Smooth surface film-forming easy-to-erase chalk liquid, preparation method thereof and liquid chalk

Abstract

The present invention provides a smooth surface film-forming and easy-to-erase chalk liquid, a preparation method thereof, and a liquid chalk. The smooth surface film-forming and easy-to-erase chalk liquid is prepared from at least the following components: 30 to 35 parts of water; 10 to 15 parts of titanium dioxide powder; 25 to 30 parts of a film-forming agent composed of sulfonic acid-modified polyvinyl alcohol, sodium carboxymethyl cellulose, and carbomer in a weight ratio of (3 to 4): (5 to 6): (2 to 3); 5 to 10 parts of methyl hydrogen silicone oil, 15 to 20 parts of a film-forming aid, 10 to 15 parts of a moisturizing lubricant, and 8 to 15 parts of a dispersant. The preparation method comprises providing sulfonic acid-modified polyvinyl alcohol; obtaining a dispersion; providing a film-forming agent composed of sulfonic acid-modified polyvinyl alcohol, sodium carboxymethyl cellulose, and carbomer in a weight ratio of (3 to 4): (5 to 6): (2 to 3); and adding a second raw material to obtain a smooth surface film-forming and easy-to-erase chalk liquid. The resulting liquid chalk has good film-forming properties, excellent wiping properties, and remains colorfast for a long time.

Description

Technical Field

[0001] The present disclosure relates to the technical field of liquid pens, and in particular to a smooth-surface film-forming and easy-to-erase chalk liquid, a preparation method thereof, and a smooth-surface film-forming and easy-to-erase liquid chalk. Background Art

[0002] Technological advancements have led to a gradual shift towards multimedia and electronic education. As writing scenarios become increasingly complex, traditional chalk cannot accommodate these diverse situations. While water-soluble chalk can be used in many situations, its poor erasability limits its widespread use.

[0003] Chinese invention patent CN102925005A discloses an energy-saving erasable pen, and Chinese invention patent CN101845251B discloses a water-based whiteboard pen ink that can be wiped dry or wet. The main ingredients of both patents include water, film-forming resins (polyvinyl alcohol resin, polyvinyl pyrrolidone, etc.), leveling agents, sulfates, castor oil, surfactants, etc., and the physical dry-erasing effect is poor after the handwriting remains on the board for a long time. Chinese invention patent CN105400295B discloses a method for preparing a liquid chalk composition. The ingredients include titanium dioxide, sodium hexametaphosphate, KM-S dispersant, film-forming agent (carboxymethyl cellulose), surfactant, stabilizer, etc., and the drying and film-forming time is relatively long. Summary of the Invention

[0004] In view of this, the purpose of the present disclosure is to provide a smooth surface film-forming and easy-to-erase chalk liquid, a preparation method thereof, and a smooth surface film-forming and easy-to-erase liquid chalk.

[0005] Based on the above objectives, the present disclosure provides a smooth surface film-forming easy-to-erase chalk liquid, comprising the following components in parts by weight:

[0006] 30-35 parts water;

[0007] 10-15 parts of titanium dioxide powder;

[0008] 25 to 30 parts of a film-forming agent; the film-forming agent includes sulfonic acid modified polyvinyl alcohol, sodium carboxymethyl cellulose and carbomer;

[0009] 5-10 parts of methyl hydrogen silicone oil;

[0010] 15-20 parts of film-forming aid;

[0011] 10-15 parts of moisturizing lubricant; and

[0012] 8 to 15 parts of dispersant.

[0013] In some embodiments, the weight ratio of the sulfonic acid-modified polyvinyl alcohol, sodium carboxymethyl cellulose and carbomer is (3-4): (5-6): (2-3).

[0014] In some embodiments, the sulfonic acid-modified polyvinyl alcohol has a sulfonate group.

[0015] In some embodiments, the sulfonate group is selected from at least one of a sodium sulfonate group, a calcium sulfonate group, a magnesium sulfonate group, and a barium sulfonate group;

[0016] and / or

[0017] The dispersant is selected from at least one of Tween, octylphenol polyoxyethylene ether and fatty alcohol polyoxyethylene ether.

[0018] In some embodiments, 5 to 10 parts of a metal salt catalyst and 1 to 3 parts of a co-solvent are further included.

[0019] In some embodiments, the film-forming aid is selected from at least one of alcohol ester, propylene glycol, ethylene glycol, benzyl alcohol and ethylene glycol butyl ether;

[0020] and / or

[0021] The moisturizing lubricant is selected from at least one of glycerol, 1,3-propylene glycol, 2-methylpropanediol, pentaerythritol, ethylene glycol and mannitol;

[0022] and / or

[0023] The metal salt catalyst is selected from at least one of hypophosphite, phosphite and phosphate; and / or

[0024] The cosolvent is selected from at least one of sodium toluenesulfonate, sodium xylenesulfonate and sodium cumenesulfonate.

[0025] The present disclosure also provides a method for preparing a smooth surface film-forming and easy-to-erase liquid chalk liquid, comprising:

[0026] Provide sulfonic acid modified polyvinyl alcohol;

[0027] Ball milling a first raw material to obtain a dispersion; the first raw material comprises 10 to 15 parts by weight of titanium dioxide powder, 30 to 35 parts by weight of water, and 8 to 15 parts by weight of a dispersant;

[0028] Providing a film-forming agent; the film-forming agent is obtained by mixing sulfonic acid modified polyvinyl alcohol, sodium carboxymethyl cellulose and carbomer;

[0029] A second raw material is added to the dispersion and stirred evenly to obtain the smooth surface film-forming easy-to-erase chalk liquid; the second raw material comprises 5 to 10 parts of methyl hydrogen silicone oil, 25 to 30 parts of a film-forming agent, 15 to 20 parts of a film-forming aid and 10 to 15 parts of a moisturizing lubricant.

[0030] In some embodiments, providing a film-forming agent specifically comprises:

[0031] The film-forming agent is obtained by mixing sulfonic acid-modified polyvinyl alcohol, sodium carboxymethyl cellulose and carbomer in a weight ratio of (3-4): (5-6): (2-3);

[0032] and / or

[0033] The provision of sulfonic acid group-modified polyvinyl alcohol specifically includes:

[0034] An allyl sulfonate solution and a vinyl acetate solution in a volume ratio of 1:4 to 1:6 are mixed and reacted at a preset temperature to obtain the sulfonic acid group-modified polyvinyl alcohol; wherein the mass fractions of the allyl sulfonate solution and the vinyl acetate solution are 9 to 11% and 43 to 47%, respectively.

[0035] In some embodiments, the preset temperature is 60-65°C.

[0036] In some embodiments, the first raw material further comprises: 5 to 10 parts by weight of a metal salt catalyst;

[0037] and / or

[0038] The second raw material further includes: 1 to 3 parts of a co-solvent.

[0039] The present application also provides a smooth surface film-forming and easy-to-erase liquid chalk, which is obtained by filling a smooth surface film-forming and easy-to-erase chalk liquid; the smooth surface film-forming and easy-to-erase chalk liquid is prepared from at least the following components in parts by weight: 30 to 35 parts of water; 10 to 15 parts of titanium dioxide powder; 25 to 30 parts of a film-forming agent; the film-forming agent includes sulfonic acid modified polyvinyl alcohol, sodium carboxymethyl cellulose and carbomer; the weight ratio of the sulfonic acid modified polyvinyl alcohol, sodium carboxymethyl cellulose and carbomer is (3 to 4): (5 to 6): (2 to 3); 5 to 10 parts of methyl hydrogen silicone oil; 15 to 20 parts of a film-forming aid; 10 to 15 parts of a moisturizing lubricant; and 8 to 15 parts of a dispersant.

[0040] As can be seen from the above, the smooth surface film-forming easy-to-erase chalk liquid provided by the present invention is composed of the following components in parts by weight: 30-35 parts of water; 10-15 parts of titanium dioxide powder; 25-30 parts of a film-forming agent; the film-forming agent includes sulfonic acid-modified polyvinyl alcohol, sodium carboxymethyl cellulose and carbomer in a weight ratio of (3-4): (5-6): (2-3); 5-10 parts of methyl hydrogen silicone oil; 15-20 parts of a film-forming aid; 10-15 parts of a moisturizing lubricant; and 8-15 parts of a dispersant. It can make the written notes quickly form a thin film in the air, and the film has excellent adhesion and good erasability. The liquid chalk prepared by combining the components has low production cost, good film-forming property, and excellent erasability. It can be written on a variety of writing environments such as blackboards, glass, and floor tiles, and will remain colorfast for a long time. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the present disclosure or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are only embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0042] Figure 1 The present invention is a flow chart of a method for preparing a smooth surface film-forming easy-to-erase chalk liquid according to an embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0044] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should have the usual meanings understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the embodiments of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. The words "include" or "comprise" and the like mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0045] Conventional liquid pens often have problems with excellent film adhesion but difficulty in wiping off, or easy wiping off but a long drying time. Therefore, conventional liquid pens struggle to achieve both film-forming and erasability.

[0046] The embodiment of the present application provides a smooth surface film-forming easy-to-erase chalk liquid, which is prepared from the following components in parts by weight: 30 to 35 parts of water; 10 to 15 parts of titanium dioxide powder; 25 to 30 parts of a film-forming agent; the film-forming agent includes sulfonic acid-modified polyvinyl alcohol, sodium carboxymethyl cellulose and carbomer; 5 to 10 parts of methyl hydrogen silicone oil; 15 to 20 parts of a film-forming aid; 10 to 15 parts of a moisturizing lubricant; and 8 to 15 parts of a dispersant.

[0047] The smooth surface film-forming easy-to-erase chalk liquid provided in the embodiments of the present application comprises the following components in parts by weight:

[0048] 30-35 parts of water; 10-15 parts of titanium dioxide powder; 25-30 parts of a film-forming agent; the film-forming agent includes sulfonic acid-modified polyvinyl alcohol, sodium carboxymethyl cellulose, and carbomer; 5-10 parts of methyl hydrogen silicone oil; 15-20 parts of a film-forming aid; 10-15 parts of a moisturizing lubricant; 15-20 parts of a film-forming aid; 10-15 parts of a moisturizing lubricant; and 8-15 parts of a dispersant. The written notes can quickly form a thin film in the air, which has excellent adhesion and erasability. The liquid chalk produced by combining these components has low production costs, good film-forming properties, and excellent erasability. It can be written on a variety of writing environments such as blackboards, glass, and floor tiles, and will remain colorfast for a long time.

[0049] Among them, titanium dioxide powder is a white powder with a spherical crystal structure. After being dispersed with water, it is mainly used as a color developer for liquid chalk.

[0050] In some embodiments, the weight ratio of the sulfonic acid-modified polyvinyl alcohol, sodium carboxymethyl cellulose, and carbomer is 3-4:5-6:2-3. This weight ratio allows the film-forming agent to have good performance, such as rapid film formation, good adhesion, and good wiping properties.

[0051] Among them, the carbomer can be carbomer 940, which has good viscosity, can further improve the film-forming property of the film-forming agent, and balance the film-forming property and wipeability.

[0052] In certain embodiments, the sulfonic acid modified polyvinyl alcohol has a sulfonate group. The sulfonate group can be selected from at least one of sodium sulfonate (SO3Na), calcium sulfonate (SO3Ca), magnesium sulfonate (SO3Mg) and barium sulfonate (SO3Ba). By introducing a hydrophilic group sulfonate group into polyvinyl alcohol, the content of the hydrophilic group in the molecule increases under the same alcoholysis degree, thereby making the sulfonic acid modified polyvinyl alcohol have better dispersibility. At the same time, the acid group also reduces the regularity of the polyvinyl alcohol molecular chain, reduces the number of oxygen bonds between the polyvinyl alcohol molecules and the molecules, and reduces the crystallinity of polyvinyl alcohol, thereby making it faster to form a film, and the film-forming product is easier to wipe.

[0053] In some embodiments, the sulfonate group is a sodium sulfonate group, which has the advantages of a wide source of materials and low cost.

[0054] In some embodiments, sulfonic acid group-modified polyvinyl alcohol can be prepared by copolymerizing an organic sulfonate with vinyl acetate. The sulfonic acid group-modified polyvinyl alcohol can be prepared by copolymerizing an organic sulfonate with vinyl acetate. The sulfonic acid group-modified polyvinyl alcohol obtained from this source has good purity.

[0055] Among them, the molecular formula of methyl hydrogen silicone oil is (CH3)3SiO[(CH3)(H)SiO]nSi(CH3) 3, Also known as hydrogen silicone oil. It can cross-link within the molecule to form a film, further improving the bonding strength between the film-forming agent and the writing surface.

[0056] In some embodiments, the dispersant is selected from at least one of Tween, octylphenol polyoxyethylene ether, and fatty alcohol polyoxyethylene ether.

[0057] In some embodiments, the dispersant is Tween.

[0058] In some embodiments, the film-forming aid is selected from at least one of alcohol ester, propylene glycol, ethylene glycol, benzyl alcohol and ethylene glycol butyl ether.

[0059] In some embodiments, the film-forming aid is selected from alcohol ester 12. By selecting alcohol ester 12 as the film-forming aid, the film-forming speed of the smooth surface film-forming easy-to-erase liquid pen can be further increased, making the film-forming product easier to wipe.

[0060] In some embodiments, the moisturizing lubricant is selected from at least one of glycerol, 1,3-propylene glycol, 2-methylpropanediol, pentaerythritol, ethylene glycol, and mannitol. These types of moisturizing lubricants can further improve the lubricity and moisturizing properties of the smooth-surface film-forming, easy-to-erase liquid pen, preventing nib clogging due to insufficient lubricity, as well as preventing unsmooth writing and fading caused by insufficient moisturizing properties.

[0061] In some embodiments, the moisturizing lubricant can be glycerol, which has good moisturizing and lubricating properties and can better improve the lubricity and moisturizing properties of the smooth surface film-forming easy-to-erase liquid pen.

[0062] In some embodiments, 5 to 10 parts of a metal salt catalyst are further included. The metal salt catalyst can enable the methyl hydrogen silicone oil to crosslink and form a film at room temperature, thereby simplifying the preparation process of the smooth film-forming, easily erasable liquid pen.

[0063] In some embodiments, the metal salt catalyst is selected from at least one of hypophosphite, phosphite, and phosphate.

[0064] In some embodiments, the metal salt catalyst is selected from phosphates, such as at least one of sodium phosphate, potassium phosphate and calcium phosphate, etc. Among them, sodium phosphate has the advantages of being readily available and low in cost.

[0065] In some embodiments, 1 to 3 parts of a co-solvent are further included. The co-solvent can improve the solubility of the raw materials of the smooth surface film-forming easy-to-erase liquid pen and improve the uniformity of the ink during writing.

[0066] In some embodiments, the co-solvent is selected from at least one of sodium toluenesulfonate, sodium xylenesulfonate, and sodium cumenesulfonate.

[0067] In some embodiments, the cosolvent is selected from sodium cumene sulfonate, which has a wide range of sources, low cost, and good coordination with sodium phosphate.

[0068] The smooth surface film-forming easy-to-erase chalk liquid provided by the embodiment of the present disclosure is prepared by selecting 30-35 parts of water, 10-15 parts of titanium dioxide powder, 25-30 parts of sulfonic acid modified polyvinyl alcohol, sodium carboxymethyl cellulose and carbomer 940 in a weight ratio of (3-4): (5-6): (2-3) as a film-forming agent, 5-10 parts of methyl hydrogen silicone oil, 8-15 parts of Tween, 15-20 parts of film-forming aid alcohol ester twelve, 10-15 parts of moisturizing lubricant glycerol, 5-10 parts of metal salt catalyst sodium phosphate and 1-3 parts of cosolvent sodium isopropylbenzene sulfonate. The written notes can quickly form a thin film in the air, and the film has excellent adhesion and good erasability. The liquid chalk prepared by the combination of the components has low production cost, good film-forming property and excellent erasability, and can be written in a variety of writing environments such as blackboards, glass, and floor tiles. It also has the advantages of low cost, smooth writing and long-lasting color retention.

[0069] See also Figure 1 Based on the same inventive concept, the present application also provides a method for preparing a smooth surface film-forming and easy-to-erase chalk liquid, comprising:

[0070] S100, provides sulfonic acid group-modified polyvinyl alcohol;

[0071] S200, ball-milling a first raw material to obtain a dispersion; the first raw material comprises 10 to 15 parts by weight of titanium dioxide powder, 30 to 35 parts by weight of water, and 8 to 15 parts by weight of a dispersant;

[0072] S300, providing a film-forming agent; the film-forming agent is obtained by mixing sulfonic acid-modified polyvinyl alcohol, sodium carboxymethyl cellulose, and carbomer in a weight ratio of (3-4):(5-6):(2-3);

[0073] S400, adding a second raw material to the dispersion and stirring uniformly to obtain the smooth surface film-forming easy-to-erase chalk liquid; the second raw material comprises 5 to 10 parts of methyl hydrogen silicone oil, 25 to 30 parts of a film-forming agent, 15 to 20 parts of a film-forming aid, and 10 to 15 parts of a moisturizing lubricant.

[0074] In some embodiments, providing the sulfonic acid group-modified polyvinyl alcohol in step S100 specifically includes: mixing an allyl sulfonate solution and a vinyl acetate solution in a volume ratio of 1:4 to 1:6, and reacting them at a predetermined temperature to obtain the sulfonic acid group-modified polyvinyl alcohol; wherein the mass fractions of the allyl sulfonate solution and the vinyl acetate solution are 9-11% and 43-47%, respectively. By copolymerizing an organic sulfonate with vinyl acetate, ethylene can be directly polymerized into polyvinyl alcohol, and a hydrophilic sulfonate group is introduced into the polyvinyl alcohol, resulting in a sulfonic acid group-modified polyvinyl alcohol with improved dispersibility, lower crystallinity, faster film formation, and easier wiping after film formation.

[0075] In some embodiments, the preset temperature may be 60-65° C. The reaction time may be 1-1.5 hours. Such reaction conditions can promote the reaction to proceed better and make the reaction more complete.

[0076] In some embodiments, after reacting at a predetermined temperature, the process further includes drying to obtain a dried product; dissolving the dried product in alcohol and heating it in a water bath to obtain a gel-like sulfonic acid-modified polyvinyl alcohol. The drying, alcohol-dissolving, and water bath heating processes can produce a sulfonic acid-modified polyvinyl alcohol of higher purity.

[0077] In some embodiments, in step S200, the first raw material further comprises 5 to 10 parts by weight of a metal salt catalyst, wherein the metal salt catalyst is selected from at least one of hypophosphite, phosphite, and phosphate.

[0078] In some embodiments, the dispersant is selected from at least one of Tween, octylphenol polyoxyethylene ether and fatty alcohol polyoxyethylene ether.

[0079] In some embodiments, the metal salt catalyst is selected from phosphates, such as at least one of sodium phosphate, potassium phosphate and calcium phosphate.

[0080] In some embodiments, alumina can be used as the rotor during ball milling, the ball-to-material ratio can be 2:1, the rotation speed can be 300-500 r / min, and the ball milling time can be 1-2 hours. Ball milling can make the sodium phosphate, titanium dioxide powder, water, and Tween more uniform.

[0081] In some embodiments, in step S300, providing the film-forming agent specifically includes: mixing and stirring sulfonic acid-modified polyvinyl alcohol, sodium carboxymethyl cellulose, and carbomer in a weight ratio of (3-4):(5-6):(2-3) to obtain the film-forming agent.

[0082] In some embodiments, the carbomer can be Carbomer 940.

[0083] In some embodiments, stirring can be performed at room temperature and a rotation speed of 200 r / min for 5 to 10 minutes. This stirring condition can make the stirring more uniform.

[0084] In some embodiments, in step S400, the second raw material further includes: 1 to 3 parts of a co-solvent.

[0085] In some embodiments, the film-forming aid is selected from at least one of alcohol ester, propylene glycol, ethylene glycol, benzyl alcohol and ethylene glycol butyl ether.

[0086] In some embodiments, the film-forming aid is selected from alcohol esters.

[0087] In some embodiments, the moisturizing lubricant is selected from at least one of glycerol, 1,3-propylene glycol, 2-methylpropanediol, pentaerythritol, ethylene glycol, and mannitol.

[0088] In some embodiments, the moisturizing lubricant can be glycerol.

[0089] In some embodiments, the co-solvent is selected from at least one of sodium toluenesulfonate, sodium xylenesulfonate, and sodium cumenesulfonate.

[0090] In some embodiments, the co-solvent is selected from sodium cumene sulfonate.

[0091] The above-mentioned preparation method is prepared using the raw materials of the smooth surface film-forming easy-to-erase chalk liquid of the above-mentioned embodiment, and has corresponding effects, which will not be described in detail here.

[0092] Based on the same inventive concept, the present application also provides a smooth-surface film-forming, easily erasable liquid chalk, which is obtained by filling a smooth-surface film-forming, easily erasable chalk liquid; the smooth-surface film-forming, easily erasable chalk liquid is prepared from at least the following components in parts by weight: 30-35 parts of water; 10-15 parts of titanium dioxide powder; 25-30 parts of a film-forming agent; the film-forming agent includes sulfonic acid-modified polyvinyl alcohol, sodium carboxymethyl cellulose, and carbomer; the weight ratio of the sulfonic acid-modified polyvinyl alcohol, sodium carboxymethyl cellulose, and carbomer is (3-4):(5-6):(2-3); 5-10 parts of methyl hydrogen silicone oil; 15-20 parts of a film-forming aid; 10-15 parts of a moisturizing lubricant; and 8-15 parts of a dispersant. That is, the smooth-surface film-forming, easily erasable liquid chalk is obtained by filling the chalk liquid described in any of the preceding items or the chalk liquid prepared by the preparation method described in any of the preceding items.

[0093] The sources of the allyl sulfonate solution, vinyl acetate solution, water, titanium dioxide powder, sodium carboxymethyl cellulose, carbomer 940, methyl hydrogen silicone oil, Tween dispersant, alcohol ester dodecahydrate film-forming aid, glycerol moisturizing lubricant, sodium phosphate metal salt catalyst, sodium cumene sulfonate cosolvent, and unmodified polyvinyl alcohol solution are not particularly limited in this application example; commercially available products familiar to those skilled in the art may be used. The following specific examples further illustrate the method for preparing the liquid chalk of this application example.

[0094] Example 1

[0095] S10: Preparation of sulfonic acid modified polyvinyl alcohol: Take 10% sodium allyl sulfonate methanol solution and 45% vinyl acetate methanol solution in a volume ratio of about 1:5, continue stirring and heat to 60°C under a nitrogen environment, react for 1.5 hours and then dry to obtain a preliminary product. The dried product is prepared into a methanol solution, sodium hydroxide methanol solution is added, heated in a water bath, and stirred for alcoholysis to obtain a gel-like sulfonic acid modified polyvinyl alcohol.

[0096] S20: Weigh 5 parts of sodium phosphate, 10 parts of titanium dioxide powder, 30 parts of water, and 3 parts of polysorbate 20. Use a ball mill (rotor made of aluminum oxide, ball-to-material ratio 2:1) at 300 rpm for 1 hour to obtain dispersion S2.

[0097] S30: 30 parts of sulfonic acid group-modified polyvinyl alcohol aqueous solution, 50 parts of sodium carboxymethyl cellulose, and 20 parts of Carbomer 940 were mixed and stirred at room temperature at a rotor speed of 200 rpm for 5 minutes to obtain film-forming agent S2.

[0098] S40: Take dispersion S2 and, while stirring, add 5 parts by weight of alcohol ester dodecahydrate, 10 parts by weight of glycerol, 5 parts by weight of methyl hydrogen silicone oil, 1 part by weight of sodium cumene sulfonate, and 25 parts by weight of film-forming agent S2. Stir thoroughly until all components are evenly dispersed and mixed to obtain chalk liquid. Pour the chalk liquid into a pen holder and seal it to obtain liquid chalk.

[0099] Example 2

[0100] S10: Preparation of sulfonic acid modified polyvinyl alcohol: Take 10% sodium allyl sulfonate methanol solution and 45% vinyl acetate methanol solution in a volume ratio of about 1:5, continue stirring and heat to 60°C under a nitrogen environment, react for 1.5 hours and then dry to obtain a preliminary product. The dried product is prepared into a methanol solution, sodium hydroxide methanol solution is added, heated in a water bath, and stirred for alcoholysis to obtain a gel-like sulfonic acid modified polyvinyl alcohol.

[0101] S20: Weigh 5 parts of sodium phosphate, 10 parts of titanium dioxide powder, 31 parts of water, and 3 parts of polysorbate 20. Use a ball mill (rotor made of aluminum oxide, ball-to-material ratio 2:1) at 300 rpm for 1.25 hours to obtain dispersion S2.

[0102] S30: 32.5 parts of a sulfonic acid group-modified polyvinyl alcohol aqueous solution, 52.5 parts of sodium carboxymethyl cellulose, and 22.5 parts of Carbomer 940 were mixed and stirred at room temperature with a rotor speed of 200 rpm for 6 minutes to obtain a film-forming agent S2.

[0103] S40: Take dispersion S2 and, while stirring, add 15 parts by weight of alcohol ester dodecahydrate, 10 parts by weight of glycerol, 7 parts by weight of methyl hydrogen silicone oil, 1 part by weight of sodium cumene sulfonate, and 26 parts by weight of film-forming agent S2. Stir thoroughly until all components are evenly dispersed and mixed to obtain chalk liquid. Pour the chalk liquid into a pen holder and seal it to obtain liquid chalk.

[0104] Example 3

[0105] S10: Preparation of sulfonic acid modified polyvinyl alcohol: Take 10% sodium allyl sulfonate methanol solution and 45% vinyl acetate methanol solution in a volume ratio of about 1:5, continue stirring and heat to 60°C under a nitrogen environment, react for 1.5 hours and then dry to obtain a preliminary product. The dried product is prepared into a methanol solution, sodium hydroxide methanol solution is added, heated in a water bath, and stirred for alcoholysis to obtain a gel-like sulfonic acid modified polyvinyl alcohol.

[0106] S20: Weigh 5 parts of sodium phosphate, 12 parts of titanium dioxide powder, 33 parts of water, and 3 parts of polysorbate (Tween). Mill the mixture using a ball mill (alumina rotor, ball-to-material ratio 2:1) at 300 rpm for 1.5 hours to obtain dispersion S2.

[0107] S30: 35 parts of a sulfonic acid group-modified polyvinyl alcohol aqueous solution, 55 parts of sodium carboxymethyl cellulose, and 25 parts of Carbomer 940 were mixed and stirred at room temperature with a rotor speed of 200 rpm for 7.5 minutes to obtain a film-forming agent S2.

[0108] S40: Take dispersion S2 and, while stirring, add 15 parts by weight of alcohol ester dodecahydrate, 10 parts by weight of glycerol, 7 parts by weight of methyl hydrogen silicone oil, 3 parts by weight of sodium cumene sulfonate, and 28 parts by weight of film-forming agent S2. Stir thoroughly until all components are evenly dispersed and mixed to obtain chalk liquid. Pour the chalk liquid into a pen holder and seal it to obtain liquid chalk.

[0109] Example 4

[0110] S10: Preparation of sulfonic acid modified polyvinyl alcohol: Take 10% sodium allyl sulfonate methanol solution and 45% vinyl acetate methanol solution in a volume ratio of about 1:5, continue stirring and heat to 60°C under a nitrogen environment, react for 1.5 hours and then dry to obtain a preliminary product. The dried product is prepared into a methanol solution, sodium hydroxide methanol solution is added, heated in a water bath, and stirred for alcoholysis to obtain a gel-like sulfonic acid modified polyvinyl alcohol.

[0111] S20: Weigh 7 parts of sodium phosphate, 14 parts of titanium dioxide powder, 34 parts of water, and 4 parts of polysorbate 20. Use a ball mill (rotor made of aluminum oxide, ball-to-material ratio 2:1) at 300 rpm for 1.75 hours to obtain dispersion S2.

[0112] S30: 37.5 parts of a sulfonic acid group-modified polyvinyl alcohol aqueous solution, 57.5 parts of sodium carboxymethyl cellulose, and 27.5 parts of Carbomer 940 were mixed and stirred at room temperature with a rotor speed of 200 rpm for 9 minutes to obtain a film-forming agent S2.

[0113] S40: Take dispersion S2 and, while stirring, add 18 parts by weight of alcohol ester dodecahydrate, 13 parts by weight of glycerol, 8 parts by weight of methyl hydrogen silicone oil, 3 parts by weight of sodium cumene sulfonate, and 29 parts by weight of film-forming agent S2. Stir thoroughly until all components are evenly dispersed and mixed to obtain chalk liquid. Pour the chalk liquid into a pen holder and seal it to obtain liquid chalk.

[0114] Example 5

[0115] S1: Preparation of sulfonic acid modified polyvinyl alcohol: Take 10% sodium allyl sulfonate methanol solution and 45% vinyl acetate methanol solution in a volume ratio of about 1:5, heat to 60°C under nitrogen environment with continuous stirring, react for 1.5 hours and dry to obtain a preliminary product, prepare the dried product into methanol solution, add sodium hydroxide methanol solution, heat in a water bath, and stir to hydrolyze to obtain a gel-like sulfonic acid modified polyvinyl alcohol.

[0116] S2: Weigh 10 parts sodium phosphate, 15 parts titanium dioxide powder, 35 parts water, and 5 parts polysorbate. Mill for 2 hours using a ball mill (alumina rotor, ball-to-material ratio 2:1) at 300 rpm to obtain dispersion S2.

[0117] S3: 40 parts of sulfonic acid group-modified polyvinyl alcohol aqueous solution, 60 parts of sodium carboxymethyl cellulose, and 30 parts of Carbomer 940 were mixed and stirred at room temperature at a rotor speed of 200 r / min for 10 minutes to obtain film-forming agent S2.

[0118] S4: Take dispersion S2 and, while stirring, add 20 parts by weight of alcohol ester dodecahydrate, 15 parts of glycerol, 10 parts of methyl hydrogen silicone oil, 3 parts of sodium cumene sulfonate, and 30 parts of film-forming agent S2. Stir thoroughly until all components are evenly dispersed and mixed to obtain chalk liquid. Pour the chalk liquid into a pen holder and seal it to obtain liquid chalk.

[0119] Example 6

[0120] The only difference from Example 4 is that the sodium phosphate and sodium cumene sulfonate in Example 4 are not included.

[0121] Comparative Example 1

[0122] The only difference from Example 4 is that titanium dioxide is used instead of titanium dioxide powder.

[0123] Comparative Example 2

[0124] The only difference from Example 4 is that unmodified polyvinyl alcohol solution is used instead of sulfonic acid group-modified polyvinyl alcohol, and the preparation of sulfonic acid group-modified polyvinyl alcohol is not included.

[0125] Comparative Example 3

[0126] The only difference from Example 4 is that sodium carboxymethylcellulose and carbomer are omitted, and only sulfonic acid group-modified polyvinyl alcohol is added, and the added amount of sulfonic acid group-modified polyvinyl alcohol is 122.5 parts.

[0127] Comparative Example 4

[0128] The only difference from Example 4 is that the amount of film-forming agent used is reduced to 20 parts.

[0129] Comparative Example 5

[0130] The only difference from Example 6 is that unmodified polyvinyl alcohol solution is used instead of sulfonic acid group-modified polyvinyl alcohol, and the preparation of sulfonic acid group-modified polyvinyl alcohol is not included.

[0131] Comparative Example 6

[0132] The only difference from Example 6 is that sodium carboxymethylcellulose and carbomer are omitted, and only sulfonic acid group-modified polyvinyl alcohol is added, and the added amount of sulfonic acid group-modified polyvinyl alcohol is 122.5 parts.

[0133] Comparative Example 7

[0134] The only difference from Example 6 is that the amount of film-forming agent used is reduced to 20 parts.

[0135] The liquid chalks prepared in Examples 1 to 6 and Comparative Examples 1 to 7 were subjected to performance tests, including a film-forming speed test, a writing fluency test, an erasability test, a writing effect test, and a fading test.

[0136] The film-forming speed test measures the average film-forming time by writing 100 characters on a 5cmx5cm square. The film-forming speed is determined by the absence of sticking to the characters when touched by a finger. Film-forming time within 30 seconds is set to 5 minutes; 30-60 seconds is set to 4 minutes; 60-90 seconds is set to 3 minutes; 90-120 seconds is set to 2 minutes; and film-forming time greater than 120 seconds is set to 1 minute.

[0137] The writing fluency test involves writing 100 words on a 5cmx5cm piece of paper. Writing fluency is determined by the absence of broken or uneven handwriting. 5, 4, 3, 2, and 1 represent good, excellent, medium, poor, and bad, respectively.

[0138] Erasability was assessed by writing 100 characters on a 5cm x 5cm piece of paper and then erasing with a commercial eraser. A score of 5 indicated no traces left after erasing, while a score of 1 indicated difficulty in erasing. 5, 4, 3, 2, and 1 indicated good, excellent, fair, poor, and poor, respectively.

[0139] The writing quality is good if 100 characters are written on a 5cmx5cm square and the characters are clear and visible from 10 meters away. 5, 4, 3, 2 and 1 represent good, excellent, medium, poor and bad respectively.

[0140] The fading performance of writing was measured by writing 100 characters on a 5cm x 5cm sheet and observing the characters after 72 hours. A score of 5 indicated complete resistance to fading, while 5, 4, 3, 2, and 1 indicated good, excellent, fair, poor, and poor, respectively.

[0141] The performance test results are shown in Table 1 below.

[0142] As shown in Table 1 below, the smooth-surface, film-forming, easily erasable liquid chalks prepared in Examples 1 to 6 of the present application exhibit excellent film-forming speed, good adhesion, and good erasability, as well as smooth writing, long-lasting, effective adhesion, and resistance to fading. Comparing Example 6 with Example 4, it can be seen that the addition of a metal salt catalyst and a cosolvent further improves the film-forming speed of the smooth-surface, easily erasable liquid chalk, while also improving writing quality and fading resistance.

[0143] Table 1 Performance of the liquid chalks prepared in Examples 1 to 6 and Comparative Examples 1 to 7

[0144]

[0145]

[0146] By comparing Example 6 with Comparative Example 5, it can be seen that when unmodified polyvinyl alcohol solution is used to replace the sulfonic acid group-modified polyvinyl alcohol of the present application, the wiping property of the smooth surface film-forming and easy-to-erase liquid chalk prepared is significantly worse, and the film forming speed and writing fluency are also worse. Comparing Example 6 with Comparative Example 6, it can be seen that when only sulfonic acid group-modified polyvinyl alcohol is used and sodium carboxymethyl cellulose and carbomer of the present application are omitted, the wiping property of the smooth surface film-forming and easy-to-erase liquid chalk prepared is significantly worse, and writing fluency and writing effect are also relatively worse. Comparing Example 6 with Comparative Example 7, it can be seen that when the content of the film-forming agent is lower than the set range of the present application, the film-forming property of the smooth surface film-forming and easy-to-erase liquid chalk prepared becomes very poor, and writing flowability and wiping property are also relatively worse.

[0147] Comparing Example 4 with Comparative Example 4, it can be seen that when titanium dioxide is used to replace the titanium dioxide powder of the present application, the wiping property of the smooth surface film-forming and easy-to-wipe liquid pen prepared is deteriorated, and it is impossible to take into account both the film-forming property and the wiping property. In addition, the writing fluency and writing effect are also significantly deteriorated. Comparing Example 4 with Comparative Example 2, it can be seen that when the unmodified polyvinyl alcohol solution is used to replace the sulfonic acid group-modified polyvinyl alcohol of the present application, the film-forming property and wiping property of the smooth surface film-forming and easy-to-wipe liquid chalk prepared are both significantly deteriorated. In addition, the writing fluency, writing effect and fading property are also significantly deteriorated. Comparing Example 4 with Comparative Example 3, it can be seen that when only sulfonic acid group-modified polyvinyl alcohol is used and the sodium carboxymethyl cellulose and carbomer of the present application are omitted, the film-forming property and wiping property of the smooth surface film-forming and easy-to-wipe liquid chalk prepared are both significantly deteriorated. In addition, the writing effect and fading property are also significantly deteriorated. Comparing the examples with comparative example 4, it can be seen that when the content of the film-forming agent is lower than the set range of the present application, the film-forming properties, wiping properties, writing effect and fading properties of the prepared smooth surface film-forming and easy-to-erase liquid chalk are significantly deteriorated.

[0148] Therefore, the smooth surface film-forming and erasable liquid chalk prepared in the embodiment of the present application can take into account both film-forming properties and erasability. At the same time, it can also take into account good writing performance such as smooth writing, long-term effective adhesion and non-fading.

[0149] The present application also provides the use of the smooth surface film-forming and erasable liquid chalk described in any one of the above technical solutions or the smooth surface film-forming and erasable liquid pen prepared by the preparation method described in the above technical solution for writing on a smooth writing surface.

[0150] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present disclosure (including the claims) is limited to these examples. Within the scope of the present disclosure, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present disclosure as described above, which are not provided in detail for the sake of simplicity.

[0151] While the disclosure has been described in conjunction with specific embodiments thereof, many alternatives, modifications and variations of these embodiments will be apparent to those skilled in the art in light of the foregoing description.

[0152] The embodiments of the present disclosure are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A smooth surface film-forming easy-to-erase chalk liquid, characterized in that: Prepared from at least the following components in parts by weight: 30-35 parts water; 10-15 parts of titanium dioxide powder; 25 to 30 parts of a film-forming agent; the film-forming agent comprises sulfonic acid-modified polyvinyl alcohol, sodium carboxymethyl cellulose and carbomer in a weight ratio of (3 to 4): (5 to 6): (2 to 3); 5-10 parts of methyl hydrogen silicone oil; 15-20 parts of film-forming aid; 10-15 parts of moisturizing lubricant; and 8 to 15 parts of dispersant; The sulfonic acid modified polyvinyl alcohol is obtained by copolymerizing allyl sulfonate and vinyl acetate; the volume ratio of allyl sulfonate solution to vinyl acetate solution is 1:4-1:6; the mass fraction of allyl sulfonate solution is 9-11%; and the mass fraction of vinyl acetate solution is 43-47%.

2. The smooth surface film-forming easy-to-erase chalk liquid according to claim 1, characterized in that The sulfonic acid group-modified polyvinyl alcohol has a sulfonate group.

3. The smooth surface film-forming easy-to-erase chalk liquid according to claim 2, characterized in that: The sulfonate group is selected from at least one of a sodium sulfonate group, a calcium sulfonate group, a magnesium sulfonate group and a barium sulfonate group.

4. The smooth surface film-forming easy-to-erase chalk liquid according to claim 1, characterized in that The film-forming aid is selected from at least one of alcohol ester lauryl alcohol, propylene glycol, ethylene glycol, benzyl alcohol and ethylene glycol butyl ether; and / or The moisturizing lubricant is selected from at least one of glycerol, 1,3-propylene glycol, 2-methylpropanediol, pentaerythritol, ethylene glycol and mannitol; and / or The dispersant is selected from at least one of Tween, octylphenol polyoxyethylene ether and fatty alcohol polyoxyethylene ether.

5. The smooth surface film-forming easy-to-erase chalk liquid according to claim 1, characterized in that: The invention also comprises 5 to 10 parts of a metal salt catalyst and 1 to 3 parts of a cosolvent.

6. The smooth surface film-forming easy-to-erase chalk liquid according to claim 5, characterized in that: The metal salt catalyst is selected from at least one of hypophosphite, phosphite and phosphate; and / or The cosolvent is selected from at least one of sodium toluenesulfonate, sodium xylenesulfonate and sodium cumenesulfonate.

7. A method for preparing a smooth surface film-forming easy-to-erase chalk liquid, characterized in that: include: Provide sulfonic acid modified polyvinyl alcohol; Ball milling a first raw material to obtain a dispersion; the first raw material comprises 10 to 15 parts by weight of titanium dioxide powder, 30 to 35 parts by weight of water, and 8 to 15 parts by weight of a dispersant; Providing a film-forming agent; the film-forming agent is obtained by mixing sulfonic acid-modified polyvinyl alcohol, sodium carboxymethyl cellulose and carbomer in a weight ratio of (3-4): (5-6): (2-3); Adding a second raw material to the dispersion and stirring evenly to obtain the smooth surface film-forming easy-to-erase chalk liquid; the second raw material comprises 5 to 10 parts of methyl hydrogen silicone oil, 25 to 30 parts of a film-forming agent, 15 to 20 parts of a film-forming aid and 10 to 15 parts of a moisturizing lubricant; Wherein, the provision of sulfonic acid group-modified polyvinyl alcohol specifically includes: An allyl sulfonate solution and a vinyl acetate solution in a volume ratio of 1:4 to 1:6 are mixed and reacted at a preset temperature to obtain the sulfonic acid group-modified polyvinyl alcohol; wherein the mass fractions of the allyl sulfonate solution and the vinyl acetate solution are 9 to 11% and 43 to 47%, respectively.

8. The preparation method according to claim 7, characterized in that The preset temperature is 60-65°C; and / or The first raw material also includes: 5 to 10 parts by weight of a metal salt catalyst; and / or The second raw material further includes: 1 to 3 parts of a co-solvent.

9. A smooth surface film-forming easy-to-erase liquid chalk, characterized in that: The invention is obtained by filling a smooth surface film-forming easy-erasable chalk liquid; the smooth surface film-forming easy-erasable chalk liquid is prepared from at least the following components in parts by weight: 30 to 35 parts of water; 10 to 15 parts of titanium dioxide powder; 25 to 30 parts of a film-forming agent; the film-forming agent comprises sulfonic acid modified polyvinyl alcohol, sodium carboxymethyl cellulose and carbomer; the weight ratio of the sulfonic acid modified polyvinyl alcohol, sodium carboxymethyl cellulose and carbomer is (3 to 4): (5 to 6): (2 to 3); 5 to 10 parts of methyl hydrogen silicone oil; 15 to 20 parts of a film-forming aid; 10 to 15 parts of a moisturizing lubricant; and 8 to 15 parts of a dispersant. Wherein, the sulfonic acid group-modified polyvinyl alcohol is obtained by copolymerization of allyl sulfonate and vinyl acetate; The volume ratio of the allyl sulfonate solution to the vinyl acetate solution is 1:4-1:6; the mass fraction of the allyl sulfonate solution is 9-11%; and the mass fraction of the vinyl acetate solution is 43-47%.

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