IL28965A - Terpolyamides of 11-amidoundecanoic acid - Google Patents

Description

FIBERS COMPRISING- TEHPOLYAMIDES OF 11-AMIDOUNDEC OIC ACID Polyamides, such as polyhexamethylene adipa-mlde (nylon 66), are well known in the art and have found significant commercial success both as synthetic textile fibers and as reinforcing fibers, for example tire yarn.

An inherent drawback in the use of polyamides to reinforce vehicle tires is their tendency to flatspot. Flatspotting is a term used to describe the out-of-roundness that occurs when a polyamide reinforced vehicle tire is allowed to rest for a period of time. That portion of the tire which is in con-tact with the pavement becomes flattened and, when the vehicle is started again, this flat spot causes vibration of the vehicle. While this phenomena of flatspotting is not completely understood 3 there is at present a great deal of effort being put into finding a solution to this problem. Lack of stability to heat and moisture has been found to be one of the factors involved in causing flatspotting and polyamides possessing increased stability to heat and moisture are highly desirable in the manufacture of nylon tire yarns since such yarns exhibit less tendency to cause flatspot in tires.

This invention pertains to new terpolyamides and more particularly to fiber -forming terpolyamides consisting of varying amounts of polyhexamethylene adipamide, polyhexamethylene terephthalamide and poly-ll-aminoundec-anoic acid.

In general;, the invention is the provision and preparation of novel terpolyamides containing polymer units selected from polyhexamethylene adipamide^ polyhexamethylene terephthalamide and poly-ll-aminoundecanoic acid terpolyamide which has better stability to heat and moisture and less tendency to cause flatspot in tires than nylon 66 .

Accordingly, it is the primary object of the invention to provide terpolyamides which will yield synthetic fiber for the production of tire yarns with increased stability to heat and moisture and reduced tendency to cause flatspotting.

The three polymer components of the terpolyamide may be used in a wide range of compositions provided the amount of polyhexamethylene terephthalamide (6TA) does not exceed about 60 mole percent. At this level of 6TA the melting point of the terpolyamide is close to 300° C which is the maximum practical limit for the manufacture of fibers from these polymers on conventional melt spinning equipment. Thus, the terpolyamides of the invention consist essentially of (A) from about 35 to 75 mole percent of polyhexamethylene adipamide, (B) from about 20 to 60 mole percent of polyhexamethylene terphthalamide and (C) from about 5 to 25 mole percent of poly-ll-aminoundecanoic acid. In a preferred embodiment of the invention the terpolyamide fibers consists of from 50 to 70 mole percent of polyhexamethylene adipamide, from 20 to 30 mole percent polyhexamethylene terephthalamide and from 10 to 25 mole percent of poly-ll-aminoundecanoic acid.

The terpolyamides of this invention may be prepared by procedures well known in the art and commonly employed in the manufacture of conventional polyamides.

That is, the reactants are heated at a temperature of from fiber forming properties, which properties are reached when the terpolyamide has an intrinsic viscosity of at least 0.4. The reaction can be conducted at superatmospheric , atmospheric, or subatmospheric pressure. Often it is desirable especially in the last stage of the reaction to employ conditions, e.g., reduced pressure which will aid in the removal of the reaction by-products. Preferably, the reaction is carried out in the absence of oxygen, for example, in an atmosphere of nitrogen or other inert gas. The monomers may be added to the polymerization autoclave together or they may be added separately, either before or after the polymerization has begun. In addition, delustrants, antioxidants, plasticizers , viscosity stabilizers, and other like modifying agents may be used in the preparation of the ter-polyamides of this invention. The synthetic linear ter-polyamides as described herein may be formed into fibers by employing known melt spinning and drawing conditions conventional for polyamides.

The invention is further illustrated by the following examples in which all parts and percents are expressed in moles unless otherwise indicated. In the examples the following abbreviations have been employed: 66 is polyhexamethylene adipamide, 6TA is polyhexamethylene terephthalamide, and 11A is poly-ll-aminoundecanoic acid.

EXAMPLE I To a stainless steel nylon polymerizer was added 228.3 grams of a 48.17 aqueous solution of 66 salt, 33-8 grams of 6TA, 12.02 grams of 11A, and approximately 10 ml of water and the autoclave temperature was raised to Water of reaction was removed during temperature increases of from 2l6°C to 250°C while autoclave pressure was main-tained at 250 psi., (17.6 Kg/Cm ) then the pressure was reduced to atmospheric during 25 minutes while increasing the temperature to 279°C to 286°C and holding for a period of 30 minutes. The resulting terpolyamide consisted of 70 mole percent of 66, 20 mole percent of 6TA and 10 mole percent of 11A. Monofilaments were melt spun at 285-289°C using conventional equipment and procedures.

EXAMPLE II Following the procedure of Example I additional terpolyamides were prepared with the percentages of the three components as indicated in Table I which gives tenacity, intrinsic viscosity and other pertinent information for the various terpolymers .

TABLE I MER NO. %66 %6TA gllA m-p°Cp|m-cresol Tenacity 1 70 20 10 260.0 1.030 5.68 2 60 30 10 272.0 0.980 6.58 3 50 25 25 245.5 1.090 6.97 4 40 40 20 281.5 1.005 5-32 Intrinsic viscosity as employed herein is defined as In which is the relative viscosity of a dilute solution of the polymer in m-cresol in the same units and at the same per lOOcc. of solution.

The increased stability to heat and moisture is demonstrated by the percent retention of sonic modulus to temperature at various conditions to humidity in Tables II and III, RH being relative humidity.

TABLE II - 0% RH SONIC MOD %Ret. Ret %ReT %Ret #Ret POLYMER @30°C @50° @80° §110° @130° A150° 1 51.52 88 79 69 57 42 2 50.31 90 85 78 65 52 3 40.79 96 84 62 37 21 4 42.20 95 87 76 55 35 Nylon 66 59-26 9 80 63 55 33 (Control) TABLE III - 30%RH SONIC MOD. JSRet 1 · $Ret . $Ret . ¾Ret .

POLYMER @30°C @45° @60° @75° β90° 1 50.31 92 81 75 60 2 55.69 90 81 73 64 3 47.48 i 83 72 61 4 52.72 90 81 74 65 Nylon 66 75.22 83 70 57 48 This stability of modulus to temperature and humidity would allow a tire to be constructed which would, have less tendency to flatspot than would be observed using nylon 66 only. The percent of sonic modulus retained at elevated temperature and 30 percent relative humidity is of particular The terpolyamides of this invention are useful in a wide range of textile and other end uses requiring stability to heat and moisture for prolonged periods of time. In the form of fibers, filaments and films they are of particular utility for reinforcement applications and primarily in fiber form for tire yarns.

The foregoing detailed description has been given for clearness of understanding only, and unnecessary limitations are not to be construed therefrom. The invention is not to be limited to the exact details shown and described since obvious modifications will occur to those skilled in the art, and any departure from the description herein that conforms to the present invention is intended to be included within the scope of the claims.

Claims (6)

HAVING NOW particularly described and ascertained the nature of our said invention and i n what manner the same is to be performed, we declare that what we claim is .:

1. A synthetic fiber, characterized by comprising a terpolyamide consisting essentially of (A) from about 35 to 75 mole percent of polyhexamethylene adipamide, (B) from about 20 to 60 mole percent of polyhexamethylene terephthalamide and (C) from about 5 to 25 mole percent of poly-ll-aminoundecanoic acid.

2. The fiber of Claim 1 , characterozed in that the terpolyamide consists essentially of (A) from 50 to 70 mole percent of polyhexamethylene adipamide, (B) from 20 to 30 mole percent of polyhexamethylene terephthalamide and (C) from 10 to 25 mole percent of poly-ll- aminoundecanoic acid.

3. . The fiber of Claim 1 , characterized by having at least 90% retention of sonic modulus at J5°C. and 30% relative humidity.

4. . The fiber of Claim 1 , characterized by having at least 80¾ retention of sonic modulus at 60°C. and 3052 relative humidity.

5. The fiber of Claim 1 , characterized in that (A) is 70 mole percent, (B) is 20 mole percent and (C) is 10 mole percent.

6. . A process for the preparation of ter- polyamides of Claim 1, characterized by heating reactants of (A), (B) and (C) to a temperature of from l80°C. to 300°C. for a period of time sufficient to produce an intrinsic viscosity of at least 0 . 4 . Dated this Seventeenth day of November 1967