阅读说明：本技术 一种耐热防护型面料的制备工艺 (Preparation process of heat-resistant protective fabric ) 是由 卢再佰 徐敏 于 2020-05-05 设计创作，主要内容包括：本发明公开了一种耐热防护型面料的制备工艺,具体制备过程如下：将耐热型聚合物加入双螺杆挤出机中进行熔融挤出,然后通过干-湿式纺丝法纺丝,然后经过水洗、干燥得到纤维丝,接着将得到的纤维丝进行纺织制备成防护面料。本发明在面料制备过程中使用的纤维是通过抗紫外线二苯甲酸、对苯二甲酸和4,6-二氨基间苯二酚二盐酸盐聚合制备,直接将含有抗紫外线结构的抗紫外线二苯甲酸引入聚合物主链上,直接通过化学作用嵌段在聚合物中,使得制备的纤维具有较高均匀稳定的抗紫外线性能,不会由于摩擦或者洗涤而剥离。(The invention discloses a preparation process of a heat-resistant protective fabric, which comprises the following specific preparation processes: adding a heat-resistant polymer into a double-screw extruder for melt extrusion, spinning by a dry-wet spinning method, washing with water, drying to obtain a fiber yarn, and spinning the obtained fiber yarn to prepare the protective fabric. The fiber used in the fabric preparation process is prepared by polymerizing the uvioresistant dibenzoic acid, the terephthalic acid and the 4, 6-diaminoresorcinol dihydrochloride, the uvioresistant dibenzoic acid containing the uvioresistant structure is directly introduced to the main chain of the polymer, and is directly blocked in the polymer through chemical action, so that the prepared fiber has higher, uniform and stable uvioresistant performance and cannot be stripped due to friction or washing.)

1. A preparation process of a heat-resistant protective fabric is characterized by comprising the following specific preparation processes:

firstly, continuously introducing nitrogen into a reaction tank for 20-30min, then adding a certain amount of 4, 6-diaminoresorcinol dihydrochloride, anti-ultraviolet dibenzoic acid, terephthalic acid, stannous chloride and polyphosphoric acid, heating to 80-83 ℃ under the protection of nitrogen for reaction for 1.5h, then adding phosphorus pentoxide into the reaction tank, heating to different temperatures for reaction for 26h, washing the obtained product with deionized water and ethanol for 5-8 times in sequence, and drying to obtain a heat-resistant polymer;

and secondly, adding the heat-resistant polymer prepared in the first step into a double-screw extruder for melt extrusion, spinning by a dry-wet spinning method, washing with water, drying to obtain fiber yarns, and spinning the obtained fiber yarns to prepare the protective fabric.

2. The process for preparing a heat-resistant protective fabric as claimed in claim 1, wherein in the first step, 4, 6-diaminoresorcinol dihydrochloride, uvioresistant dibenzoic acid and terephthalic acid are mixed according to the mass ratio of 1:0.76-0.78:0.26-0.29, wherein 7.2-7.3g of stannous chloride, 8.25-8.27kg of polyphosphoric acid and 670-675g of phosphorus pentoxide are added to each mole of 4, 6-diaminoresorcinol dihydrochloride.

3. The preparation process of the heat-resistant protective fabric according to claim 1, wherein the temperature rise process in the first step is heating to 130 ℃ for reaction for 3 hours, heating to 160 ℃ for reaction for 13 hours, and heating to 180 ℃ for reaction for 10 hours.

4. The preparation process of the heat-resistant protective fabric according to claim 1, wherein the preparation method of the ultraviolet-resistant dibenzoic acid comprises the following steps:

step 1: adding a sodium hydroxide solution with the mass concentration of 2% and acetone into a reaction tank at the same time, heating to 60-70 ℃, then adding 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole and silyl hindered amine into the reaction tank, carrying out constant-temperature reflux reaction for 7-8H, carrying out reduced pressure distillation to recover the solvent until the reactant is viscous, discharging the material when the reactant is hot, separating out crystals after the reactant is cooled slightly, filtering, washing with water and drying to obtain dibenzotriazole hindered amine;

step 2: adding 98% of aniline into a reaction tank, stirring and heating to 80 ℃, adding an acetone solution and a hydrochloric acid solution with the mass concentration of 38%, adding dibenzotriazole hindered amine, heating to 105-108 ℃, removing air in the tank, continuing heating to 130-133 ℃, controlling the pressure in the reaction tank to be maintained at 0.16-0.17MPa, carrying out heat preservation reaction for 10-10.5h, stopping heating, adding water for diluting, adding alkali for neutralizing, distilling to remove unreacted aniline, collecting an acetone solvent, cooling and crystallizing, and then washing and drying with water-ethanol in sequence to obtain the dianiline ultraviolet resistant agent;

and step 3: adding the dianiline-based anti-ultraviolet agent, anhydrous magnesium sulfate and DMF into a reaction tank at the same time, stirring and mixing for 3-5min, dropwise adding a p-formylbenzoic acid ethanol solution with the mass concentration of 60%, controlling the dropwise adding to be complete within 2h, heating to 70-75 ℃, carrying out reflux reaction for 10-12h, distilling to recover the solvent, and then washing and drying with water and ethanol in sequence to obtain the anti-ultraviolet dibenzoic acid.

5. The process for preparing the heat-resistant protective fabric according to claim 4, wherein in the step 1, the 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole, the silyl hindered amine, the sodium hydroxide with the mass concentration of 2%, and the acetone in a mass ratio of 1: 0.65-0.66:0.21-0.23: 7-7.5.

6. The process for preparing heat-resistant protective fabric according to claim 4, wherein 198g of aniline 190-198, 1.71-1.74kg of acetone and 1.25-1.28kg of 38% hydrochloric acid solution are added to each kg of dibenzotriazole-based hindered amine in step 2.

7. The process as claimed in claim 4, wherein 252-259g of p-formylbenzoic acid, 1.23-1.25kg of DMF, and 162g of anhydrous magnesium sulfate are added to each kg of the dianilino-based anti-UV agent in step 3.

8. The preparation process of the heat-resistant protective fabric according to claim 4 or 5, wherein the silane-based hindered amine is prepared by the following specific steps: dissolving 2,2,6, 6-tetramethylpiperidone in acetone to prepare a reaction solution with the mass concentration of 40%, then adding 3-glycidyl ether oxypropyltriethoxysilane and the prepared reaction solution into a reaction tank at the same time, heating to 70-75 ℃, carrying out reflux reaction for 2-3h, then carrying out distillation to recover acetone to obtain a solid product, washing the solid product with water for 4-5 times, and drying to obtain the silyl hindered amine.

9. The process for preparing a heat-resistant protective fabric according to claim 8, wherein 2,2,6, 6-tetramethylpiperidone and 3-glycidyl ether oxypropyltriethoxysilane are mixed in a ratio of 1: 0.95-0.96.

Technical Field

The invention belongs to the field of fabric preparation, and relates to a preparation process of a heat-resistant protective fabric.

Background

Because the poly-p-phenylene benzobisoxazole fiber is an organic fiber with excellent mechanical property, heat resistance and flame retardance due to a highly ordered orientation structure of a rigid rod-shaped molecular structure of the poly-p-phenylene benzobisoxazole fiber, the poly-p-phenylene benzobisoxazole fiber is widely applied to the high temperature protection fields of fire fighting, heat insulation gloves and the like, but the poly-p-phenylene benzobisoxazole fiber cannot resist ultraviolet irradiation, the tensile strength retention rate of the poly-p-phenylene benzobisoxazole fiber is reduced to below 50% after the poly-p-phenylene benzobisoxazole fiber is irradiated for 100 hours under the action of ultraviolet rays, the use of the prepared fabric is greatly influenced, in the prior art, in order to improve the ultraviolet resistance, an ultraviolet resistant coating is coated on the surface of the fiber or an ultraviolet resistant agent is added in the fiber melting preparation process and is directly mixed through physical action, but because the prepared fabric is easy, affecting the ultraviolet resistance.

Disclosure of Invention

The invention aims to provide a preparation process of a heat-resistant protective fabric, wherein fibers used in the preparation process of the fabric are prepared by polymerizing uvioresistant dibenzoic acid, terephthalic acid and 4, 6-diaminoresorcinol dihydrochloride, the uvioresistant dibenzoic acid containing an uvioresistant structure is directly introduced to a polymer main chain, and is directly blocked in the polymer through chemical action, so that the prepared fibers have higher, uniform and stable uvioresistant performance and cannot be stripped due to friction or washing, and further, the problem that in the prior art, in order to improve the uvioresistant performance of the prepared fibers, the ultraviolet-resistant components on the surfaces are easily stripped due to long-term friction or washing action by coating a layer of uvioresistant coating on the surfaces of the fibers or adding an uvioresistant agent in the fiber melting preparation process and directly mixing through physical action is solved, but the prepared fabric is easy to strip the uviore, thereby causing the problem that the content is reduced and the ultraviolet resistance performance is influenced.

The purpose of the invention can be realized by the following technical scheme:

a preparation process of a heat-resistant protective fabric comprises the following specific preparation processes:

firstly, continuously introducing nitrogen into a reaction tank for 20-30min, then adding a certain amount of 4, 6-diaminoresorcinol dihydrochloride, anti-ultraviolet dibenzoic acid, terephthalic acid, stannous chloride and polyphosphoric acid, heating to 80-83 ℃ under the protection of nitrogen for reaction for 1.5h, then adding phosphorus pentoxide into the reaction tank, heating to different temperatures for reaction for 26h, washing the obtained product with deionized water and ethanol for 5-8 times in sequence, and drying to obtain a heat-resistant polymer;

and secondly, adding the heat-resistant polymer prepared in the first step into a double-screw extruder for melt extrusion, spinning by a dry-wet spinning method, washing with water, drying to obtain fiber yarns, and spinning the obtained fiber yarns to prepare the protective fabric.

The method comprises the following steps of carrying out polymerization reaction on two dibasic acids of anti-ultraviolet dibenzoic acid and terephthalic acid and 4, 6-diaminoresorcinol dihydrochloride simultaneously, damaging a fair surface structure and a rigid rod-shaped molecular structure of main chain molecules due to a twisted non-planar structure between two benzoic acid groups in the anti-ultraviolet dibenzoic acid in the prepared poly (p-phenylene benzobisoxazole), and further reducing the high temperature resistance of the prepared polymer.

The ultraviolet-resistant dibenzoic acid is directly blocked on a main chain of a heat-resistant polymer, so that the ultraviolet-resistant dibenzoic acid is directly grafted on the polymer through a chemical bond effect, because the ultraviolet-resistant dibenzoic acid contains an o-hydroxybenzotriazole structure, because the electronegativity of an oxygen atom is greater than that of a nitrogen atom, the density of an electron cloud is biased to the oxygen atom, the compound stably exists in a phenol structure of an intramolecular hydrogen bond, the polymer can absorb ultraviolet energy through ultraviolet irradiation, the density of the electron cloud on the nitrogen atom is increased, the intramolecular hydrogen bond is broken, protons are transferred to the nitrogen atom from the oxygen atom, and then the protons are transferred to a carbon atom of a benzene ring through the oxygen atom to form a quinone structure, because of the existence of carbon anions, the structure is unstable, the compound is converted into the phenol structure through heat release, and further, the light energy is converted into the heat energy, so that a part, and a part of absorbed energy acts on the heat-resistant polymer, the polymer generates alkyl free radicals, alkoxy free radicals and peroxy alkyl free radicals, the absorbed ultraviolet energy also acts on hindered amine groups, and the hindered amine groups generate nitroxide free radicals, wherein the nitroxide free radicals have the performance of capturing free radicals, can efficiently capture the alkyl free radicals, the alkoxy free radicals and the peroxy alkyl free radicals generated by the polymer, and further ensure that the heat-resistant polymer is not oxidized by the free radicals.

Preferably, in the first step, 4, 6-diaminoresorcinol dihydrochloride, uvioresistant dibenzoic acid and terephthalic acid are mixed according to the mass ratio of 1:0.76-0.78:0.26-0.29, wherein 7.2-7.3g of stannous chloride, 8.25-8.27kg of polyphosphoric acid and 670-675g of phosphorus pentoxide are added in each mole of 4, 6-diaminoresorcinol dihydrochloride;

preferably, the temperature rise process in the first step is raising the temperature to 130 ℃ for reaction for 3h, raising the temperature to 160 ℃ for reaction for 13h, and raising the temperature to 180 ℃ for reaction for 10 h.

The specific preparation method of the silyl hindered amine comprises the following steps:

dissolving 2,2,6, 6-tetramethylpiperidone in acetone to prepare a reaction solution with the mass concentration of 40%, then adding 3-glycidyl ether oxypropyltriethoxysilane and the prepared reaction solution into a reaction tank at the same time, heating to 70-75 ℃, carrying out reflux reaction for 2-3h, then carrying out distillation to recover acetone to obtain a solid product, washing the solid product with water for 4-5 times, and drying to obtain the silyl hindered amine.

The 3-glycidyl ether oxypropyltriethoxysilane contains epoxy groups, and can perform alkaline ring-opening reaction with amino groups in 2,2,6,6 tetramethyl piperidone, so that silane groups are introduced into hindered amine, and the high-temperature resistance of the hindered amine can be effectively improved.

Preferably, 2,2,6, 6-tetramethylpiperidone and 3-glycidoxypropyltriethoxysilane are mixed in a ratio of the amounts of the substances of 1:0.95 to 0.96.

The preparation method of the uvioresistant dibenzoic acid comprises the following steps:

step 1: adding a sodium hydroxide solution with the mass concentration of 2% and acetone into a reaction tank at the same time, heating to 60-70 ℃, then adding 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole and silyl hindered amine into the reaction tank, carrying out constant-temperature reflux reaction for 7-8H, carrying out reduced pressure distillation to recover the solvent until the reactant is viscous, discharging the material when the reactant is hot, separating out crystals after the reactant is cooled slightly, filtering, washing with water and drying to obtain dibenzotriazole hindered amine; under the alkaline condition, active hydrogen on two adjacent carbon atoms of a carbonyl group of the silyl hindered amine is abstracted by alkali to generate two carbanions, the carbanions can perform 1, 4-conjugate addition with 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole, the formed adduct abstracts a proton from a solvent to form enol, and then tautomerism is performed to form a product;

step 2: adding 98% of aniline into a reaction tank, stirring and heating to 80 ℃, adding an acetone solution and a hydrochloric acid solution with the mass concentration of 38%, adding dibenzotriazole hindered amine, heating to 105-108 ℃, removing air in the tank, continuing heating to 130-133 ℃, controlling the pressure in the reaction tank to be maintained at 0.16-0.17MPa, carrying out heat preservation reaction for 10-10.5h, stopping heating, adding water for diluting, adding alkali for neutralizing, distilling to remove unreacted aniline, collecting an acetone solvent, cooling and crystallizing, and then washing and drying with water-ethanol in sequence to obtain the dianiline ultraviolet resistant agent; amino in aniline is a strong electron-donating group, can activate a benzene ring, and can perform alkylation reaction with aldehyde and ketone at para position under the catalytic action of protonic acid;

and step 3: adding the dianiline-based anti-ultraviolet agent, anhydrous magnesium sulfate and DMF into a reaction tank at the same time, stirring and mixing for 3-5min, dropwise adding a p-formylbenzoic acid ethanol solution with the mass concentration of 60% into the reaction tank, controlling the dropwise adding to be complete within 2h, heating to 70-75 ℃, carrying out reflux reaction for 10-12h, distilling and recovering the solvent, and then washing and drying by using water and ethanol in sequence to obtain the anti-ultraviolet dibenzoic acid; the dianilino-based anti-ultraviolet agent contains a primary amine group, and can perform nucleophilic addition reaction with aldehyde group in p-formylbenzoic acid to form a compound containing-C ═ N-bond.

Preferably, in step 1, 2- [ 2-hydroxy-5- [2- (methacryloyloxy) ethyl ] phenyl ] -2H-benzotriazole, silyl hindered amine, sodium hydroxide with a mass concentration of 2%, and acetone in a mass ratio of 1: 0.65-0.66:0.21-0.23: 7-7.5;

preferably, 198g of aniline 190-198g, 1.71-1.74kg of acetone and 1.25-1.28kg of 38% hydrochloric acid solution are added into each kilogram of dibenzotriazole-based hindered amine in the step 2;

preferably, 252-259g of p-formylbenzoic acid, 1.23-1.25kg of DMF and 162g of anhydrous magnesium sulfate are added into each kilogram of the dianilino ultraviolet resistant agent in the step 3.

The invention has the beneficial effects that:

1. the fiber used in the preparation process of the fabric is prepared by polymerizing uvioresistant dibenzoic acid, terephthalic acid and 4, 6-diaminoresorcinol dihydrochloride, the uvioresistant dibenzoic acid containing an uvioresistant structure is directly introduced to a main chain of a polymer, and is directly blocked in the polymer through chemical action, so that the prepared fiber has higher, uniform and stable uvioresistant performance and cannot be stripped due to friction or washing, and further the problem that in the prior art, in order to improve the uvioresistant performance of the fabric, the uvioresistant component on the surface is easily stripped due to long-term friction or cleaning action of the prepared fabric, the uvioresistant component is directly mixed through physical action by coating a layer of uvioresistant coating on the surface of the fiber or adding an uvioresistant agent in the fiber melting preparation process is solved, the ultraviolet resistance of the glass is affected.

2. The ultraviolet-resistant dibenzoic acid contains a hindered amine structure and a benzotriazole structure, partial ultraviolet rays are firstly absorbed by the benzotriazole structure, then radicals generated by the action of residual ultraviolet rays on a polymer are captured by the hindered amine, and the influence of high-strength ultraviolet rays can be eliminated by the synergistic effect of the hindered amine and the polymer, so that the problem of weak action on ultraviolet rays caused by the independent use of an ultraviolet absorbent or a stabilizer is effectively solved.

3. According to the invention, siloxane bonds are introduced into each anti-ultraviolet dibenzoic acid, so that the high temperature resistance of the polymer can be improved, the two dibasic acids of the anti-ultraviolet dibenzoic acid and the terephthalic acid are effectively prevented from carrying out polymerization reaction with 4, 6-diaminoresorcinol dihydrochloride, and the prepared poly (p-phenylene benzobisoxazole) damages the fair surface structure and the rigid rod-shaped molecular structure of main chain molecules due to the twisted non-planar structure between two benzoic acid groups in the anti-ultraviolet dibenzoic acid, thereby reducing the high temperature resistance of the prepared polymer.

Detailed Description

The technical solution of the present invention is further illustrated by the following specific examples.

Examples and comparative examples of (a) hindered amine preparation method: