CN111608016B - High-strength and high-flexibility crepe paper and preparation method thereof - Google Patents
High-strength and high-flexibility crepe paper and preparation method thereof Download PDFInfo
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- CN111608016B CN111608016B CN202010317659.5A CN202010317659A CN111608016B CN 111608016 B CN111608016 B CN 111608016B CN 202010317659 A CN202010317659 A CN 202010317659A CN 111608016 B CN111608016 B CN 111608016B
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- 238000002360 preparation method Methods 0.000 title claims abstract description 10
- 229920000587 hyperbranched polymer Polymers 0.000 claims abstract description 73
- -1 polyimino Polymers 0.000 claims abstract description 54
- 238000004537 pulping Methods 0.000 claims abstract description 30
- 238000001035 drying Methods 0.000 claims abstract description 25
- 229920001131 Pulp (paper) Polymers 0.000 claims abstract description 22
- 239000000835 fiber Substances 0.000 claims abstract description 21
- 206010040954 Skin wrinkling Diseases 0.000 claims abstract description 20
- 239000011268 mixed slurry Substances 0.000 claims abstract description 18
- 238000010009 beating Methods 0.000 claims abstract description 16
- 238000002156 mixing Methods 0.000 claims abstract description 14
- 238000007872 degassing Methods 0.000 claims abstract description 10
- 238000007865 diluting Methods 0.000 claims abstract description 10
- 238000012216 screening Methods 0.000 claims abstract description 10
- 238000003756 stirring Methods 0.000 claims abstract description 10
- 239000002002 slurry Substances 0.000 claims abstract description 9
- 239000002994 raw material Substances 0.000 claims abstract description 5
- 239000002023 wood Substances 0.000 claims abstract description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 48
- BAPJBEWLBFYGME-UHFFFAOYSA-N Methyl acrylate Chemical compound COC(=O)C=C BAPJBEWLBFYGME-UHFFFAOYSA-N 0.000 claims description 34
- RPNUMPOLZDHAAY-UHFFFAOYSA-N Diethylenetriamine Chemical compound NCCNCCN RPNUMPOLZDHAAY-UHFFFAOYSA-N 0.000 claims description 29
- 238000000034 method Methods 0.000 claims description 28
- 150000001732 carboxylic acid derivatives Chemical class 0.000 claims description 22
- 150000003242 quaternary ammonium salts Chemical group 0.000 claims description 22
- 230000008569 process Effects 0.000 claims description 17
- 239000011259 mixed solution Substances 0.000 claims description 15
- YQFOHQBSENCNTR-UHFFFAOYSA-M oxiran-2-ylmethyl(tripropyl)azanium;chloride Chemical compound [Cl-].CCC[N+](CCC)(CCC)CC1CO1 YQFOHQBSENCNTR-UHFFFAOYSA-M 0.000 claims description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 11
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 10
- 229910000831 Steel Inorganic materials 0.000 claims description 9
- 239000010959 steel Substances 0.000 claims description 9
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 8
- 239000011261 inert gas Substances 0.000 claims description 8
- 239000002253 acid Substances 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 7
- 239000007795 chemical reaction product Substances 0.000 claims description 6
- 238000001914 filtration Methods 0.000 claims description 5
- 239000000243 solution Substances 0.000 claims description 5
- 230000002194 synthesizing effect Effects 0.000 claims description 2
- 230000000844 anti-bacterial effect Effects 0.000 abstract description 6
- 238000006243 chemical reaction Methods 0.000 description 15
- 229920002678 cellulose Polymers 0.000 description 12
- 239000001913 cellulose Substances 0.000 description 12
- 229910052739 hydrogen Inorganic materials 0.000 description 11
- 239000001257 hydrogen Substances 0.000 description 11
- 241000894006 Bacteria Species 0.000 description 10
- 230000000052 comparative effect Effects 0.000 description 10
- 125000001841 imino group Chemical group [H]N=* 0.000 description 9
- 238000004806 packaging method and process Methods 0.000 description 9
- 238000005516 engineering process Methods 0.000 description 8
- 239000002893 slag Substances 0.000 description 7
- 230000015572 biosynthetic process Effects 0.000 description 6
- 238000005520 cutting process Methods 0.000 description 6
- 238000003786 synthesis reaction Methods 0.000 description 6
- 125000003277 amino group Chemical group 0.000 description 5
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 5
- 238000009740 moulding (composite fabrication) Methods 0.000 description 5
- FERIUCNNQQJTOY-UHFFFAOYSA-N Butyric acid Chemical compound CCCC(O)=O FERIUCNNQQJTOY-UHFFFAOYSA-N 0.000 description 4
- 238000004132 cross linking Methods 0.000 description 4
- 125000004433 nitrogen atom Chemical group N* 0.000 description 4
- 229920000742 Cotton Polymers 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 125000004185 ester group Chemical group 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 239000005022 packaging material Substances 0.000 description 3
- 239000002981 blocking agent Substances 0.000 description 2
- 210000002421 cell wall Anatomy 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 239000004744 fabric Substances 0.000 description 2
- FUZZWVXGSFPDMH-UHFFFAOYSA-N hexanoic acid Chemical compound CCCCCC(O)=O FUZZWVXGSFPDMH-UHFFFAOYSA-N 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- WWZKQHOCKIZLMA-UHFFFAOYSA-N octanoic acid Chemical compound CCCCCCCC(O)=O WWZKQHOCKIZLMA-UHFFFAOYSA-N 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 235000017166 Bambusa arundinacea Nutrition 0.000 description 1
- 235000017491 Bambusa tulda Nutrition 0.000 description 1
- 241001330002 Bambuseae Species 0.000 description 1
- 206010016322 Feeling abnormal Diseases 0.000 description 1
- 235000015334 Phyllostachys viridis Nutrition 0.000 description 1
- 238000007259 addition reaction Methods 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 230000001580 bacterial effect Effects 0.000 description 1
- 239000011425 bamboo Substances 0.000 description 1
- 239000011203 carbon fibre reinforced carbon Chemical group 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 125000003700 epoxy group Chemical group 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 238000010409 ironing Methods 0.000 description 1
- 238000006068 polycondensation reaction Methods 0.000 description 1
- 125000002924 primary amino group Chemical group [H]N([H])* 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 238000007142 ring opening reaction Methods 0.000 description 1
- 230000001954 sterilising effect Effects 0.000 description 1
- 238000004659 sterilization and disinfection Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- 230000037303 wrinkles Effects 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H27/00—Special paper not otherwise provided for, e.g. made by multi-step processes
- D21H27/02—Patterned paper
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
- C08G73/02—Polyamines
- C08G73/0206—Polyalkylene(poly)amines
- C08G73/0213—Preparatory process
- C08G73/0226—Quaternisation of polyalkylene(poly)amines
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H11/00—Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/20—Macromolecular organic compounds
- D21H17/33—Synthetic macromolecular compounds
- D21H17/34—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
- D21H17/41—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups
- D21H17/44—Synthetic macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing ionic groups cationic
- D21H17/45—Nitrogen-containing groups
- D21H17/455—Nitrogen-containing groups comprising tertiary amine or being at least partially quaternised
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Paper (AREA)
- Macromolecular Compounds Obtained By Forming Nitrogen-Containing Linkages In General (AREA)
Abstract
The invention relates to the technical field of papermaking, and discloses high-strength and high-flexibility crepe paper and a preparation method thereof. The crepe paper comprises the following raw materials in parts by weight: 90-96 parts of coniferous needle and 4-10 parts of polyimino hyperbranched polymer. The preparation method comprises the following steps: carrying out disintegration and fiber defibering treatment on the coniferous wood to obtain wood pulp; pulping wood pulp to fibrillate fibers, and controlling the beating degree to be 22-35 DEG SR; adding the polyimino hyperbranched polymer into the pulped slurry, and stirring and mixing to obtain mixed slurry; and diluting, deslagging, degassing, screening the mixed slurry, then carrying out mesh part forming, squeezing and dewatering, drying, and then carrying out wrinkling treatment, thus obtaining the high-strength and high-flexibility crepe paper after drying. The crepe paper has good flexibility, high dry strength, difficult breakage when stretched and good antibacterial capacity.
Description
Technical Field
The invention relates to the technical field of papermaking, in particular to high-strength and high-flexibility crepe paper and a preparation method thereof.
Background
The crepe paper is a packaging material for a trolley, an operating room table surface, a spread sheet in an aseptic area and the like, and is suitable for sterilization after packaging of medical equipment. As a disposable packaging material, the crepe paper is used for packaging hospital regeneration equipment, can overcome the defect of short storage life of the traditional cotton cloth packaging material, saves the links of cotton cloth packaging such as recovery, cleaning, ironing, finishing, transportation and the like, is convenient to use, and has very wide market prospect.
Chinese patent publication No. CN104088191A discloses a medical crepe paper base paper and a manufacturing method thereof, the manufacturing method comprises the following steps: (1) respectively pulping 30-50 parts by weight of bamboo pulp and 25-40 parts by weight of cotton pulp by using a hydraulic pulper, and pulping by using a tandem double disc mill until the pulp reaches 18-25 DEG SR and 21-24 DEG SR respectively; (2) pumping the two pulped pulps to a mixing tank for fully mixing to obtain mixed pulp, and then mixing the mixed pulp with 15-30 parts by weight of wood pulp pulped to 15-25 DEG SR in advance to obtain total mixed pulp; (3) feeding the total mixed pulp into a stainless steel mixing tank, adding 0.5-1.5 parts by weight of PPE wet strength agent into the stainless steel mixing tank, and uniformly stirring to obtain paper pulp; (4) pulp grinding → homogenizing → paper making → wrinkling → drying to obtain the medical crepe paper base paper. Although the wet strength of the crepe base paper is increased by the wet strength agent, the dry strength of the crepe base paper is limited and the crepe base paper is easily broken when tensioned.
Disclosure of Invention
In order to solve the technical problems, the invention provides high-strength and high-flexibility crepe paper and a preparation method thereof. The crepe paper has good flexibility, high dry strength and low possibility of being damaged when stretched.
The specific technical scheme of the invention is as follows:
the high-strength and high-flexibility crepe paper comprises the following raw materials in parts by weight: 90-96 parts of coniferous needle and 4-10 parts of polyimino hyperbranched polymer.
the-NH-in the multi-imino hyperbranched polymer molecular chain can form hydrogen bonds with hydroxyl in cellulose, so that the hydrogen bonds participate in the hydrogen bond combination of cellulose molecules on the surface of the fiber, the number of the hydrogen bonds naturally formed in a combination area among fibers is supplemented, the binding force among the fibers is increased, and the tensile strength of the crepe paper is increased. Meanwhile, a large number of-C-N-flexible chain structures exist in the polyimino hyperbranched polymer, the flexibility of a molecular chain is large, and compared with the mode that cellulose is directly crosslinked through hydroxyl, the flexibility of paper can be improved through crosslinking of the polyimino hyperbranched polymer.
Preferably, the polyimino hyperbranched polymer is a quaternary ammonium salt modified polyimino hyperbranched polymer.
The quaternary ammonium salt modified polyimino hyperbranched polymer grafts the quaternary ammonium salt on the molecular chain of the polyimino hyperbranched polymer, and the quaternary ammonium salt can penetrate through the bacterial cell wall and kill bacteria, so that the crepe paper can have an antibacterial function and prevent medical instruments from being polluted by the bacteria.
Preferably, the preparation process of the quaternary ammonium salt modified multi-imino hyperbranched polymer is as follows:
(a) dissolving a polyimino hyperbranched polymer into water, adding a glycidyl tripropyl ammonium chloride solution, and reacting for 3-5 h at 90-100 ℃;
(b) adding acetone to precipitate the reaction product, filtering, and dissolving the filter residue with ethanol;
(c) and (c) repeating the step (b) for 2-3 times, and drying filter residues to obtain the quaternary ammonium salt modified multi-imino hyperbranched polymer.
The principle of modification of the polyimino hyperbranched polymer is that epoxy groups in glycidyl tripropyl ammonium chloride and imino groups in the hyperbranched polymer are subjected to ring-opening reaction, so that quaternary ammonium salt groups are grafted to the polyimino hyperbranched polymer, and the reaction formula of the imino groups and the glycidyl tripropyl ammonium chloride is as follows:
in addition to endowing the multi-imino hyperbranched polymer with antibacterial capacity, glycidyl tripropyl ammonium chloride can increase steric hindrance by grafting to N atoms in-NH-and inhibit hydrogen bonds from being formed between the N atoms and-OH of cellulose, so that the number of imino groups in the multi-imino hyperbranched polymer, which can form hydrogen bonds with hydroxyl groups, can be reduced, and the phenomenon that the softness of crepe paper is influenced due to excessive crosslinking of the cellulose caused by excessive number of the imino groups can be prevented.
Preferably, in the step (a), the mass ratio of the polyimino hyperbranched polymer to the glycidyl tripropyl ammonium chloride is 1: 8-15.
The relative amount of the polyimino hyperbranched polymer and the glycidyl tripropyl ammonium chloride needs to be controlled within a certain range for the following reasons: if the relative dosage of the polyimino hyperbranched polymer is too large, the antibacterial capacity of the glycidyl tripropyl ammonium chloride on the crepe paper is limited, and the cellulose is excessively crosslinked due to a large amount of imino groups in the molecular chain of the hyperbranched polymer, so that the flexibility of the crepe paper is influenced; if the relative amount of glycidyl tripropyl ammonium chloride is too large, the imino group in the polyimino hyperbranched polymer is insufficient, and the effect of enhancing the dry strength of crepe paper is limited. According to the invention, a large number of experiments are researched, the mass ratio of the polyimino hyperbranched polymer to the glycidyl tripropyl ammonium chloride is controlled within the range of 1: 8-15, and the crepe paper can be ensured to have high dry strength and good flexibility.
Preferably, the preparation process of the polyimino hyperbranched polymer is as follows:
(i) synthesizing: dropwise adding a mixed solution of methyl acrylate and methanol into diethylenetriamine under the protection of inert gas, wherein the molar ratio of the diethylenetriamine to the methyl acrylate is 1: 1-2, reacting at 20-25 ℃ for 3-4 h, distilling under reduced pressure to remove the methanol, heating to 130-150 ℃, and reacting at 0.1-0.5 kPa for 1.5-2.5 h;
(ii) end capping: adding diethylenetriamine and blocked carboxylic acid in a molar ratio of 1: 8-10 into the mixed solution obtained in the step (i), continuously reacting for 1-2 h at 130-150 ℃ and 0.1-0.5 kPa, and then continuously reacting until the acid value is reduced to below 30 by pressurizing to 0.06-0.08 MPa.
In the step (i), amino in diethylenetriamine and carbon-carbon double bond in methyl acrylate are subjected to addition reaction to mainly generate two products; and then, by the reaction between the ester group and the amino group, the two reactants and the two reaction products are subjected to polycondensation to form the polyimino hyperbranched polymer. The reaction of the synthesis process of the polyimino hyperbranched polymer in the process is as follows:
in the step (ii), the blocked carboxylic acid is linked to the amino group of diethylenetriamine to prevent the amino group at the terminal of the hyperbranched polymer from continuing to react with the ester group to extend the molecular chain, thereby controlling the molecular chain length and preventing the cellulose from being excessively crosslinked due to the excessively long chain to affect the flexibility of the crepe paper.
Preferably, in step (ii), the end-capping carboxylic acid is a flexible chain carboxylic acid.
The flexible chain carboxylic acid is used as the end capping agent, so that the influence of the flexible chain carboxylic acid on the flexibility of the multi-imino hyperbranched polymer molecular chain can be prevented, and the flexibility of the crepe paper can be ensured.
Preferably, in step (ii), the flexible chain carboxylic acid is CH3(CH2)nCOOH, wherein n is 2-8.
A method for preparing the high-strength and high-flexibility crepe paper comprises the following steps:
(1) pulping: carrying out disintegration and fiber defibering treatment on the coniferous wood to obtain wood pulp;
(2) pulping: pulping wood pulp to fibrillate fibers, and controlling the beating degree to be 22-35 DEG SR;
(3) modulation: adding the polyimino hyperbranched polymer into the pulped slurry, and stirring and mixing to obtain mixed slurry;
(4) copying: and diluting, deslagging, degassing, screening the mixed slurry, then carrying out mesh part forming, squeezing and dewatering, drying, and then carrying out wrinkling treatment, thus obtaining the high-strength and high-flexibility crepe paper after drying.
Preferably, in the step (4), the wet vat creping technology is adopted for the creping treatment, and the water content of the paper discharged from the vat is controlled to be 55-65%.
Preferably, in the step (4), the wrinkling treatment adopts a steel scraper with the hardness 10-15 lower than that of the vat and the thickness of 0.7-0.8 mm, and the included angle between the scraper and the vat is 7-9 degrees.
By controlling the thickness of the scraper and the included angle between the scraper and the vat, wrinkles can be fine and deep, so that the flexibility of the paper is increased, and smooth and soft feeling is given to people.
Compared with the prior art, the invention has the following advantages:
(1) the addition of the polyimino hyperbranched polymer can enable the crepe paper to have higher dry strength and softness;
(2) the quaternary ammonium salt modified multi-imino hyperbranched polymer can enable the crepe paper to have better antibacterial capacity and flexibility.
Detailed Description
The present invention will be further described with reference to the following examples.
General examples
The high-strength and high-flexibility crepe paper is prepared by the following steps:
(1) preparing a polyimino hyperbranched polymer:
(1.1) Synthesis: dropwise adding a mixed solution of methyl acrylate and methanol into diethylenetriamine under the protection of inert gas, wherein the molar ratio of the diethylenetriamine to the methyl acrylate is 1: 1-2, reacting at 20-25 ℃ for 3-4 h, distilling under reduced pressure to remove the methanol, heating to 130-150 ℃, and reacting at 0.1-0.5 kPa for 1.5-2.5 h;
(1.2) end capping: adding diethylenetriamine and blocked carboxylic acid in a molar ratio of 1: 8-10 into the mixed solution obtained in the step (1.1), continuously reacting for 1-2 hours at 130-150 ℃ and 0.1-0.5 kPa, and then pressurizing to 0.06-0.08 MPa to continuously react until the acid value is reduced to below 30; the end-capped carboxylic acid is CH3(CH2)nCOOH, wherein n is 2-8.
(2) Pulping: taking 90-96 parts of coniferous leaves, and performing disintegration and fiber fluffing treatment to obtain wood pulp;
(3) pulping: pulping wood pulp to fibrillate fibers, and controlling the beating degree to be 22-35 DEG SR;
(4) modulation: adding 4-10 parts of the polyimino hyperbranched polymer prepared in the step (1) into the pulped slurry, and stirring and mixing to obtain mixed slurry;
(5) copying: diluting the mixed slurry, removing slag, degassing, screening, and then carrying out net part forming, squeezing dehydration and drying; then, carrying out wrinkling treatment by adopting a wet vat wrinkling technology, wherein a steel scraper with the hardness being 10-15% lower than that of the vat and the thickness being 0.7-0.8 mm is adopted in the process, the included angle between the scraper and the vat is 7-9 degrees, and the water content of paper discharged from the vat is controlled to be 55-65%; drying to obtain the high-strength and high-flexibility crepe paper.
Optionally, the polyimino hyperbranched polymer is used after being modified by quaternary ammonium salt, and the modification steps are as follows:
(a) dissolving a polyimino hyperbranched polymer into water, adding a glycidyl tripropyl ammonium chloride solution, and reacting for 3-5 h at 90-100 ℃; wherein the mass ratio of the polyimino hyperbranched polymer to the glycidyl tripropyl ammonium chloride is 1: 8-15;
(b) adding acetone to precipitate the reaction product, filtering, and dissolving the filter residue with ethanol;
(c) and (c) repeating the step (b) for 2-3 times, and drying filter residues to obtain the quaternary ammonium salt modified multi-imino hyperbranched polymer.
Example 1
The high-strength and high-flexibility crepe paper is prepared by the following steps:
(1) preparing a polyimino hyperbranched polymer:
(1.1) Synthesis: dropwise adding a mixed solution of methyl acrylate and methanol into diethylenetriamine under the protection of inert gas, wherein the molar ratio of the diethylenetriamine to the methyl acrylate is 1:2, reacting at 25 ℃ for 3h, distilling under reduced pressure to remove the methanol, heating to 140 ℃, and reacting at 0.3kPa for 2 h;
(1.2) end capping: adding diethylenetriamine and a blocked carboxylic acid in a molar ratio of 1:8 into the mixed solution obtained in the step (1.1), continuing the reaction at 140 ℃ and 0.3kPa for 2h, and then continuing the reaction under a pressure of 0.07MPa until the acid value is reduced to below 30; the end-capped carboxylic acid is n-butyric acid;
(2) pulping: taking 96 parts of needle leaves, and obtaining wood pulp after pulping by a hydrapulper and defibering by a defibering machine;
(3) pulping: conveying the wood pulp into a disc grinder for beating, fibrillating fibers, and controlling the beating degree to be 30 DEG SR;
(4) modulation: adding 4 parts of the polyimino hyperbranched polymer prepared in the step (1) into the pulped slurry, and stirring and mixing to obtain mixed slurry;
(5) copying: diluting the mixed slurry, removing slag, degassing, screening, forming a net part by using a circular net former, and then squeezing, dehydrating and drying; then adopting a wet method vat wrinkling technology to carry out wrinkling treatment, wherein a steel scraper with the hardness 15 lower than that of the vat and the thickness of 0.7mm is adopted in the process, the included angle between the scraper and the vat is 7 degrees, and the water content of paper discharged from the vat is controlled to be 60 percent; drying to obtain high-strength and high-flexibility crepe paper;
(6) and (4) rewinding the high-strength and high-flexibility crepe paper which is manufactured by the paper making process, and performing edge cutting, slitting and packaging.
Example 2
The high-strength and high-flexibility crepe paper is prepared by the following steps:
(1) preparing a polyimino hyperbranched polymer:
(1.1) Synthesis: dropwise adding a mixed solution of methyl acrylate and methanol into diethylenetriamine under the protection of inert gas, wherein the molar ratio of the diethylenetriamine to the methyl acrylate is 1:1, reacting for 4 hours at 20 ℃, distilling under reduced pressure to remove the methanol, heating to 130 ℃, and reacting for 2.5 hours at 0.1 kPa;
(1.2) end capping: adding diethylenetriamine and a blocked carboxylic acid in a molar ratio of 1:9 into the mixed solution obtained in the step (1.1), continuing the reaction at 130 ℃ and 0.1kPa for 1.5h, and then continuing the reaction under a pressure of 0.06MPa until the acid value is reduced to below 30; the end-capped carboxylic acid is n-hexanoic acid;
(2) pulping: taking 93 parts of needle leaves, and obtaining wood pulp after pulping by a hydrapulper and defibering by a defibering machine;
(3) pulping: conveying the wood pulp into a disc grinder for beating, fibrillating fibers, and controlling the beating degree to be 22 DEG SR;
(4) modulation: adding 7 parts of the polyimino hyperbranched polymer prepared in the step (1) into the pulped slurry, and stirring and mixing to obtain mixed slurry;
(5) copying: diluting the mixed slurry, removing slag, degassing, screening, forming a net part by using a circular net former, and then squeezing, dehydrating and drying; then adopting a wet large cylinder wrinkling technology to perform wrinkling treatment, wherein a steel scraper with the hardness lower than that of a large cylinder by 10 and the thickness of 0.8mm is adopted in the process, the included angle between the scraper and the large cylinder is 8 degrees, and the moisture of paper discharged from the large cylinder is controlled to be 55 percent; drying to obtain high-strength and high-flexibility crepe paper;
(6) and (4) rewinding the high-strength and high-flexibility crepe paper which is manufactured by the paper making process, and performing edge cutting, slitting and packaging.
Example 3
The high-strength and high-flexibility crepe paper is prepared by the following steps:
(1) preparing a polyimino hyperbranched polymer:
(1.1) Synthesis: dropwise adding a mixed solution of methyl acrylate and methanol into diethylenetriamine under the protection of inert gas, wherein the molar ratio of the diethylenetriamine to the methyl acrylate is 1:1.5, reacting at 25 ℃ for 3h, then distilling under reduced pressure to remove the methanol, raising the temperature to 150 ℃, and reacting at 0.5kPa for 1.5 h;
(1.2) end capping: adding diethylenetriamine and a blocked carboxylic acid in a molar ratio of 1:10 into the mixed solution obtained in the step (1.1), continuing the reaction at 150 ℃ and 0.5kPa for 1h, and then continuing the reaction under a pressure of 0.08MPa until the acid value is reduced to below 30; the end-capped carboxylic acid is n-octanoic acid;
(2) pulping: taking 90 parts of needle leaves, and obtaining wood pulp after pulping by a hydrapulper and defibering by a defibering machine;
(3) pulping: conveying the wood pulp into a disc mill for beating, fibrillating fibers, and controlling the beating degree to be 22-35 DEG SR;
(4) modulation: adding 10 parts of the polyimino hyperbranched polymer prepared in the step (1) into the pulped slurry, and stirring and mixing to obtain mixed slurry;
(5) copying: diluting the mixed slurry, removing slag, degassing, screening, forming a net part by using a circular net former, and then squeezing, dehydrating and drying; then adopting a wet method vat wrinkling technology to carry out wrinkling treatment, wherein a steel scraper with the hardness lower than that of the vat by 10 and the thickness of 0.8mm is adopted in the process, the included angle between the scraper and the vat is 9 degrees, and the water content of paper discharged from the vat is controlled to be 65 percent; drying to obtain high-strength and high-flexibility crepe paper;
(6) and (4) rewinding the high-strength and high-flexibility crepe paper which is manufactured by the paper making process, and performing edge cutting, slitting and packaging.
Example 4
The high-strength and high-flexibility crepe paper is prepared by the following steps:
(1) preparing a polyimino hyperbranched polymer:
(1.1) Synthesis: dropwise adding a mixed solution of methyl acrylate and methanol into diethylenetriamine under the protection of inert gas, wherein the molar ratio of the diethylenetriamine to the methyl acrylate is 1:2, reacting at 25 ℃ for 3h, distilling under reduced pressure to remove the methanol, heating to 140 ℃, and reacting at 0.3kPa for 2 h;
(1.2) end capping: adding diethylenetriamine and a blocked carboxylic acid in a molar ratio of 1:8 into the mixed solution obtained in the step (1.1), continuing the reaction at 140 ℃ and 0.3kPa for 1.5h, and then continuing the reaction under a pressure of 0.07MPa until the acid value is reduced to below 30; the end-capped carboxylic acid is n-butyric acid;
(2) preparing a quaternary ammonium salt modified multi-imino hyperbranched polymer:
(2.1) dissolving the polyimino hyperbranched polymer prepared in the step (1) into water, adding a glycidyl tripropyl ammonium chloride solution, and reacting for 4 hours at 95 ℃; wherein the mass ratio of the polyimino hyperbranched polymer to the glycidyl tripropyl ammonium chloride is 1: 10;
(2.2) adding acetone to precipitate a reaction product, filtering, dissolving filter residues by using ethanol, adding acetone to precipitate the reaction product, and filtering;
(2.3) drying the filter residue obtained in the step (2.2) to obtain the quaternary ammonium salt modified polyimino hyperbranched polymer;
(3) pulping: taking 96 parts of needle leaves, and obtaining wood pulp after pulping by a hydrapulper and defibering by a defibering machine;
(4) pulping: conveying the wood pulp into a disc grinder for beating, fibrillating fibers, and controlling the beating degree to be 30 DEG SR;
(5) modulation: adding 4 parts of the quaternary ammonium salt modified polyimino hyperbranched polymer prepared in the step (2) into the pulped slurry, and stirring and mixing to obtain mixed slurry;
(6) copying: diluting the mixed slurry, removing slag, degassing, screening, forming a net part by using a circular net former, and then squeezing, dehydrating and drying; then adopting a wet method vat wrinkling technology to carry out wrinkling treatment, wherein a steel scraper with the hardness 15 lower than that of the vat and the thickness of 0.7mm is adopted in the process, the included angle between the scraper and the vat is 7 degrees, and the water content of paper discharged from the vat is controlled to be 60 percent; drying to obtain high-strength and high-flexibility crepe paper;
(7) and (4) rewinding the high-strength and high-flexibility crepe paper which is manufactured by the paper making process, and performing edge cutting, slitting and packaging.
Comparative example 1
The high-strength and high-flexibility crepe paper is prepared by the following steps:
(1) pulping: pulping the needle leaves by a hydrapulper and defibering by a defibering machine to obtain wood pulp;
(2) pulping: conveying the wood pulp into a disc grinder for beating, fibrillating fibers, and controlling the beating degree to be 30 DEG SR;
(3) copying: diluting the pulped pulp, removing slag, degassing, screening, performing net part forming by using a circular net former, and then squeezing, dehydrating and drying; then adopting a wet method vat wrinkling technology to carry out wrinkling treatment, wherein a steel scraper with the hardness 15 lower than that of the vat and the thickness of 0.7mm is adopted in the process, the included angle between the scraper and the vat is 7 degrees, and the water content of paper discharged from the vat is controlled to be 60 percent; drying to obtain high-strength and high-flexibility crepe paper;
(4) and (4) rewinding the high-strength and high-flexibility crepe paper which is manufactured by the paper making process, and performing edge cutting, slitting and packaging.
Comparative example 2
The high-strength and high-flexibility crepe paper is prepared by the following steps:
(1) preparing a polyimino hyperbranched polymer: dropwise adding a mixed solution of methyl acrylate and methanol into diethylenetriamine under the protection of inert gas, wherein the molar ratio of the diethylenetriamine to the methyl acrylate is 1:1, reacting at 25 ℃ for 3h, distilling under reduced pressure to remove the methanol, heating to 140 ℃, and reacting at 0.3kPa for 4 h;
(2) pulping: taking 96 parts of needle leaves, and obtaining wood pulp after pulping by a hydrapulper and defibering by a defibering machine;
(3) pulping: conveying the wood pulp into a disc grinder for beating, fibrillating fibers, and controlling the beating degree to be 30 DEG SR;
(4) modulation: adding 4 parts of the polyimino hyperbranched polymer prepared in the step (1) into the pulped slurry, and stirring and mixing to obtain mixed slurry;
(5) copying: diluting the mixed slurry, removing slag, degassing, screening, forming a net part by using a circular net former, and then squeezing, dehydrating and drying; then adopting a wet method vat wrinkling technology to carry out wrinkling treatment, wherein a steel scraper with the hardness 15 lower than that of the vat and the thickness of 0.7mm is adopted in the process, the included angle between the scraper and the vat is 7 degrees, and the water content of paper discharged from the vat is controlled to be 60 percent; drying to obtain high-strength and high-flexibility crepe paper;
(6) and (4) rewinding the high-strength and high-flexibility crepe paper which is manufactured by the paper making process, and performing edge cutting, slitting and packaging.
The crepe papers obtained in examples 1 to 4 and comparative examples 1 to 2 were tested for tensile strength, elongation, clark drape value, and bacteria resistance, and the results are shown in table 1. The clark drape value can be used to characterize creped paper softness, with a lower clark drape value indicating greater softness.
TABLE 1
Comparative example 1 is different from example 1 in that example 1 has a polyimino hyperbranched polymer added to crepe paper, and comparative example 1 has no polyimino hyperbranched polymer added thereto, and the other conditions are the same. As seen from table 1, the crepe paper prepared in example 1 has significantly increased tensile strength, elongation, and bacteria resistance, reduced clark drape value, and better softness from the hand, compared to comparative example 1. The reason for this may be: the-NH-in the multi-imino hyperbranched polymer can form hydrogen bonds with hydroxyl in cellulose so as to participate in the hydrogen bond combination of cellulose molecules on the surface of the fiber, supplement the number of the hydrogen bonds naturally formed in a combination area among fibers, and increase the binding force among the fibers, so that the tensile strength and the elongation of the crepe paper can be increased, and the bacteria resistance of the crepe paper can be improved by improving the crosslinking degree among the fibers; meanwhile, the multi-imino hyperbranched polymer has a large number of-C-N-flexible chain structures, and the molecular chain has higher flexibility, so that the softness and the drapability of the paper can be improved.
The difference between the comparative example 2 and the example 1 is that in the preparation process of the polyimino hyperbranched polymer, the blocking agent and the rest of the diethylenetriamine are added after the reaction for 2 hours and then the reaction is carried out for 2 hours in the example 1, while in the comparative example 2, the reaction is continued for 4 hours, the diethylenetriamine is added once before the reaction, and the blocking agent and the diethylenetriamine are not added in the middle, and other conditions are the same. From table 1, the crepe paper prepared in example 1 has reduced tensile strength, elongation and bacteria resistance compared to comparative example 2, but the clark drape value is reduced and the crepe paper prepared in example 1 is softer from the hand. The reason for this may be: the blocked carboxylic acid is connected to the amino group of the diethylenetriamine, so that the amino group at the tail end of the hyperbranched polymer is prevented from continuously reacting with the ester group to prolong the molecular chain, the length of the molecular chain is controlled, and the phenomenon that the cellulose is excessively crosslinked due to the overlong chain to influence the flexibility of the crepe paper is prevented.
Example 4 differs from example 1 in that the quaternary ammonium salt modified polyimino hyperbranched polymer is used in example 4, whereas the polyimino hyperbranched polymer used in example 1 is not modified with quaternary ammonium salt, and the other conditions are the same. From table 1, the crepe paper obtained in example 4 has a decreased tensile strength and elongation compared to example 1, but is still higher than comparative example 1, and the crepe paper obtained in example 4 has a decreased clark drape value, an increased bacteria resistance, and a softer crepe paper than example 1. The reason for this may be: the quaternary ammonium salt modified multi-imino hyperbranched polymer grafts the quaternary ammonium salt on the molecular chain of the multi-imino hyperbranched polymer, and the quaternary ammonium salt can penetrate through the cell wall of bacteria and kill the bacteria, so that the crepe paper can be endowed with an antibacterial function, and the bacteria resistance is improved; meanwhile, the quaternary ammonium salt is grafted to the N atom in the-NH-to increase the steric hindrance and inhibit the N atom from forming hydrogen bonds with-OH of the cellulose, so that the number of imino groups capable of forming hydrogen bonds with hydroxyl in the multi-imino hyperbranched polymer is reduced, excessive crosslinking of the cellulose caused by excessive number of imino groups is prevented, and the flexibility and the drapability of the crepe paper can be improved; and, although the reduction of the number of imino groups results in a reduction of the crepe paper tensile strength and elongation, it is still higher than the prior art without the addition of polyimino hyperbranched polymers.
The raw materials and equipment used in the invention are common raw materials and equipment in the field if not specified; the methods used in the present invention are conventional in the art unless otherwise specified.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and all simple modifications, alterations and equivalents of the above embodiments according to the technical spirit of the present invention are still within the protection scope of the technical solution of the present invention.
Claims (9)
1. The high-strength and high-flexibility crepe paper is characterized by comprising the following raw materials in parts by weight: 90-96 parts of coniferous needle and 4-10 parts of polyimino hyperbranched polymer; the preparation process of the polyimino hyperbranched polymer comprises the following steps:
(i) synthesizing: dropwise adding a mixed solution of methyl acrylate and methanol into diethylenetriamine under the protection of inert gas, wherein the molar ratio of the diethylenetriamine to the methyl acrylate is 1: 1-2, reacting at 20-25 ℃ for 3-4 h, distilling under reduced pressure to remove the methanol, heating to 130-150 ℃, and reacting at 0.1-0.5 kPa for 1.5-2.5 h;
(ii) end capping: adding diethylenetriamine and blocked carboxylic acid in a molar ratio of 1: 8-10 into the mixed solution obtained in the step (i), continuously reacting for 1-2 h at 130-150 ℃ and 0.1-0.5 kPa, and then continuously reacting until the acid value is reduced to below 30 by pressurizing to 0.06-0.08 MPa.
2. The high strength and high flexibility crepe paper according to claim 1, wherein the polyimino hyperbranched polymer is a quaternary ammonium salt modified polyimino hyperbranched polymer.
3. The high strength and high flexibility crepe paper according to claim 2, wherein the quaternary ammonium salt modified polyimino hyperbranched polymer is prepared by the following process:
(a) dissolving a polyimino hyperbranched polymer into water, adding a glycidyl tripropyl ammonium chloride solution, and reacting for 3-5 h at 90-100 ℃;
(b) adding acetone to precipitate the reaction product, filtering, and dissolving the filter residue with ethanol;
(c) and (c) repeating the step (b) for 2-3 times, and drying filter residues to obtain the quaternary ammonium salt modified multi-imino hyperbranched polymer.
4. The high-strength and high-flexibility crepe paper according to claim 3, wherein in the step (a), the mass ratio of the polyimino hyperbranched polymer to the glycidyl tripropyl ammonium chloride is 1: 8-15.
5. A high strength, high flexibility crepe paper according to claim 1, wherein in step (ii), the blocked carboxylic acid is a flexible chain carboxylic acid.
6. A high strength, high flexibility crepe paper according to claim 5, wherein in step (ii), the flexible chain carboxylic acid is CH3(CH2)nCOOH, wherein n = 2-8.
7. A method for preparing a high strength and high flexibility crepe paper according to any one of claims 1 to 6, characterised in that it comprises the following steps:
(1) pulping: carrying out disintegration and fiber defibering treatment on the coniferous wood to obtain wood pulp;
(2) pulping: pulping wood pulp to fibrillate fibers, and controlling the beating degree to be 22-35 DEG SR;
(3) modulation: adding the polyimino hyperbranched polymer into the pulped slurry, and stirring and mixing to obtain mixed slurry;
(4) copying: and diluting, deslagging, degassing, screening the mixed slurry, then carrying out mesh part forming, squeezing and dewatering, drying, and then carrying out wrinkling treatment, thus obtaining the high-strength and high-flexibility crepe paper after drying.
8. The method of claim 7, wherein in step (4), the creping process employs a wet vat creping technique that controls sheet exit vat moisture to be 55-65%.
9. The method according to claim 7 or 8, wherein in the step (4), the creping treatment is performed by using a steel doctor blade with the hardness 10-15 lower than that of the vat and the thickness 0.7-0.8 mm, and the included angle between the doctor blade and the vat is 7-9 degrees.
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