Photochromic fleece fabric and method of making the same

Abstract

The application discloses a photochromic plush fabric and a preparation method thereof, and belongs to the technical field of functional textile materials. The photochromic plush fabric is formed by warp knitting or knitting processing of a photochromic plush fiber with a skin-core structure; the fiber comprises a polyester skin layer accounting for 60-80% in mass and a photochromic core layer accounting for 20-40% in mass; the core layer is composed of 5-15% photochromic microcapsules, 70-85% linear low-density polyethylene carrier resin and 5-10% additives. Through skin-core composite melt spinning and low-temperature color fixing process, the application solves five big bottlenecks of uneven discoloration, hand feeling deterioration, poor washing resistance, low safety and difficult mass production of traditional photochromic plush fabrics. The obtained fabric can quickly and uniformly develop color under ultraviolet light in 1-3s, and can reversibly fade in 5-12s; the hand feeling is fluffy and soft; the discoloration intensity retention rate is greater than or equal to 85% after 50 times of washing, and meets the A-class standard of GB18401-2010. The preparation process is simple, mass production is strong, and the application can be widely applied to the fields of toys, clothes, home furnishing and automobile interior decoration.

Description

Technical Field

[0001] This invention relates to the field of functional textile fabric technology, specifically to a photochromic plush fabric and its preparation method. Background Technology

[0002] Plush fabrics, with their excellent properties such as fluffiness, softness, skin-friendliness, warmth, and comfort, have long been widely used in plush toys, winter clothing, home cushions, blankets, and automotive interiors. However, with the upgrading of consumption and the growth of personalized demands, traditional plush fabrics, with their static appearance of only a single color and no dynamic changes, are unable to meet the market's pursuit of products with fun, interactivity, and high added value.

[0003] Photochromic materials are a class of functional materials that undergo reversible color changes when excited by light of specific wavelengths (especially ultraviolet light). In recent years, they have been explored for application in textiles to impart dynamic color-changing properties to fabrics. Currently, common methods for introducing photochromic materials into textiles mainly include:

[0004] Coating method: Photochromic materials are attached to the surface of fabrics by padding, spraying or scraping.

[0005] Masterbatch spinning method: The photochromic material is blended with the spinning melt to directly spin colored fibers.

[0006] However, there are a series of technical bottlenecks when directly transferring the above technologies to plush fabrics:

[0007] First, the fibers on the surface of plush fabrics are clustered and have a large specific surface area. When using traditional coating processes, the photochromic paste is prone to accumulate at the root of the fibers or randomly agglomerate, resulting in a "patchy" appearance or localized lack of color when changing color, with extremely poor color uniformity.

[0008] Secondly, in order to ensure the color-changing effect, the coating process often requires increasing the amount of adhesive or using high-temperature baking to fix the color. This causes the plush fibers to stick together, lie flat or even felt, making the fabric stiff and hard, and significantly reducing its fluffiness and softness.

[0009] Secondly, the bonding between photochromic materials and fibers is mostly physical adhesion, which makes them very easy to detach during washing, leading to a rapid decline in the color-changing function. At the same time, most photochromic materials themselves have insufficient resistance to light aging, and their sensitivity decreases significantly after long-term cyclic color changes.

[0010] In addition, some photochromic compounds and their auxiliary agents pose potential risks of biotoxicity or skin irritation, and therefore cannot meet the safety standards for infant and toddler textiles.

[0011] Finally, since photochromic materials are generally not resistant to high temperatures, they are prone to decomposition or deactivation under the high-temperature conditions of melt spinning, making it difficult to achieve stable mass production using the masterbatch spinning method.

[0012] Therefore, how to develop a photochromic plush fabric that can achieve a uniform, vibrant, fast-response, and reversible photochromic effect, while fully preserving the inherent fluffy and soft feel of plush fabric, and possessing excellent washability, durability, and safety, has become a technical challenge that urgently needs to be solved in this field. Summary of the Invention

[0013] (a) Technical problems to be solved

[0014] This invention aims to overcome the problems of uneven color change, deteriorated feel, poor washability, insufficient safety and poor mass production stability of existing photochromic plush fabrics, and provides a photochromic plush fabric with uniform color change, fast response, fluffy and soft feel, washability and lightfastness, safety and environmental protection, as well as its preparation method.

[0015] (II) Technical Solution

[0016] To achieve the above objectives, the present invention provides the following technical solution:

[0017] In a first aspect, the present invention provides a photochromic plush fabric, the fabric being made of core-sheath structure photochromic plush fibers through weaving or knitting.

[0018] The core-sheath structure photochromic plush fiber includes:

[0019] The outer layer, composed of polyester fibers, accounts for 60%-80% of the total fiber mass;

[0020] The core layer, a photochromic functional layer, accounts for 20%-40% of the total fiber mass. The core layer is formed by melt composite spinning of a mixture containing photochromic microcapsules, carrier resin and auxiliaries.

[0021] Furthermore, the photochromic microcapsules account for 5%-15% of the total mass of the core layer, the carrier resin accounts for 70%-85% of the total mass of the core layer, and the additives account for 5%-10% of the total mass of the core layer.

[0022] Furthermore, the photochromic microcapsules are microcapsules with spiropyran-based photochromic compounds as the core material and polyurea resin as the wall material, and the microcapsule particle size is 1-5 μm.

[0023] Furthermore, the carrier resin is linear low-density polyethylene with a melt index of 20-50 g / 10 min.

[0024] Further, the additive is composed of a dispersant, a UV absorber, and an antioxidant, wherein the dispersant accounts for 60%-80% of the total mass of the additive, the UV absorber accounts for 15%-30% of the total mass of the additive, and the antioxidant accounts for 1%-10% of the total mass of the additive; wherein,

[0025] The dispersant is poly-α-methylstyrene;

[0026] The ultraviolet absorber is bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate;

[0027] The antioxidant is pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxy)phenylpropionate.

[0028] Furthermore, the photochromic plush fabric has a weight of 190-800 g / m² and a pile height of 1-150 mm.

[0029] The photochromic plush fabric exhibits a color development response time of 1-3 seconds under 1.0-1.5 mW / cm² ultraviolet light irradiation; after the light is removed, the fading response time is 5-12 seconds.

[0030] After 50 standard washes, the color-changing intensity retention rate of the photochromic plush fabric is ≥85%; after 1000 UV-protected cyclic aging tests, the color-changing sensitivity decrease rate is ≤10%.

[0031] Secondly, the present invention provides a method for preparing the photochromic plush fabric, comprising the following steps:

[0032] S1. Preparation of core-sheath structure photochromic plush fiber:

[0033] S11. Preparation of leather material: Dry the polyester fiber chips and control the moisture content to ≤50ppm;

[0034] S12. Preparation of core layer mixture: Mix the photochromic microcapsules, carrier resin and additives evenly according to the formula to obtain the core layer mixture;

[0035] S13, Composite Melt Spinning: The sheath material and the core mixture are added to a twin-screw extruder. The extrusion temperature of the sheath is controlled at 220-240℃, and the extrusion temperature of the core is controlled at 160-180℃. The core-sheath composite spinning assembly is used for extrusion molding. After cooling, oiling, stretching, crimping, heat setting, and cutting, a sheath-core structure photochromic plush fiber is obtained.

[0036] S2. Plush fabric weaving: The core-sheath structure photochromic plush fibers obtained in step S1 are woven into plush fabric using warp knitting or weft knitting processes.

[0037] S3. Finishing: The plush fabric obtained in step S2 is subjected to the following treatments in sequence:

[0038] S31, Pre-set condition: Temperature 120-140℃, vehicle speed 15-25m / min;

[0039] S32, Low-temperature composite color fixing: Immerse the product in a color fixing solution at 80-85℃ for 10-20 minutes;

[0040] S33. Softening Finish: Use amino silicone oil softener, with an application rate of 2%-5% of the fabric weight;

[0041] S34. Drying and shaping: Temperature 90-110℃, speed 10-20m / min;

[0042] S35, Raising and trimming: Control the pile height to 1-150mm.

[0043] Furthermore, the color-fixing solution mentioned in step S32 is an aqueous polyurethane emulsion with a mass concentration of 10-20 g / L.

[0044] Thirdly, the present invention provides an application of the photochromic plush fabric prepared by the method described above in toys, clothing, home furnishings or automotive interiors.

[0045] Fourthly, the present invention provides a core-sheath structure photochromic plush fiber, comprising:

[0046] The outer layer, composed of polyester fibers, accounts for 60%-80% of the total fiber mass;

[0047] The core layer, a photochromic functional layer, accounts for 20%-40% of the total fiber mass. The core layer is formed by melt composite spinning of a mixture containing photochromic microcapsules, carrier resin and auxiliaries.

[0048] The photochromic microcapsules are microcapsules with spiropyran-based photochromic compounds as the core material and polyurea resin as the wall material, and the microcapsule particle size is 1-5 μm;

[0049] The carrier resin is linear low-density polyethylene;

[0050] The additives consist of dispersants, ultraviolet absorbers, and antioxidants.

[0051] (III) Beneficial Effects

[0052] (1) The present invention discloses a photochromic plush fabric and its preparation method. The fabric employs a core-sheath composite spinning process to pre-disperse photochromic microcapsules uniformly in the fiber core layer, fundamentally avoiding the problem of uneven color change caused by the aggregation and accumulation of photochromic materials on the plush surface in traditional coating processes. At the same time, the microcapsule encapsulation technology keeps the photochromic compound in a stable microenvironment, resulting in high color development sensitivity, rapid color development within 1-3 seconds, and complete fading within 5-12 seconds, providing rich dynamic visual effects.

[0053] (2) The present invention provides a photochromic plush fabric and its preparation method. The core carrier resin is selected as low melting point linear low polyethylene, which can be spun together with the outer polyester at a low temperature of 160-180℃ to avoid damage to the photochromic material at high temperature. The finishing stage adopts low temperature color fixing at 80-85℃, which is much lower than the high temperature baking temperature of 130-150℃ in the traditional process, thus eliminating the phenomenon of fiber overheating shrinkage, adhesion and felting. The finished fabric has the same fluffiness, softness and elasticity recovery as ordinary plush fabric.

[0054] (3) This invention discloses a photochromic plush fabric and its preparation method. The photochromic microcapsules are encapsulated inside the core-sheath structure, rather than simply attached to the fiber surface. Combined with a low-temperature color-fixing process, the core resin and the sheath fiber form a strong interface bond, resulting in extremely strong resistance to washing and shedding. After 50 standard household washes, the color change intensity retention rate is ≥85%, which is much higher than that of coated photochromic fabrics (usually ≤40%). The ultraviolet absorbers and antioxidants added in the additives significantly improve the anti-photoaging performance of the photochromic material, and the color change sensitivity decreases by ≤10% after 1000 cycles of aging.

[0055] (4) The present invention discloses a photochromic plush fabric and its preparation method. Environmentally friendly spiropyran photochromic compounds are selected, and their biotoxicity is significantly reduced after microencapsulation. The carrier resin, LLDPE, is a food contact grade material, and all additives are non-toxic and environmentally friendly. The preparation process involves no solvents and contains no formaldehyde, heavy metals, phthalates, or other harmful substances. The finished fabric meets the requirements of GB 18401-2010 "National Basic Safety Technical Specifications for Textile Products" Class A (Infant Products) and can be safely used in sensitive areas such as infant toys and intimate apparel.

[0056] (5) The present invention provides a photochromic plush fabric and its preparation method. The core layer is produced by low-temperature melt spinning, which avoids the decomposition and deactivation of the photochromic material at high temperature. The microcapsule wall material polyurea resin has good thermal stability and mechanical strength and can withstand the shear force during the spinning process. The core-sheath structure gives the fiber excellent spinnability. The continuous spinning time can reach more than 72 hours, the breakage rate is ≤0.5 times / ton, and the yield is ≥95%, which meets the conditions for large-scale industrial production. Attached Figure Description

[0057] Figure 1 This is a schematic diagram of the process for preparing photochromic plush fabric in an embodiment of the present invention. Detailed Implementation

[0058] The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0059] This invention provides a photochromic plush fabric, characterized in that the fabric is made of core-sheath structure photochromic plush fibers through weaving or knitting.

[0060] The core-sheath structure photochromic plush fiber includes:

[0061] The outer layer is composed of polyester fibers, accounting for 60%-80% of the total fiber mass.

[0062] Core layer: a photochromic functional layer, accounting for 20%-40% of the total fiber mass. The core layer is formed by melt composite spinning of a mixture containing photochromic microcapsules, carrier resin and auxiliaries.

[0063] In a preferred embodiment of the present invention, the photochromic microcapsules account for 5%-15% of the total mass of the core layer, the carrier resin accounts for 70%-85% of the total mass of the core layer, and the additives account for 5%-10% of the total mass of the core layer.

[0064] As a preferred embodiment of the present invention, the photochromic microcapsule is a microcapsule with a spiropyran-based photochromic compound as the core material and polyurea resin as the wall material, and the microcapsule particle size is 1-5 μm.

[0065] As a preferred embodiment of the present invention, the carrier resin is linear low-density polyethylene (LLDPE) with a melt index (190℃ / 2.16kg) of 20-50g / 10min.

[0066] In a preferred embodiment of the present invention, the additive is composed of a dispersant, an ultraviolet absorber and an antioxidant, wherein the dispersant accounts for 60%-80% of the total mass of the additive, the ultraviolet absorber accounts for 15%-30% of the total mass of the additive, and the antioxidant accounts for 1%-10% of the total mass of the additive.

[0067] In a preferred embodiment of the present invention, the dispersant is poly(α-methylstyrene); the ultraviolet absorber is bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate; and the antioxidant is pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxy)phenylpropionate.

[0068] As a preferred embodiment of the present invention, the fineness of the photochromic plush fiber of the core-sheath structure is 50D-150D, and the fineness of the single filament is 2D-5D.

[0069] As a preferred embodiment of the present invention, the photochromic plush fabric has a weight of 190-800 g / m² and a pile height of 1-150 mm.

[0070] As a preferred embodiment of the present invention, the photochromic plush fabric has a color development response time of 1-3s under ultraviolet light irradiation of 1.0-1.5mW / cm²; and a fading response time of 5-12s after the light is removed.

[0071] As a preferred embodiment of the present invention, the photochromic plush fabric retains ≥85% of its color intensity after 50 standard washes; and decreases ≤10% of its color sensitivity after 1000 UV-avoidance cyclic aging tests.

[0072] This invention also provides a preparation method embodiment A, specifically for the preparation of a photochromic plush fabric, comprising the following steps:

[0073] S1. Preparation of core-sheath structured photochromic plush fiber

[0074] Skin layer: Polyester fiber chips (intrinsic viscosity 0.65 dL / g), dried to a moisture content ≤50 ppm;

[0075] Core layer mixture: by mass percentage, photochromic microcapsules 10%, linear low-density polyethylene (LLDPE, melt index 30 g / 10 min) 82%, and additives 8%; wherein the additives consist of dispersant polyα-methylstyrene 70%, ultraviolet absorber bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate 25%, and antioxidant pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyphenylpropionate) 5%;

[0076] Photochromic microcapsules: The core material is a spiropyran compound (CAS No.: 2744-50-5), the wall material is polyurea resin, and the average particle size of the microcapsules is 3μm.

[0077] The sheath material and the core mixture are fed into a twin-screw extruder. The sheath extrusion temperature is 230℃ and the core extrusion temperature is 170℃. The extrusion is carried out through a core-sheath composite spinning assembly. The mass ratio of sheath to core is 70:30. After cooling, oiling, stretching, crimping, heat setting, and cutting, a sheath-core structure photochromic polyester fiber with a fineness of 75D / 36F is obtained.

[0078] S2, plush fabric weaving

[0079] The fibers obtained in step S1 are woven into a plush fabric using a warp knitting machine. The fabric structure is warp-knitted plush fabric, machine number E22.

[0080] S3, Post-processing

[0081] Pre-set conditions: 130℃, vehicle speed 20m / min;

[0082] Low-temperature composite color fixing: The color fixing solution is an aqueous polyurethane emulsion with a concentration of 15 g / L, a temperature of 82℃, and an immersion time of 15 min.

[0083] Softening treatment: Amino silicone oil softener, used at 3% of the fabric weight;

[0084] Drying and shaping: 100℃, speed 15m / min;

[0085] Raising and trimming: Raise the nap repeatedly using a raising machine until the nap height reaches 10mm, then trim it smooth with a trimming machine to obtain the finished product.

[0086] Performance test results of the photochromic plush fabric prepared in this embodiment:

[0087] Weight: 450g / m²; Pile height: 10mm; Color development response time (1.2mW / cm² UV light): 1.8s; Fading response time (removal of light source): 7s; Color change intensity retention rate after 50 washes: 91%; Color change sensitivity reduction rate after 1000 UV-protected cycles: 7%; Softness (heart-shaped method): 80mm; Formaldehyde content: Not detected; pH value: 6.5; Decomposable carcinogenic aromatic amine dyes: Not detected; Complies with GB 18401-2010 Class A standard.

[0088] This invention also provides a preparation method embodiment B, which differs from the preparation method embodiment A in that: the mass ratio of the skin layer to the core layer is 80:20; the mass percentage of photochromic microcapsules in the core layer mixture is adjusted to 15%, the carrier resin LLDPE is adjusted to 75%, and the additives are adjusted to 10% (of which dispersant is 80%, ultraviolet absorber is 15%, and antioxidant is 5%); the fiber fineness is 100D / 48F; the fabric weight is 550g / m², and the pile height is 12mm.

[0089] Performance test results:

[0090] Color development response time: 1.5s; fading response time: 6s; color intensity retention rate after 50 washes: 93%; color sensitivity reduction rate after 1000 cycles: 6%; softness: 78mm.

[0091] This invention also provides a preparation method embodiment C, which differs from the preparation method embodiment A in that: the mass ratio of the skin layer to the core layer is 60:40; the mass percentage of photochromic microcapsules in the core layer mixture is adjusted to 5%, the carrier resin LLDPE is adjusted to 85%, and the additives are adjusted to 10% (of which the dispersant is 60%, the ultraviolet absorber is 30%, and the antioxidant is 10%); the fiber fineness is 50D / 24F; the fabric weight is 350g / m², and the pile height is 6mm.

[0092] Performance test results:

[0093] Color development response time: 2.5s; fading response time: 10s; color intensity retention rate after 50 washes: 86%; color sensitivity reduction rate after 1000 cycles: 9%; softness: 83mm.

[0094] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A photochromic plush fabric, characterized in that, The fabric is made of core-sheath structure photochromic plush fibers through weaving or knitting. The core-sheath structure photochromic plush fiber includes: The outer layer, composed of polyester fibers, accounts for 60%-80% of the total fiber mass; The core layer, a photochromic functional layer, accounts for 20%-40% of the total fiber mass. The core layer is formed by melt composite spinning of a mixture containing photochromic microcapsules, carrier resin and auxiliaries.

2. The photochromic plush fabric according to claim 1, characterized in that, The photochromic microcapsules account for 5%-15% of the total mass of the core layer, the carrier resin accounts for 70%-85% of the total mass of the core layer, and the additives account for 5%-10% of the total mass of the core layer.

3. The photochromic plush fabric according to claim 1 or 2, characterized in that, The photochromic microcapsules are microcapsules with spiropyran-based photochromic compounds as the core material and polyurea resin as the wall material, and the microcapsule particle size is 1-5 μm.

4. The photochromic plush fabric according to claim 1 or 2, characterized in that, The carrier resin is linear low-density polyethylene with a melt index of 20-50 g / 10 min.

5. The photochromic plush fabric according to claim 1 or 2, characterized in that, The additives consist of dispersants, ultraviolet absorbers, and antioxidants, wherein the dispersants account for 60%-80% of the total mass of the additives, the ultraviolet absorbers account for 15%-30% of the total mass of the additives, and the antioxidants account for 1%-10% of the total mass of the additives; wherein, The dispersant is poly-α-methylstyrene; The ultraviolet absorber is bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate; The antioxidant is pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxy)phenylpropionate.

6. The photochromic plush fabric according to claim 1, characterized in that, The photochromic plush fabric has a weight of 190-800g / m² and a pile height of 1-150mm. The photochromic plush fabric exhibits a color development response time of 1-3 seconds under 1.0-1.5 mW / cm² ultraviolet light irradiation. After the light is removed, the fading response time is 5-12 seconds; After 50 standard washes, the color-changing intensity retention rate of the photochromic plush fabric is ≥85%; after 1000 UV-protected cyclic aging tests, the color-changing sensitivity decrease rate is ≤10%.

7. A method for preparing the photochromic plush fabric according to any one of claims 1-6, characterized in that, Includes the following steps: S1. Preparation of core-sheath structure photochromic plush fiber: Preparation of leather material: Dry the polyester fiber chips and control the moisture content to ≤50ppm; Core layer mixture preparation: The photochromic microcapsules, carrier resin and additives are mixed evenly according to the formula to obtain the core layer mixture; Composite melt spinning: The sheath material and the core mixture are added to a twin-screw extruder. The extrusion temperature of the sheath is controlled at 220-240℃ and the extrusion temperature of the core is controlled at 160-180℃. The core-sheath composite spinning assembly is used for extrusion molding. After cooling, oiling, stretching, crimping, heat setting and cutting, sheath-core structure photochromic plush fiber is obtained. S2. Plush fabric weaving: The core-sheath structure photochromic plush fibers obtained in step S1 are woven into plush fabric using warp knitting or weft knitting processes. S3. Finishing: The plush fabric obtained in step S2 is subjected to the following treatments in sequence: Pre-set conditions: temperature 120-140℃, vehicle speed 15-25m / min; Low-temperature composite color fixing: Immerse the product in a color fixing solution at 80-85℃ for 10-20 minutes; Softening treatment: Use amino silicone oil softener, with an application rate of 2%-5% of the fabric weight; Drying and shaping: Temperature 90-110℃, speed 10-20m / min; Raising and trimming: Control the pile height to 1-150mm.

8. The method according to claim 7, characterized in that, The color-fixing solution mentioned in step S32 is an aqueous polyurethane emulsion with a mass concentration of 10-20 g / L.

9. The use of a photochromic plush fabric prepared by the method of any one of claims 7-8 in toys, clothing, home furnishings or automotive interiors.

10. A core-sheath structure photochromic plush fiber, characterized in that, include: The outer layer, composed of polyester fibers, accounts for 60%-80% of the total fiber mass; The core layer, a photochromic functional layer, accounts for 20%-40% of the total fiber mass. The core layer is formed by melt composite spinning of a mixture containing photochromic microcapsules, carrier resin and auxiliaries. The photochromic microcapsules are microcapsules with spiropyran-based photochromic compounds as the core material and polyurea resin as the wall material, and the microcapsule particle size is 1-5 μm; The carrier resin is linear low-density polyethylene; The additives consist of dispersants, ultraviolet absorbers, and antioxidants.

Images