the cleaning performance of P1 at 300 strokes. This improvement was not as pronounced in P4 compared to P3, but a significant improvement in cleaning was still observed, especially at 100 brush strokes. This data also suggests that the improvement in cleaning performance by abrasive silica particles according to the present invention is most pronounced at low brush strokes.

[0186] Relative properties - Abrasive silica particles Tables 8 and 9 compare some of the properties of the first abrasive silica A1-A3 and the second abrasive (and optionally third abrasive) silica B1-B4. Combinations that provide abrasive silica particles according to the present invention are shown in bold.

[0187] [Table 10]

[0188] [Table 11]

[0189] While the present invention has been described in detail, it should be understood that various changes, substitutions, and modifications are intended without departing from the principles and scope of the invention. Therefore, the scope of the invention as defined herein and in particular in the appended claims should be interpreted with appropriate equivalents in mind. “a,” “an,” and “the” do not exclude the presence of multiple references unless explicitly indicated by the context. Any or optional feature or activity may or may not be present; one or the other is intended. In embodiments, any(s) features may be present; alternatively, any(s) features may not be present. In this specification, ranges may be expressed as “from” a particular value and / or “to” another particular value, intended to include the endpoints of the range.

Claims

1. Abrasive silica particles suitable for use in toothpaste compositions, wherein the particles are A first abrasive silica particle in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, A second abrasive silica particle in an amount of up to 7% by weight relative to the total weight of the abrasive silica particles, Includes, The weight median particle size (d) of the second abrasive silica particles. ５０ ) is the weight median particle size (d) of the first abrasive silica particles. ５０ ) is smaller than the d of the first abrasive silica particles. ５０ The value is between 15% and 70%, and The first silica particles have an RDA value that is 10% to 70% of the relative dentin abrasion (RDA) value of the second silica particles. The first silica particles have an RDA value of 30 to 120, and The second silica particles have an RDA value of 120 to 300. Abrasive silica particles.

2. The abrasive silica particles according to claim 1, wherein the oil absorption value of the second abrasive silica particles is 30% to 70% of the oil absorption value of the first abrasive silica particles.

3. The weight median particle size (d) of the second silica particle ５０ ) is the d of the first silica particle. ５０ 15% to 65% of the first silica particles, optionally d ５０ Abrasive silica particles according to claim 1 or claim 2, wherein the value is 15% to 55%.

4. Abrasive silica particles according to claim 1 or 2, wherein the first silica particles have an RDA value that is 10% to 50% of the relative dentin abrasion (RDA) value of the second silica particles, for example, 15% to 40%.

5. The abrasive silica particles according to claim 1 or 2, wherein the second silica particles have an RDA value of 150 to 180.

6. The abrasive silica particles according to claim 1 or 2, wherein the second silica particles are present in an amount of 1% to 7% by weight, and optionally 2% to 7% by weight, relative to the total weight of the abrasive silica particles.

7. The polishable silica particles according to claim 1 or 2, wherein the first polishable silica is amorphous precipitated silica, and / or the second polishable silica is amorphous precipitated silica.

8. The first silica particle d ５０ Abrasive silica particles according to claim 1 or 2, wherein the particle size is 15 μm or less, optionally 5 μm to 15 μm, optionally 7 μm to 14 μm, and optionally 8 μm to 13 μm.

9. The first silica particles have a d of 35 µm or less, optionally 25 µm to 35 µm ９０ value, and 90% by weight of the particles contained in the first silica particles have a d ９０ The abrasive silica particles according to claim 1 or 2, having a diameter smaller than the value.

10. The d of the second silica particle ５０ Abrasive silica particles according to claim 1 or 2, wherein the particle size is 9 μm or less, optionally 1 μm to 9 μm, optionally 2 μm to 8 μm, and optionally 2 μm to 6 μm.

11. The second silica particles are 25 μm or less, optionally 20 μm or less, optionally 3 μm to 25 μm, and optionally 3 μm to 20 μm. ９０ The value is such that 90% by weight of the particles contained in the second silica particles is d ９０ Abrasive silica particles according to claim 1 or 2, having a diameter smaller than the value.

12. The first silica particles are d ５０ The value, and d from 25 μm to 35 μm ９０ The value is such that 90% by weight of the particles contained in the first silica is d ９０ Having a diameter smaller than the value, The second silica particles are d, which are 2 μm to 6 μm in size. ５０ The value, and d from 3 μm to 25 μm ９０ Abrasive silica particles according to claim 11, having a value.

13. The abrasive silica particles according to claim 1 or 2, wherein the second silica particles have an oil absorption value of 120 g / 100 g or less, and optionally 85 g / 100 g or less.

14. The abrasive silica particles according to claim 1 or 2, wherein the first abrasive silica particles have an oil absorption value of 150 g / 100 g or less.

15. Abrasive silica particles according to claim 1 or 2, wherein the first silica particles have a plastic abrasion value (PAV) of 2 to 8, and the PAV of the first silica particles is smaller than the PAV of the second silica particles.

16. Abrasive silica particles according to claim 1 or 2, wherein the second silica particles have a plastic abrasion value (PAV) of 7 to 50, and the PAV of the second silica particles is greater than the PAV of the first silica particles.

17. The abrasive particles further comprise third abrasive silica particles, wherein the weight median particle size (d) of the third silica particles ５０ ) is the d of the first silica particle. ５０ Smaller than the d of the first silica particle ５０ The abrasive silica particles according to claim 1, wherein the amount is 15% to 70%, and the total weight of the second silica particles and the third silica particles does not exceed 7% by weight of the total weight of the abrasive silica particles.

18. Abrasive silica particles according to claim 1 or 2, substantially comprising only the first silica particles and the second silica particles.

19. The abrasive silica particles according to claim 1 or 2, wherein the oil absorption value of the abrasive silica particles is 150 g / 100 g or less.

20. The abrasive silica particles according to claim 1 or 2, wherein the abrasive silica particles have an RDA of 150 or less, optionally 120 or less, optionally 100 or less, and / or the abrasive silica particles have an RDA of 30 or more.

21. The abrasive silica particles have an FT of 40 to 100, optionally 50 to 95, and optionally even more than 60 to 95. １００ Abrasive silica particles according to claim 1 or 2, having a cleaning value.

22. A composition for use in toothpaste, comprising the abrasive silica particles described in claim 1 and optionally a carrier.

23. The composition according to claim 22, further comprising silica particles not described in claim 1 or 2, wherein the silica particles are optionally a thickening agent.

24. The composition according to claim 22, further comprising one or more surfactants.

25. A toothpaste comprising abrasive silica particles according to claim 1 or 2, or the composition according to claim 22.

26. The toothpaste according to claim 25, wherein the toothpaste is a paste.

27. The toothpaste according to claim 26, comprising 0.1% to 50% by weight of abrasive silica particles according to claim 1 or 2 or the composition according to claim 22 or 24, and optionally comprising 1% to 30% by weight of abrasive silica according to claim 1 or 2 or the composition according to claim 22 or 24.

28. A method for producing abrasive silica particles used in toothpaste compositions, The present invention provides polishable silica particles by combining first polishable silica particles and second polishable silica particles. The first abrasive silica particles are present in an amount of at least 90% by weight relative to the total weight of the abrasive silica particles, and the second abrasive silica particles are present in an amount of up to 7% by weight relative to the total weight of the abrasive silica particles, and The weight median particle size (d) of the second abrasive silica. ５０ ) is smaller than the first abrasive silica, and the d of the first silica particles ５０ The value is between 15% and 70%, and The first silica particles have an RDA value that is 10% to 70% of the relative dentin abrasion (RDA) value of the second silica particles. The first silica particles have an RDA value of 30 to 120, and The second silica particles have an RDA value of 120 to 300. method.

29. The aforementioned combining step includes combining the first abrasive silica particles, the second abrasive silica particles, and the third abrasive silica particles to provide the abrasive silica particles, Weight median particle size d of the third abrasive silica particle ５０ However, it is smaller than the first abrasive silica particles, and the weight median particle diameter d of the first abrasive silica particles ５０ The method according to claim 28, wherein the amount is 15% to 70%, and the total weight of the second abrasive silica particles and the third abrasive silica particles does not exceed 7% by weight of the total weight of the abrasive silica particles.

30. The method according to claim 28 or 29, wherein the combining comprises mixing the abrasive silica particles, and optionally, the mixing provides a homogeneous mixture of the abrasive silica particles.

31. The method according to claim 28 or 29, wherein the method is a method for preparing abrasive silica particles according to claim 1 or 2.

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