PREPARATION METHOD OF HEAT-NOT-BURN CIGARETTE PAPER WITH BORON NITRIDE AS THERMALLY-CONDUCTIVE FILLER

Abstract

Clean version of the Abstract A preparation method of a heat-not-burn cigarette paper with boron nitride as a thermally-conductive filler incl tides: mixing po .ssiuxr oleate, polyvinyl alcohol (PVA) and water, thoroughly stirring under an ultrasonic condition, aging, and filtering until there is no precipitate; thoroughly mixing a resulting mixed solution with a softwood pulp and a hardwood. pulp to obtain a coarse pulp; and under stirring, adding boron nitride and calcium carbonate as a filler to the coarse pulp, heating to 60° C., and stirring for thorough mixing to obtain a pulp for sizing and papermaking. The present disclosure effectively improves the stability of a cigarette paper by improving a coefficient of thermal conductivity of the paper. Boron nitride, when used as a thermally-conductive filler in a thin-walled or paper product, enables high heat removal capacity. The preparation method retains the original whiteness and transparency of the cigarette paper, and provides high conductivity.

Claims

1. A preparation method of a heat-not-burn cigarette paper with boron nitride as a thermally-conductive filler, comprising a conventional cigarette paper making process of pulp preparation, sizing and papermaking, pre-drying, surface coating, post-drying, and calendering to obtain a paper, wherein the pulp preparation specifically comprises: (1) preparation of a coarse pulp mixing 0.05 to 0.1 part by weight of potassium oleate, 0.1 to 0.2 part by weight of polyvinyl alcohol (PVA), and 5 parts by weight of water to obtain a first mixed solution, thoroughly stirring the first mixed solution for 30 min under an ultrasonic condition, aging the first mixed solution for 2 hours, and filtering the first mixed solution until there is no precipitate; and thoroughly mixing the first mixed solution with 15 to 25 parts by weight of a softwood pulp and 50 to 70 parts by weight of a hardwood pulp to obtain the coarse pulp; (2) milling with a filler under stirring, adding 1 to 15 parts by weight of boron nitride and 20 to 50 parts by weight of calcium carbonate as a filler to the coarse pulp to obtain a second mixed solution, heating the second mixed solution to 60° C., and stirring the second mixed solution for thorough mixing to obtain a pulp for the sizing and papermaking.

2. The method according to claim 1, wherein the surface coating refers to coating 1 to 3 parts by weight of polyacrylamide (PAM) as an additive on a surface of a cigarette paper by roller coating using a coating machine.

3. The method according to claim 1, wherein the PVA has a molecular weight ranging from 200 to 3000.

4. The method according to claim 1, wherein the boron nitride is particles having an average particle size of 12 μm to 16 μm.

5. A pulp comprising boron nitride as a thermally-conductive filler for preparing a heat-not-burn cigarette paper, wherein a raw material formula of the pulp comprises the following components in parts by weight: 0.05 to 0.1 part of potassium oleate, 0.1 to 0.2 part of PVA, 5 parts of water, 15 to 2.5 parts of a softwood pulp, 50 to 70 parts of a hardwood pulp, 1 to 15 parts of boron nitride, and 20 to 50 parts of calcium carbonate.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The present disclosure will be further described in detail below in conjunction with specific examples. The examples enable those skilled in the art to understand the present disclosure more comprehensively, but do not limit the present disclosure in any way.

[0028] A preparation method of a heat-not-burn. cigarette paper with boron nitride as a thermally-conductive filler is provided, including the following steps: [0029] (1) preparation of a coarse pulp

[0030] 0.05 to 0.1 part by weight of potassium oleate, 0.1 to 0.2 part by weight of PVA., and 5 parts by weight of water are mixed, thoroughly stirred for 30 min under an ultrasonic condition, aged for 2 hours, and filtered until there is no precipitate; and a resulting mixed solution is thoroughly, mixed with 15 to 25 parts by weight of a softwood pulp and 50 to 70 parts by weight of a hardwood pulp to obtain the coarse pulp; [0031] (2) milling with a filler

[0032] under stirring, 1 to 15 parts by weight of boron nitride and 20 to 50 parts by weight of calcium carbonate are added as a filler to the coarse pulp, and a resulting mixture is heated to 60° C. and stirred for thorough mixing to obtain a pulp for sizing and papermaking; [0033] (3) sizing and papermaking; [0034] (4) pre-drying; [0035] (5) surface coating;

[0036] 1 to 3 parts by weight of PAM are added as a surface coating additive in a coating machine; [0037] (6) post-drying; and [0038] (7) calendering to obtain a paper.

[0039] The above steps (3) to (4) and (6) to (7) can be conducted according to methods and parameters of the conventional cigarette paper making process, which are not particularly limit :d in the present disclosure.

[0040] Relevant data of Examples 1 to 3 are shown in Table 1 (data in the table indicate the parts by weight of a corresponding component):

TABLE-US-00001 TABLE 1 Example No. 1 2 3 Step (1): preparation of a coarse pulp Potassium oleate 0.08 0.05 0.10 PVA 0.10 0.15 0.20 Water 5 5 5 Softwood pulp 22 25 15 Hardwood pulp 50 60 70 Step (2): milling with a filler Boron nitride particles 1 8 15 Calcium carbonate filler 50 32 20 Step (6): surface coating PAM 1 2 3

[0041] Technical effect verification

[0042] The heat-not-burn cigarette paper was baked at 300° C. for 5 min in a box-type resistance furnace, during which the degree of discoloration was observed.

TABLE-US-00002 TABLE 2 Example 1 Example 2 Example 3 Control group Test results of The original The The The cigarette cigarette paper color is original original paper is baked in basically color is color is yellowed and resistance retained, basically retained. brown spots furnace and the retained. start to cigarette appear locally. paper is only slightly yellow. Thermal 0.55 0.76 0.94 0.33 conductivity (W/m .Math. K)

[0043] A cigarette paper processing technology of the control group is different from that of Example 1 only in that no boron nitride particles are added.

[0044] The present disclosure has been described in detail herein and specific embodiments of the present disclosure are illustrated through examples in the example section. Various modifications and replacements can also be made to the present disclosure. However, it should be understood that the present disclosure is not limited to the specific forms disclosed herein. On the contrary, the present disclosure covers all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.