X-ray proof lead-free fiber, method for producing the same, and flexible fabric

Abstract

The present application relates to a kind of X-ray-proof lead-free fiber and its preparation method and flexible fabric, X-ray-proof lead-free fiber has skin-core structure, containing radiation protection particle I in skin layer, irregularly shaped groove is distributed on the surface of skin layer, and groove can carry out multiple reflection and scattering to X-ray;Preparation method is as follows: after being configured respectively core layer spinning solution and skin layer spinning solution containing soluble salt, using coaxial wet spinning process spinning, namely, X-ray-proof lead-free fiber;Wherein, soluble salt is sodium chloride and / or calcium chloride, coagulation bath is one or more of water, ethanol and acetic acid;Application is just X-ray-proof lead-free fiber for preparing X-ray-proof flexible fabric.The method of the present application is simple, the performance of X-ray-proof lead-free fiber prepared is excellent, and the X-ray-proof flexible fabric prepared has high radiation protection performance and good moisture absorption, air permeability, elasticity and other wearing performance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of X-ray protection, and particularly relates to an X-ray-proof lead-free fiber, a preparation method thereof and a flexible fabric. BACKGROUND

[0002] Common electronic products in life will have a certain radiation, and X-rays are high-energy electromagnetic waves with extremely short wavelengths and great energy, and have strong penetration ability and ionization effect. In medicine, X-rays can be used for perspective, and in industry, X-rays can be used for flaw detection. However, long-term exposure to X-rays will damage the normal structure of cells and human tissues, and cause great harm to the human body. Therefore, the harm of radiation to humans in life is getting more and more attention. For example, personnel in specific environments such as hospitals and nuclear power plants need to wear specific protective clothing.

[0003] The existing anti-radiation clothing mainly has the following ways: one is lead protective clothing, which is mainly made of metal lead wire as yarn through weaving, knitting and other manufacturing methods to form lead clothing, or lead plates are integrated into the shell of the textile clothing. However, the clothing made of lead has a thickness of more than 5 mm, and has poor resilience and fatigue resistance. Lead as a heavy metal makes the lead clothing too heavy, resulting in poor wearing performance. At the same time, lead is highly toxic and harmful to the human body. One is lead-free protective clothing, which mainly adds lanthanide elements and tungsten, bismuth compounds with high atomic number (Z) and high density (p) to the yarn, or performs coating on the surface of the fabric, so as to obtain lead-free clothing with anti-radiation performance. Compared with lead clothing, lead-free clothing has better wearing performance, and the resilience, moisture absorption and mechanical properties are improved. However, the shielding efficiency and protection performance of lead-free clothing against X-rays are poor. Therefore, it is necessary to further research a high-protection lead-free material to effectively protect against X-rays. The high-protection lead-free material needs to meet two requirements: one is high shielding efficiency against X-rays, and the other is good wearing performance, that is, both anti-radiation and comfortable to wear.

[0004] Patent CN104292868A discloses a wood fiber for preventing X-ray radiation and a manufacturing method thereof. The wood fiber is mainly composed of wood fiber with a mass ratio of 40-45wt%, nano-silver fiber with a mass ratio of 1.1-2.1wt%, wheat straw fiber with a mass ratio of 16-18wt%, and aluminum silicate fiber with a mass ratio of 8-10wt%. Barium sulfate, an X-ray shielding agent, is modified and added to the wood fiber. The fiber has the characteristics of good mechanical properties and good textile processing properties. However, since the X-ray shielding agent is only barium sulfate, there is a weak absorption zone, and the protection efficiency against X-rays is low.

[0005] Patent CN109338741B discloses a lead-free X-ray protection plate and a preparation method thereof, which is obtained by mixing chemical fibers, modified silicone rubber, bismuth borate, lanthanum powder, tungsten trioxide and the like to be suitable for a subject, and has the advantages of low toxicity and low cost, but the shielding efficiency is only 47%, which is far from enough for the protection of important parts.

[0006] Patent CN105513660B discloses a new type of radiation protection gloves and a manufacturing method thereof, which is obtained by adding lanthanum trioxide, tungsten trioxide and aluminum fluoride into natural rubber to achieve the radiation protection performance, and also has the problems of rare earth element mining pollution and hazards in use. SUMMARY

[0007] The purpose of the present application is to solve the problems existing in the prior art, and to provide a lead-free fiber for preventing X-rays, a preparation method thereof and a flexible fabric.

[0008] To achieve the above purpose, the technical solution adopted by the present application is as follows:

[0009] A lead-free fiber for preventing X-rays has a skin-core structure, the skin layer contains radiation protection particles I, and the surface of the skin layer is distributed with irregular grooves capable of reflecting and scattering X-rays multiple times.

[0010] As a preferred technical solution:

[0011] The lead-free fiber for preventing X-rays as described above has an average groove depth of 0.05-0.25mm, an average cross-sectional area of the groove of 0.08-0.15mm 2 , and a number of grooves in each square centimeter of area of 600-1300; the shape of the groove can reflect, scatter and absorb X-rays multiple times, and the greater the depth and the more the number of grooves per unit area, the greater the above-mentioned influence, thereby improving the shielding ability of X-rays. In addition, the special structure of the groove can improve the air permeability between fibers, ensuring the protection performance while improving the wearing performance.

[0012] The lead-free fiber for preventing X-rays as described above has an average diameter of the radiation protection particles I of 40-100nm, a content of the radiation protection particles I in the skin layer of 35-65wt%, and a thickness of the skin layer of 0.10-0.30mm.

[0013] The lead-free fiber for preventing X-rays as described above further contains radiation protection particles II in the core layer.

[0014] The X-ray-proof lead-free fiber as described above, wherein the average diameter of the radiation-proof particles II is 20-50 nm, the content of the radiation-proof particles II in the core layer is 50-80 wt%, and the diameter of the core layer is 0.15-0.35 mm.

[0015] The X-ray-proof lead-free fiber as described above, wherein the radiation-proof particles I are barium sulfate, and the radiation-proof particles II are one or more of tungsten carbide, tungsten oxide and bismuth oxide.

[0016] The X-ray-proof lead-free fiber as described above, wherein the base material of the skin layer and the core layer is independently selected from one or more of polyurethane (PU), polyamide (PA), cellulose (CAB), polyvinyl chloride (PVC) and polyvinyl alcohol (PVA).

[0017] The application further provides a method for preparing the X-ray-proof lead-free fiber as described above, wherein the core layer spinning solution and the skin layer spinning solution containing the easily soluble salt are prepared respectively, and then the coaxial wet spinning process is used to spin, so as to obtain the X-ray-proof lead-free fiber; wherein the easily soluble salt is sodium chloride and / or calcium chloride, and the coagulation bath is one or more of water, ethanol and acetic acid; in the coaxial wet spinning process, the easily soluble salt in the skin layer spinning solution is soluble in the coagulation bath, so that the easily soluble salt enters the coagulation bath, and thus the skin layer forms grooves.

[0018] As a preferred technical solution:

[0019] The method as described above, wherein the solvent in the skin layer spinning solution or the core layer spinning solution is DMF; the concentration of the easily soluble salt in the skin layer spinning solution is 25-55 wt%, and the high concentration of the easily soluble salt is to form more and deeper grooves on the surface; the total concentration of the substances other than the solvent and the easily soluble salt is 8-20 wt%; and the total concentration of the substances other than the solvent in the core layer spinning solution is 15-20 wt%.

[0020] The method as described above, wherein the jet speed of the core layer spinning solution is greater than the jet speed of the skin layer spinning solution, the jet speed of the core layer spinning solution is 0.1-0.3 mm / min, and the jet speed of the skin layer spinning solution is 0.05-0.15 mm / min, so as to ensure that the skin layer and the core layer are closely attached and no pores are generated.

[0021] The method as described above, wherein the density of the coagulation bath is the same as the density of the X-ray-proof lead-free fiber, so as to ensure that the fiber is not affected by gravity in the coagulation bath; when the fiber is jetted to the coagulation bath at the jetting port, if the density of the fiber is too small than the density of the coagulation bath, the fiber will float up due to the effect of buoyancy, so that the fiber is deformed at the jetting port; if the density of the fiber is too large than the density of the coagulation bath, the fiber will be thinned due to the effect of gravity, so that the diameters of different parts of the fiber are different, and thus the fiber is uneven, so that the mechanical properties and the like are poor.

[0022] The method as described above, after the spinning is finished, heating treatment is also carried out, the temperature of the heating treatment is higher than the glass transition temperature of the X-ray-proof lead-free fiber, and the time is 5-20 min; during the coaxial wet spinning process, the skin layer and the core layer will relatively slide when being stretched, which will affect the mechanical properties of the fiber such as the rebound, breaking strength and elongation, and the heating treatment of the fiber in the application will make the skin layer tightly adhere to the surface of the core layer, so that the relative sliding is avoided.

[0023] The application further provides an X-ray-proof flexible fabric, which has a multi-layer structure, and at least one layer is a functional layer, and the functional layer is made of the X-ray-proof lead-free fiber according to any one of the above.

[0024] As a preferred technical scheme:

[0025] The X-ray-proof flexible fabric as described above has the air permeability of 45-400 mm / s, the average recovery angle of 63.24-81.67°, the moisture regain of 1.2%-3.5%, the lead equivalent of 0.31-0.55 mm Pb, and the shielding efficiency of X-rays of more than 91%.

[0026] Beneficial effects:

[0027] The application enhances the moisture permeability, rebound performance, fatigue resistance and other wearing properties of the fabric on the premise of meeting and enhancing the X-ray-proof performance. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is a schematic view of the cross section of the X-ray-proof lead-free fiber of the application;

[0029] In the figure, 1 is a groove, 2 is a skin layer, and 3 is a core layer. DETAILED DESCRIPTION

[0030] The application will be further described below in combination with the specific embodiments. It should be understood that these embodiments are only used for illustrating the application and are not used for limiting the scope of the application. In addition, it should be understood that after reading the content of the application, those skilled in the art can make various modifications or changes to the application, and these equivalent forms also fall within the scope defined by the appended claims of the application.

[0031] The manufacturers and brands of the raw materials in the following embodiments are as follows:

[0032] The polyurethane is TPU-9380A from Haisite Material Company;

[0033] The polyamide is PA6-EPR27 from Suzhou Qianhui Import & Export Plasticization;

[0034] Cellulose: the manufacturer is Shanghai Chemical Raw Material Wholesale and Retail, the brand is HPMC400;

[0035] Polyvinyl chloride: the manufacturer is Dongguan Jin Heng Plastic Co., Ltd., the brand is PVC16-2000 mesh;

[0036] Polyvinyl alcohol: the manufacturer is Shanghai Chenqi Chemical Technology Co., Ltd., the brand is PVA0588;

[0037] Barium sulfate: the manufacturer is Shanghai Chenqi Chemical Technology Co., Ltd.;

[0038] Polylactic acid (PLA): the manufacturer is Suzhou Qianhui Import & Export Plastic Co., Ltd., the brand is PLA-FY801.

[0039] The test methods of performance indicators in the following examples are as follows:

[0040] Average recovery angle: using YG541C full-automatic fabric wrinkle elasticity tester, the sample prepared according to the test standard of GB / T3819-1997 Determination of Fabric Crease Recovery of Textiles- Recovery Angle Method is folded and pressed under the specified conditions for 300s, after the load is removed, the sample is allowed to recover for 15s and 300s, respectively, the acute and slow crease recovery angles are measured, and the measured angle is used to represent the crease recovery ability of the fabric.

[0041] Air permeability: according to the national standard GB / T5453-1997 Determination of Air Permeability of Textile Fabrics, the air flow through the circular air hole with a diameter of 20cm2 in a certain time under a pressure difference of 100Pa is tested by YG461N digital fabric air permeability tester.

[0042] Moisture regain: moisture regain is the percentage of the difference between the wet weight and the dry weight of the sample to the dry weight; the common measurement method is oven method; oven method is to use electric heating wire to heat, when the temperature in the oven rises to the specified value, the sample is put into the oven, so that the water in the textile material evaporates in the air, and the air exchange device is used to exhaust the wet air outside the oven; due to the continuous evaporation and loss of water in the textile material, the mass is continuously reduced, when the mass is constant, it is the dry weight of the textile material (all mass loss during drying process is water), and the moisture regain is calculated.

[0043] Lead equivalent: The lead equivalent of the same kind of protective material with the same thickness is not fixed, and the lead equivalent of some protective materials changes with the X-ray peak tube voltage used; for protective materials and products containing lead, the lead equivalent changes little with the X-ray peak tube voltage used, but lead has a "weak absorption zone" for ionizing radiation with an X-ray peak tube voltage between 40.0-88.0 keV; and for protective materials and products not containing lead, the lead equivalent changes greatly with the X-ray peak tube voltage used. For the test of the lead equivalent of X-ray protective clothing of the same kind of protective material, the lead equivalent value should be tested at different tube voltages within a certain range, and the test value should be not less than 5, and the minimum value is used to determine the lead equivalent grade of the protective material;

[0044] Shielding efficiency for X-rays: The lead equivalent of the composite sample is detected according to the provisions of GBZ / T 147-2002, the X-ray tube voltage is 130 kV, the filter copper plate thickness is 0.25 mm, and the shielding efficiency for X-rays is calculated according to the following formula:

[0045] η = n0-n d n0-n b × 100%;

[0046] In the formula: η represents the shielding efficiency for X-rays (%); n0 is the dose rate without the sample; n d is the dose rate after the sample; and n b is the background dose rate.

[0047] Fiber CV value: Using an electronic CV tester with a twisting device, the sample prepared according to the test standards of "GB / T 6502-86 Sampling Method for Synthetic Fiber Filament and Textured Yarn", "GB 6529-86 Standard Atmosphere for Conditioning and Testing of Textiles", and "GB 8170-87 Numerical Rounding Scheme" is used to measure the chemical fiber filament CV value. The CV tester can convert the mass change of the filament into corresponding electrical signal change, and through integral calculation, the mass unevenness in the length of the test sample, i.e. the CV value, is calculated and expressed in %.

[0048] Example 1

[0049] A method for preparing an X-ray protective lead-free fiber, comprising the following steps:

[0050] (1) Preparation of raw materials:

[0051] Easily soluble salt: sodium chloride;

[0052] Coagulation bath: water;

[0053] Skin base material: polyurethane;

[0054] Radiation protection particle I: barium sulfate, average diameter 40 nm;

[0055] Core layer base material: polyurethane;

[0056] Radiation protection particle II: tungsten carbide, average diameter 20 nm;

[0057] Solvent: DMF;

[0058] (2) Configure the sheath layer spinning solution and the core layer spinning solution;

[0059] Sheath layer spinning solution: composed of sheath layer base material, solvent, radiation protection particle I, and easily soluble salt, the concentration of the easily soluble salt is 55 wt%, the total concentration of the substances in the sheath layer spinning solution except the solvent and the easily soluble salt is 20 wt%;

[0060] Core layer spinning solution: composed of core layer base material, solvent, and radiation protection particle II, the total concentration of the substances in the core layer spinning solution except the solvent is 20 wt%;

[0061] (3) After spinning by using the coaxial wet spinning process, heat treatment is carried out at a temperature of 80℃ for 20 min, and then the X-ray protection lead-free fiber is obtained, wherein the jet speed of the core layer spinning solution is 0.1 mm / min, and the jet speed of the sheath layer spinning solution is 0.09 mm / min.

[0062] The finally prepared X-ray protection lead-free fiber has a sheath-core structure, the sheath layer 2 contains the radiation protection particle I, and the core layer 3 contains the radiation protection particle II. Figure 1

[0063] The thickness of the sheath layer 2 is 0.15 mm, the surface of the sheath layer 2 is distributed with grooves 1, the average depth of the grooves 1 is 0.05 mm, the average cross-sectional area of the grooves 1 is 0.08 mm 2 , the number of the grooves 1 in each square centimeter area is 900, and the content of the radiation protection particle I in the sheath layer 2 is 65 wt%;

[0064] The diameter of the core layer 3 is 0.35 mm, and the content of the radiation protection particle II in the core layer 3 is 80 wt%;

[0065] The evenness CV value of the X-ray protection lead-free fiber is 0.61%.

[0066] An X-ray protection flexible fabric prepared by using the above X-ray protection lead-free fiber has a multi-layer structure, the number of layers is 3, the number of functional layers is 2, the functional layer is a woven fabric prepared by using the above X-ray protection lead-free fiber, the square meter gram weight of the functional layer is 190 g / m 2 , the number of wearing layers is 1, the wearing layer is a woven fabric prepared by using cotton fiber, and the square meter gram weight of the wearing layer is 210 g / m 2 ​The wearing layer is placed in the inner layer of the fabric (the side close to the skin), and the functional layer is placed in the outer side of the fabric (the side close to the air).

[0067] The prepared X-ray-proof flexible fabric has an air permeability of 360 mm / s, an average recovery angle of 81.67°, a moisture regain of 3.5%, a lead equivalent of 0.55 mm Pb, and an X-ray shielding efficiency of 99%.

[0068] Example 2

[0069] A method for preparing an X-ray-proof lead-free fiber, comprising the following steps:

[0070] (1) Preparation of raw materials:

[0071] Easily soluble salt: sodium chloride;

[0072] Coagulation bath: water;

[0073] Skin layer substrate: polyamide;

[0074] Radiation protection particle I: barium sulfate, with an average diameter of 70 nm;

[0075] Core layer substrate: cellulose;

[0076] Radiation protection particle II: tungsten carbide, with an average diameter of 35 nm;

[0077] Solvent: DMF;

[0078] (2) Preparation of skin layer spinning solution and core layer spinning solution;

[0079] Skin layer spinning solution: composed of skin layer substrate, solvent, radiation protection particle I, and easily soluble salt, the concentration of the easily soluble salt is 70 wt%, and the total concentration of substances in the skin layer spinning solution except the solvent and the easily soluble salt is 15 wt%;

[0080] Core layer spinning solution: composed of core layer substrate, solvent, and radiation protection particle II, the total concentration of substances in the core layer spinning solution except the solvent is 20 wt%;

[0081] (3) After spinning by using the coaxial wet spinning process, heating treatment is performed at a temperature of 110°C for 15 min, and an X-ray-proof lead-free fiber is obtained, wherein the jet speed of the core layer spinning solution is 0.1 mm / min, and the jet speed of the skin layer spinning solution is 0.09 mm / min.

[0082] The finally prepared X-ray-proof lead-free fiber has a skin-core structure, the skin layer contains radiation protection particle I, and the core layer contains radiation protection particle II;

[0083] The thickness of the skin layer is 0.18 mm, the skin layer surface is distributed with grooves, the average depth of the grooves is 0.12 mm, and the average cross-sectional area of the grooves is 0.12 mm 2 The number of grooves per square centimeter is 1020, and the content of the radiation protection particles I in the skin layer is 55 wt%;

[0084] The diameter of the core layer is 0.35 mm, and the content of the radiation protection particles II in the core layer is 70 wt%;

[0085] The CV value of the strip unevenness of the X-ray protection lead-free fiber is 1.12%.

[0086] An X-ray protection flexible fabric made of the above X-ray protection lead-free fiber has a multi-layer structure, the number of layers is 3, the functional layer is 2 layers, the functional layer is a woven fabric made of the above X-ray protection lead-free fiber, and the square meter gram weight of the functional layer is 170 g / m 2 The wearing layer is 1 layer, the wearing layer is a woven fabric made of PLA, and the square meter gram weight of the wearing layer is 330 g / m 2 . Among them, the wearing layer is placed in the inner layer of the fabric (close to the skin side), and the functional layer is placed on the outer side of the fabric (close to the air side).

[0087] The air permeability of the prepared X-ray protection flexible fabric is 90 mm / s, the average recovery angle is 64.41°, the moisture regain is 1.5%, the lead equivalent is 0.42 mm Pb, and the X-ray shielding efficiency is 97%.

[0088] Example 3

[0089] A preparation method of an X-ray protection lead-free fiber, which is basically the same as that of Example 2, except that when spinning by using the coaxial wet spinning process, the jet speed of the core layer spinning solution is 0.08 mm / min.

[0090] An X-ray protection flexible fabric, which is basically the same as that of Example 2, except that the X-ray protection lead-free fiber used in the functional layer is the X-ray protection lead-free fiber of Example 3.

[0091] The air permeability of the X-ray protection flexible fabric is 120 mm / s, the average recovery angle is 58.21°, the moisture regain is 1.3%, the lead equivalent is 0.39 mm Pb, and the X-ray shielding efficiency is 95%.

[0092] Comparing Example 3 with Example 2, it can be seen that the skin layer of Example 2 is closely attached to the core layer without any gap, while the skin layer of Example 3 has a gap between the skin layer and the core layer, because the jet speed of the core layer spinning solution of Example 3 is less than that of the skin layer spinning solution, resulting in that the length of the skin layer fiber is longer than that of the core layer fiber per unit time, and then the skin layer fiber is bent, causing a gap between the skin layer and the core layer; the gap between the skin layer and the core layer will cause the fiber to not be stretched at the same time under stress, thereby causing the mechanical properties of the fabric to deteriorate; in addition, due to the gap between the fibers that make up the fabric, the radiation performance is lost at the gap, causing the shielding performance of the fabric to X-rays to decrease.

[0093] Comparative Example 1

[0094] A method for preparing a lead-free X-ray-proof fiber, which is basically the same as Example 3, except that the easily soluble salt in the skin layer spinning solution in step (2) is replaced by an equal amount of solvent.

[0095] An X-ray-proof flexible fabric, which is basically the same as Example 3, except that the functional layer uses the lead-free X-ray-proof fiber of Comparative Example 1.

[0096] The prepared X-ray-proof flexible fabric has an air permeability of 110 mm / s, an average recovery angle of 61.54°, a moisture regain of 1.2%, a lead equivalent of 0.30 mm Pb, and a shielding efficiency of 89% to X-rays.

[0097] Comparing Comparative Example 1 with Example 3, the lead equivalent and the shielding efficiency of the X-ray-proof flexible fabric of Example 3 are higher than those of Comparative Example 1, and the wearability is better, because the surface of the skin layer of the lead-free X-ray-proof fiber of Comparative Example 1 does not have grooves, and the X-ray-proof flexible fabric of Example 3 has the effect of multiple reflection and absorption of X-rays by the grooves on the surface of the skin layer of the fiber in addition to the absorption and reflection of X-rays by the fiber, so the lead equivalent and the shielding efficiency of the X-ray-proof flexible fabric of Example 3 are higher than those of Comparative Example 1.

[0098] Example 4

[0099] A method for preparing a lead-free X-ray-proof fiber, the steps of which are as follows:

[0100] (1) Preparation of raw materials:

[0101] Easily soluble salt: calcium chloride;

[0102] Coagulation bath: acetic acid;

[0103] Skin layer base material: cellulose;

[0104] Radiation-proof particles I: barium sulfate, with an average diameter of 80 nm;

[0105] Core layer substrate: polyamide;

[0106] Radiation protection particles I: tungsten oxide, average diameter 30 nm;

[0107] Solvent: DMF;

[0108] (2) Configure the skin layer spinning solution and the core layer spinning solution;

[0109] The skin layer spinning solution is composed of the skin layer substrate, the solvent, the radiation protection particles I, and the easily soluble salt, the concentration of the easily soluble salt is 60wt%, and the total concentration of the substances in the skin layer spinning solution except the solvent and the easily soluble salt is 15wt%;

[0110] The core layer spinning solution is composed of the core layer substrate, the solvent, and the radiation protection particles II, and the total concentration of the substances in the core layer spinning solution except the solvent is 15wt%;

[0111] (3) After spinning by using the coaxial wet spinning process, heat treatment is carried out at a temperature of 90℃ for 5min, and the X-ray protection lead-free fiber is obtained, wherein the jet speed of the core layer spinning solution is 0.2mm / min, and the jet speed of the skin layer spinning solution is 0.15mm / min.

[0112] The finally prepared X-ray protection lead-free fiber has a skin-core structure, the skin layer contains the radiation protection particles I, and the core layer contains the radiation protection particles II;

[0113] The thickness of the skin layer is 0.1mm, the skin layer surface is distributed with grooves, the average depth of the grooves is 0.06mm, the average cross-sectional area of the grooves is 0.09mm 2 , the number of grooves in each square centimeter area is 1300, and the content of the radiation protection particles I in the skin layer is 65wt%;

[0114] The diameter of the core layer is 0.25mm, and the content of the radiation protection particles II in the core layer is 60wt%;

[0115] The CV value of the evenness of the X-ray protection lead-free fiber is 1.24%.

[0116] An X-ray protection flexible fabric prepared by using the above X-ray protection lead-free fiber has a multi-layer structure, the number of layers is 3, the functional layer is 1 layer, the functional layer is a knitted fabric prepared by using the above X-ray protection lead-free fiber, and the square meter gram weight of the functional layer is 120g / m 2 , the wearing layer is 2 layers, the wearing layer is a knitted fabric prepared by using cotton fiber, and the square meter gram weight of the wearing layer is 430g / m 2 .

[0117] Among them, the wearing layer is placed in the inner layer of the fabric (close to the skin side), and the functional layer is placed on the outer side of the fabric (close to the air side).

[0118] The air permeability of the X-ray-proof flexible fabric prepared is 400 mm / s, the average recovery angle is 69.35°, the moisture regain is 3.2%, the lead equivalent is 0.37 mm Pb, and the shielding efficiency for X-rays is 95%.

[0119] Example 5

[0120] A method for preparing X-ray-proof lead-free fiber, which is basically the same as that in Example 4, except that the coagulation bath is ethanol when the spinning is performed by using the coaxial wet spinning process.

[0121] The CV value of the evenness of the X-ray-proof lead-free fiber is 3.2%.

[0122] An X-ray-proof flexible fabric, which is basically the same as that in Example 4, except that the X-ray-proof lead-free fiber used in the functional layer is the X-ray-proof lead-free fiber of Example 5.

[0123] The air permeability of the X-ray-proof flexible fabric prepared is 145 mm / s, the average recovery angle is 59.32°, the moisture regain is 1.2%, the lead equivalent is 0.31 mm Pb, and the shielding efficiency for X-rays is 91%.

[0124] As can be seen from the comparison between Example 5 and Example 4, if the density of the X-ray-proof lead-free fiber is greater than the density of the coagulation bath, the X-ray-proof lead-free fiber will be thinned due to the effect of gravity, resulting in different diameters of different parts of the fiber, unevenness, and thus poor mechanical properties. In addition, when the fiber with a large CV value of unevenness is used to prepare a fabric, the density of the fabric will be uneven, and the part with a lower density (smaller fabric density) will have poor shielding performance for X-rays, and thus poor radiation-proof performance.

[0125] Comparative Example 2

[0126] A method for preparing X-ray-proof lead-free fiber, which is basically the same as that in Example 5, except that the easily soluble salt in the sheath spinning solution in step (2) is replaced by an equal amount of solvent.

[0127] An X-ray-proof flexible fabric, which is basically the same as that in Example 5, except that the X-ray-proof lead-free fiber used in the functional layer is the X-ray-proof lead-free fiber of Comparative Example 2.

[0128] The air permeability of the X-ray-proof flexible fabric prepared is 135 mm / s, the average recovery angle is 61.53°, the moisture regain is 1.1%, the lead equivalent is 0.23 mm Pb, and the shielding efficiency for X-rays is 87%.

[0129] Comparing Example 5 with Comparative Example 2, the lead equivalent and shielding efficiency of the X-ray shielding flexible fabric in Example 5 are higher than those of Comparative Example 2, and the wearability is better, because the fiber skin layer surface in Comparative Example 2 has no groove, and the X-ray shielding flexible fabric in Example 5 has the effect of multiple reflection and absorption of X-rays by the groove on the fiber skin layer surface in addition to the absorption and reflection of X-rays by the fiber, so the lead equivalent and shielding efficiency of the X-ray shielding flexible fabric in Example 5 are higher than those of Comparative Example 2.

[0130] Example 6

[0131] A preparation method of an X-ray shielding lead-free fiber, comprising the following steps:

[0132] (1) Preparation of raw materials:

[0133] Easily soluble salt: calcium chloride;

[0134] Coagulation bath: acetic acid;

[0135] Skin layer substrate: polyvinyl chloride;

[0136] Radiation protection particles I: barium sulfate, with an average diameter of 60 nm;

[0137] Core layer substrate: polyvinyl alcohol;

[0138] Radiation protection particles II: bismuth oxide, with an average diameter of 40 nm;

[0139] Solvent: DMF;

[0140] (2) Preparation of skin layer spinning solution and core layer spinning solution;

[0141] Skin layer spinning solution: composed of skin layer substrate, solvent, radiation protection particles I, and easily soluble salt, the concentration of the easily soluble salt is 50 wt%, and the total concentration of substances in the skin layer spinning solution except the solvent and the easily soluble salt is 8 wt%;

[0142] Core layer spinning solution: composed of core layer substrate, solvent, and radiation protection particles II, the total concentration of substances in the core layer spinning solution except the solvent is 15 wt%;

[0143] (3) After spinning by using coaxial wet spinning process, heating treatment is carried out at a temperature of 80°C for 5 min, and the X-ray shielding lead-free fiber is obtained, wherein the jet speed of the core layer spinning solution is 0.3 mm / min, and the jet speed of the skin layer spinning solution is 0.15 mm / min.

[0144] The finally obtained X-ray shielding lead-free fiber has a skin-core structure, the skin layer contains radiation protection particles I, and the core layer contains radiation protection particles II;

[0145] The thickness of the skin layer is 0.3 mm, and the skin layer surface is distributed with grooves, the average depth of the grooves is 0.25 mm, and the average cross-sectional area of the grooves is 0.13 mm 2 The number of grooves per square centimeter area is 950, and the content of the radiation protection particles I in the skin layer is 60 wt%;

[0146] The diameter of the core layer is 0.15 mm, and the content of the radiation protection particles II in the core layer is 50 wt%;

[0147] The CV value of the strip unevenness of the X-ray protection lead-free fiber is 0.72%.

[0148] An X-ray protection flexible fabric made of the above X-ray protection lead-free fiber has a multi-layer structure, the number of layers is 3, the functional layer is 2 layers, the functional layer is a woven fabric made of the above X-ray protection lead-free fiber, and the square meter gram weight of the functional layer is 265 g / m 2 The wearing layer is 1 layer, and the wearing layer is a woven fabric made of PLA, and the square meter gram weight of the wearing layer is 145 g / m 2 .

[0149] Among them, the wearing layer is placed in the inner layer of the fabric (close to the skin side), and the functional layer is placed on the outer side of the fabric (close to the air side).

[0150] The air permeability of the prepared X-ray protection flexible fabric is 50 mm / s, the average recovery angle is 75.23°, the moisture regain is 1.2%, the lead equivalent is 0.38 mm Pb, and the X-ray shielding efficiency is 98%.

[0151] Example 7

[0152] A preparation method of an X-ray protection lead-free fiber, which is basically the same as that of Example 6, except that after spinning by the coaxial wet spinning process, no heating treatment is performed.

[0153] At the same time, the same length (100 mm) of the X-ray protection lead-free fiber of Example 6 and Example 7 is stretched by 100% and released, and the length (103 mm) of the X-ray protection lead-free fiber of Example 6 after release is less than the length (112 mm) of the X-ray protection lead-free fiber of Example 7, so it can be known that the skin layer and the core layer of the X-ray protection lead-free fiber of Example 6 do not slip obviously.

[0154] An X-ray protection flexible fabric, which is basically the same as Example 6, except that the X-ray protection lead-free fiber used in the functional layer is the X-ray protection lead-free fiber of Example 7.

[0155] The air permeability of the X-ray-proof flexible fabric is 45 mm / s, the average recovery angle is 63.24°, the moisture regain is 1.4%, the lead equivalent is 0.34 mm Pb, and the shielding efficiency for X-rays is 95%.

[0156] Comparing Example 7 with Example 6, it can be seen that the lead equivalent and the shielding efficiency of the X-ray-proof flexible fabric of Example 6 are superior to those of Example 7, because the fibers in Example 7 are difficult to recover to the original length after being stretched, resulting in that the diameter of the fibers in the length direction of the X-ray-proof flexible fabric is reduced and the gap between the fibers is larger than that of Example 6, thereby leading to poor radiation-proof performance, so that the lead equivalent and the shielding efficiency of the X-ray-proof flexible fabric of Example 7 are lower than those of Example 6.

[0157] Example 8

[0158] A preparation method of a lead-free X-ray-proof fiber, comprising the following steps:

[0159] (1) Preparation of raw materials:

[0160] Easily soluble salt: calcium chloride;

[0161] Coagulation bath: acetic acid;

[0162] Skin layer substrate: polyvinyl alcohol;

[0163] Radiation-proof particle I: barium sulfate, with an average diameter of 50 nm;

[0164] Core layer substrate: polyvinyl chloride;

[0165] Radiation-proof particle II: bismuth oxide, with an average diameter of 35 nm;

[0166] Solvent: DMF;

[0167] (2) Preparation of skin layer spinning solution and core layer spinning solution;

[0168] Skin layer spinning solution: composed of skin layer substrate, solvent, radiation-proof particle I, and easily soluble salt, the concentration of the easily soluble salt is 40 wt%, and the total concentration of the substances in the skin layer spinning solution except the solvent and the easily soluble salt is 10 wt%;

[0169] Core layer spinning solution: composed of core layer substrate, solvent, and radiation-proof particle II, the total concentration of the substances in the core layer spinning solution except the solvent is 20 wt%;

[0170] (3) After spinning by using coaxial wet spinning process, heating treatment is performed at a temperature of 90°C for 15 min, to obtain the lead-free X-ray-proof fiber, wherein the jet speed of the core layer spinning solution is 0.1 mm / min, and the jet speed of the skin layer spinning solution is 0.09 mm / min.

[0171] The finally prepared X-ray-proof lead-free fiber has a skin-core structure, the skin layer contains the radiation-proof particle I, and the core layer contains the radiation-proof particle II;

[0172] The thickness of the skin layer is 0.25 mm, the surface of the skin layer is distributed with grooves, the average depth of the grooves is 0.18 mm, and the average cross-sectional area of the grooves is 0.15 mm 2 The number of grooves per square centimeter is 600, and the content of the radiation-proof particle I in the skin layer is 45 wt%;

[0173] The diameter of the core layer is 0.25 mm, and the content of the radiation-proof particle II in the core layer is 80 wt%;

[0174] The CV value of the evenness of the X-ray-proof lead-free fiber is 1.14%.

[0175] An X-ray-proof flexible fabric prepared from the above X-ray-proof lead-free fiber has a multi-layer structure, the number of layers is 3, the functional layer is 1 layer, the functional layer is a knitted fabric prepared from the above X-ray-proof lead-free fiber, and the square meter gram weight of the functional layer is 125 g / m 2 The wearing layer is 2 layers, the wearing layer is a knitted fabric prepared from cotton fiber, and the square meter gram weight of the wearing layer is 235 g / m 2 .

[0176] The wearing layer is arranged in the inner layer of the fabric (close to the skin side), and the functional layer is arranged on the outer side of the fabric (close to the air side).

[0177] The prepared X-ray-proof flexible fabric has an air permeability of 400 mm / s, an average recovery angle of 75.32°, a moisture regain of 3.2%, a lead equivalent of 0.39 mm Pb, and an X-ray shielding efficiency of 96%.

[0178] Example 9

[0179] A preparation method of an X-ray-proof lead-free fiber, comprising the following steps:

[0180] (1) Preparation of raw materials:

[0181] Easily soluble salt: mixture of sodium chloride and calcium chloride with a mass ratio of 1:1;

[0182] Coagulation bath: mixture of ethanol and acetic acid with a mass ratio of 1:1;

[0183] Skin layer substrate: mixture of polyurethane and polyamide with a mass ratio of 1:1;

[0184] Radiation-proof particle I: barium sulfate, with an average diameter of 100 nm;

[0185] Core layer substrate: mixture of cellulose and polyvinyl chloride with a mass ratio of 1:1;

[0186] Radiation protection particle II: mixture of tungsten carbide and tungsten oxide with a mass ratio of 1:1, average diameter of 50 nm;

[0187] Solvent: DMF;

[0188] (2) Configure the skin layer spinning solution and the core layer spinning solution;

[0189] The skin layer spinning solution is composed of a skin layer base material, a solvent, a radiation protection particle I, and a readily soluble salt, the concentration of the readily soluble salt is 55wt%, and the total concentration of the substances in the skin layer spinning solution except the solvent and the readily soluble salt is 20wt%;

[0190] The core layer spinning solution is composed of a core layer base material, a solvent, and a radiation protection particle II, and the total concentration of the substances in the core layer spinning solution except the solvent is 20wt%;

[0191] (3) After spinning by using the coaxial wet spinning process, heating treatment is carried out at a temperature of 70℃ for 10 min, and thus the X-ray protection lead-free fiber is obtained, wherein the jet speed of the core layer spinning solution is 0.15 mm / min, and the jet speed of the skin layer spinning solution is 0.13 mm / min.

[0192] The finally prepared X-ray protection lead-free fiber has a skin-core structure, the skin layer contains the radiation protection particle I, and the core layer contains the radiation protection particle II;

[0193] The thickness of the skin layer is 0.22 mm, the skin layer surface is distributed with grooves, the average depth of the grooves is 0.14 mm, the average cross-sectional area of the grooves is 0.12 mm 2 , the number of grooves in each square centimeter area is 1100, and the content of the radiation protection particle I in the skin layer is 65wt%;

[0194] The diameter of the core layer is 0.35 mm, and the content of the radiation protection particle II in the core layer is 80wt%;

[0195] The evenness CV value of the X-ray protection lead-free fiber is 0.62%.

[0196] An X-ray protection flexible fabric prepared by using the above X-ray protection lead-free fiber has a multi-layer structure, the number of layers is 3, the number of functional layers is 2, the functional layer is a woven fabric prepared by using the above X-ray protection lead-free fiber, the square meter gram weight of the functional layer is 275g / m 2 , the number of wearing layers is 1, the wearing layer is a woven fabric prepared by using cotton fiber, and the square meter gram weight of the wearing layer is 130g / m 2 .

[0197] Among them, the wearing layer is placed in the inner layer of the fabric (close to the skin side), and the functional layer is placed on the outer side of the fabric (close to the air side).

[0198] The air permeability of the obtained X-ray-proof flexible fabric was 350 mm / s, the average recovery angle was 66.21°, the moisture regain was 2.9%, the lead equivalent was 0.52 mm Pb, and the shielding efficiency for X-rays was 99%.

Claims

1. A method for producing an X-ray-proof, lead-free fiber, characterized in that, The core layer spinning solution and the skin layer spinning solution containing the easily soluble salt are configured respectively, and then the coaxial wet spinning process is adopted to spin, so as to obtain the X-ray-proof lead-free fiber; the easily soluble salt is sodium chloride and / or calcium chloride, and the coagulation bath is one or more of water, ethanol and acetic acid; The X-ray-proof lead-free fiber has a skin-core structure, the skin layer contains radiation-proof particles I, and the surface of the skin layer is distributed with grooves, the average depth of the grooves is 0.05-0.25mm, the average cross-sectional area of the grooves is 0.08-0.15mm 2 , the number of grooves in each square centimeter area is 600-1300, the content of the radiation-proof particles I in the skin layer is 35-65wt%, and the thickness of the skin layer is 0.10-0.30mm The core layer also contains the anti-radiation particle II, and the content of the anti-radiation particle II in the core layer is 50-80wt%; The jet speed of the core layer spinning solution is greater than the jet speed of the skin layer spinning solution, the jet speed of the core layer spinning solution is 0.1-0.3mm / min, and the jet speed of the skin layer spinning solution is 0.05-0.15mm / min; The density of the coagulation bath is the same as the density of the X-ray-proof lead-free fiber; After the spinning is completed, heating treatment is also performed, the temperature of the heating treatment is higher than the glass transition temperature of the X-ray-proof lead-free fiber, and the time is 5-20min.

2. The method for preparing X-ray shielding lead-free fiber according to claim 1, characterized in that, The solvent in the skin layer spinning solution or the core layer spinning solution is DMF; the concentration of the easily soluble salt in the skin layer spinning solution is 25-55wt%, and the total concentration of the substances other than the solvent and the easily soluble salt is 8-20wt%; the total concentration of the substances other than the solvent in the core layer spinning solution is 15-20wt%.

3. The method for preparing X-ray shielding lead-free fiber according to claim 1, characterized in that, The base material of the skin layer and the core layer is independently selected from one or more of polyurethane, polyamide, cellulose, polyvinyl chloride and polyvinyl alcohol.

4. The method for preparing X-ray shielding lead-free fiber according to claim 1, characterized in that, The average diameter of the anti-radiation particle I is 40-100nm.

5. The method for preparing X-ray shielding lead-free fiber according to claim 1, characterized in that, The average diameter of the anti-radiation particle II is 20-50nm, and the diameter of the core layer is 0.15-0.35mm.

6. A flexible fabric for protection against X-rays, characterized in that The X-ray-proof lead-free fiber is prepared by the method as claimed in any one of claims 1-5.

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