JPS5823914A - High-tenacity polyester yarn having improved thermal dimensional stability and chemical - Google Patents

Abstract

PURPOSE:The titled high-tenacity yarns, capable of giving drawn yarns having specific characteristics prepared by melt spinning, cooling and drawing the solidified yarns, and exhibiting specific characteristics after a specific heat treatment, having a low shrinkage and work loss, and well handled. CONSTITUTION:Polyester yarns, capable of giving drawn yarns having an intrinsic viscosity >=0.7, a diethylene glycol content <=1.5mol%, based on terephthalic acid residues, and a carboxylic group content >=20 equivalents/10<6>g, an average birefringence of 0.165-0.190, a fineness per fiber <=5.0 deniers, a dry heat shrinkage (175 deg.C for 30min) of 7.0-10.0%, and a work loss (sample length of 10 inches, strain speed of 0.5 inches/min at 150 deg.C and a stress between 0.6g/denier and 0.05g/denier) of 0.0240-0.035 inch.pound/1,000 deniers. The tenacity retention in the dry heat treatment at 240 deg.C for 1min at a constant length is >=95%, and the dry heat shrinkage is <=3.0% with the work loss <=0.0200 inch.pound.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a polyester high tenacity yarn with excellent thermal dimensional stability and chemical stability.

Polyester high-strength yarn, represented by polyester tire cord, has a length of 11 m with excellent balance in terms of physical properties! In recent years, it has come to be widely used in large quantities as industrial edge wire.

In recent years, the price of raw materials for organic fibers in particular has risen significantly, and raw material costs for polyester, especially polyethylene terephthalate, have been increasing at a lower rate than for other organic fibers such as nylon, and the price will continue to rise in the future. It is predicted that the preester high tenacity yarn will maintain its superiority in the industry, and it is thought that the usage of preester high tenacity yarn will further increase.

However, depending on the application, thermal dimensional stability and chemical stability
Furthermore, it is a fact that VC is required to have improved adhesion to reinforced materials such as T5. ! However, improvements in the thermal dimensional stability have been proposed, such as polyester fibers with a relatively low intrinsic viscosity (for example, Japanese Patent Application Laid-Open No. 3-3-3, 11152) and highly oriented non-polyester fibers. Drawn yarn c 11 POY) l Polyester fiber by drawing method (e.g. U F4 P 4. tea, o
ss) $11kll [Retei.

Regarding improvement of chemical stability, method C of reducing the amount of carboxyl groups in polyester, for example, JP-A-56-1
16816) and other proposals have been made.

Regarding the improvement of adhesion with FCF film, a method of treating with an epoxy-based or incyanate-based Asahi ring agent during the spinning and drawing process (for example, Japanese Patent Publication No. 47-497111) has been proposed. The proposal is considered to have achieved some results in terms of requests for individual improvements.However, the recent rise in oil prices has spurred the world to try out energy-saving technologies, and the loss rate in manufacturing workers has decreased. Improvement of any7omity of materials for the purpose of
Considering the goal of improving polyester high-strength yarns, it is predicted that in addition to the above-mentioned improvement in thermochemical stability, it will be necessary to improve the quality (a=photonity).

Considering the above-mentioned prior art in this context, the first method to reduce the intrinsic viscosity and improve dimensional stability is to improve the yarn strength and fatigue resistance in the state in which the fiber #I is used. Not only is it low, but for example, when high temperature treatment is applied in the adhesive treatment process to improve adhesion to the wire, some cords may melt and break if exposed to haze, which has a low intrinsic viscosity. This tends to cause problems with uniformity.

F OY 't [It Le U RP 4.195.052
(Although the fibers obtained by method D have succeeded in improving the thermal dimensional stability with almost no decrease in yarn strength or fatigue resistance compared to the case where the intrinsic viscosity is lowered,
The shrinkage rate of the raw yarn (yarn before heat treatment) during heat treatment is low (due to the low shrinkage of the generated tesin, troubles may occur depending on the diffusi! yarn, and the t'L
7. In fibers, there is inevitably a large difference in the degree of molecular chain orientation between the inner and outer layers of a single yarn, so the molecular 4-polarization in the inner layer of a single yarn is large, and when the mechanical loss tangent (tlnδ) is measured, The α absorption peak temperature obtained by the conventional method is approximately 10υ lower than that of the same type of high-strength yarn, and the diffusion of water, acetic acid, alkali, etc. into the single fiber is quick, and Obtained by law! t.Polyester tire cord with improved chemical stability is inferior in chemical stability compared to the same type of high-strength yarn VC.
Since the chemical stability has not been thoroughly improved at the laboratory level, problems with adhesiveness occur.The same is true of polyester tire cords with improved adhesion.The present inventor has focused on this point. As a result of intensive research, we have come to invent the f9 ester high strength yarn described below which has excellent thermal dimensional stability and chemical stability as a solution to the above problems.

That is, the polyester high strength yarn of the present invention is a polyester ff1l containing polyethylene prephthalate as a main component.
NFC drawn yarn obtained by melt spinning, then cooling and solidifying, and rough drawing, and has the following properties: (1) *@viscosity 0.7 or more (1) Diethylene glycol to terephthalic acid residue Content: 1.5 mol or less (machi carboxyl group amount: 20 equivalents/10@f or less Q/,
Average birefringence 0.165 to 0.190 (V)
Single yarn denier h5.0 denier or less (dry heat shrinkage rate of 7.0 inches to 1 when free heat treated at -175℃ for 30 minutes)
0J1 Clamp 6/I Test length 10 inch, strain rate 0.5 inch/min, temperature 150°C Q, 67/d and 0.
Hysteresis Luzo was measured at a stress between 0.05 Ji'/d and the large work loss was 0.02 per 1000 denier.
40-0.035 inches 11 Bon F Roughly Cough Stretched Yarn K This is a polyester high-strength yarn that exhibits the following gluteal tube properties when subjected to dry heat treatment at 240° C. for 1 minute.

(1) Strong retention rate due to the above dry heat treatment: S- or higher (
b) Free heat shrinkage at 175℃ for 30 minutes, dry heat shrinkage of S, O- or less (0) Sample length: 10 inches, strain rate: S inches, 7 minutes.
Temperature J [o, s P/d and 0. (15
The hysteresis loop tm is determined by the stress between /-/d, and the work loss obtained is 90.0200 for 1000 denier.
Carboxyl group content of high tenacity yarn less than inch Φ V is 11/10
When using the high-strength yarn as a rubber reinforcing agent, the wrinkled high-strength yarn must be surface-treated with an epoxidized metal material and/or an incyanate compound during the spinning and drawing process. More preferred.

The following 4-reproduced stell high-strength yarn and its manufacturing method K")
A will be explained including the theoretical background. As a result of recent research by the present inventors, the following findings have been obtained. If we define an amorphous state as an ordered state in which crystal diffraction cannot be measured in detail, then we can define a state in which the orientation of the molecular chains has advanced to a certain extent (for example, expressed quantitatively by the birefringence value) even though it is amorphous. In this case, the fiber obtained by drawing an undrawn yarn of 10XIO'' or more in the case of polyethylene terephthalate is a non-oriented amorphous undrawn yarn (5
1 G-” or less))
Thermal shrinkage rate becomes smaller. That is, in the case where an amorphous undrawn yarn is drawn to advance the molecular orientation (1 degree) without causing C-oriented crystallization to some extent.

It is presumed that the essential stretching strain of the drawn yarn is smaller than that in the case where non-oriented amorphous undrawn yarn is drawn.

On the other hand, the molecular orientation of the spun yarn in melt spinning is determined by the tension applied to the yarn at the solidification point, according to Rentsur et al.
8)) Based on this theoretical background, the present inventor has conducted extensive studies on electroconductive stretching. 11 fruits.

(f) Single-hole discharge rate [lower, increase the spinning speed, move the point where the quench wind blows closer to the nozzle after being discharged from the spinneret, etc. to the spinning yarn device under relatively high tension. You can turn it into something! ! (To) The temperature difference between the inner and outer layers of one filament is large under the melting conditions where the yarn is placed on top under high tension.I47
The difference in elongation viscosity becomes larger ep, resulting in a tension difference between the inner and outer layers of the filament at the solidification point, resulting in a large birefringence difference between the inner and outer layers of the filament.Thus, during drawing, the surface layer, which is highly oriented, Since the maximum drawing ratio is determined, it is difficult to obtain high strength, and until now, amorphous yarns with a certain degree of orientation have not been used as undrawn yarns for high strength yarns.

However, by reducing the single-hole discharge rate, the birefringence difference (δΔn) between the surface layer and the center of the undrawn yarn can be reduced to the average birefringence (λT
It was discovered that in 1), the dividing scale value becomes smaller, making it easier to obtain high strength.

Next, the Nobori ester high tenacity yarn of the present invention and its spinning drawing◆
I will explain the matter in detail.

Since the polyester in the present invention is mainly intended to be supplied as a high-strength fiber for industrial use, at least 95 moles or more of the constituent units are polyethylene terephthalate units, and the IJ ester has a delicate intrinsic viscosity (
1lIII of phenol/tetrachloroethane-674
II & middle 30'O 115jl, same below) Vlo, 7
It needs to be 0 or more.

The high-strength yarn according to the present invention may be subjected to heat treatment close to its melting point due to its purpose of use, but since the melting point of polyester decreases as the diethylene glycol content increases, the diethylene glycol content of the high-strength yarn is superimposed, and the terephthalate Must be 1.1 s mol or less per acid residue
In addition, as mentioned above, the high tenacity yarn according to the present invention has a fiber strength A of 2.0 equivalents, which improves chemical stability by lowering the carbon content. /10'f or less, and (Kl 2 equivalents/LO@P
It is desirable that the following is true, so for example, when supplying a solid phase resin tube for spinning to F-A+L-1-, etc., the intrinsic viscosity of the filament should be 0.7 S or more, and the carboxyl group content should be 14
It is well known that the equivalent weight is less than 710@f, especially less than 6%/LO@f, and when using a polymer with a large amount of carboxylic groups, triphenyl is added to the extruder. A polymer with a triarylphosphine such as phosphine or a triarylphosphine as a catalyst is used as a catalyst.
01 vs- or more Q, j% vt- or less is added, and the carboxyl group terminals are blocked by adding an epoxy nide such as phenyl glycidyl ether, 2vt- or more g, Q vl- or less of the polymer. There is a need.

The polymer tube is extruded from a spinneret in a molten state.

Immediately after the thread passes through the heat-insulating cylinder without using the so-called heating ta'! O~110Ga/-e
The yarn is solidified at tP9I by the cooling air having a wind speed of C and a temperature of 10℃. Yarn tension at the assimilation point is important because yarn tension dictates the birefringence of the spun yarn. Yarn tension after solidification/l'
Although it increases monotonically due to the tension caused by the air, it is unrelated to the orientation of the molecular chains of the yarn. Therefore, in the case of birefringence or superposition of the spun yarn as in the present invention, the tension at the assimilation point increases. Controlling this is the key to skill. The factors that determine the solidification point tension are the single hole discharge rate, the distance from the nozzle to the point where the cooling air hits the yarn, and the spinning speed. It is sufficient if the spinning conditions are given as jL, but in the present invention, 1.6XIO'dyn
e/sF to y, s X 1 of dyne/-
It is desirable to have between 2.b, most preferably 2. OX 10' dyn@/rs” to 6.
It is desirable to have a 5 x 10' dyne/lo gap. By doing so, as will be described later, a low heat shrinkage rate that is advantageous for heat setting during the adhesive treatment process when used as a tire cord is achieved. Highly oriented undrawn yarn C giving a fiber tube with
Figure 1 shows the relationship between the tension at the solidification point and the value of undrawn yarn*m-fold.

When the thus-obtained Daisuke yarn is directly wound or once rolled and then stretched, the spun yarn is already oriented in the state where it is subjected to so-called neck stretching using heating. Therefore, heating the yarn at the temperature given by the prior art causes crystallization, so the intrinsic viscosity I of the undrawn yarn
IV, when the average birefringence is expressed in Anpoy, the roller surface temperature is (90+ (ff -0,11) x 4
．． It is important to keep the 5-bynpcyrX concentration below 3°C. There is no substantial difference from the conventional technology in terms of contact drawing by such methods.
P! 1. ! IL111? )K.

In this case, the temperature of the heated steam F
It is desirable that the temperature is higher than or equal to imioυ and lower than or equal to 610°C.As mentioned above, the high tenacity ester yarn of the present invention already has a difference in orientation between the outside and outside of the fixture in the KFOY state. The fibers after stretching also have a difference in the degree of orientation of molecular chains.

Therefore, the average birefringence of the drawn 11OIll anchor is a lower birefringence than that of the same type of fiber according to the prior art. If the average birefringence becomes I than 0.110, the number of yarn breakages during stretching will increase, which is undesirable from a productivity standpoint.
If the value is less than 0,1@I, high strength cannot be obtained, so the average birefringence of the fiber after drawing should be less than 0,1
Does it have to be less than @o?

The single yarn denier of the high tenacity yarn of the present invention is one of the important constituent features of the present invention. In other words, when the single yarn denier becomes large, the difference in the degree of orientation of the molecular chains in the filament between the surface area and the center area increases, making it difficult to obtain high strength. As already disclosed by the inventor in 08P 4164114K,
For the llI properties, especially the mechanical properties, of the high-strength yarn used as the TM reinforcing fiber, the value in the state after being subjected to heat gm after dilution is important. This is because even if there is a relatively large difference in the values before defrosting due to differences in manufacturing processes, the difference in values after defrosting is very small.

The same applies to the present invention, and the characteristics such as low shrinkage and low work loss are required in the state in which the fiber is used, and it is not necessary for K1-1 to have low shrinkage and low work loss before dipping. No-〇 If the shrinkage is too low, it may cause trouble depending on the dip machine.

However, as in the present invention, the drawn yarn of heat II & pre-treatment is 17!
The dry heat shrinkage rate when heated at 1℃ for 30 minutes was 7-
The sample length is 10 inches and the strain rate is 0.
1 inch/minute, temperature! ■Hysteresis luzo was measured at stress between o, s P/d and L (HP/d) under the condition of ℃, and the work loss obtained was 0.0 per 10009''neel!
40-0.031 inch -nd (measurement method follows URP4xssos*) and scissor-drawn yarn is 24
When dry-heating at 0°C for 1 minute at a constant length (assuming the process of C and Z), the yarn strength after dry-heat treatment is 9, which is the strength before heat treatment.
If it is 8- or more, and the dry heat shrinkage rate is 3.091G or less when free heat treated with 171110 for 30 minutes, it is p, trial length!
・0.6 t/d and 0.05 inch, strain rate 0.5 inch/min, temperature 110°C Hysteresis through with stress between /d! The work loss obtained by measuring -1'
If the bond is less than 0.0200 inch bond per 1000 denier, the polyester high tenacity yarn will have low shrinkage and low work loss, but will not have the above-mentioned defects and will have good handling. The high strength yarn of the present invention is particularly useful as a reinforcing material for tires, belts, conveyor belts, etc.

Next, the present invention will be explained based on Examples.

Example 1 Intrinsic viscosity 1.11 Diethylene glycol content 1. Omoh
The drawn yarn obtained by latent-melt spinning and drawing polyethylene phthalate having a carboxyl group content of 10 and an equivalent weight of 71 o@t under the conditions shown in Table IK is as shown in Table IK.
It is recognized that the thermal stability is significantly superior to Comparative Example 1 using the conventional technology. Example I Using the same polyethylene terephthalate polymer as in Example 1, n L was added to polyethylene terephthalate during melting.
) 13 yenylphosphine t O,I Wt −>
and phenyl glycidyl ether in 1. □ Carboxyl group content 28a amount/10. Comparative row of fibers C and carboxyl group weight 8 equivalents/10.?
Comparing the chemical stability with Fiber C Comparative Example 3), the results are as shown in Table 2. Chemical stability was evaluated by hydrolysis resistance and ammonia decomposition resistance. The strong retention rate after aging and the dissociation rate of ester bonds were calculated as a proportion to the total ester bonds using the following formula. □1 is the intrinsic viscosity of the fiber before deterioration 〇This formula is calculated in the solvent of Zeno/tetrachloroethane=@/4! The column is determined by the error degree [da) P
/f' (J-number average molecular weight 4 relational expression % formula % Ammonia decomposition resistance is strong retention after 2 hours of deterioration in an ammonia gas atmosphere of 188"O (ammonia gas flow rate 206a/min) The dissociation rate and the dissociation rate of ester bonds were determined as a proportion to the total ester bonds using the above formula.The spinning and drawing conditions were the same as in Example 1. It can be seen that the polyester fiber of Comparative Example 2, which was drawn from FOYVt from FOYVt, has inferior chemical stability compared to Comparative Example 3). It is estimated that this is due to the fact that the absorption peak temperature of the amorphous chain is about 10υ in the case of the polyester fiber based on P (J Y t@) compared to the conventional fiber. Even in the case of Yt-mediated polyester fibers, the shortcomings were eliminated by reducing the amount of carboxyl groups.Accordingly, the low shrinkage polyester fibers made from the 1jIIK of the present invention have improved dimensional stability as well as thermochemical stability. It is understood that the reduction in the content of carboxyl groups is a superimposition for the purpose of this.

Example island intrinsic viscosity IJ, zF ethylene glycol content 0.・When melt-spinning polyethylene terephthalate tfIII with mole-1 force A & filler group content 11/10”P, tridecylphostin to,
osl amount 1, olefin phenylphenol dicyl ether k t-0.5 weight-pumping added, polio-temperature 30
1℃, single hole discharge rate 1.48? /min, extrude the melt at a nozzle number of 500, and set the nozzle distance sa &
The yarn was cooled with cooling air at a speed of 0.6 m/sea and a temperature of 101), and the yarn was coated with 20% epoxidized glycerin.
wt - After applying the added spinning oil, ztgom/
The birefringence of the spun yarn at this time was o, o s s. Cough spun thread immediately 44! 2.3 using heated steam of I'O
It was stretched to double its original size and rolled up at a speed of 4,014 m.

As Comparative Example 4, the intrinsic viscosity was 1. (1) Polyethylene terephthalate with a zoethylene glycol content of 9G and a polyacyl group content of 12 weight/10@P was melt-spun fIII under the same conditions as in this example. The various tatami properties are shown in Table 3. The meat fibers thus obtained were twisted in a number of twists of 40 x 4G (T
/ lo (to)) twin thread cord and pear, made of linseed and formalin roots tex - so-called one-bath dizzo treatment (processing temperature 240°C) t - dizzo coat F4
We compared the K11 landing strength of the 1st grade. The results are shown in Table 4.

Table 4 It can be seen that the cord of Example 3, which was silicated with EVO side during fiber preparation, had good adhesive strength, and that Comparative Example 4, which had a high diethylene glycol content, had inferior strength after diluting. It is understood that in order to improve the thermochemical stability as well as the dimensional stability of the low shrinkage polyester fiber according to the invention, it is important to reduce the diethylene glycol content.

[Brief explanation of the drawing]

The gi diagram is a graph showing the relationship between the solidification point tension and the undrawn yarn birefringence Δn, and FIG. 2 is a graph showing the mechanical loss tangent (tan δ)-temperature (T) curve liI.

Claims (1)

[Claims] 1. &4 whose main component is diethylene tere-2-thalerate
Liester tS melt-spun, then cooled and solidified, and further stretched to obtain a dangerously drawn yarn, as shown below (1
) to (b), and furthermore, the drawn yarn K24@”
When dry heat treatment was performed at a constant temperature of 0 for 1 minute, the following C13~
(0) High strength polyester yarn with excellent thermal dimensional stability and chemical stability. (b) mi @ viscosity 0.7 or more (1) Diethylene glycol content relative to terephthalic acid residue 1.5 mol or less (carboxyl I&number 2o equivalent amount/10.? or less ←
) Hirayan birefringence 0.1115 o, is. (■ Single yarn denier, o denier or less (v9 17s
IE heat 15Ui rate when doing free heat geography for 30 minutes at υ7. o S vs L 10.0% (b) Sample length 10 inches, strain rate 0. Under the conditions of I inch/min and temperature of 150°C, the work loss caused by hysteresis at stress between OJ P/d and osy/a is too denier 0.0240 to o, o s. S inch bond (tortoise) Strong retention rate 9sts due to the above fixed length dry heat treatment
Above (b) After free heat treatment at 17 I 13 for 30 minutes, the dry heat shrinkage rate was 3.0- or less (0), sample length 10 inches, strain rate 0.3 inches/min,
0.6 p/d and 0.0 fJF at a temperature of 156°C
With a stress between /d and a constant hysteresis of the Luso tube, the resulting work loss is 0.0. (The polyester high-strength yarn according to claim 1, in which the carboxyl group erosion amount is 1!00 inch bond or less2, and the amount of carboxyl group is less than or equal to 1!00 inch bond).3. and/or a polyester high-strength yarn as described in claim 72 for reinforcement of TM, which has been surface-treated with an incyanate compound.