A method for preparing a low-conductivity liquid crystal glass substrate backing paper

Abstract

The application discloses a kind of preparation methods of low conductivity liquid crystal glass substrate backing paper, and relate to papermaking technical field.The paper uses bleached conifer pulp and bleached broadleaf wood pulp as raw material, is prepared into slurry, then is beaten, is matched slurry, is impurity purification, shaping drying, surface coating, calendering, slitting, dust removal is obtained;The prepared paper has low conductivity, good strength, high cleanliness, good flatness, paper pH value is neutral and the like characteristics, significantly improves the problem of paper drop caused by static adsorption performance existing at present.The preparation method of liquid crystal glass substrate backing paper provided by the application can reduce the conductivity of liquid crystal glass substrate backing paper, improve its adsorption performance, provide technical support for the development of relatively weak domestic traditional glass backing paper, and has wide application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of papermaking, and particularly relates to a preparation method of low-conductivity liquid crystal glass substrate backing paper. BACKGROUND

[0002] With the development of science and technology and the increasing demand of the market for various intelligent devices, the requirements for liquid crystal glass substrates are gradually increasing, and in recent years, the demand growth rate in China has remained at 10%, which has broad development prospects.

[0003] Since liquid crystal glass substrates do not allow any surface scratches, contamination and bubbles, etc., protective paper is often used to separate and protect the liquid crystal glass substrates during transportation and storage. Compared with traditional mold powder, liquid crystal substrate glass protective paper usually needs to have good flatness, high cleanliness and strength, stable pH value and reasonable conductivity, and has the advantages of good isolation uniformity, simple use process, stable performance, strong versatility, etc. as an isolation protective layer. The glass substrate protective paper can inhibit or kill mold, thereby playing the roles of protection, corrosion resistance, covering layer and protective film, and also playing the role of a glass friction pad, which can effectively protect the film surface of the glass.

[0004] When producing glass substrates, the spacer paper is padded under the glass substrate, and if the electrostatic adsorption capacity is weak, paper dropping phenomenon is easily caused during use, thereby causing the production line to stop and even causing equipment damage. Therefore, good conductivity performance is an important indicator of glass substrate protective paper. When the paper conductivity is > 50 μS / cm, the static electricity on the paper is released too quickly, which eventually causes paper dropping and other situations; and when the paper conductivity is < 50 μS / cm, the paper adsorption capacity is good. However, the high-end liquid crystal glass substrate protective paper also has problems such as high requirements, great manufacturing difficulty and high cost. Patent CN 113026426A and CN 111691219 A respectively disclose a high-tear CTP version backing paper and a preparation method thereof and a glass mold-resistant backing paper and a preparation method thereof, which improve the tear resistance and mold resistance of the backing paper; patent CN 115058913A discloses a preparation method of a high-hygroscopicity glass backing paper, which improves the problems of moisture and mold. However, there are few reports on the improvement of the conductivity performance, and most of the high-end liquid crystal substrate glass protective paper is manufactured abroad, and most of the domestic production is low-end paper. At the same time, the dependence on imported protective paper also limits the development of domestic glass substrate protective paper. SUMMARY

[0005] The application aims to provide a preparation method of low-conductivity liquid crystal glass substrate backing paper, which has low conductivity, good strength, high cleanliness, good flatness, neutral pH value and other characteristics, and significantly improves the current problems of paper dropping caused by electrostatic adsorption performance.

[0006] The technical scheme adopted by the application to achieve the above-mentioned purpose is:

[0007] The low-conductivity liquid crystal glass substrate backing paper has an initial conductivity of ≤30.5 μs / cm, preferably ≤19.1 μs / cm, a basis weight of 40-60 g / m 2 , and a pH value of 6.5-7.5.

[0008] The application further discloses a preparation method of the low-conductivity liquid crystal glass substrate backing paper, which comprises the following steps:

[0009] Step 1, bleaching conifer pulp and bleaching broadleaf wood pulp, and mixing them into pulp liquor after disintegration;

[0010] Step 2, beating;

[0011] Step 3, adding a pH regulator to the pulp after beating treatment;

[0012] Step 4, purifying ferromagnetic impurities in the prepared pulp during conveying;

[0013] Step 5, squeezing, drying, applying a surface additive, and drying again;

[0014] Step 6, then soft calender finishing, internal moisture balance, and finally cutting, destaticizing, dust removing and high-cleaning treatment of the paper roll after papermaking to obtain the low-conductivity liquid crystal glass substrate backing paper.

[0015] The application provides a preparation method of a low-conductivity liquid crystal glass substrate backing paper, which comprises the following steps: raw material slurry preparation, beating, slurry preparation, impurity removal and purification, shaping and drying, surface application, calendering, slitting and dust removal, and finally obtaining a paper product; the raw material should be wood pulp with low ash content and resin content, mainly mixed use of bleached coniferous wood pulp and broadleaf wood pulp, the beating process can improve the internal bonding strength between fibers, however, excessive beating will cause difficulty in wet section dehydration and decrease in bulk, therefore, a proper pulp consistency should be selected; in the slurry preparation process, boric acid, citric acid, aluminum sulfate and the like are used to adjust pH to achieve the purpose of mildew prevention and the like; in addition, in the impurity removal and purification process, a disc type permanent magnet iron remover or a grid type permanent magnet iron remover is used to remove ferromagnetic impurities in the pulp to reduce the conductivity of the product; in the shaping and drying and surface application processes, a surface additive is added to enhance the strength of the paper and maintain low conductivity as much as possible; after the processes of soft calendering, internal moisture balancing, slitting and dust removal, the required low-conductivity liquid crystal glass substrate backing paper can be obtained.

[0016] Preferably, the mass ratio of the bleached coniferous pulp to the bleached broadleaf wood pulp is 1:0.8-3.

[0017] Preferably, the pulp consistency of the beating is 3.5%-4.5%, the pulp degree is 35-45SR, and the wet weight is 2.0-4.0g.

[0018] Preferably, the pH regulator is selected from one of boric acid, citric acid and aluminum sulfate.

[0019] Preferably, the addition amount of the pH regulator is 5-25kg / ton of paper.

[0020] Preferably, after the pressing and dewatering, the dry content of the paper is 28-43%.

[0021] Preferably, the surface additive is selected from one of carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, hyaluronic acid, starch, vegetable glue and hemicellulose, or selected from one of carboxymethyl cellulose derivative, methyl cellulose derivative, hydroxyethyl cellulose derivative, polyvinyl alcohol derivative, hyaluronic acid derivative, starch derivative, vegetable glue derivative and hemicellulose derivative.

[0022] Preferably, the concentration of the surface additive is 0.5-2.5wt%.

[0023] Preferably, in the process of applying the surface additive, the surface additive application amount on the surface of the paper is 5-20g / m 2 .

[0024] The application further discloses a preparation method of the carboxymethyl cellulose derivative.

[0025] The application discloses a preparation method of a carboxymethyl cellulose derivative, which modifies carboxymethyl cellulose by using 3-acetoxy-2-methyl benzoyl chloride to obtain the carboxymethyl cellulose derivative, and uses the carboxymethyl cellulose derivative to prepare a low-conductivity liquid crystal glass substrate backing paper, so that the low-conductivity liquid crystal glass substrate backing paper has good tensile strength, tear strength and low conductivity, and has a neutral pH.

[0026] Specifically, the preparation method of the carboxymethyl cellulose derivative comprises the following steps.

[0027] The carboxymethyl cellulose is added into N,N-dimethylacetamide (the mass-volume ratio of the two is 1g: 15-30mL), then triethylamine is added, and stirring is carried out at room temperature for 28-35min; then the N,N-dimethylacetamide solution of 3-acetoxy-2-methyl benzoyl chloride is slowly added under a nitrogen atmosphere, and reaction is carried out at 60-80℃ for 2-6h; ethanol precipitation, suction filtration and drying are carried out to obtain the carboxymethyl cellulose derivative.

[0028] Preferably, the molar ratio of the triethylamine to the 3-acetoxy-2-methyl benzoyl chloride is 1:0.8-1.3; the mass ratio of the carboxymethyl cellulose to the 3-acetoxy-2-methyl benzoyl chloride is 1:0.32-0.47; and the mass-volume ratio of the 3-acetoxy-2-methyl benzoyl chloride to the N,N-dimethylacetamide in the N,N-dimethylacetamide solution of the 3-acetoxy-2-methyl benzoyl chloride is 1g:1-3mL.

[0029] The application further discloses application of the carboxymethyl cellulose derivative prepared by the preparation method in preparation of a low-conductivity liquid crystal glass substrate backing paper.

[0030] The application has the following beneficial effects:

[0031] The application provides a preparation method of a low-conductivity liquid crystal glass substrate backing paper, which uses bleached conifer pulp and bleached broad-leaved wood pulp as raw materials, prepares a pulp solution, and then obtains the backing paper through beating, pulp mixing, impurity removal and purification, shaping and drying, surface coating, calendering, slitting and dust removal; the preparation method is convenient, stable and reliable, can effectively avoid problems such as mold and scratches on the surface of the glass, has excellent electrostatic adsorption performance, improves product quality and market competitiveness, and has a wide application prospect.

[0032] Therefore, the application provides a preparation method of low-conductivity liquid crystal glass substrate backing paper, and the paper prepared by the method has low conductivity, good strength, high cleanliness, good flatness, neutral pH value, and significantly improved problems of paper dropping caused by electrostatic adsorption. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 A flow chart for preparing low-conductivity liquid crystal glass substrate backing paper for Example 1;

[0034] Figure 2 Test results of infrared spectrum of carboxymethyl cellulose derivative and carboxymethyl cellulose prepared for Example 3;

[0035] Figure 3 Test results of infrared spectrum of polyvinyl alcohol derivative and polyvinyl alcohol prepared for Example 5. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the application more clear and definite, the technical scheme of the application is further described in detail below in combination with specific embodiments:

[0037] Example 1:

[0038] A preparation method of low-conductivity liquid crystal glass substrate backing paper, comprising:

[0039] Step 1, after bleaching conifer pulp (purchased from Shandong Daoxin New Material Co., Ltd.) and bleaching broadleaf wood pulp (purchased from Shandong Daoxin New Material Co., Ltd.) are disintegrated, the pulp is mixed into a slurry according to a mass ratio of 1:1;

[0040] Step 2, the wood pulp fibers are flocked by beating, the beating process concentration is 4.0wt%, the beating degree is 40°SR, and the wet weight is 3.2g;

[0041] Step 3, boric acid is added as a pH regulator in the slurry treated by beating according to a dosage of 10kg / ton of paper;

[0042] Step 4, the prepared slurry is purified of ferromagnetic impurities by a de-ironer during conveying, and the slurry concentration is adjusted to 3.0wt%; Step 5, the slurry treated by purification is subjected to press dewatering (the dryness content of the paper is 32%), drying, and application of 1.5wt% of carboxymethyl cellulose, the application amount being 10g / m 2 , and then dried again;

[0043] Step 6, the dried paper is subjected to soft calendering finishing to improve the surface smoothness, and then is subjected to internal moisture balance to improve the flatness of the paper, and finally the paper roll after the paper machine is subjected to cutting, electrostatic dust removal and high cleaning treatment to obtain the low conductivity liquid crystal glass substrate backing paper; the process is as shown in Figure 1 The paper basis weight is 50.3 g / m 2 .

[0044] Example 2

[0045] A preparation method of a low conductivity liquid crystal glass substrate backing paper, comprising the following steps:

[0046] Step 1, after bleaching conifer pulp and bleaching broadleaf wood pulp are disintegrated, the pulp is mixed into a slurry according to a mass ratio of 1:1.2;

[0047] Step 2, the wood pulp fibers are separated and flocked by beating, the beating process concentration is 3.8wt%, the beating degree is 40°SR, and the wet weight is 3.0g;

[0048] Step 3, boric acid is added as a pH regulator in an amount of 15kg / ton of paper to the pulp after beating treatment;

[0049] Step 4, the prepared pulp is purified of ferromagnetic impurities by an iron remover during conveying, and the pulp concentration is adjusted to 3.0wt%; Step 5, the purified pulp is subjected to press dewatering (the dryness content of the paper is 32%), drying, and application of 1.0wt% of carboxymethyl cellulose, the application amount being 10g / m 2 , and then is dried again;

[0050] Step 6, the dried paper is subjected to soft calendering finishing to improve the surface smoothness, and then is subjected to internal moisture balance to improve the flatness of the paper, and finally the paper roll after the paper machine is subjected to cutting, electrostatic dust removal and high cleaning treatment to obtain the low conductivity liquid crystal glass substrate backing paper; the paper basis weight is 50.1g / m 2 .

[0051] Example 3

[0052] A preparation method of a low conductivity liquid crystal glass substrate backing paper, which is different from example 1 in that a carboxymethyl cellulose derivative is used instead of carboxymethyl cellulose; the paper basis weight is 50.2g / m 2 .

[0053] A preparation method of a carboxymethyl cellulose derivative, comprising the following steps:

[0054] Carboxymethyl cellulose is added into N,N-dimethylacetamide (mass-volume ratio of 1g:15mL), then triethylamine is added, stirred at room temperature for 28min, then 3-acetoxy-2-methylbenzoyl chloride N,N-dimethylacetamide solution is slowly added under nitrogen atmosphere, and reaction is carried out at 60 DEG C for 6h, ethanol is precipitated, suction filtration is carried out, and drying is carried out to obtain the carboxymethyl cellulose derivative; wherein the molar ratio of triethylamine to 3-acetoxy-2-methylbenzoyl chloride is 1:0.8; the mass ratio of carboxymethyl cellulose to 3-acetoxy-2-methylbenzoyl chloride is 1:0.32; and the mass-volume ratio of 3-acetoxy-2-methylbenzoyl chloride to N,N-dimethylacetamide in 3-acetoxy-2-methylbenzoyl chloride N,N-dimethylacetamide solution is 1g:1mL.

[0055] Example 4:

[0056] A preparation method of a low-conductivity liquid crystal glass substrate backing paper is different from that of example 1 in that polyvinyl alcohol is used instead of carboxymethyl cellulose; and the paper formation basis weight is 50.3g / m 2 .

[0057] Example 5:

[0058] A preparation method of a low-conductivity liquid crystal glass substrate backing paper is different from that of example 4 in that a polyvinyl alcohol derivative is used instead of polyvinyl alcohol; and the paper formation basis weight is 50.2g / m 2 .

[0059] A preparation method of a polyvinyl alcohol derivative comprises: grafting reaction of 2-furan carboxylic acid allyl ester and polyvinyl alcohol to obtain the polyvinyl alcohol derivative.

[0060] The application discloses a preparation method of a polyvinyl alcohol derivative, which uses 2-furan carboxylic acid allyl ester to modify polyvinyl alcohol to obtain the polyvinyl alcohol derivative, and uses the polyvinyl alcohol derivative to prepare a low-conductivity liquid crystal glass substrate backing paper, so that the low-conductivity liquid crystal glass substrate backing paper has good tensile strength, tear degree and low conductivity, and has neutral pH, and significantly improves the current paper dropping problem caused by electrostatic adsorption performance.

[0061] Specifically, the preparation method of the polyvinyl alcohol derivative comprises the following steps:

[0062] In the polyvinyl alcohol, dimethyl sulfoxide (both mass volume ratio: 1g: 17-23mL) is added, stirring at 85-95℃ for 2.5-3h, then under the condition of 200-250W microwave irradiation activation for 20-30s, at room temperature, 2-furan carboxylic acid allyl ester, potassium persulfate is added to dimethyl sulfoxide (2-furan carboxylic acid allyl ester and dimethyl sulfoxide molar volume ratio: 1mol: 0.15-0.2L), stirring for 15-25min, then added to the above activated polyvinyl alcohol solution, under the condition of nitrogen atmosphere, 350-450W microwave irradiation activation for 35-50s, deionized water precipitation, centrifugation, acetone washing 3-5 times, drying, polyvinyl alcohol derivative is prepared.

[0063] The molar ratio of polyvinyl alcohol to 2-furan carboxylic acid allyl ester is 1:0.25-0.35; the molar ratio of 2-furan carboxylic acid allyl ester to potassium persulfate is 1:0.001-0.0015.

[0064] Further,

[0065] A method for preparing a polyvinyl alcohol derivative, comprising the following steps:

[0066] In the polyvinyl alcohol, dimethyl sulfoxide (both mass volume ratio: 1g: 17mL) is added, stirring at 85℃ for 3h, then under the condition of 200W microwave irradiation activation for 30s, at room temperature, 2-furan carboxylic acid allyl ester, potassium persulfate is added to dimethyl sulfoxide (the molar ratio of polyvinyl alcohol to 2-furan carboxylic acid allyl ester is 1:0.25; the molar ratio of 2-furan carboxylic acid allyl ester to potassium persulfate is 1:0.001; the molar volume ratio of 2-furan carboxylic acid allyl ester to dimethyl sulfoxide is 1mol: 0.15L), stirring for 15min, then added to the above activated polyvinyl alcohol solution, under the condition of nitrogen atmosphere, 350W microwave irradiation activation for 35s, deionized water precipitation, centrifugation, acetone washing 3 times, drying, polyvinyl alcohol derivative is prepared.

[0067] Comparative Example 1:

[0068] A method for preparing a low-conductivity liquid crystal glass substrate pad paper, comprising:

[0069] Step 1, after the bleaching of coniferous pulp and bleaching of broad-leaved wood pulp is disintegrated, the pulp is mixed into a slurry according to a mass ratio of 1:1;

[0070] Step 2, the wood pulp fibers are flocked by beating, the beating process concentration is 4.0wt%, the beating degree is 40°SR, and the wet weight is 3.2g;

[0071] Step 3, boric acid is added to the pulp treated by beating as a pH adjuster according to a dosage of 10kg / ton of paper;

[0072] Step 4, configure the slurry concentration to be 3.0wt%;

[0073] Step 5, the prepared slurry is dried by a long net forming drying cylinder;

[0074] Step 6, the dried paper is finished by soft calendering to improve the surface smoothness, and then is balanced in internal moisture to improve the flatness of the paper, finally the paper roll after the paper machine is cut, destaticized, dusted and cleaned to obtain the low conductivity liquid crystal glass substrate backing paper; the basis weight of the finished paper is 50.2g / m 2 .

[0075] Comparative Example 2:

[0076] A preparation method of a low conductivity liquid crystal glass substrate backing paper, comprising:

[0077] Step 1, after bleaching conifer pulp and bleaching broadleaf wood pulp are disintegrated, the pulp is mixed into a slurry according to a mass ratio of 1:1.2;

[0078] Step 2, the wood pulp fibers are separated and flocked by beating, the beating process concentration is 3.8wt%, the beating degree is 40°SR, and the wet weight is 3.0g;

[0079] Step 3, boric acid is added as a pH adjuster to the slurry after beating treatment, and the amount of boric acid added is 15kg / ton of paper;

[0080] Step 4, configure the slurry concentration to be 3.0wt%;

[0081] Step 5, the prepared slurry is dried by a long net forming drying cylinder;

[0082] Step 6, the dried paper is finished by soft calendering to improve the surface smoothness, and then is balanced in internal moisture to improve the flatness of the paper, finally the paper roll after the paper machine is cut, destaticized, dusted and cleaned to obtain the low conductivity liquid crystal glass substrate backing paper; the basis weight of the finished paper is 50.1g / m 2 .

[0083] Test Example:

[0084] 1. Infrared spectrum test

[0085] The sample is tested by using a Fourier infrared spectrometer by KBr tabletting method.

[0086] The carboxymethyl cellulose derivative prepared in Example 3 and carboxymethyl cellulose are tested by the above method, and the results are shown in Figure 2 . As can be seen from Figure 2 , compared with the infrared spectrum of carboxymethyl cellulose, the infrared spectrum of the carboxymethyl cellulose derivative is in the range of 1400-1600cm -1The infrared characteristic absorption peak of benzene ring exists, which indicates that 3-acetoxy-2-methylbenzoyl chloride participates in the reaction of generating the carboxymethyl cellulose derivative.

[0087] The above tests were conducted on the polyvinyl alcohol derivative prepared in Example 5 and polyvinyl alcohol, and the results are shown in Table 3. Figure 3 Figure 3 As can be seen from Table 3, compared with the infrared spectrum of polyvinyl alcohol, the infrared spectrum of the polyvinyl alcohol derivative has an infrared characteristic absorption peak of C=O bond in ester group at 1739 cm -1 and an infrared characteristic absorption peak of C=C bond in furan group at 1622 cm -1 , which indicates that allyl 2-furancarboxylate participates in the reaction of generating the polyvinyl alcohol derivative.

[0088] 2. Tensile strength test

[0089] The tensile strength of the sample was tested according to the standard GB / T 12914-2018 by using S81502 computer-controlled tensile testing machine.

[0090] Table 1 Longitudinal tensile strength of low-conductivity liquid crystal glass substrate dunnage samples

[0091] Experimental grouping Longitudinal tensile strength (KN / m) Example 1 4.6 Example 2 4.1 Example 3 5.6 Example 4 4.5 Example 5 5.6 Comparative Example 1 4.2 Comparative Example 2 3.7

[0092] Table 2 Transverse tensile strength of low-conductivity liquid crystal glass substrate dunnage samples

[0093] Experimental grouping Transverse tensile strength (KN / m) Example 1 1.5 Example 2 1.2 Example 3 2.1 Example 4 1.5 Example 5 2.0 Comparative Example 1 1.3 Comparative Example 2 1.0

[0094] The above tests were conducted on the low-conductivity liquid crystal glass substrate dunnage prepared in Examples 1-5 and Comparative Examples 1-2, and the results are shown in Tables 1 and 2. As can be seen from Tables 1 and 2, compared with Comparative Examples 1 and 2, the longitudinal tensile strength and the transverse tensile strength of the low-conductivity liquid crystal glass substrate dunnage prepared in Example 1 are improved, which indicates that the preparation method of the low-conductivity liquid crystal glass substrate dunnage provided by the present application has good longitudinal tensile strength and transverse tensile strength compared with the prior art. Compared with Example 1, the longitudinal tensile strength and the transverse tensile strength of the low-conductivity liquid crystal glass substrate dunnage prepared in Example 3 are also improved, which indicates that the carboxymethyl cellulose derivative prepared by using 3-acetoxy-2-methylbenzoyl chloride for the preparation of the low-conductivity liquid crystal glass substrate dunnage has good longitudinal tensile strength and transverse tensile strength. Compared with Example 4, the longitudinal tensile strength and the transverse tensile strength of the low-conductivity liquid crystal glass substrate dunnage prepared in Example 5 are also improved, which indicates that the polyvinyl alcohol derivative prepared by using allyl 2-furancarboxylate for the preparation of the low-conductivity liquid crystal glass substrate dunnage has good longitudinal tensile strength and transverse tensile strength.

[0095] 3. Tear degree test ​

[0096] The transverse tear strength of the sample is tested by a paper tear tester.

[0097] Table 3 Tear strength of low conductivity liquid crystal glass substrate dunnage paper samples

[0098] Experimental grouping Tear degree (mN) Example 1 400 Example 2 350 Example 3 470 Example 4 390 Example 5 450 Comparative Example 1 380 Comparative Example 2 310

[0099] The low conductivity liquid crystal glass substrate dunnage paper prepared in Examples 1-5 and Comparative Examples 1-2 is tested by the above method, and the results are shown in Table 4. As shown in Table 4, the conductivity of Example 1 and Comparative Example 1, and Example 2 and Comparative Example 2 is decreased, which indicates that the preparation method of the low conductivity liquid crystal glass substrate dunnage paper provided by the present application has lower conductivity compared with the prior art. The conductivity of Example 3 and Example 1 is also decreased, which indicates that the carboxymethyl cellulose derivative prepared by 3-acetoxy-2-methylbenzoyl chloride is used for the preparation of the low conductivity liquid crystal glass substrate dunnage paper, and the low conductivity liquid crystal glass substrate dunnage paper has lower conductivity. The conductivity of Example 5 and Example 4 is also decreased, which indicates that the polyvinyl alcohol derivative prepared by 2-furancarboxylic acid allyl ester is used for the preparation of the low conductivity liquid crystal glass substrate dunnage paper, and the low conductivity liquid crystal glass substrate dunnage paper has lower conductivity.

[0100] 4. Conductivity test

[0101] The conductivity of the sample is tested by a digital conductivity meter.

[0102] Table 4 Conductivity of low conductivity liquid crystal glass substrate dunnage paper samples

[0103]

[0104]

[0105] The low conductivity liquid crystal glass substrate dunnage paper prepared in Examples 1-5 and Comparative Examples 1-2 is tested by the above method, and the results are shown in Table 4. As shown in Table 4, the conductivity of Example 1 and Comparative Example 1, and Example 2 and Comparative Example 2 is decreased, which indicates that the preparation method of the low conductivity liquid crystal glass substrate dunnage paper provided by the present application has lower conductivity compared with the prior art. The conductivity of Example 3 and Example 1 is also decreased, which indicates that the carboxymethyl cellulose derivative prepared by 3-acetoxy-2-methylbenzoyl chloride is used for the preparation of the low conductivity liquid crystal glass substrate dunnage paper, and the low conductivity liquid crystal glass substrate dunnage paper has lower conductivity. The conductivity of Example 5 and Example 4 is also decreased, which indicates that the polyvinyl alcohol derivative prepared by 2-furancarboxylic acid allyl ester is used for the preparation of the low conductivity liquid crystal glass substrate dunnage paper, and the low conductivity liquid crystal glass substrate dunnage paper has lower conductivity.

[0106] 5. pH test

[0107] The pH of the surface of the sample was tested according to the test standard GB / T 13528-2015.

[0108] Table 5 pH of low conductivity liquid crystal glass substrate dunnage samples

[0109] Experimental grouping pH Example 1 6.8 Example 2 6.6 Example 3 6.9 Example 4 7.0 Example 5 6.8 Comparative Example 1 7.0 Comparative Example 2 7.0

[0110] The low conductivity liquid crystal glass substrate dunnage prepared in Examples 1-5 and Comparative Examples 1-2 was subjected to the above test, and the results are shown in Table 5. As can be seen from Table 5, the pH of the low conductivity liquid crystal glass substrate dunnage measured in Examples 1-5 and Comparative Examples 1-2 is not significantly different, indicating that the pH of the low conductivity liquid crystal glass substrate dunnage prepared in the present application is relatively stable.

[0111] The conventional techniques in the above examples are prior art known to those skilled in the art, and therefore will not be described in detail here.

[0112] The above description is merely a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, and all such changes or replacements should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A low conductivity liquid crystal glass substrate dunnage, characterized by: The low-conductivity liquid crystal glass substrate base paper has an initial conductivity of ≤ 30.5 μs / cm; the low-conductivity liquid crystal glass substrate base paper has a basis weight of 40-60 g / m 2 ; the low-conductivity liquid crystal glass substrate base paper has a pH of 6.5-7.5; The low-conductivity liquid crystal glass substrate backing paper contains carboxymethyl cellulose derivatives, which are prepared by modifying carboxymethyl cellulose with 3-acetoxy-2-methyl benzoyl chloride; the mass ratio of carboxymethyl cellulose to 3-acetoxy-2-methyl benzoyl chloride is 1:0.32-0.

47.

2. The preparation method of the low-conductivity liquid crystal glass substrate backing paper according to claim 1, comprising: Step 1, mixing bleached conifer pulp and bleached broadleaf wood pulp after disintegration into pulp liquor; Step 2, beating; Step 3, adding a pH regulator to the pulp after beating treatment; Step 4, purifying ferromagnetic impurities during the conveying of the prepared pulp; Step 5, dewatering by pressing, drying, applying a surface additive, and drying again; Step 6, then finishing by soft calendering, internal moisture balancing, and finally cutting, destaticizing, dust removing, and high cleaning treatment of the paper roll after papermaking to obtain the low-conductivity liquid crystal glass substrate backing paper; the surface additive is selected from carboxymethyl cellulose derivatives; the carboxymethyl cellulose derivatives are prepared by modifying carboxymethyl cellulose with 3-acetoxy-2-methyl benzoyl chloride; the mass ratio of carboxymethyl cellulose to 3-acetoxy-2-methyl benzoyl chloride is 1:0.32-0.47; the concentration of the surface additive is 0.5-2.5 wt%.

3. The method for preparing a low-conductivity liquid crystal glass substrate pad paper according to claim 2, characterized in that: the mass ratio of the bleached conifer pulp to the bleached broadleaf wood pulp is 1:0.8-3.

4. The method of claim 2, wherein the low- conductivity liquid-crystal glass substrate backing paper is prepared by the steps of: the pulp consistency of the beating is 3.5%-4.5%, the degree of beating is 35-45°SR, and the wet weight is 2.0-4.0 g. ​ 5. The method for preparing a low-conductivity liquid crystal glass substrate pad paper according to claim 2, characterized in that: the pH regulator is selected from one of boric acid, citric acid, or aluminum sulfate.

6. The method of claim 2, wherein the low- conductivity liquid-crystal glass substrate dunnage is prepared by the steps of: the addition amount of the pH regulator is 5-25 kg / ton of paper. ​ 7. The use of the carboxymethyl cellulose derivatives prepared by the preparation method of claim 2 in the preparation of low-conductivity liquid crystal glass substrate backing paper.

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