JPS602781A - Adhesive treatment of rubber reinforcing polyester fiber - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for adhesion treatment of polyester fibers for rubber reinforcement, which has improved adhesion to rubber.

Polyester fibers generally have excellent properties such as tensile strength and dimensional stability, and are suitable as rubber reinforcing materials for automobile tires, conveyor belts, belts, hoses, etc. However, since polyester fiber has poor adhesion to rubber,
Many proposals have been made to date to improve adhesiveness.

For example, a method in which polyester fibers are treated with a first treatment bath containing a polyepoxide compound and an aromatic polyisocyanate compound, and then treated with a second treatment bath containing resorcinol, formaldehyde, and rubber latex (Japanese Patent Publication No. 42-11
No. 482) is known. However, although the fibrous material treated with this method exhibits adhesive properties with relatively hard rubber, it has the disadvantage that the fibrous material becomes hard and difficult to bend during molding, and its fatigue resistance is significantly reduced. be.

Therefore, the present inventors aimed to eliminate the drawbacks of the above-mentioned conventional methods, to obtain polyester fibers that maintain good bending hardness and fatigue resistance inherent to polyester fibers, and have desirably improved adhesion to rubber. As a result of extensive research, we found that after polyester fibers were treated with a first treatment bath containing a polyepoxide compound and carbon black in a specific proportion, a second bath containing a resorcinol autoformaldehyde snow rubber latex mixture and a blocked polyino/anate compound in a specific proportion was used. The present invention was achieved by discovering that the above object can be effectively achieved by treating with two treatment baths.

That is, the present invention combines polyester fibers with (W) a polyepoxide compound and (Xl carbon black, (W)
+ Treated with a first treatment solution consisting of an aqueous solution containing 0.3 to 20 parts by weight (X) per part by weight of OO and having a concentration of the iW+ in the range of 0.5 to 15% by weight, and then (Y) Resol 7 formaldehyde rubber latex mixture 3 and (Z + blocked polyisocyanate compound, (Y) per 100 parts by weight (solid content) (z)
The present invention provides a method for producing polyester fibers having excellent adhesion to rubber, which is characterized in that the second treatment bath comprises an aqueous solution containing 5 to 30 parts by weight of the polyester fiber.

The polyester fiber used in the present invention means a yarn, cord, or woven fabric made of aromatic or naphthalene ring-containing linear polyester such as polyethylene terephthalate and polyethylene naphthalate. It goes without saying that the form of the polyester fiber varies depending on its intended use, but the treatment of the present invention can be applied to any form. For example, after being treated in the first treatment bath in the form of a yarn, it may be formed into a cord or woven fabric and then treated in the second treatment bath, or the yarn may be treated in the form of a cord in the first treatment bath.
It may be treated in a treatment bath and then in a second treatment bath.

The fwl polyepoxide compound used in the first treatment bath of the present invention is a compound having two or more epoxy groups in one molecule, and includes polyhydric alcohols such as ethylene glycol, glycerol, sorbitol, pentaerythritol, and polyethylene glycol, and epichlorohydrin. Examples include reaction products of halogen-containing epoxides such as ``resolnon formaldehyde resin'' and reaction products of polyhydric phenols such as ``resolnon formaldehyde resin'' and the above-mentioned halogen-containing epoxides. Preferably, a reaction product obtained by reacting a polyhydric alcohol, such as glycerol, with epichlorohydrin is used.

The (X) carbon black used in the first treatment bath of the present invention is preferably blended as an aqueous dispersion using an arbitrary dispersant. Average particle size for carbon black is 1
Carbon blank used in the rubber industry from 1m□ to soom7□, e.g. 3.71 F, 15AF%
HA T, GPF, FT, M T, E P C, M
P C, F F, S RF, etc. are used.

The first treatment bath in the present invention is an aqueous liquid containing the fW+ polyepoxide compound and fX1 carbon blank as main components, and further contains a dispersant for the carbon blank and a caustic hoop. The proportion of carbon black is (W) 1oO per part by weight (x)o, 3 to 20 parts by weight, especially 08 to 10
Parts by weight, and the concentration of the above (W) is 0.5 to 15% by weight
, especially in the range of 2 to 10% by weight. Here, the blending ratio of the above [X) carbon black is I
If the amount is less than 3 parts by weight, the adhesion of the treated polyester fibers to the rubber will not be sufficiently improved, and if it exceeds 20 parts by weight, the adhesion to the rubber will deteriorate, which is not preferable. In addition, if the degree of (V/) polyepoxide compound in the first treatment bath is less than 0.5% by weight, the adhesion rate of the treatment agent to the polyester fibers will be too low, and adhesion to rubber will not be sufficiently developed. If the amount exceeds 15% by weight, the adhesion rate of the treatment agent to the fibers increases, making the treated fibers hard and resulting in a decrease in fatigue resistance, which is not preferable.

- What is fY) resolnon formaldehyde rubber latex mixture used in the second treatment bath of the strength tree invention?
An initial condensate obtained by reacting resorcin and formaldehyde under an alkali catalyst is mixed with rubber latex such as polygetadiene, styrene-butane rubber, acrylonitrile-butadiene rubber, vinylpyridine-styrene-butadiene rubber, and natural rubber, and the mixture is aged to produce a polyisocyanate compound. is an addition compound of a polyisocyanate compound and a blocking agent, specifically tolylene diisocyanate, metaphenylene diisocyanate,
Polyisocyanate compounds such as diphenylenemethane diisocyanate, hexamethylene diisocyanate, and triphenylmethane triiso,'anate, phenols such as phenol, cresol, and resolnonol, lactams such as caprolactam and valerolactam, acetoxydim, methyl ethyl ketone oxime, etc. Oxime! , t-butanol, t-pentanol, tertiary alcohols, and a blocking agent such as ethyleneimine.

The second treatment bath in the present invention is an aqueous liquid containing the above-mentioned (yl resorcinol-formaldehyde-rubber latex mixture (hereinafter abbreviated as RFL)) and (Zl blocked polyincyanate compound, in which (yl R
The ratio of F L and (2) printed polyisocyanate compound is (y) 1 o o weight part (Z) 5 to 30
It is necessary that the amount is in the range of 10 to 25 parts by weight. If the blending ratio of the above (2) blocked polyisocyanate/compound is less than 5 parts by weight, the adhesion of the treated polyester fiber to rubber will be poor, resulting in a 3 od
If the amount exceeds 1.5 parts, the treated polyester fiber becomes hard and fatigue resistance decreases, which is not preferable. Further, the solid content concentration of the second treatment layer is usually approximately 15 to 25% by weight.

The second treatment bath of the present invention is prepared, for example, by the following procedure. First, water, resorcinol, formaldehyde, and caustic soda are reacted in a conventional manner to obtain a resorcinol/formaldehyde initial condensate, which is then mixed with rubber latex and aged to obtain RFL. Next, a blocked polyisocyanate compound is mixed with this RFL and a predetermined degree of lamination is obtained, thereby obtaining a second treatment bath.

It is desirable that RFL be aged for 24 hours or more at a temperature of usually 20 to 30°C. Note that the second treatment bath can also be prepared by adding a blocked polyiso/anate compound to RFL and then aging it. RFL is sufficiently ripened in advance, and a blocked polyisocyanate compound is added to the treatment group Ri+. It can also be made available for use.

In the present invention, methods for adhering polyester fibers using the first treatment bath and second treatment bath include a method of immersing the polyester fiber &fL in each treatment bath, and a method of spraying a treatment liquid onto the polyester fiber from a nozzle. You can use any method such as The amount of solid content deposited in each treatment bath on the polyester fibers is 0.05 to 63% by weight, preferably 0.3 to 22% by weight as the first treatment bath composition, and 40 to ZO weight% as the second treatment bath composition. 45-60% by weight is suitable. If the amount of each solid content attached is too small, the adhesion of the fiber to the rubber will be poor, and if it is too large, the adhesive-treated polyester fiber will tend to become hard, which is not preferable. In order to control the amount of solid matter adhering to the polyester fibers in the treatment bath, means such as squeezing with a pressure roller, blowing off with air, suction, etc. may be used.

In the present invention e, after treating the polyester fiber with the first treatment bath, it is dried at a temperature of room temperature to is O'C.
Temperature from 0'C to 250C, preferably 180'C to 2
Preferably, the heat treatment is performed at a temperature of 20°C. Next, after being treated with a second treatment bath, it is dried at a temperature of 6oC to 150C, and
Temperatures from 00'C to 260C, preferably from 230C to 25
By heat-treating at a temperature of 0° C., the desired polyester fiber for rubber reinforcement is obtained. If the heat treatment temperature is too low, the adhesion of the fiber to the rubber will be insufficient.
On the other hand, if the heat treatment temperature is too high, the polyester fibers will melt and the strength will drop significantly, making it unsuitable for practical use.

The polyester fibers thus treated by the method of the present invention have general properties such as excellent tensile strength and dimensional stability for rubber reinforcement, are especially flexible, have low bending hardness, and have good moldability. 101 has excellent fatigue resistance, and has extremely high adhesion to chilled fibers and rubber JI with polyvarnish when subjected to a peel adhesion test after being vulcanized by embedding in compounded rubber.

Although it is not clear why treated polyester fibers that are softer and have an extremely high rubber adhesion rate can be obtained than the present invention,
The bonding force between the polyepoxide compound and the polyester fiber during the first treatment is strengthened by the carbon black, and the bonding force between the polyepoxide compound and the components contained in the second treatment is further strengthened by the presence of the carbon blank. It is thought that this is because

Furthermore, when we extrapolate the mechanism from the characteristics of carbon black, we find that it is as follows. Let's do it. That is, functional groups such as carbonyl groups, carbonyl groups, quinone groups, hydroxyl groups, etc. present on the surface layer of carbon black particles react with the polyepoxide compound or blocked polyisocyanate compound that is the processing component to form strong chemical bonds. The formation of rubber particles and the structural characteristics of the large surface area of the particles increase the number of contact points with each component in the treatment bath and strengthen the cohesive force within the adhesive layer. It is presumed that a strong adhesive bond can be obtained between the polyester fiber and the polyester fiber.

The present invention will be explained in more detail below from Example t.

In the examples, the inter-ply peel force indicates the adhesive force between polyester fiber and rubber, and a treated cord is inserted between two ply treated cords at a 90 degree angle, and cross-ply (cord density 30 end/25 wt
x), it was embedded in a carcass compounded rubber for automobile tires, vulcanized in a press e at 150°C for 60 minutes, and then the force required to peel the plies at a tensile speed of 50wAZ was applied at kg720m. Rubber adhesion rate is also a measure of the adhesion of rubber to polyester fibers.
114 was observed with the naked eye, and the percentage of rubber adhering to the cord surface was determined in five stages (A (rubber adhesion rate: 81
~too%), B (rubber adhesion rate 61~8o%), C (rubber adhesion rate 41~6 Q 9i; ), D (fld with rubber
rate 21-40%), E (rubber adhesion rate 20% or less J, 1M
This is a classification symbol.

The bending hardness of the cord is measured using a set of tapers, and the larger the measured tuna, the harder it is. The strength retention rate is a measure of fatigue resistance.The cord is subjected to repeated fatigue at 5% elongation and 10% compression for 48 hours (+705 rpm) between rotating disks using a Gutdrich disk tester.
) is the percentage of strength remaining after application.

Example 1 Glycerol polygrindyl ether (manufactured by Nagashio Sangyo Co., Ltd.,
Dinacol EX-314, polyepoxide compound) 5
Add 995 g of distilled water and dissolve uniformly. Meanwhile, 24 g of distilled water, 5 g of 1% caustic soda aqueous solution, 1 g of sodium ligninsulfonate (dispersant), and carbon black (
HAF (manufactured by Asahi Carbon Co., Ltd.) 10 g was milled using a ball mill.
After dispersing for 8 hours, 024 g of this dispersion was added to and mixed with the polyepoxy 7 water/F main liquid, and the resulting mixed solution was used as a first treatment bath. This seventh treatment consists of polyepoxide compound 1
It contains 1.20'lJ parts of carbon black per 00 parts by weight.

Meanwhile, 360.48 g of distilled water, Resol 77189816
An initial condensate of 27.67 g of 7% formaldehyde and 51 g of a 1% aqueous sodium hydroxide solution was prepared, and the condensate was mixed with vinylpyridine-styrene-butadiene-terpolymer latex (Nippon Zeon Co., Ltd. 2518FS 40.5% emulsified gf).
1. ) 422.99 g.

28% ammonia 19.45% (5% and distilled water 99%)
Add to 51 g of the mixed solution while stirring slowly to form M1 for 24 hours. Add diphenylmethane to the resorcinol/formaldehyde/rubber latex mixture after aging
A 25% aqueous dispersion a' Og of a phenol-blocked diincyanate (Hylen MP manufactured by DuPont) was added in fractions, and the resulting mixture was used as a second treatment bath. This second treatment bath contained 10 parts by weight of a blocked incyanate compound per 100 parts by weight of the solid content of the resorcinol/formaldehyde/rubber latex mixture.

Next, a cord consisting of 1,500,072 polyester fibers with a first twist of 40 times/10"I and a second twist of 40 times/10" (7) was processed using a combination treater processing machine (manufactured by C-A Ritzler). 1 After immersion in a treatment bath, at 100°C
The film was dried for 150 seconds at 200° C. and then heat-treated at 200° C. for 30 seconds. Then, after immersing this cord in a second treatment bath, 10
It was dried at 0°C for 150 seconds and then heat-treated at 245°C for 60 seconds. The polyester cord treated in this way had a solids content of 0.07% by weight in the first treatment bath and a solids content of 5% in the second treatment bath.
2% by weight of each was attached. Regarding the obtained processed code, the peeling strength between ply, rubber adhesion rate, cord strength,
The cord bending hardness and strength retention after fatigue were measured.

The results are shown in Table 1.

In addition, the ratio of fW) polyepoxide compound concentration and (Xl carbon black) in the first treatment bath and the ratio of (Y) resorgin formaldehyde rubber latex mixture and (2) blocked polyisocyanate compound in the second treatment bath t. As shown in Table 1, various treatment baths were prepared with various modifications, and the adhesive treatment of the cylindrical polyester cord was carried out in the same manner as above.Table 1 also shows the results of evaluating the characteristics of the treated cord.

As is clear from the results in Table 1, the method of the present invention (JK
The polyester cords obtained by processing 1 to 16) have excellent adhesion to and adhesion to rubber, and have balanced bending hardness and fatigue resistance. On the other hand, if the addition of carbon black to the first treatment bath is zero or too small (118, 20), if the first treatment bath lacks a polyepoxide compound (A17), the second treatment bath contains a blocked isocyanate compound. If (Ai
q) and when the amount is too small (42+), the adhesion to the rubber is poor, and when the second treatment bath contains too much Plack Germany/Anate compound (JIC22), the cord becomes hard and fatigue resistance decreases. Therefore, it is undesirable.

Patent applicant Higashi Shikikai Co., Ltd. 436-

Claims (1)

[Claims] Contains polyester fibers for rubber reinforcement at a ratio of 0.3 to 20 parts by weight of (X) per 100 parts by weight of (W) polyepoxide compound and (FW of Xi carbon black), and the concentration of the above (W) is 0.5 ~15 wt.
) A method for adhesion treatment of polyester fibers for rubber reinforcement, characterized in that the treatment is carried out in a second treatment bath consisting of an aqueous liquid containing 5 to 60 parts by weight (Z) per 100 parts by weight (solid content).