High-fluffiness elastic polyester wool top and preparation method thereof

Abstract

The invention provides a high-fluffy elastic polyester wool top and a preparation method thereof, a third monomer 1, 3-propylene glycol and a fourth monomer 1, 4-cyclohexanedimethanol are introduced in a stage of synthesizing polyester by taking terephthalic acid and ethylene glycol as raw materials to carry out co-esterification, pre-polycondensation and final polycondensation reaction, the molar weight ratio does not exceed 10%; a special-shaped spinning spinneret plate is adopted in the spinning stage, and polyester wool tops with high fluffiness and excellent stretching and compression-resistant rebound rate are obtained through drafting and sizing. The high-fluffiness elastic polyester wool tops can be used independently and can also be used after being blended with wool and the like. The high-fluffiness elastic polyester wool top shows plump, smooth, stiff and smooth effects, and is often used for manufacturing knitwear, sweater and other clothes and bedding articles, sofa covers and other household articles.

Description

Technical Field

[0001] The invention belongs to the technical field of new fiber material development, and relates to a high-loft elastic polyester top and a preparation method thereof. Specifically, a third and a fourth monomer are introduced into polyester synthesis to carry out co-esterification and polycondensation reaction to prepare a modified polyester, and then the polyester top is spun through a shaped spinneret to obtain a high-loft polyester top with excellent tensile strength and anti-compression resilience. Background Art

[0002] Polyester is an important textile raw material with many excellent properties, such as high breaking strength and elastic modulus, good wear resistance, excellent heat setting effect, etc. Polyester is widely used in clothing and decoration. The main material of polyester is polyethylene terephthalate. Polyester tops are a new type of textile material made of polyester fibers and are widely used in the production of textile products. Polyester tops are strips formed by processing polyester fibers, with excellent wear resistance, wrinkle resistance and stability. These characteristics make polyester tops widely used in the textile industry, such as making sweater textiles, bedding, sofa covers and other household items. Polyester top products with fluffy and elastic properties can not only improve warmth during wearing, but also improve elasticity, wrinkle resistance and aesthetics, which is the direction of high value-added product development.

[0003] CN 115726056 A A thin and breathable cashmere-like polyester wool top, which relates to the technical field of polyester wool top, is made by spinning polyester fiber and acrylic fiber; the polyester fiber includes the following components by weight: 85-100 parts of PET fiber slices; 4-8 parts of silane coupling agent; 3-6 parts of sodium dodecylbenzene sulfonate; 10-16 parts of attapulgite; 8-12 parts of softener; 1-3 parts of antioxidant; the acrylic fiber includes the following components by weight: 85-100 parts of polyacrylonitrile copolymer; 3-5 parts of silane coupling agent; 2-5 parts of antioxidant. By adopting the above technical scheme, polyester fiber and acrylic fiber are blended, and the polyester fiber and acrylic fiber are modified respectively, the fabric woven from the wool top has good air permeability, low surface density, and is lighter and thinner.

[0004] CN 110331452 B The production process of flat polyester wool tops, raw material drying → screw extrusion spinning → winding and bundling → tow post-processing → tow cutting and strip making → one-pass needle combing → two-pass needle combing → ball-forming needle combing. The flat polyester wool tops produced by the above method have flat filaments, long fibers, high brightness, elastic and smooth hand feeling, strong three-dimensional sense, and are more suitable for dyeing than ordinary chemical fibers, so they are suitable for the production of imitation fur clothing.

[0005] It is difficult to solve the problem that the hollow structure of conventional PET polyester raw materials cannot be maintained due to "collapse" during the forming process when spinning high profile fibers. In addition, it is also a technical problem how to achieve the fluffiness and rebound under the conditions of stretching and compression of conventional polyester wool tops during wearing. The present invention obtains a special spinning raw material by chemical copolymerization modification in the polyester synthesis stage, and then realizes the preparation of high-fluff elastic polyester wool tops by optimizing the spinning components and processes. Summary of the invention

[0006] The purpose of the present invention is to provide a high-loft elastic polyester top with a hollowness of 25-45%, a compression rebound rate of ≥80%, and a stretch rebound rate of ≥85% and a preparation method thereof.

[0007] To achieve the above object, the technical solution of the present invention is as follows:

[0008] The invention aims at the problem of insufficient performance of existing polyester tops in applications, which limits their application and promotion, and especially aims at the demand for bulkiness and shape-retaining performance in applications. In the stage of synthesizing polyester using terephthalic acid and ethylene glycol as raw materials, a third monomer 1,3-propylene glycol and a fourth monomer 1,4-cyclohexanedimethanol are introduced to carry out co-esterification, pre-polycondensation and final polycondensation reaction, and the molar ratio of the third monomer to the fourth monomer relative to ethylene glycol is not more than 10%. In the spinning stage, a special-shaped spinning spinneret is used, and then the polyester top with high bulkiness and excellent tensile strength and anti-compression resilience is obtained through drawing and shaping.

[0009] A method for preparing high-loft elastic polyester tops as described above, wherein the terephthalic acid, ethylene glycol, the third monomer 1,3-propylene glycol, the fourth monomer 1,4-cyclohexanedimethanol and a catalyst are mixed and beaten and then reacted, and the beating is performed by mechanical stirring in a vertical reactor at a speed of 30-50 r / min;

[0010] The molar ratio of the reaction of terephthalic acid and ethylene glycol is 1:1.1-1.5;

[0011] The mixed molar ratio of the third monomer 1,3-propylene glycol and the fourth monomer 1,4-cyclohexanedimethanol is 5:95-10:90 of ethylene glycol;

[0012] The molar ratio of the third monomer 1,3-propylene glycol to the fourth monomer 1,4-cyclohexanedimethanol is 20:80-80:20;

[0013] A method for preparing high-loft elastic polyester top as described above, wherein the reaction catalyst is a mixed catalyst of titanium glycolate and antimony glycolate;

[0014] The total amount of the mixed catalyst added is 30-300 ppm of the mass fraction of terephthalic acid;

[0015] The mass ratio of the mixed catalyst titanium glycolate and antimony glycolate is 1:99-10:90;

[0016] In the method for preparing high-loft elastic polyester tops as described above, terephthalic acid, ethylene glycol, a third monomer 1,3-propylene glycol, and a fourth monomer 1,4-cyclohexanedimethanol are subjected to co-esterification, pre-polycondensation, and final polycondensation reactions.

[0017] The co-esterification reaction temperature is 225-240°C, the co-esterification reaction pressure is controlled at 0-300KPa, and the reaction time is 2.5-4.5h;

[0018] The pre-polycondensation reaction temperature is 245-260°C, the reaction pressure is controlled at 100KPa, and the reaction time is 0.5-1.5h;

[0019] The final polycondensation reaction temperature is 265-280°C, the reaction pressure is controlled at 0-100Pa, and the reaction time is 1.5-3.0h;

[0020] The method for preparing high-loft elastic polyester sliver as described above comprises the following steps: co-esterification, pre-polycondensation and final polycondensation of terephthalic acid, ethylene glycol, a third monomer 1,3-propylene glycol and a fourth monomer 1,4-cyclohexanedimethanol to obtain a modified PET polyester.

[0021] The modified PET polyester has an intrinsic viscosity of 0.66-0.75 dL / g, a melting point of 240-252°C, a melt index of 20-45 g / 10min, and a slice b value of ≤5;

[0022] A method for preparing high-loft elastic polyester tops as described above, wherein the prepared modified PET polyester is then shaped and spun;

[0023] The shaped spinning shown uses an eight-leaf hollow spinning spinneret, the spinning cooling temperature is controlled at 16-20°C, the melt solidifies quickly, the spinning speed is 2400-3200m / min, and then the fineness is obtained by drawing and shaping. The specification is 1.5D-5D / 75-102F;

[0024] According to the above-mentioned method for preparing a high-loft elastic polyester top, the polyester top has high loft and excellent tensile and anti-compression resilience, the hollowness of the polyester top is 25-45%, the compression rebound rate is ≥80%, and the tensile rebound rate is ≥85%. The high-loft elastic polyester top can be used alone or blended with wool. The high-loft elastic polyester top shows a full, smooth and crisp effect, and is often used to make knitwear, sweaters and other clothing, as well as bedding, sofa covers and other household items.

[0025] Principle of the Invention

[0026] Polyester tops are an important product form of polyester and are often used to make knitwear, sweaters and other clothing, as well as bedding, sofa covers and other household items. Improving the performance of polyester tops has always been a very concerned issue in this field. It is difficult to solve the problem of the hollow structure being "collapsed" during the forming process of conventional polyester during high-profile spinning, resulting in the inability to maintain the hollowness. In addition, how to achieve the fluffiness and rebound of conventional polyester tops under stretching and compression conditions during the wearing process is also a technical problem. In summary, this is because conventional polyester melts cannot always solve the outlet expansion effect and the extrusion deformation of the primary yarn during the stretching process during the profile spinning process. The present invention is to prepare a special spinning raw material by chemical copolymerization modification in the polyester synthesis stage, and then to achieve the preparation of high-fluffy elastic polyester tops by optimizing the spinning components and processes.

[0027] In the synthesis stage, the third monomer 1,3-propylene glycol and the fourth monomer 1,4-cyclohexanedimethanol are introduced into the polyester synthesis stage with terephthalic acid and ethylene glycol as raw materials for co-esterification, pre-condensation and final polycondensation reaction, wherein the molar ratio of the third monomer to the fourth monomer relative to ethylene glycol does not exceed 10%. The introduction of the third monomer 1,3-propylene glycol adds side methyl groups on the basis of diols to improve the elastic properties of polyester; the introduction of the fourth monomer 1,4-cyclohexanedimethanol is to enhance the rigidity and resilience of polyester. The third monomer 1,3-propylene glycol and the fourth monomer 1,4-cyclohexanedimethanol are both added in the esterification stage for co-esterification with terephthalic acid and ethylene glycol, and the molar ratio of the third monomer to the fourth monomer relative to ethylene glycol does not exceed 10%, otherwise the excessive addition ratio will lead to a significant decrease in the crystallization properties of the modified PET polyester, which cannot meet the requirements of fiber forming applications.

[0028] The reaction catalyst is a mixed catalyst of titanium glycolate and antimony glycolate. The use of titanium glycolate alone will cause serious yellowing of the prepared modified polyester chips due to its high activity. The use of antimony glycolate alone has low catalytic activity, and the molecular weight of the prepared modified polyester cannot meet the spinning requirements. The use of titanium glycolate and antimony glycol mixed catalyst, with antimony glycolate as the main component and titanium glycolate as the auxiliary component, can achieve the best match between the molecular weight and hue of the prepared modified polyester. The reaction goes through co-esterification, pre-polycondensation, and final polycondensation. Co-esterification can realize the reaction of monomers to form oligomers; pre-polycondensation is carried out under low vacuum conditions, which can realize further esterification reactions and further increase the molecular weight of oligomers. Pre-polycondensation is a necessary unit, otherwise directly entering the final polycondensation stage from co-esterification will cause the oligomers to be extracted from the system under high vacuum conditions. The prepared modified polyester is then melt-spun, and an eight-leaf hollow special-shaped spinning spinneret is used for melt spinning. The spinning cooling temperature is controlled at 16-20°C, the melt solidifies quickly, and the spinning speed is 2400-3200m / min. Compared with conventional PET polyester, the spinning cooling temperature of the present invention is lower, so that the spinning melt can be quickly solidified after extrusion to ensure the maintenance of its special-shaped structure, and the rigid structure of the primary filament in the polyester melt is not easy to deform during the stretching process, and will not be easily flattened under the action of external force.

[0029] Beneficial Effects

[0030] (1) The present invention introduces a third monomer 1,3-propylene glycol and a fourth monomer 1,4-cyclohexanedimethanol at a relatively low content into conventional PET polyester synthesis. The introduction of the third monomer 1,3-propylene glycol adds a side methyl group on the basis of the diol to improve the elastic properties of the polyester; the introduction of the fourth monomer 1,4-cyclohexanedimethanol is to enhance the rigidity and resilience of the polyester. The existing polymerization equipment is not changed, and the process is easy to operate.

[0031] (2) The present invention further performs melt spinning on the basis of chemical modification of polyester melt, adopts an eight-leaf hollow special-shaped spinning spinneret, controls the spinning cooling temperature at 16-20°C, and rapidly solidifies the melt. The prepared polyester tops are highly fluffy and have excellent tensile strength and anti-compression resilience. High-loft elastic polyester tops can be used alone or blended with wool. High-loft elastic polyester tops show a full, smooth and crisp effect, and are often used to make knitwear, sweaters and other clothing, as well as bedding, sofa covers and other household items. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is an enlarged view of the cross section of the eight-leaf hollow fiber. DETAILED DESCRIPTION

[0033] Example 1 / 2 / 3:

[0034] After terephthalic acid, ethylene glycol, the third monomer 1,3-propylene glycol, the fourth monomer 1,4-cyclohexanedimethanol, a catalyst, etc. are mixed and beaten, and then co-esterification, pre-polycondensation, and final polycondensation reactions are performed to obtain modified PET polyester. The co-esterification reaction temperature is 225-240°C, the co-esterification reaction pressure is controlled at 240-260KPa, and the reaction time is 3-4h; the pre-polycondensation reaction temperature is 245-260°C, the reaction pressure is controlled at 100KPa, and the reaction time is 0.5-1.0h; the final polycondensation reaction temperature is 265-280°C, the reaction pressure is controlled at 0-100Pa, and the reaction time is 2.0-2.5h.

[0035] The molar ratio of the reaction of terephthalic acid and ethylene glycol is 1:1.1, the mixed molar ratio of the third monomer 1,3-propylene glycol and the fourth monomer 1,4-cyclohexanedimethanol is 5:95 of ethylene glycol, the total added amount of ethylene glycol titanium and ethylene glycol antimony mixed catalyst is 30ppm of the mass fraction of terephthalic acid, and the mass ratio between ethylene glycol titanium and ethylene glycol antimony is 1:99.

[0036] In Examples 1, 2, and 3, the molar ratios of the third monomer 1,3-propylene glycol to the fourth monomer 1,4-cyclohexanedimethanol are 20:80, 50:50, and 80:20, respectively.

[0037] The prepared modified PET polyester is then subjected to profile spinning, and an eight-leaf hollow spinning spinneret is used for the profile spinning. The spinning cooling temperature is controlled at 16-20°C, the melt solidifies quickly, and the spinning speed is 2700-2900m / min. After stretching and shaping, a high-loft elastic polyester top with a specification of 1.5D-5D / 75-102F in fineness is obtained.

[0038] Embodiment 4 / 5 / 6:

[0039] The molar ratio of terephthalic acid and ethylene glycol in the reaction of Example 1-3 was changed to 1:1.5, the mixed molar ratio of the third monomer 1,3-propylene glycol and the fourth monomer 1,4-cyclohexanedimethanol was changed to 9:91 of ethylene glycol, the total added amount of ethylene glycol titanium and ethylene glycol antimony mixed catalyst was changed to 100 ppm of the mass fraction of terephthalic acid, the mass ratio of ethylene glycol titanium and ethylene glycol antimony was changed to 5:95, and other conditions remained unchanged, and Examples 4-6 were obtained respectively.

[0040] Example 7 / 8 / 9:

[0041] The molar ratio of terephthalic acid and ethylene glycol in the reaction of Examples 1-3 was changed to 1:1.5, the mixed molar ratio of the third monomer 1,3-propylene glycol and the fourth monomer 1,4-cyclohexanedimethanol was changed to 9:91 of ethylene glycol, the total added amount of ethylene glycol titanium and ethylene glycol antimony mixed catalyst was changed to 300 ppm of the mass fraction of terephthalic acid, the mass ratio of ethylene glycol titanium and ethylene glycol antimony was changed to 10:90, and other conditions remained unchanged, and Examples 7-9 were obtained respectively.

[0042] Example 10 / 11 / 12:

[0043] The mixed molar ratio of the third monomer 1,3-propylene glycol and the fourth monomer 1,4-cyclohexanedimethanol in Examples 1-3 was changed to 9:91 of ethylene glycol, the total addition amount of ethylene glycol titanium and ethylene glycol antimony mixed catalyst was 300 ppm of the mass fraction of terephthalic acid, and other conditions remained unchanged, to obtain Examples 10-12 respectively.

[0044] Example 13 / 14 / 15:

[0045] The molar ratio of terephthalic acid to ethylene glycol in the reaction of Examples 1-3 was changed to 1:1.5, the total amount of ethylene glycol titanium and ethylene glycol antimony mixed catalyst added was 300 ppm of the mass fraction of terephthalic acid, and other conditions remained unchanged, thereby obtaining Examples 13-15 respectively.

[0046] The relevant performance parameters of the high-loft elastic polyester tops prepared in each embodiment are shown in Table 1.

[0047] The present invention provides a high-loft elastic polyester top and a preparation method thereof. In the stage of synthesizing polyester using terephthalic acid and ethylene glycol as raw materials, a third monomer 1,3-propylene glycol and a fourth monomer 1,4-cyclohexanedimethanol are introduced to carry out co-esterification, pre-polycondensation and final polycondensation reaction, wherein the molar ratio of the third monomer to the fourth monomer relative to ethylene glycol is not more than 10%; a special-shaped spinning spinneret is used in the spinning stage, and then the polyester top with high loft and excellent tensile and anti-compression resilience is obtained through drafting and shaping. The high-loft elastic polyester top can be used alone or blended with wool. The high-loft elastic polyester top shows a full, smooth and crisp effect, and is often used to make knitwear, sweaters and other clothing, as well as bedding, sofa covers and other household items.

[0048] Table 1:

[0049] Example Hollowness(%) Compression rebound rate (%) Tensile resilience (%) 1 20 85 87 2 25 82 86 3 30 80 85 4 32 90 88 5 37 87 89 6 40 85 90 7 42 93 94 8 43 97 98 9 45 100 100 10 36 91 91 11 38 93 93 12 43 91 95 13 35 95 91 14 38 93 93 15 40 95 94

Claims

1. A method for preparing high-loft elastic polyester top, characterized in that: In the stage of synthesizing polyester using terephthalic acid and ethylene glycol as raw materials, a third monomer 1,3-propylene glycol and a fourth monomer 1,4-cyclohexanedimethanol are introduced to carry out co-esterification, pre-polycondensation and final polycondensation reactions, and the molar ratio of the third monomer to the fourth monomer relative to ethylene glycol is not more than 10%; in the spinning stage, an eight-leaf hollow spinning spinneret is used to obtain eight-leaf hollow fibers, which are then stretched and shaped to obtain polyester tops with high fluffy elasticity.

2. A method for preparing high-loft elastic polyester top according to claim 1, characterized in that: The molar ratio of the reaction of terephthalic acid and ethylene glycol is 1:1.1-1.5; the mixed molar ratio of the third monomer 1,3-propylene glycol and the fourth monomer 1,4-cyclohexanedimethanol is 5:95-10:90 of ethylene glycol; the molar ratio of the third monomer 1,3-propylene glycol to the fourth monomer 1,4-cyclohexanedimethanol is 20:80-80:

20.

3. The method for preparing high-loft elastic polyester top according to claim 1, characterized in that: Terephthalic acid, ethylene glycol, the third monomer 1,3-propylene glycol, the fourth monomer 1,4-cyclohexanedimethanol and a catalyst are mixed and slurried for reaction. The slurrying is carried out by mechanical stirring in a vertical reactor at a rotation speed of 30-50 r / min.

4. A method for preparing high-loft elastic polyester top according to claim 3, characterized in that: Terephthalic acid, ethylene glycol, the third monomer 1,3-propylene glycol, and the fourth monomer 1,4-cyclohexanedimethanol are mixed and slurried before reacting. The reaction catalyst is a mixed catalyst of ethylene glycol titanium and ethylene glycol antimony. The total addition amount is 30-300ppm of the mass fraction of terephthalic acid, and the mass ratio between ethylene glycol titanium and ethylene glycol antimony is 1:99-10:

90.

5. The method for preparing high-loft elastic polyester top according to claim 1, characterized in that: The co-esterification reaction temperature is 225-240°C, the co-esterification reaction pressure is controlled at 0-300KPa, and the reaction time is 2.5-4.5h; the pre-polycondensation reaction temperature is 245-260°C, the reaction pressure is controlled at 100KPa, and the reaction time is 0.5-1.5h; the final polycondensation reaction temperature is 265-280°C, the reaction pressure is controlled at 0-100Pa, and the reaction time is 1.5-3.0h.

6. A method for preparing high-loft elastic polyester top as claimed in claim 1, characterized in that: The modified PET polyester prepared by co-esterification, pre-polycondensation and final polycondensation of terephthalic acid, ethylene glycol, the third monomer 1,3-propylene glycol and the fourth monomer 1,4-cyclohexanedimethanol has an intrinsic viscosity of 0.66-0.75 dL / g, a melting point of 240-252°C, a melt index of 20-45 g / 10min, and a slice b value of ≤5.

7. A method for preparing high-loft elastic polyester top as described in claim 1, wherein the spinning cooling temperature in the spinning stage is controlled at 16-20°C, the melt solidifies rapidly, the spinning speed is 2400-3200m / min, and then the yarn is stretched and shaped to obtain a specification of 1.5D-5D / 75-102F in fineness.

8. A high-loft elastic polyester top, prepared according to the preparation method according to any one of claims 1 to 7, having high loft and excellent tensile and anti-compression resilience, the hollowness of the polyester top is 25-45%, the compression rebound rate is ≥80%, and the tensile rebound rate is ≥85%.

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