Patent Description:
Nicotine in e-liquid for electronic cigarettes generally has three forms: a free-base form, a singly protonated form, and a doubly protonated form. The absorption rates of different forms of nicotine at different positions of the respiratory system differ from each other, affecting the satisfaction of users when vaping electronic cigarettes. A lower degree of protonation of nicotine indicates a higher level of satisfaction.

The absorption rate of nicotine is slow in the mouth and the upper airway, and fast in the lung, which may reach <NUM>% to <NUM>%. Due to characteristics of the human body biofilm, nicotine in the protonated forms cannot enter blood through the biofilm in the lung, but nicotine in the free-base form can quickly pass through the biofilm. In addition, the buffer in the lung of a human body is slightly basic (PH=<NUM>), and a certain proportion of nicotine deposited in the lung will enter the blood in the singly protonated form and the free-base form.

In the related art, e-liquids including nicotine salts with a lower degree of protonation has been prepared, and the e-liquids can provide a good user experience by formulating the components in the free-base form and the singly protonated form. However, the process for preparing the nicotine salts is relatively complex and has technological barriers. In addition, diversified requirements of different users can only be met by preparing e-liquids with different formulations.

Publication<CIT> discloses an inhalation device for delivering a deliverable agent in the form of an aerosol or vapor to a user. The device comprises a solid, porous carrier material having a defined porosity, and a deliverable agent located within the pores of the carrier material. The device is operable to heat the carrier material and vaporize the deliverable agent. Publication <CIT> discloses a smoking article that can provide an inhalable substance in a form suitable for inhalation by a consumer. The article comprises a cartridge with an inhalable substance medium therein, control housing that includes an electrical energy source and an electrical power source, and a heating member that may be located in either the cartridge or the control housing. The control housing further may include puff-actuated current actuation components and current regulation components. <CIT> relates to chemically bonded ceramic precursor material of aluminates and silicates exhibiting a controlled release rate and properties that make the material suitable as a carrier material used in drug delivery. Publications <CIT>, <CIT> and <CIT> also contain information that are relevant to the present application.

A technical problem to be solved by the present invention is to provide an improved ceramic vaporization core, and further provide a method for fabricating the improved ceramic vaporization core and a vaporizer.

A technical solution adopted by the present invention to solve the technical problem is to construct a ceramic vaporization core, including a porous body and a heating body disposed on the porous body, wherein the porous body includes at least one porous ceramic layer doped with hydroxyl group-containing matrix.

The at least one porous ceramic layer doped with hydroxyl group-containing matrix includes components in parts by weight as follows: <NUM> to <NUM> parts by the weight of ceramic powder doped with hydroxyl group compound and <NUM> to <NUM> parts by the weight of pore-forming agent.

The ceramic powder doped with hydroxyl group compound includes components in parts by weight as follows: <NUM> to <NUM> parts by the weight of main blank material, <NUM> to <NUM> parts by the weight of albite, <NUM> to <NUM> parts by the weight of fat clay, and <NUM> to <NUM> parts by the weight of hydroxyapatite.

Preferably, the main blank material includes one or more of: aluminum oxide, silicon oxide, silicon carbide, cordierite, silicon nitride, aluminum nitride, and mullite; and/or
the pore-forming agent includes at least one of: starch, graphite, polystyrene microspheres, and polymethyl methacrylate microspheres.

Preferably, the porous body further includes at least one microporous ceramic layer; the at least one porous ceramic layer doped with hydroxyl group-containing matrix and the at least one microporous ceramic layer are sequentially disposed in the flow direction of e-liquid; and
the pore size of the at least one microporous ceramic layer is less than the pore size of the at least one porous ceramic layer doped with hydroxyl group-containing matrix.

Preferably, a plurality of porous ceramic layers doped with hydroxyl group-containing matrix and a plurality of microporous ceramic layers are provided; and
the porous ceramic layers doped with hydroxyl group-containing matrix and the microporous ceramic layers are sequentially and alternately disposed in the flow direction of e-liquid.

Preferably, the pore size d50 of the at least one microporous ceramic layer is <NUM> to <NUM>; and/or
the pore size d90 of the at least one porous ceramic layer doped with hydroxyl group-containing matrix is <NUM> to <NUM>.

Preferably, the porosity of the at least one porous ceramic layer doped with hydroxyl group-containing matrix is <NUM>% to <NUM>%; and/or
the porosity of the at least one microporous ceramic layer is <NUM>% to <NUM>%.

Preferably, the porous body includes a vaporization surface and a liquid absorbing surface opposite to the vaporization surface;.

The present invention further constructs a method for fabricating a ceramic vaporization core as defined in the precedent paragraphs, including:.

Preferably, before the preparing the first mixed powder into a first blank and sintering the first blank, the method further includes:.

Preferably, before the sintering, the method further includes: inserting a heating body into the side of the second blank that is away from the first blank.

The present invention further constructs a vaporizer, including the ceramic vaporization core according to the present invention.

The following beneficial effects are achieved by implementing the vaporizer, the ceramic vaporization core, and the method for fabricating the ceramic vaporization core of the present invention: The configuration of the at least one porous ceramic layer doped with hydroxyl group-containing matrix in the ceramic vaporization core allows hydrogen ions in nicotine in e-liquid that passes through the porous body and has not been vaporized to react with hydroxyl groups, to reduce the degree of protonation of nicotine in the e-liquid, thereby improving the absorption degree of nicotine in the lung and improving user experience.

The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:.

In order to provide a clearer understanding of the technical features, the objectives, and the effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

It should be understood that, terms such as "front", "rear", "left", "right", "upper", "lower", "first", and "second" are merely for ease of describing the technical solutions of the present invention rather than indicating that the mentioned apparatus or component needs to have a particular difference. Therefore, these terms should be not construed as a limitation to the present invention. It should be noted that, when a component is considered to be "connected to" another component, the component may be directly connected to the another component, or an intermediate component may also be present. Unless otherwise defined, meanings of all technical and scientific terms used in this specification are the same as that usually understood by a person skilled in the technical field to which the present invention belongs. In this specification, terms used in the specification of the present invention are merely intended to describe objectives of the specific embodiments, but are not intended to limit the present invention.

<FIG> shows some exemplary embodiments of a vaporizer of the present invention. The vaporizer may include a base <NUM>, a housing <NUM> sleeved on the base <NUM>, and a ceramic vaporization core <NUM> of the present invention. An upper part of the housing <NUM> may be formed with a liquid storage cavity to store e-liquid. The ceramic vaporization core may be disposed in the housing <NUM> and mounted on the base <NUM>. An electrode component may be disposed on the base <NUM> to connect a power supply device to the ceramic vaporization core <NUM>, to supply power to the ceramic vaporization core <NUM>.

As shown in <FIG>, the ceramic vaporization core <NUM> may include a porous body <NUM> and a heating body <NUM>. The porous body <NUM> may be used for liquid absorbing and liquid storage, and includes a vaporization surface and a liquid absorbing surface. The vaporization surface may be defined on the side away from the liquid storage cavity. The liquid absorbing surface may be opposite to the vaporization surface and may be located on the side close to the liquid storage cavity, and may be configured to absorb the e-liquid from the liquid storage cavity. The heating body <NUM> may be disposed on the porous body <NUM>. The heating body <NUM> may be disposed on the outer surface of the porous body <NUM>. Specifically, the heating body may be disposed on the vaporization surface and may form an integral structure with the porous body <NUM> through sintering. It may be understood that, the heating body <NUM> is not limited to being disposed on the vaporization surface, but may also be buried in the porous body <NUM>.

Further, in some embodiments, the porous body <NUM> may include a porous ceramic layer <NUM> doped with hydroxyl group-containing matrix and a microporous ceramic layer <NUM>. The porous ceramic layer <NUM> doped with hydroxyl group-containing matrix and the microporous ceramic layer <NUM> are sequentially disposed in the flow direction of the e-liquid. Specifically, the porous ceramic layer <NUM> doped with hydroxyl group-containing matrix is disposed on the side away from the vaporization surface, and the liquid absorbing surface may be defined on the side of the porous ceramic layer <NUM> facing away from the vaporization surface; and the microporous ceramic layer <NUM> is disposed on the side of the porous ceramic layer <NUM> doped with hydroxyl group-containing matrix facing away from the liquid absorbing surface, and the vaporization surface is defined on the side of the microporous ceramic layer facing away from the porous ceramic layer <NUM> doped with hydroxyl group-containing matrix. In some embodiments, the porous ceramic layer <NUM> doped with hydroxyl group-containing matrix may be used for reducing the degree of protonation of the e-liquid; and provides e-liquid guiding and storage function. A main function of the microporous ceramic layer <NUM> is to control the particle size of vaporized particles. It may be understood that, in some other embodiments, the number of the porous ceramic layers <NUM> doped with hydroxyl group-containing matrix and the number of the microporous ceramic layers <NUM> are not limited to one, and may be more than one. When the porous body <NUM> includes a plurality of porous ceramic layers <NUM> doped with hydroxyl group-containing matrix and a plurality of microporous ceramic layers <NUM>, the porous ceramic layers <NUM> doped with hydroxyl group-containing matrix and the microporous ceramic layer <NUM> may be sequentially and alternately disposed in the flow direction of the e-liquid.

Further, according to the invention, the porous ceramic layer <NUM> doped with hydroxyl group-containing matrix is formed by mixing and sintering <NUM> to <NUM> parts by the weight of ceramic powder doped with hydroxyl group compound and <NUM> to <NUM> parts by the weight of pore-forming agent. The ceramic powder doped with hydroxyl group compound includes <NUM> to <NUM> parts by the weight of main blank material, <NUM> to <NUM> parts by the weight of albite, <NUM> to <NUM> parts by the weight of fat clay, and <NUM> to <NUM> parts by the weight of hydroxyapatite. Specifically, in some embodiments, the main blank material may be aluminum oxide. It may be understood that, in some other embodiments, the main blank material may be not limited to aluminum oxide, and may be one or more of aluminum oxide, silicon oxide, silicon carbide, cordierite, silicon nitride, aluminum nitride, and mullite. The main blank material may be used for forming a blank. The albite may be used as an auxiliary ingredient to reduce drying shrinkage and deformation of the blank, improve the drying performance, and shorten the drying time, and may be used as a flux to be filled in the blank during sintering, to compact the blank to reduce pores and improve the light transmittance of the blank. The fat clay may be used for enhancing a bonding force of the main blank material. The hydroxyapatite may be used for reducing the degree of protonation of nicotine. A reaction mechanism of the hydroxyapatite with acid is: Ca<NUM>(PO<NUM>)<NUM>(OH)<NUM>+<NUM>+=3Ca<NUM>(PO<NUM>)<NUM>+Ca<NUM>++<NUM><NUM>O. In some embodiments, the pore-forming agent may be selected from at least one of starch, graphite, polystyrene (PS) microspheres, and polymethyl methacrylate (PMMA) microspheres, and may be used for forming pores in the ceramic blank, to form the ceramic blank into the porous body <NUM>.

Further, in some embodiments, the porous ceramic layer <NUM> doped with hydroxyl group-containing matrix has a pore size d90 of <NUM> to <NUM> and a porosity of <NUM>% to <NUM>%, and may be configured for e-liquid guiding and storage and configured to reduce the degree of protonation of nicotine in the e-liquid before vaporization.

Further, in some embodiments, the microporous ceramic layer <NUM> may be made of common ceramic material, and the pore size of the microporous ceramic layer <NUM> is less than the pore size of the porous ceramic layer <NUM> doped with hydroxyl group-containing matrix, so that the particle size of the vaporized particles can be controlled, and the proportion of vapor passing through the microporous ceramic layer <NUM> that can be absorbed by the lung can be adjusted. In some embodiments, the microporous ceramic layer <NUM> has a pore size d50 of <NUM> to <NUM> and a porosity of <NUM>% to <NUM>%.

Further, in some embodiments, the heating body <NUM> may be a metal sheet, which may be partially embedded in the porous body <NUM> and configured to generate heat when being electrified, to vaporize the e-liquid close to the vaporization surface of the porous body <NUM>. In some other embodiments, the heating body may be alternatively formed by sintering of conductive slurry screen-printed on the porous body.

A method for fabricating the ceramic vaporization core includes the following steps:
<NUM> to <NUM> parts by the weight of main blank material, <NUM> to <NUM> parts by the weight of albite, <NUM> to <NUM> parts by the weight of fat clay, and <NUM> to <NUM> parts by the weight of hydroxyapatite are mixed to form ceramic powder doped with hydroxyl group compound.

The main blank material is selected from one or more of aluminum oxide, silicon oxide, silicon carbide, cordierite, silicon nitride, aluminum nitride, and mullite. Specifically, the main blank material may be aluminum oxide.

<NUM> to <NUM> parts by the weight of the ceramic powder doped with hydroxyl group compound and <NUM> to <NUM> parts by the weight of pore-forming agent are mixed to form first mixed powder.

The pore-forming agent can volatilize at a high temperature to form pores, and may be selected from at least one of starch, graphite, PS microspheres, and PMMA microspheres.

The first mixed powder is prepared into a first blank.

Specifically, the first mixed powder is prepared into the first blank through dry pressing, hot pressing, or gel casting.

Before the preparing the first mixed powder into a first blank and sintering the first blank, the method further includes:
mixing <NUM> to <NUM> parts by the weight of the main blank material, <NUM> to <NUM> parts by the weight of albite, and <NUM> to <NUM> parts by the weight of fat clay to form ceramic powder.

<NUM> to <NUM> parts by the weight of the ceramic powder and <NUM> to <NUM> parts by the weight of the pore-forming agent are mixed to form second mixed powder.

The second mixed powder is prepared into a second blank.

Specifically, the second mixed powder is prepared into the second blank through dry pressing, hot pressing, or gel casting.

The second blank is stacked with the first blank, to be sintered together with the first blank.

Before the sintering, the method further includes: inserting a heating body into the side of the second blank away from the first blank; and sintering the first blank.

Specifically, the first blank, the second blank, and the heating body form an integral structure through sintering.

Specific examples are described below (unless otherwise particularly stated, the following examples do not include other components that are not clearly pointed out except inevitable impurities):.

Ca<NUM>(PO<NUM>)<NUM>(OH)<NUM>+<NUM>+=3Ca<NUM>(PO<NUM>)<NUM>+Ca<NUM>++<NUM><NUM>O.

Nicotine may be present in the e-liquid in the following three forms:
<CHM>.

The relationship of conversion between the three forms of nicotine is as follows:
<CHM>.

A doubly protonated form NicH<NUM><NUM>+ is primarily ionized to generate one H+ and a singly protonated form NicH+. The singly protonated form NicH+ is then ionized to generate one H+ and a free-base form Nic, which is equivalent to a secondary ionization of the doubly protonated form NicH<NUM><NUM>+. Generally, the primary ionization is more likely to occur than the secondary ionization.

As can be known from <NUM> to <NUM>, after a nicotine-containing e-liquid passes through the ceramic vaporization core doped with hydroxyapatite, H+ generated from the ionization of a large part of the doubly protonated form NicH<NUM><NUM>+ and a small part of the singly protonated form NicH+ in the nicotine reacts with the hydroxyapatite to generate the singly protonated form NicH+ and the free-base nicotine.

Using a cartridge with a <NUM> e-liquid storage tank as an example, the content of nicotine in the nicotine-containing e-liquid is generally <NUM>/mL, <NUM>/mL, <NUM>/mL, <NUM>/mL, and <NUM>/mL. The following calculation is performed by using a cartridge with a <NUM> e-liquid storage tank having a nicotine content of <NUM>/mL:
nicotine content: <NUM>/mL*<NUM>=<NUM>.

The contents of nicotine in different forms may be directly reflected on the pH value of the e-liquid, as shown in <FIG>. The experimental data is as follows:.

As can be seen from <FIG>, when the pH value was <NUM>, the nicotine was present in the singly protonated form and free-base form, and the ratio of the singly protonated form to the free-base form was <NUM>:<NUM>; and when the pH value was <NUM>, the nicotine was present in the doubly protonated form and free-base form, and the ratio of the doubly protonated form to the free-base form was <NUM>:<NUM>. Calculation is performed below by using examples in which the pH values are <NUM> and <NUM> respectively.

To reduce the degree of protonation, i.e., to change the doubly protonated form to the singly protonated form, an amount of hydroxyapatite that needs to be added is:
<NUM> mmol*<NUM>*<NUM>/mmol=<NUM>.

After the e-liquid reacts with the hydroxyapatite, the nicotine is present in the singly protonated form and free-base form, and the ratio of the singly protonated form to the free-base form is <NUM>:<NUM>. When the pH value is <NUM>, the contents of the substances in the e-liquid are as follows:.

To reduce the degree of protonation, i.e., to change part of the nicotine in the singly protonated form to the free-base form, an amount of hydroxyapatite that needs to be added is:.

The variations in the pH after the e-liquid passed through the ceramic vaporization core doped with hydroxyapatite were measured using a pH meter. The data is as shown in the following table.

<FIG> shows experimental data of the absorption of an aerosol in different parts of a human body. As can be known from <FIG>, the alveoli mainly absorbed aerosol particles with a particle size of less than <NUM>.

Vapor passing through a porous ceramic was collected, and the particle size distribution of the vapor was tested. The results are as shown in the following table:.

As can be known from the data in the foregoing table, when d50 of the porous ceramic was less than <NUM>, <NUM>% of particles of vapor generated by the ceramic vaporization core had a particle size of not greater than <NUM>. As can be known from <NUM> and <NUM>, by controlling the pore size distribution of the porous ceramic vaporization core to make its d50 less than <NUM>, the particle size d50 of the vapor was not greater than <NUM>, and particles having such a particle size can easily enter the lung and can easily solidify to be transmitted to and deposited in the lung, thereby improving the absorption rate in the lung.

The foregoing two sets of experimental data show that the vaporization core prepared according to the embodiments of this application can reduce the degree of protonation of nicotine in the e-liquid, and can adjust the particle size distribution of the aerosol after vaporization, so that most particles have a particle size of less than <NUM>, and can easily solidify to be transmitted to and deposited in the lung, thereby improving the absorption rate in the lung.

Claim 1:
A ceramic vaporization core, comprising:
a porous body (<NUM>); and
a heating body (<NUM>) disposed on the porous body (<NUM>),
wherein the porous body (<NUM>) comprises at least one porous ceramic layer (<NUM>) doped with hydroxyl group-containing matrix;
characterized in that
the at least one porous ceramic layer (<NUM>) doped with hydroxyl group-containing matrix comprises components in parts by weight as follows:
<NUM> to <NUM> parts by the weight of ceramic powder doped with hydroxyl group compound; and
<NUM> to <NUM> parts by the weight of pore-forming agent; and
wherein the ceramic powder doped with hydroxyl group compound comprises components in parts by weight as follows:
<NUM> to <NUM> parts by the weight of main blank material;
<NUM> to <NUM> parts by the weight of albite;
<NUM> to <NUM> parts by the weight of fat clay; and
<NUM> to <NUM> parts by the weight of hydroxyapatite.