KR101561788B1 - Process of coating pbo fibers for reinforcing uv-stability - Google Patents

Abstract

The present invention relates to a method for coating by melting the master batch mixed with a thermoplastic polyester elastomer (TPE), a UV absorbing agent, and a UV stabilizer on a surface of a PBO fiber. According to the present invention, provided is a PBO fiber applicable to an extreme environment exposed to ultraviolet rays or visible rays, or required for thermal resistance or the like, by improving UV stability of a PBO fiber, reducing breakage of a chemical bond inside the fiber, and solving a problem such as strength reduction or the like.

Description

TECHNICAL FIELD [0001] The present invention relates to a coating method for enhancing UV stability of PBO fibers,

The present invention relates to the melting and coating of a master batch of a mixture of thermoplastic polyester elastomer (TPE), UV absorber and UV stabilizer on the surface of PBO fibers.

Due to the rapid expansion of the scale and scope of the industry, it is required to develop a critical performance fiber material that exhibits its performance and functions even in extreme environments such as space environment or polar environment. These high-strength and high-performance fiber materials are generally used as reinforcing materials for composites. The performance of the composites is reduced to 30 ~ 50% of the performance of the fiber material itself. If the use environment is extreme conditions such as space environment and polar environment As the performance deteriorates further, the performance of the reinforcing fiber material itself must be maximized.

On the other hand, Heterocyclic Aromatic Polymer (HAP) can be used for the production of carbon fibers which require complicated post-processes such as stabilization / It is not only economically and environmentally advantageous compared to aramid fibers but also has high mechanical properties (tensile strength 42 g / d) and LOI value (68%) exceeding aramid, and is attracting attention as a high performance fiber material for extreme environments.

Polybezoxazole (PBO) fiber, which is a typical HAP super fiber, has excellent properties in strength, modulus, heat resistance and flame retardancy, superior to conventional high performance super fibers. Especially, strength / elastic modulus and heat resistance / Which is a very innovative material that possesses two extreme performances.

Toyobo Co., Ltd.'s Zylon has the world's best properties in strength, elastic modulus, heat resistance, and chemical resistance, but has performance limitations such as low compressive strength, deterioration by residual solvent, and low UV stability. Although the PBO fiber is required to be used in an extreme environment due to its characteristics, many studies have been conducted on the decrease in the strength by UV, but the cause of the PBO fiber has not been clarified at a fundamental level. But it is still at a level that prevents the decrease in strength through the method.

Korean Patent Publication No. 10-2006-0052680 (published on May 19, 2006)

Therefore, it is a technical object of the present invention to provide a coating method for improving the UV stability of PBO fibers through a sand coating process so that the physical properties of PBO are not lowered by a UV light source.

Therefore, according to the present invention, it is possible to improve the UV stability of PBO fibers, characterized in that the coating masterbatch made by mixing the thermoplastic polyester elastomer (TPE), the UV absorbent and the UV stabilizer is melted and coated on the surface of the PBO fiber and dried. A coating method is provided.

Hereinafter, the present invention will be described in more detail.

The coating method for enhancing the UV stability of the PBO fiber of the present invention is to melt and coat the master batch in which the surface of the PBO fiber is mixed with the thermoplastic polyester elastomer (TPE), the UV absorbent and the UV stabilizer.

The PBO fiber has a problem in that the chemical bond inside the fiber is broken due to exposure to ultraviolet rays or visible light, resulting in a decrease in strength. The coating stability of the PBO fiber can be improved by the coating method of the present invention.

A masterbatch for coating made by mixing a thermoplastic polyester elastomer (TPE), a UV absorber and a UV stabilizer is used to coat the surface of the PBO fiber of the present invention,

The thermoplastic polyester elastomer (TPE) is used to coat the PBO fiber itself with a high-strength resin to protect the high-strength properties in an extreme environment. The thermoplastic polyester elastomer (TPE) is excellent in strength and moldability, has an excellent elastomer performance, has excellent flexural fatigue characteristics, high temperature heat resistance and low temperature impact resistance, and also has superior heat resistance, abrasion resistance, chemical resistance, Excellent compatibility with fibers.

The thermoplastic polyester elastomer (TPE) is a thermoplastic polyester-based copolymer elastomer based on polyester. The polybutylene terephthalate ester (PBT) which is crystalline in a hard segment (hard block) and has a molecular structure in a soft segment It is made of amorphous polyester or polyether. It is characterized by high elasticity equivalent to rubber and high softening point, and high continuous use temperature.

(Styrene), TPE-U (polyurethane), and TPE-V (vulcanized) as the blend of the thermoplastic polyester elastomer (TPE) -E (polyester ester), TPE-A (polyamide), and the like.

It is preferable that the UV absorber is Chigaurd 234 (Tinuvin 234) of the formula 1 or Chigaurd 1064 (Cysorb UV-1164) of the formula 2 and the UV stabilizer is Chigaurd 944 (Chimassorb 944) , The thermoplastic polyester elastomer (TPE) used in the present invention is converted into heat energy by converting the free radicals generated by absorbing UV in the UV absorbent through the mixing of the UV absorbent and the UV stabilizer, and further, the freedom The radicals are cleaved and hydroperoxide decomposed, so that the UV stability can be improved more effectively.

[Chemical Formula 1]

(2)

(3)

Since the working temperature of the thermoplastic polyester elastomer (TPE) is 220 to 250 ° C, it is considered that mixing with Chigaurd 2364 (melting point 137 to 141 ° C) which is relatively higher than Chigaurd 1064 (melting point 89 to 91 ° C) is easy. In the case of Chigaurd 234, when the melting point of Chigaurd 234 reaches 137-141 ° C, the solid in the powder state changes to liquid, and since it has a boiling point of 300 ° C or higher, it can be mixed as a liquid in the TPE without gasification. Note that Chigaurd 1064 has a relatively low melting point of 89 to 91 ° C and may be destroyed (carbonized) during high-temperature M / B operations.

The coating masterbatch of the present invention is prepared by mixing 1 to 2 wt% of a UV absorber, 0.5 to 1 wt% of a UV stabilizer and a thermoplastic polyester elastomer (TPE) as a remainder. When the UV absorber is less than 1 wt% The UV stability is lowered and the strength of the yarn is lowered. When the UV absorbing agent concentration is more than 2% by weight, the same performance is exhibited and the UV stability is not changed. However, And even when the amount of the UV stabilizer is less than 0.5% by weight, there is a problem that the UV stability is lowered and the strength of the yarn is lowered, and even when the amount exceeds 1% by weight, there is no great change in the UV stability.

The coating of the surface of the PBO fiber is carried out using a general sand coater, the working speed being such that the PBO fiber prevents the occurrence of surface fuzz and the fiber is located at the center of the coated resin at a somewhat lower speed of 50 to 70 m / min Should proceed.

Therefore, according to the present invention, it is possible to improve the UV stability of PBO fibers, thereby reducing the chemical bond breakage inside the fibers, thereby solving the problem of reduction in strength, and being applicable to extreme environments where exposure to ultraviolet rays or visible light, A rubber compound such as a tire, a belt, a hose or the like, a reinforcement fiber of various resins (FRP), a protective garment such as a bulletproof vest or a helmet, a protective garment such as a heat resistant garment, an earphone utilizing the strength, elasticity, heat resistance and flame retardancy A cord reinforcing material such as a cord, an optical fiber cable tension member, a heat-resistant felt, a filter, and the like.

Fig. 1 is a SEM photograph of a coating cut surface of Example 1 of the present invention,
FIG. 2 is a SEM photograph of a coating cut surface of Example 2 of the present invention,
Fig. 3 is a graph showing the rate of decrease in strength of TPE base coated yarn according to UV irradiation time.

The following examples illustrate non-limiting examples of coating methods for improving the UV stability of the PBO fibers of the present invention.

[Examples 1 and 2]

1. Master batch manufacturing for coating

(Chigaurd 234, Chiguard 1064) and a UV stabilizer (Chigaurd 944) having physical properties shown in Table 1 were mixed in a blending ratio shown in Table 2, melted, dried To prepare a master batch for coating.

division Type Drug name shape color apply Molecular formula Molecular Weight Melting point
(° C) Boiling point
(° C) use
density U
V
Suction
Number
My Benzo-
triazoles type Chiguard
234
(Tinuvin
234) Powder Off-
White PET, PC, POM, Nylon, TPE compounding C ₃ O ₂₉ N ₃ O 447.6 137-141 > 300 0.1 to 0.5% Triazine type Chiguard
1064
(Cysorb
UV-1164) Powder Light
yellow PP / PE / TPE C ₃₃ H ₃₉ N ₃ O 2 509.7 89 to 91 C - 0.1 to 0.5% U
V
within
tablet
My - Chiguard
944
(Chimassorb
944) Powder
/
granule Light
yellow Olefin
(PP, PE) - 2,000 3,300 softening range
100 to 135 - 0.2% - 0.5%

division Coating resin additive Quantity Example 1 TPE (98.5%) Chiguard 234 (1%) 40kg Chiguard 944 (0.5%) Example 2 TPE (98.5%) Chiguard 1064 (1%) 40kg Chiguard 944 (0.5%)

2. Textile Coating

The used yarn was PBO 250d (Japan, Zylon), and the used resin was sampled and co-coated by using the M / B resin using a sand coating machine. The working temperature was 220 ~ 250 ℃ for TPE and the working speed was 50m / min.

3. Results of physical property test

end. UV stability analysis

The UV stability test equipment was used for the test, and the light source was M400 with a UV output of 400W at a wavelength of 300-500nm for short-time comparison test. The irradiation distance was fixed at 13cm to allow irradiation of light throughout the coating . The UV stability of the coatings was analyzed by the strength analysis of the coatings over time. The finished coatings were analyzed by the tensile strength test KS K 0412 filament yarn test method.

Table 3 shows the intensity values of the coating films before and after irradiation of the light source. As a result, it was found that the strength reduction ratio of TPE + 234 + 944 of Example 1 was significantly improved from 8.87% to 0.87% as compared with that of general TPE. On the other hand, in the case of TPE + 1064 + 944 of Example 2, there is no significant difference in strength reduction ratio compared with general TPE, and it is seen that the strength decrease is more serious after 5 hours. It can be seen that Chiguard 234 (137 ~ 141 ℃), which is higher than Chiguard 1064 (89 ~ 91 ℃) with low melting point for TPE resin and suitable for original TPE compounding, is more suitable for improving UV stability.

Sample No. Example 1 Example 2 Coating TPE + 234 + 944 TPE + 1064 + 944 Before the survey 36.79 38.32 1 hours 36.47 35.59 Strength reduction rate (%) 0.87 7.12 3 hours 32.99 30.44 Strength reduction rate (%) 10.33 20.56 5 hours 30.98 27.68 Strength reduction rate (%) 15.79 27.77

(Unit: g / d)

FIG. 3 is a graph showing the degradation rate of the TPE base coated yarn according to the UV irradiation time. It can be seen that the UV stability was exhibited when the intensity of the TPE + 234 + 944 coated yarn was minimized by UV irradiation.

I. Cross-section analysis of PBO coating

As a result of SEM analysis to analyze the cross section of the coated yarn, the cross sections as shown in Figs. 1 and 2 were confirmed.

Claims (3)

A coating method for improving the UV stability of PBO fibers, characterized in that a coating masterbatch prepared by mixing a thermoplastic polyester elastomer (TPE), a UV absorber and a UV stabilizer is melted and coated on the surface of PBO fiber and dried. The PBO fiber of claim 1, wherein the UV absorber is Chitaurd 234 (Tinuvin 234) or Chigaurd 1064 (Cysorb UV-1164), which is a benzotriazole system, and Chigaurd 944 (Chimassorb 944) Coating method for improving the UV stability of the coating film. 2. The PBO fiber according to claim 1, wherein the coating masterbatch comprises a mixture of 1 to 2% by weight of a UV absorber, 0.5 to 1% by weight of a UV stabilizer, and a thermoplastic polyester elastomer (TPE) ≪ / RTI >

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