Breathable skin-friendly antibacterial sunscreen fabric and preparation method thereof

Abstract

The invention discloses a breathable skin-friendly antibacterial sunscreen fabric and a preparation method thereof. Comprising the following steps: weaving sunscreen fabric grey cloth; performing enzyme treatment before dyeing, then modifying with chitosan, dyeing the gray fabric with a lotus leaf natural dye, and performing after-finishing on the dyed gray fabric with a nano-zinc oxide finishing agent to obtain the breathable skin-friendly antibacterial sunscreen fabric. The sunscreen fabric adopts the cotton fiber and jute fiber blended fabric as the gray fabric, and has the advantages of good comfort, moisture permeability, air permeability and the like. After the fabric is subjected to chitosan modification, lotus leaf natural dye dyeing and nano ZnO finishing agent finishing, the fabric has good anti-ultraviolet performance and antibacterial effect, and the UPF value is gt; 50, the inhibition rate on escherichia coli and staphylococcus aureus reaches 90% or above, the inhibition rate on candida albicans reaches 85% or above, and the washing fastness is good. And the prepared fabric is breathable, skin-friendly, green and environment-friendly, is beneficial to keeping the body dry and comfortable, and is suitable for being worn in hot summer.

Description

Technical Field

[0001] The present invention relates to the field of functional textile fabrics, and particularly to a breathable, skin-friendly, antibacterial and sunscreen fabric and a preparation method thereof. Background Art

[0002] Ultraviolet rays are divided into three bands according to different wavelengths: UVA (400nm - 320nm), UVB (320nm - 280nm), and UVC (280nm - 200nm). In daily life, since UVC in sunlight is absorbed and blocked by the ozone layer when passing through the atmosphere, it will not cause direct harm to the human body. The remaining UVA and UVB pass through the atmosphere and reach the earth's surface. UVA accounts for 95% - 98% of the total amount of ultraviolet rays, with relatively low energy. It can penetrate glass, certain clothes, and the epidermis of humans. Excessive exposure can damage the skin and subcutaneous tissues, cause the skin to darken, induce skin diseases, and cause immune suppression, etc.; UVB accounts for 2% - 5% of the total amount of ultraviolet rays, with high energy. It can penetrate the epidermis of humans, causing sunburn, skin tumors, dermatitis, etc. Therefore, although a certain amount of ultraviolet radiation helps the human body absorb vitamin D, in most cases, we need to take protective measures against excessive ultraviolet rays to avoid damage to our skin and accelerated aging.

[0003] Conventional anti-ultraviolet fabrics mainly achieve anti-ultraviolet finishing through ultraviolet shielding agents, endowing textiles with the ability to resist ultraviolet rays. Ultraviolet shielding agents are divided into inorganic and organic categories. Inorganic ultraviolet shielding agents mainly achieve the purpose of anti-ultraviolet by reflecting or refracting ultraviolet rays. For example, fine powders such as ceramic powder and metal oxides are combined with fibers or fabrics. They have no light energy conversion effect, but simply increase the reflection of ultraviolet rays on the fabric surface, thereby preventing ultraviolet rays from penetrating the fabric. Organic ultraviolet shielding agents are called ultraviolet absorbers, which have the ability to absorb ultraviolet rays and convert them into heat energy and electromagnetic waves to achieve the purpose of anti-ultraviolet. Currently, the organic anti-ultraviolet absorbers applied to textiles mainly include ultraviolet absorbers such as salicylates, benzophenones, benzotriazoles, and triazines. Some ultraviolet absorbers have a cytotoxic effect, can cause irritation to the skin, and cause certain harm to the human body.

[0004] Most of the sunscreen clothing fabrics on the market at present are mainly made of chemical fibers. This is because there are ultraviolet absorption groups in the chemical structures of such fibers (such as polyester, acrylic, etc.), and they themselves have a certain absorption effect on ultraviolet rays. With the addition of inorganic powders or post-treatment with ultraviolet organic shielding agents, good anti-ultraviolet effects can be achieved. However, the moisture absorption performance of such fibers is often poor, and it is easy to produce a stuffy feeling after wearing, and the fabric may cause certain irritation to the skin. Natural fibers usually have high breathability and moisture absorption. Among natural fibers, hemp fibers have many voids of different sizes inside, and grooves and cracks are also distributed on the fiber surface. These special structures can effectively absorb light waves and have good anti-ultraviolet performance. Its disadvantage is that the elasticity of hemp fibers is small, the porosity of pure hemp fabrics is large, and the ultraviolet transmittance increases; aromatic amino acids in the molecular structures of protein fibers such as wool can effectively absorb part of the ultraviolet rays, but they are not used for summer clothing; and cotton has a weak absorption ability for it. Therefore, such fibers are less used in manufacturing sunscreen fabrics.

[0005] Natural plant extracts usually contain a large number of chromogenic groups, such as vinyl, carbonyl, benzene ring, etc. These unsaturated groups endow the fabric with color, and components such as polyphenols (such as flavonoids, tannins), anthraquinones (such as alizarin) and curcumin in plant dyes have strong ultraviolet absorption characteristics between 200nm and 400nm, and have good ultraviolet absorption effects. Natural plant dyes are natural components extracted from plants, have good biocompatibility and safety, and generally do not cause adverse reactions such as allergies compared with synthetic ultraviolet absorbers. Using plant dyes in sunscreen products can not only provide a certain sunscreen effect, but also reduce the harm to human skin. In the general environment of green environmental protection, circular economy, and low-carbon development, green, natural, and environmentally friendly finishing methods will be the focus of future industry development.

[0006] Although plant dyes are naturally non-toxic, have an ultraviolet absorption mechanism and broad-spectrum antibacterial activity, and have good biodegradability, they are suitable for anti-ultraviolet and antibacterial of skin-friendly textiles. However, at present, the anti-ultraviolet protection effects of most natural dyes are limited and unstable. They are easy to fade after light exposure or washing, resulting in rapid attenuation of anti-ultraviolet performance, poor color fastness and durability, and easy loss of antibacterial components after washing or rubbing. Therefore, how to improve the anti-ultraviolet and antibacterial protection intensity and durability of natural plant dyes is the problem to be further solved by the present invention. Summary of the Invention

[0007] In view of the above problems and deficiencies, the purpose of the present invention is to provide a breathable, skin-friendly, antibacterial sunscreen fabric and its preparation method, and the fabric has good moisture absorption and breathability, excellent anti-ultraviolet performance and antibacterial performance, and good durability.

[0008] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0009] An air-permeable, skin-friendly, antibacterial and sunscreen fabric and its preparation method. The preparation process includes:

[0010] S1: Weave cotton fibers and hemp fibers into a blank fabric for sunscreen fabric;

[0011] S2: Pretreat the blank fabric with a composite enzyme, clean it after the treatment is completed, and set aside for later use;

[0012] S3: Prepare a chitosan solution with a concentration of 2 - 3% using an acetic acid aqueous solution, add the blank fabric treated in S2, with a bath ratio of 1:30 - 35, modify it at 70 - 80 °C for 30 - 40 min, take it out, wash it, and set aside for later use to obtain the treated sunscreen fabric; S4: Extract natural lotus leaf dye and dye the treated blank fabric for sunscreen fabric with the natural dye;

[0013] S5: Prepare a mordant solution, mordant the dyed blank fabric, take it out, wash it clean, and dry it;

[0014] S6: Conduct post-treatment on the blank fabric dyed in S5 with a nano-zinc oxide finishing agent to obtain an air-permeable, skin-friendly, antibacterial and sunscreen fabric.

[0015] Preferably, in step S1, the fabric is made of a blend of cotton fibers and ramie fibers. Among them, the mass ratio of cotton fibers is 60% - 70%, and the mass ratio of ramie fibers is 30% - 40%. The weaving structure of the blank fabric is a plain weave structure; Further preferably, the yarn fineness of the blend of cotton fibers and hemp fibers is 40s / 1 - 60s / 1, and the fabric density is 95 g / m 2 ~110 g / m 2 .

[0016] Preferably, in step S2, the enzyme used is a composite enzyme composed of a complex of acidic cellulase and pectinase, and the mass ratio of the two is 7:3; The treatment method is to prepare an enzyme solution of 10 - 15 g / L, adjust the pH value to 4 - 5, with a bath ratio of 1:15 - 20, and treat it at 50 - 60 °C for 40 - 50 min.

[0017] Preferably, in step S4, the natural plant dye used is natural lotus leaf dye.

[0018] Further preferably, the extraction method of natural lotus leaf dye includes the following steps:

[0019] (1) Wash, remove impurities, and dry the collected lotus leaves, and then crush them to obtain lotus leaf powder;

[0020] (2) Weigh a certain amount of lotus leaf powder, add a 60 - 70% ethanol (v / v) solution, and conduct extraction at 60 - 70 °C for 1 - 2 h, with a solid-liquid ratio of 1:15 - 20;

[0021] (3) Filter after extraction, and extract the filter residue again under the same conditions once;

[0022] (4) Filter, take the supernatant, combine the two filtrates, concentrate, and freeze-dry to obtain the natural lotus leaf dye.

[0023] Flavonoids are present in relatively high amounts and in a variety of types in lotus leaves. Research shows that approximately 25 flavonoid compounds have been isolated from lotus leaves, mainly including lotus glycoside, quercetin, isoquercetin, rutin, kaempferol, etc. In addition, there are also various alkaloids. These substances have good absorption effects on ultraviolet rays and also have certain antibacterial effects.

[0024] In step S4, the method of dyeing the sunscreen fabric blank with the natural lotus leaf dye is as follows: Prepare a lotus leaf natural dye solution with a concentration of 3% - 5% o.w.f., a bath ratio of 1:30 - 1:40, pH = 7. Add the modified blank fabric, start dyeing at 30°C, keep the temperature constant at 80°C for 1 h, wring out the dye after cooling to room temperature, and take it out.

[0025] Preferably, in step S5, prepare a mordant solution with a concentration of 2 - 4% o.w.f., a bath ratio of 1:25 - 35. Mordant the dyed blank fabric at 55 - 65°C for 25 - 35 min, take it out, wash it, and dry it.

[0026] Further preferably, the mordant is alum.

[0027] Preferably, in step S6, the finishing process of the blank fabric is as follows: Prepare a nano-zinc oxide finishing solution with a concentration of 10 - 20 g / L. Dip and roll the blank fabric twice (the pick-up rate is 60% - 70%), and dry it at 70°C - 90°C.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] 1. The present invention uses a blended fabric of cotton fiber and hemp fiber as the blank fabric, enabling the fabric to combine the advantages of cotton and hemp, having good comfort, breathability, abrasion resistance, and stiffness. In hot weather, the heat and sweat generated by the human body can be dissipated in a timely manner, making it more comfortable to wear.

[0030] 2. The present invention uses the natural lotus leaf dye as a dyeing agent to dye the fabric. While endowing the fabric with color, it can also provide good anti-ultraviolet and antibacterial effects, having good biocompatibility and safety, and no irritation to human skin. Before dyeing, it is modified by chitosan, and after dyeing, it is compounded with nano-zinc oxide. The amino group of chitosan forms a coordination bond with the polyphenol hydroxyl group of the dye, and nano-zinc oxide is anchored on the fiber surface through hydrogen bonds, forming a physical barrier layer, and forming a triple protection system of chitosan modification-natural dye complexation-nano-zinc oxide between the natural dye, realizing double protection at the molecular-nano level and improving the long-term anti-ultraviolet and antibacterial properties.

[0031] 3. The present invention also uses a composite enzyme (acidic cellulase and pectinase) treatment to expose more active sites on the fabric, providing more anchoring points for the subsequent adsorption of chitosan and dyes, and also improving the fiber breathability. Chitosan modification cationizes the fabric surface, significantly enhancing the dye uptake rate and color fastness of the lotus leaf dye. The ultraviolet shielding effect of nano-zinc oxide can also slow down the photo-degradation of the natural lotus leaf dye, effectively improving the color fastness. In addition, the different antibacterial mechanisms of chitosan and nano-zinc oxide can play a synergistic antibacterial effect. The destructiveness of chitosan to the bacterial cell membrane is conducive to the entry of Zn 2+ in 2+ and the reactive oxygen species generated by catalysis into the cell to damage intracellular substances, improving the antibacterial performance. Detailed implementation manners

[0032] The present invention will be further described below. The following examples are only used to more clearly illustrate the technical solution of the present invention and cannot be used to limit the protection scope of the present invention.

[0033] Example 1

[0034] (1) Wash, remove impurities, and dry the collected lotus leaves, and then crush them to obtain lotus leaf powder;

[0035] (2) Weigh the lotus leaf powder, add a 65% ethanol (v / v) solution, and perform extraction at 60 °C for 1.5 h, with a material-liquid ratio of 1:15 (g:mL);

[0036] (3) Filter, extract the filter residue again under the same conditions; filter, combine the two filtrates, concentrate, and freeze-dry to obtain the natural lotus leaf dye.

[0037] Example 2

[0038] (1) Blended 65% cotton fiber and 35% hemp fiber, with the warp fineness of 40s / 1 and the weft fineness of 60s / 1, to weave a plain weave structure greige fabric, and the greige fabric weight is 110 g / m 2 ;

[0039] (2) Prepare a 15 g / L composite enzyme solution (the mass ratio of acidic cellulase and pectinase is 7:3), adjust the pH value to 4 - 5, add the greige fabric, with a bath ratio of 1:20, treat at 55 °C for 45 min, wash, and take out. Prepare a 2% chitosan solution with an acetic acid aqueous solution, add the treated greige fabric, with a bath ratio of 1:30, modify at 80 °C for 30 min, take out, wash, and set aside;

[0040] (3) Prepare a dye solution of the natural lotus leaf dye prepared in Example 1 with a concentration of 5% o.w.f., with a bath ratio of 1:30,

[0041] pH = 7, add the modified greige fabric, dye at 30 °C, keep the temperature constant at 80 °C for 1 h, wring out the dye after cooling to room temperature, take out and set aside;

[0042] (4) Prepare an alum solution with a concentration of 3% o.w.f., bath ratio: 1:30, mordant the dyed grey fabric at 60 °C for 30 min, take it out, wash it, and dry it.

[0043] (5) Prepare a nano-zinc oxide finishing solution with a concentration of 10 g / L (Changzhou Meisheng Biomaterials Co., Ltd. ZNO), dip-dye and pad the mordanted grey fabric twice (pick-up rate 60%), and dry it at 70 °C.

[0044] Example 3

[0045] (1) Blended 70% cotton fiber and 30% hemp fiber, warp fineness is 50s / 1, weft fineness is 60s / 1, weave a plain weave grey fabric, the weight of the grey fabric is 100 g / m 2 ;

[0046] (2) Prepare an enzyme solution with a concentration of 10 g / L, adjust the pH value to 4 - 5, add the grey fabric, bath ratio 1:15, treat it at 50 °C for 50 min, wash it, and take it out. Prepare a chitosan solution with a concentration of 2% with an acetic acid aqueous solution, add the treated grey fabric, bath ratio 1:35, modify it at 80 °C for 40 min, take it out, wash it, and set aside;

[0047] (3) Prepare a lotus leaf natural dye solution with a concentration of 4% o.w.f. prepared in Example 1, bath ratio is 1:30,

[0048] pH = 7, add the modified grey fabric, dye it at 30 °C, keep it at a constant temperature of 80 °C for 1 h, wring out the dye after cooling to room temperature, and take it out for standby;

[0049] (4) Prepare an alum solution with a concentration of 3% o.w.f., bath ratio: 1:30, mordant the dyed grey fabric at 60 °C for 30 min, take it out, wash it, and dry it.

[0050] (5) Prepare a nano-zinc oxide finishing solution with a concentration of 15 g / L (Changzhou Meisheng Biomaterials Co., Ltd. ZNO), dip-dye and pad the mordanted grey fabric twice (pick-up rate 70%), and dry it at 90 °C.

[0051] Example 4

[0052] (1) Blended 60% cotton fiber and 40% hemp fiber, warp fineness is 60s / 1, weft fineness is 60s / 1, weave a plain weave grey fabric, the weight of the grey fabric is 95 g / m 2 ;

[0053] (2) Prepare an enzyme solution with a concentration of 13 g / L, adjust the pH value to 4 - 5, add the grey fabric, with a liquor ratio of 1:20, treat at 60 °C for 40 min, wash thoroughly, and take out. Prepare a 2% chitosan solution with an acetic acid aqueous solution, add the treated grey fabric, with a liquor ratio of 1:30, modify at 70 °C for 35 min, take out, wash, and set aside;

[0054] (3) Prepare a natural lotus leaf dye solution prepared in Example 1 with a concentration of 5% o.w.f., with a liquor ratio of 1:40,

[0055] pH = 7, add the modified grey fabric, dye at 30 °C, keep at a constant temperature of 80 °C for 1 h, wring out the dye after cooling to room temperature, take out and set aside;

[0056] (4) Prepare an alum solution with a concentration of 3% o.w.f., liquor ratio: 1:30, mordant the dyed grey fabric at 60 °C for 30 min, take out, wash thoroughly, and dry.

[0057] (5) Prepare a nano-zinc oxide finishing solution with a concentration of 20 g / L (ZNO of Changzhou Meisheng Biomaterials Co., Ltd.) dip the mordanted grey fabric twice and pad (pick-up rate 70%), dry at 80 °C.

[0058] Comparative Example 1

[0059] The preparation method of this example is the same as that of Example 2, the difference is that: the grey fabric is not pretreated with the composite enzyme. Other operations are the same as those in Example 2.

[0060] Comparative Example 2

[0061] The preparation method of this example is the same as that of Example 2, the difference is that in step (2), only acidic cellulase is used as the enzyme (enzyme concentration 15 g / L, other conditions remain unchanged), and pectinase is omitted. Other operations are the same as those in Example 2.

[0062] Comparative Example 3

[0063] The preparation method of this example is the same as that of Example 2, the difference is that chitosan is not used for modification before dyeing. Other operations are the same as those in Example 2.

[0064] Comparative Example 4

[0065] The preparation method of this example is the same as that of Example 2, the difference is that: the post-mordanting is replaced with pre-mordanting, and other operations are the same as those in Example 2.

[0066] The specific steps are as follows:

[0067] (1)-(2): The same as Example 1.

[0068] (3) Prepare an alum solution with a concentration of 3% o.w.f., bath ratio: 1:30. For the pretreated fabric in step (2), carry out mordanting at 60 °C for 30 min, take it out, wash it, and dry it.

[0069] (4) Prepare a lotus leaf natural dye solution with a concentration of 5% o.w.f. prepared in Example 1, bath ratio is 1:30,

[0070] pH = 7. Add the mordanted fabric, dye at 30 °C, keep the temperature constant at 80 °C for 1 h. After cooling to room temperature, wring out the dye and take it out for standby;

[0071] (5) Prepare a nano-zinc oxide finishing solution with a concentration of 10 g / L (ZNO from Changzhou Meisheng Biomaterials Co., Ltd.), dip the mordanted fabric two times and pad (padding rate 60%), and dry it at 70 °C.

[0072] Comparative Example 5

[0073] This example has the same preparation method as Example 2, the difference is that post-mordanting is replaced by simultaneous mordanting method, and other operations are the same as those in Example 2.

[0074] The specific steps are as follows:

[0075] (1)-(2): The same as Example 1.

[0076] (3) Prepare a lotus leaf natural dye solution with a concentration of 5% o.w.f. prepared in Example 1, bath ratio 1:30, add 3% o.w.f. alum, adjust pH = 7, add the pretreated fabric in step (2), dye at 30 °C, keep the temperature constant at 80 °C for 1 h. After cooling to room temperature, wring out the dye and take it out for standby;

[0077] (4) Prepare a nano-zinc oxide finishing solution with a concentration of 10 g / L (ZNO from Changzhou Meisheng Biomaterials Co., Ltd.), dip the mordanted fabric two times and pad (padding rate 60%), and dry it at 70 °C.

[0078] Comparative Example 6

[0079] This example has the same preparation method as Example 2, the difference is that the mordant is replaced by ferrous sulfate. Other operations are the same as those in Example 2.

[0080] Comparative Example 7

[0081] This example has the same preparation method as Example 2, the difference is that cotton fiber and linen fiber are used for blended spinning. Other operations are the same as those in Example 2.

[0082] Comparative Example 8

[0083] This example has the same preparation method as Example 2, the difference is that the fabric is woven with all-cotton yarn. Other operations are the same as those in Example 2.

[0084] Comparative Example 9

[0085] The preparation method of this example is the same as that of Example 2, except that the grey fabric is not dyed. Other operations are the same as those of Example 2.

[0086] Comparative Example 10

[0087] The preparation method of this example is the same as that of Example 2, except that after dyeing, the fabric is not post-treated with the nano-ZnO finishing agent. Other operations are the same as those of Example 2.

[0088] Comparative Example 11

[0089] The preparation method of this example is the same as that of Example 2, except that the grey fabric is not dyed and the fabric is not post-treated with the nano-ZnO finishing agent. Other operations are the same as those of Example 2.

[0090] Comparative Example 12

[0091] The preparation method of this example is the same as that of Example 2, except that nano-zinc oxide finishing is carried out first and then chitosan modification is carried out.

[0092] (1) Blend 65% cotton fiber with 35% hemp fiber, the warp fineness is 40s / 1, the weft fineness is 60s / 1, and weave a plain weave grey fabric with a grey fabric weight of 110 g / m 2 ;

[0093] (2) Prepare a 15 g / L composite enzyme solution (the mass ratio of acidic cellulase to pectinase is 7:3), adjust the pH value to 4 - 5, add the grey fabric, the bath ratio is 1:20, treat at 55 °C for 45 min, wash and take out. Prepare a 10 g / L nano-ZnO finishing solution (Changzhou Meisheng Biomaterials Co., Ltd. ZNO), dip-dye and pad the treated grey fabric twice (the padding rate is 60%), and dry at 70 °C.

[0094] (3) Prepare a 2% chitosan solution with an acetic acid aqueous solution, add the fabric treated in step (2), the bath ratio is 1:30, modify at 80 °C for 30 min, take out, wash, and set aside;

[0095] (4) Prepare a lotus leaf natural dye solution with a concentration of 5% o.w.f. prepared in Example 1, the bath ratio is 1:30, pH = 7, add the fabric modified in step (3), dye at 30 °C, keep the temperature constant at 80 °C for 1 h, wring out the dye after cooling to room temperature, take out and set aside;

[0096] (5) Prepare a 3% o.w.f. alum solution, the bath ratio: 1:30, mordant the dyed fabric at 60 °C for 30 min, take out, wash, and dry.

[0097] Performance Test

[0098] Colorfastness to rubbing: Test was carried out with reference to GB / T 3920-2008 "Textiles - Tests for colorfastness - Colorfastness to rubbing".

[0099] Colorfastness to soaping: Test was carried out with reference to GB / T 3921-2008 "Textiles - Tests for colorfastness - Colorfastness to soaping".

[0100] Antibacterial performance: Test was carried out with reference to GB / T 20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Oscillation method". The antibacterial properties against Staphylococcus aureus (ATCC 6538) Gram-positive bacteria, Escherichia coli (ATCC 11229) Gram-negative bacteria and Candida albicans (ATCC 10231) were tested respectively.

[0101] UV protection performance: Test was carried out with reference to GB / T 18830-2009 "Evaluation of ultraviolet radiation protection performance of textiles".

[0102] Moisture permeability: Test was carried out with reference to GB / T 12704.1-2009 "Textiles - Test method for fabric moisture permeability - Part 1: Moisture absorption method".

[0103] Air permeability: Test was carried out with reference to GB / T 5453-1997 "Determination of air permeability of textiles".

[0104] Table 1 Test results of colorfastness

[0105]

[0106] As can be seen from Table 1, the colorfastness to rubbing and colorfastness to soaping of the fabric prepared in Example 2 are both at level 4 or above.

[0107] For the fabric in Comparative Example 1, it was not treated with enzyme before dyeing, and its colorfastness to rubbing and colorfastness to soaping were lower compared with those in Example 2. Opening the fiber pores by enzyme treatment before dyeing can improve the dye adsorption rate and dye uptake rate, and the penetration of dyes into the fiber interior is more conducive to improving colorfastness. In Comparative Example 2, single acid enzyme treatment left pectin residues on cellulose, resulting in fewer binding sites for chitosan and dyes, and lower colorfastness. In Comparative Example 3, no chitosan modification was carried out, and the number of binding sites between dyes and the fabric was less compared with that after modification, resulting in lower colorfastness. In Comparative Examples 4-5, pre-mordanting and simultaneous mordanting were carried out with alum respectively, and in Comparative Example 6, post-mordanting was carried out with ferrous sulfate, and their colorfastness was not as high as that of post-mordanting with alum in Example 2. In Comparative Example 12, most of the sites and gaps of the fabric were occupied by nano-zinc oxide first, resulting in a reduction in the subsequent binding sites between dyes and fibers and a decrease in colorfastness.

[0108] Table 2 Antibacterial Test Results

[0109]

[0110]

[0111]

[0112] As can be seen from Table 2, the antibacterial effect of the fabrics prepared in Examples 2-4 is excellent, with the inhibition effect on the three kinds of bacteria being more than 85%, and the antibacterial performance decreases slightly after 20 washes, indicating good wash resistance.

[0113] In Comparative Example 11, only chitosan modification was carried out, and the inhibition effect of the grey fabric without lotus leaf dyeing and nano-ZnO treatment on the three kinds of bacteria was poor. In Comparative Example 3, the antibacterial performance was greatly improved after lotus leaf dyeing and nano-ZnO treatment, but it still did not reach the effect of the examples because chitosan modification was not carried out. In Comparative Example 10, after chitosan modification and lotus natural dyeing but without nano-ZnO post-treatment, the inhibition effect on the three kinds of bacteria did not reach the effect of the examples either. In Comparative Example 9, after chitosan modification and post-treatment with nano-ZnO finishing agent but without lotus natural dyeing, the antibacterial effect also did not reach the effect of the examples. Chitosan modification provides cationic sites and itself also has antibacterial effects, which plays a synergistic role with nano-ZnO. In addition, lacking any one of these steps will also damage the stability of the triple protection system of chitosan modification-natural dye complexation-nano-zinc oxide composite of the fabric, resulting in a decrease in wash resistance.

[0114] In Comparative Example 1, no enzyme treatment was carried out, or in Comparative Example 2, only single enzyme treatment was carried out, resulting in lower dye loading and ZnO loading, slightly weaker antibacterial effect, and decreased wash resistance. In Comparative Example 8, using all-cotton fabric as the grey fabric also had a relatively weak antibacterial performance, and the wash resistance of the all-cotton structure decreased compared to the hemp structure. In Comparative Example 12, the order was reversed, resulting in nano-zinc oxide occupying most of the sites and gaps of the fabric first, leading to a decrease in the binding of chitosan and dye to the fiber, a decrease in the dyeing rate, and a decrease in antibacterial performance and wash resistance.

[0115] Table 3 Performance Test Results

[0116]

[0117]

[0118] As can be seen from Table 3, the UPF value of the breathable, skin-friendly, antibacterial and sunscreen fabrics prepared in Examples 2-4 reached more than 80, meeting the national standard requirement of UPF>40 for anti-ultraviolet products, showing good anti-ultraviolet effect, and the anti-ultraviolet effect only decreased slightly after 20 washes.

[0119] The grey fabric without dyeing or nano-ZnO finishing in Comparative Example 11 does not have ultraviolet resistance effect. The UPF value of the grey fabric in Comparative Example 10 after being dyed with natural lotus leaf dye can reach 50. + After the post-treatment with nano-ZnO in the Examples, the performance is further improved. The ultraviolet resistance effects of the grey fabrics in Comparative Example 10 only dyed with natural lotus leaf dye and Comparative Example 9 only treated with nano-ZnO post-treatment process are both inferior to the effect after the combination of the two. In addition, the prepared breathable, skin-friendly, antibacterial and sunscreen fabric has good air permeability and moisture permeability, which are superior to those of pure cotton fabrics and cotton / linen fabrics. The air permeability, moisture permeability and ultraviolet resistance performance all decrease without enzyme treatment or single enzyme treatment, and the moisture permeability performance of the fabric without chitosan finishing decreases.

[0120] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and its concept of the present invention, making equivalent substitutions or changes should be covered within the protection scope of the present invention.

Claims

1. A method for preparing a breathable, skin-friendly and antibacterial sunscreen fabric, characterized in that, It includes the following preparation steps: S1: Weave cotton fibers and hemp fibers into a sunscreen fabric greige. S2: Pretreat the greige with a composite enzyme, wash it clean after the treatment, and set aside for later use. S3: Prepare a chitosan solution, add the greige treated in S2, with a bath ratio of 1:30 - 35, modify it at 70 - 80 °C, take it out after modification, wash it, and set aside for later use to obtain the treated sunscreen greige. S4: Extract the natural lotus leaf dye and dye the treated sunscreen greige with the natural dye. S5: Prepare a mordant solution, mordant the dyed greige, take it out, wash it clean, and dry it. S6: Conduct post-treatment on the greige dyed in S5 with a nano-zinc oxide finishing agent to obtain a breathable, skin-friendly, antibacterial sunscreen fabric.

2. The preparation method of the breathable, skin-friendly and antibacterial sunscreen fabric according to claim 1, wherein In step S1, the mass ratio of cotton fiber is 60% - 70%, and the mass ratio of hemp fiber is 30% - 40%; the hemp fiber is specifically hemp fiber; the weaving structure of the grey cloth is plain weave structure; the fineness of the yarn spun from the blended cotton fiber and hemp fiber is 40s / 1 - 60s / 1, and the fabric density is 95g / m 2 ~110g / m 2 .

3. The preparation method of the breathable, skin-friendly and antibacterial sunscreen fabric according to claim 1, wherein In step S2, the enzyme used is a composite enzyme composed of an acidic cellulase and pectinase, and the mass ratio of the two is 7:

3. The treatment method is to prepare an enzyme solution with a concentration of 10 - 15 g / L, adjust the pH value to 4 - 5, with a bath ratio of 1:15 - 20, and treat it at 50 - 60 °C for 40 - 50 min.

4. The preparation method of the breathable, skin-friendly and antibacterial sunscreen fabric according to claim 1, characterized in that, In step S3, the mass concentration of the chitosan solution is 2 - 3%, and the modification time is 30 - 40 min.

5. The preparation method of the breathable, skin-friendly and antibacterial sunscreen fabric according to claim 1, characterized in that, In step S4, the extraction method of the natural lotus leaf dye is as follows: (1) Wash, remove impurities, and dry the collected lotus leaves, then crush them to obtain lotus leaf powder. (2) Weigh the lotus leaf powder, add an ethanol solution with a volume fraction of 60 - 70%, and conduct extraction at 60 - 70 °C for 1 - 2 h, with a solid-liquid ratio of 1:15 - 20. (3) Filter after extraction, and extract the residue under the same conditions once again. (4) Filter, take the supernatant, combine the two filtrates, concentrate, and freeze-dry to obtain the natural lotus leaf dye.

6. The preparation method of the breathable, skin-friendly and antibacterial sunscreen fabric according to claim 1, characterized in that, In step S4, the method of dyeing the sunscreen fabric greige with the natural lotus leaf dye is as follows: Prepare a lotus leaf natural dye solution with a concentration of 3% - 5% o.w.f., with a bath ratio of 1:30 - 1:40, pH = 7, add the modified greige, enter the dye bath at 30 °C, keep it at a constant temperature of 80 °C for 1 h, wring out the dye after cooling to room temperature, and take it out.

7. The preparation method of the breathable, skin-friendly and antibacterial sunscreen fabric according to claim 1, characterized in that, In step S5, the specific mordanting conditions are: Prepare a mordant solution with a concentration of 2 - 4% o.w.f., bath ratio: 1:25 - 35, mordant the dyed greige at 55 - 65 °C for 25 - 35 min, take it out, wash it clean, and dry it.

8. The preparation method of the breathable, skin-friendly and antibacterial sunscreen fabric according to claim 1, characterized in that, The mordant is alum.

9. The preparation method of the breathable, skin-friendly and antibacterial sunscreen fabric according to claim 1, characterized in that, In step S6, the finishing process of the nano-zinc oxide finishing agent on the dyed greige is: Prepare a nano-zinc oxide finishing solution with a concentration of 10 - 20 g / L, dip and roll the greige twice, with a liquor pickup rate of 60% - 70%, and dry it at 70 °C - 90 °C.

10. A breathable, skin-friendly, antibacterial sunscreen fabric prepared by the method according to any one of claims 1 - 9.

Images