DD238056A5 - COMPOSITION FOR USE IN THE FAST POLYMERIZATION OF EPSILON-CAPROLACTAMIC FOR THE FORMATION OF NYLON-6 BLOCK COPOLYMERS - Google Patents

Abstract

The invention relates to a composition for use in the rapid polymerization of e-caprolactam to form a nylon 6 block polymer. According to the invention, it contains an acyl lactam and a magnesium halide, formed by the reaction of 20.2 equivalents of a functional acid halide material with a balance of magnesium dactyl. The lactam of Magnesiumdilactams is suitably selected from the group consisting of 2-pyrrolidone, e-caprolactam and laurolactam.

Description

Polyether, a polyester or a hydrocarbon having a molecular weight of at least 1,000 and wherein X is chlorine.

13. A composition according to claim 12, characterized in that the functional acid halide material has at least three acid halide groups.

14. The composition according to claim 12, characterized in that η is at least 3.

Composition according to Claim 12, characterized in that the polyether segment is polyethylene oxide, polypropylene oxide or poly (tetramethylene oxide) and the hydrocarbon segment is polybutadiene or polybotadiene-co-acrylonitrile.

16. A composition according to claim 12, characterized in that it is obtained by reacting 2 equivalents of acid halide with one mole of magnesium dactyl.

Field of application of the invention

The invention relates to a composition for use in the rapid polymerization of ε-caprolactam to form nylon 6 block copolymers.

Characteristic of the known technical solutions

In general, nylon block copolymers may consist of alternating blocks of polyamide segments and other segments such as elastomeric segments of polymer groups, e.g. As polyethers, polyesters, hydrocarbons or polysiloxanes exist. These nylon block copolymers may vary depending on the structure of the elastomeric segment from which the

Block polymer is prepared, either linear or branched. A more detailed description of the structure and method of making a particular type of nylon block copolymer can be found in U.S. Patent No. 4,031,164. From US-PS (Reissue Patent) 30371, the reaction between bisimide and polyol in the presence of a catalyst for the formation of functionalized acyllactam materials emerges. These functionalized acyl lactams can then be reacted with additional lactam monomer in the presence of a catalyst to produce nylon block copolymers. It may be advisable to neutralize the catalyst after the production of the functionalized materials prior to the addition of lactam monomer in order to eliminate difficulties in controlling the initiation of lactam polymerization during the preparation of nylon block copolymers.

In US Pat. Nos. 4,676,225 and 4,677,093, which are also pending and assigned to the same assignee as the present application, functionalized acyl lactam compounds prepared by the reaction between acid halides and lactam monomer are described. These acyl lactams may be reacted simultaneously or subsequently with additional lactam monomer in the presence of a nylon block copolymer forming catalyst. As can be seen from these applications, the process for producing functional acyl lactam materials provides for the reaction of functional acid halide material with lactam monomer in the presence of an acid scavenger. The acid scavenger reacts with the generated acid to form a salt which precipitates out of the solution and is removed by filtration. It has previously been known from GB-PS 1057153 that functionalized acid halides can be reacted with lactam monomer in the presence of a catalyst for the in situ formation of acyl lactam initiators and initiate the formation of nylon block copolymers, and US Pat. No. 3,451,963 discloses that the N- Halogen metal-lactam catalyst can be prepared in the polymerization of caprolactam to form nylon-6 in situ by the reaction of metallacl and a metal halide.

A priority DD-PA from which the present application was filed relates to a process for the preparation of a nylon 6-block copolymer which comprises reacting a functionalized acid halide material with a solution of magnesium dilactam in ε-caprolactam to form a storable solution of functionalized acyl lactam material, containing magnesium halide, and then adding further magnesium dilactam solution and ε-caprolactam to form a reaction mixture in which ε-caprolactam is rapidly polymerized by the addition to the functionalized acyl lactam material. The reaction mixture can be used for casting blocks of nylon 6 copolymer and for reaction injection molding of such copolymers. The method therefore dispenses with separate intermediate preparation of functionalized acyl lactam material by reacting functionalized acid halide material with a lactam in the presence of an acid acceptor because the acid acceptor salt precipitates and requires a complex filtration step to remove the salt. The process offers the further advantage of a much more durable initiator agent than the functionalized acid halide material itself.

Object of the invention

With the invention, a composition is to be provided, which is advantageously used in the aforementioned method.

Explanation of the essence of the invention

The invention relates to a storable composition of functionalized acyl lactam material and magnesium halide which is the initiator for the polymerization of caprolactam and which reacts with magnesium dilactam to form a halomagnesium lactam catalyst for the rapid polymerization of caprolactam. The amount of functionalized acid halide material and magnesium dilactam used to prepare the composition is selected to provide 2 ± 0.2 equivalents of acid halide per mole of magnesium dilactam. If the amount of acid halide is substantially more than 2 equivalents, the excess may lead to some instability of the functionalized acyl lactam material. If the amount is significantly less than 2 equivalents, then some halogen magnesium lactam is formed which may result in the premature polymerization of ε-caprolactam present in the acyl lactam solution prior to the addition of magnesium dactyl in the particular polymerization step. In the formation of the acyl lactam magnesium halide solution, it is therefore advisable to adjust the amount of the functional acid halide material so that 2 equivalents per mole of magnesium dilactam are available.

Nylon block copolymers of the new type generally consist of alternating blocks of polyamide segments (-NH-Y-CO-) _m , wherein Y is pentamethylene and m is an integer greater than one, and elastomeric segments of polymer radicals, e.g. As residues of polyester, hydrocarbons, polyesters or polysiloxanes or combinations thereof. As used herein, the term "functional acid halide material" means an oligomer or polymer containing at least one acid halide group per molecule The halide is represented by an N-lactam group represented by the formula

C = O

- N

wherein W is a C ₃ -C ₁₂ alkylene or a substituted alkylene radical, after the reaction with a magnesium dilactam of the following formula:

C-N-Mg-N

to provide the functional acyl lactam material which serves as the initiator species for the polymerization of ε-caprolactam to obtain the nylon 6 block copolymer. The term "acid halide group according to the invention is understood to mean the halide derivative of a carboxylic acid, a sulfonic acid, a phosphoric acid or another equivalent acid. The preferred acid halide group is derived from a carboxylic acid group, with chlorine being the preferred halide substituent. The functional acid halide material preferably has at least two acid halide groups, and most preferably at least three acid halide groups. The term "acid halide functionality" refers to the number of acid halide groups having one molecule of the above-defined "acid halide functional material". The major types of oligomers or polymers useful in the practice of the invention are those which provide elastomeric segments in a nylon block copolymer when incorporated therein. Suitable oligomeric or polymeric starting materials have a molecular weight in the range of about 200 to about 15,000 and include polyalkylene ethers, hydrocarbons such as polyalkenes, polyalkadienes and alkadiene copolymers, polyesters containing polyalkylene, polyalkadiene, alkadiene copolymer or polyalkylene ether segments, and polysiloxanes selected. When incorporated into nylon block copolymers in an amount of at least 50% by weight, such segments impart to the copolymers a characteristic tensile recovery of at least about 50%. The tensile recovery is determined on a dry polymer specimen in the formed state which has been expanded to 50% of its original length (1) and held for 10 minutes in this state before the tension is released. Ten minutes after relaxation, the length of the specimen (I ₁ -) is measured again. The percentage recovery is

1.5 1 - l _r χ 100

0.5 1

While it is also required that the nylon block copolymer must have an elastomer content of at least 50% by weight in order to determine whether or not it will behave as an elastomeric segment as defined above, it should be noted that the amount of elastomer segment is not limited to at least 50% by weight in the nylon block copolymers prepared according to the present invention because lower and higher levels in the range of 10 to 90% by weight also impart improved properties to the nylon polymer.

A preferred functional acid halide material used in the new process has the following general formula:

wherein the Z segment is a polyether, a polyester containing polyether or hydrocarbon segments, a hydrocarbon, a polysiloxane, or combinations thereof, wherein A is a component selected from the group consisting of

O0 0 0 0

Il Il Il fl if

- C - R - 4C} < ₀ > -C'-, -CCiSO ₂ - and POR ₁ -;

wherein b is an integer of 1, 2 or 3;

R is a polyfunctional radical derived from an acyclic or cyclic hydrocarbon or ether compound having a molecular weight of about 300 or less, preferably a cyclic hydrocarbon, or more preferably benzene;

R _{1 is selected} from the group consisting of alkyl, aryl, aralkyl, alkyloxy, aryloxy, aralkyloxy and halo groups; η is an integer of one or higher, preferably at least 2 and most preferably at least 3, and X is a halide and preferably chloride.

These preferred functional acid halides can generally be obtained by the reaction of 1 equivalent of hydroxy-functionalized oligomers and polymers such as hydroxy-functionalized polyethers, hydrocarbons, polyesters containing polyether segments. Polyesters containing hydrocarbon segments, or polysiloxanes, with 2 equivalents of polyfunctional acid halides, preferably polyfunctional aromatic halides such as isophthaloyl and terephthalyl chloride, in the presence of an acid scavenger such as an amine.

O0 0 0

The Α-group is preferably - C - C - ΟαβΓ - C "" ι * v ^ / j-) wherein round b has the meaning described above, and it is best

? 0

it

-C-R

The functional acid halides are derived from oligomers or polymers having molecular weights of from about 200 to about 1500P, but preferably from about 1000 to about 10000. Preferred functional acid halides are those derived from polyether diols and polyols having molecular weights of greater than about 1000 and preferably between about 2,000 and about 8,000. Other preferred functional materials are those derived from hydrocarbon diols and polyols and have molecular weights of at least about 1,000, and preferably about 2,000 to about 5,000. Still other preferred functional materials include polyester ether groups or polyester hydrocarbon groups and are prepared by reacting 1 equivalent of polyether diols or polyols or hydrocarbon diols or polyols having molecular weights of at least about 1000 with less than 2 equivalents of di-tertiary functional acid halides are prepared so that a limited degree of chain extension of the diols or polyols is achieved by the formation of ester groups. All references herein to molecular weight refer to the number average molecular weight which is determined by methods well known in the art.

Suitable polyether starting materials for the functional acid halide material and the acyl lactam derived therefrom are the various polyalkylene oxides such as polyethylene oxides, polypropylene oxides and polytetramethylene oxides). Examples of suitable polymer hydrocarbons are the various polyalkanes and polyalkadienes and alkaldiene copolymers such as polyethylene, polypropylene and polybutadiene, and copolymers of butadiene and acrylonitrile. Examples of suitable polyesters are those made by the reaction of polyether polyols such as polyoxypropylene polyols or polyoxyethylene polyols with polyfunctional acid halides such as terephthalyl chloride to form a polyester ether, or by reacting a polymer hydrocarbon polyol such as polybutadiene diol with a polyfunctional acid halide such as terephthalyl chloride to form a polyester hydrocarbon. Examples of suitable polysiloxanes are silicon polycarbinol and polydimethylsiloxane diols and polyols. A representative of a nylon 6 block copolymer prepared from the preferred functional acid halide material described above would have the following general structure:

N fCO-Y-NH * A (-NH-Y-CO * O-Z-O-

(-CO-Y-NH * _m A (-NH-Y-CO- * N

^m 2 3

wherein: Y, Z, A and η are as defined above; and m, mi, m ₂ and m _{3 are} integers of one or more. The magnesium dilicactams useful for said application can be prepared from any suitable lactam such as ε-caprolactam, 2-pyrrolidone, laurolactam or other caprolactams as ε-caprolactam. Preferred magnesium dilactams are magnesium di-2-pyrrolidone and magnesium di (ε-caprolactam).

A process for the preparation of magnesium dilactam consists of reacting the lactam monomer in question with an alkyl oxide of magnesium and removing the alkanol formed in the reaction by distilling off from the reaction mixture. As will be understood by those skilled in the art, there are other possible possibilities for the preparation of magnesium dactylamines, and the invention is not intended to be limited to the procedure described above. For ease of handling, the magnesium dlactam is preferably dissolved in ε-caprolactam for later use in the polymerization of ε-caprolactam. The magnesium dilactam readily reacts with the functional acid halide material in any manner. For example, it may be added to a solution of functional acid halide material dissolved in a suitable inert solvent, such as tetrahydrofuran, and stirred vigorously to complete the reaction. The solvent can then be driven off to recover the acyl lactam magnesium halide compound. If ε-caprolactam is used as the solvent for the magnesium dilactam, then the product will also contain ε-caprolactam, and further ε-caprolactam may be added to obtain a solution melt of appropriate viscosity for handling and pumping. This solution represents the first solution of the process of the invention. Since the acyl lactam is an initiator for the polymerization of ε-caprolactam, it is to be ensured that substantially all of the magnesium dilactam added to the acid halide functional material for conversion to acyl lactam is converted to an inactive magnesium halide , This can be done by using 2 ± 0.2 equivalents of acid halide functionality per mole of magnesium dilactam in preparing the composition. Preferably, 2 equivalents of acid halide functionality is provided for each mole of magnesium dilactam. In this way, the possibility of the formation of halomagnesium lactam in the first solution of an active catalyst for the polymerization of ε-caprolactam in the presence of an initiator, turned off and premature polymerization is avoided.

Another method is a solution of magnesium dilactam in ε-caprolactam. If the first and second solutions are brought into reactive contact at an appropriate reaction temperature, then it is believed that the magnesium dilactam of the second solution reacts with the magnesium dihalide present in the first solution and lactam magnesium halide is formed in situ to be a very effective catalyst to provide for lactam polymerization. The amount of additional magnesium dilactam to be applied should be greater than the amount of deactivating impurities and sufficient to polymerize the ε-caprolactam. This amount will vary depending on the concentration of impurities and depending on which rate of polymerization is considered desirable in the particular application. The preferred amount of additional magnesium dilactam will generally be from about 0.5 mole to about 1 mole per equivalent of acid halide functionality of the functional acid halide material used to prepare the acyl lactam magnesium chloride solution.

The mixing of the first and second solutions and the filling of the mixture into a mold can be carried out in various ways. In general, the first and second solution of the casting and reaction injection molding process, where a rapid reaction is required, are rapidly and thoroughly mixed and the mixture is immediately poured into the mold. It may be any form temperature at which the polymerization reaction proceeds, and in general it will be between about 8O ⁰ C and about 250 ⁰ C and preferably between about 100 ⁰ C and about 16O ⁰ C. It should be noted, however, that there are various ways of mixing these substances in the production of nylon block copolymers.

embodiments

The following examples illustrate the preparation of the composition according to the invention and the method of producing nylon block copolymers. Parts and percentages are by weight unless otherwise specified.

example 1 Preparation of magnesium di-pyrrolidone in caprolactam

Into a 1-liter four-necked flask equipped with stirrer, distillation head, thermometer and stopper and placed in an oil bath were placed 12 grams (g) of magnesium, 200 milliliters (ml) of ethanol and 100 milliliters of heptane. This solution was boiled by increasing the bath temperature to about 31 ⁰ C to reflux, with the piston was in a nitrogen atmosphere. The temperature of the solution was about 72 ° C. To this refluxing solution was added 80 ml of 2-pyrrolidone while stirring the solution. About 10 minutes after the addition of 2-pyrrolidone, the ethanol and heptane were distilled off under atmospheric pressure. Next, 140 g of molten caprolactam was added and the bath temperature was raised to about 12O ⁰ C and the flask placed under vacuum. The pressure was then slowly lowered to 7 millimeters (mm) Hg (933.2 Pa) to thereby remove even more ethanol and heptane, which were collected in a dry ice-acetone trap. Into the flask was added 248 g of melted dried caprolactam, maintaining the pressure at 7 mm Hg. The temperature of the oil bath was slowly increased to about 140 ⁰ C, and the pressure was lowered to 2mm Hg (266.7Pa). After removal of 171.4 g of material, the hot solution was cooled to 85 ° C. and then placed in a double-walled plastic bag and placed on dry ice to cool and solidify After solidification, the resulting solidified solution was crushed into fine particles , 6g of material containing 0.5 mole of magnesium di-2-pyrrolidone in caprolactam.

Example 2 Preparation of Functional Acid Chloride Material

A functionalized acid halide material was prepared by reacting a three hydroxyl functionalized polyether with a di-functional acid halide. The resulting functionalized material is a preferred functional acid halide material as described above.

Into a 2-titer flask, 67 ml of triethylamine and 80 ml of tetrahydrofuran were charged to 801 g of an ethylene oxide-covered poly (oxypropylene) triol (approximate molecular weight 4800), 81.4 g of terephthaloyl chloride and 400 g of tetrahydrofuran over about 10 minutes. The molar ratio of triol to dihydrogen chloride was 2: 5. This mixture was kept under a nitrogen atmosphere at room temperature for 3 hours. The resulting mixture was then filtered to yield a pale yellow filtrate. Of the remaining tetrahydrofuran, a small sample using a rotary evaporator at a water bath temperature of 60 to 70 ⁰ C was taken to calculate the yield of recovered functional Säurehalogenidmaterial. The yield was 759.1 g of functional acid chloride material in tetrahydrofuran.

Example 3 Preparation of acyl lactam magnesium chloride solution

An acyl lactam solution of the invention was prepared by reacting 2 equivalents of the acid chloride functional material of Example 2 with one mole of magnesium di-pyrrolidone from the Example 1 composition. Into a flask containing 1143.1 g of the tetrahydrofuran solution of the functional acid halide material of Example 2 were added 134 g of the solution of magnesium di-pyrrolidone prepared in Example 1. The resulting mixture was stirred vigorously at room temperature and then immersed in water through a 60 to

Examples 4 to 6 Preparation of nylon e-block copolymer

The composition prepared in Example 3 was used in the following three Examples 4 to 6 to show the production of nylon block copolymer having the magnesium di-pyrrolidone prepared in Example 1. Three test tubes were each filled with 5.7 g of the material prepared in Example 3 and 20 g of distilled caprolactam. Each jar was placed in an oil bath maintained at a temperature of 130 ° C. Once the temperature of the materials in each of the glasses reached equilibrium, an amount of the magnesium di-pyrrolidone-caprolactam solution of Example 1 was added to each example and the duration of the polymerization was determined. Table I below lists the amount of magnesium dipyrrolidone-caprolactam solution added in each example and the polymerization time.

Table I

Example of MGPC Solution (g) Polymerization Time (s)

4 1.7 15-20 5 0.8 30 6 0.4 No reaction after 10 minutes

Example 7

In this example, 95 g of a _f composition prepared as in Example 3 above, along with 132 g caprolactam and 3 mL of a 4% aqueous copper (II) acetate solution, were added to a 500 mL four-necked flask equipped with a stirrer, nitrogen inlet , Thermocouple, heating mantle and vacuum distillation head. The mixture was heated to about 130 ° C with stirring. After removal of 25 ml of material by vacuum distillation, the mixture was cooled and kept at 100 ° C under vacuum for use.

A second flask was charged with 26 g of a solution of 1 M magnesium di-2-pyrrolidone in caprolactam and 174 g anhydrous caprolactam. After degassing the mixture, the temperature was raised and the mixture kept under vacuum at 100 ° C for use.

Equal volumes of each of the solution prepared as above were separately pumped by means of gear pumps 2Zenith no. 5 in a Kenics Static Mixer of 0.64 cm x 20.3 cm, and the mixture was heated in a pre-to 130 ⁰ C with Teflon coated form of 20.3cm x 20.3cm χ 0.32cm. From exothermic temperature curves, it was determined whether the polymerization was complete within 104 seconds of filling the mold. The material was left in the mold for a further 200 seconds to a total of about 5 minutes. Test specimens were cut from the resulting casting in order to be able to determine the various mechanical properties essentially according to the following methods:

Tensile strength ASTM 638 (units in pounds persquareinch [psi] or megapascal [MPa]).

Tear Resistance: ASTM D1004 (units in pound-force per linear inch [pli] or Newton per meter [N / m]).

Flexural modulus: ASTM D638 (units in pounds persquareinch [psi] or Megapascal [MPa]).

Tensile strain: ASTM D638 (units in%)

Notched Izod Impact Strength: ASTM D256 (units in foot-pounds per inch notch [ft.Ibs./in.] Or joules-per-meter [J / m]).

The properties of the shaped sample of Example 7 are listed in the following table.

Table II Plastic deformation (7370) 50.8 tensile strenght fracture (6690) 46.1 (PSI) MPa Plastic deformation 8.5 Strain % fracture 90 (1608) 282 tear (220,000) 1517 (PLI) N / m (5.5) 293 Impact strength (Ft.lbs / in.) L / m

The examples described above demonstrate the use of magnesium di-2-pyrrolidone as magnesium dilactam to prepare the acyl lactam solution (the first solution of the process of the invention) and the preparation of nylon block copolymer from this solution. It will be appreciated that other magnesium dilactams such as magnesium di (scaprolactam) can be used in the above examples instead of magnesium di-2-pyrrolidone. Although the preferred embodiments have been described and illustrated, various changes and substitutions may be made without departing from the content and scope of the illustration. Therefore, the invention has been described by way of illustration and not limitation.

Claims (12)

claims: A composition for use in the rapid polymerization of ε-caprolactam to form nylon 6 block copolymers, characterized in that the composition comprises an acyl lactam and magnesium halide and formed by the reaction of 2 ± 0.2 equivalents of a functional acid halide material with one mole of magnesium dactyl is. 2. Composition according to claim 1, characterized in that the lactam of Magnesiumdilactams from the 2-. Pyrrolidone, ε-caprolactam and laurolactam comprehensive group is selected. A composition according to claim 1, characterized in that the acid halide group of the functional acid halide material is a cabonic acid halide. 4. A composition according to claim 3, characterized in that the halogen of the acid halide group is' chlorine. A composition according to claim 4, characterized in that the acid halide functional material is derived from a polyether, a polyester or a hydrocarbon having a molecular weight between about 200 and about 15,000. A composition according to claim 4, characterized in that the functional acid halide material is derived from a polyether, a polyester or a hydrocarbon having a molecular weight of at least 1000. 7. A composition according to claim 1, characterized in that it is obtained by the reaction of 2 equivalents of acid halide with one mole of magnesium dactyl. 8. The composition according to claim 7, characterized in that it is the magnesium dilactam is magnesium di-2-pyroolidone. A composition according to claim 1, characterized in that it consists of an acyl lactam and magnesium halide dissolved in ε-caprolactam and formed by the reaction of 2 ± 0.2 equivalents of an acid halide functional material with one mole of a magnesium dimethyl lactam, wherein the acid halide functional material comprises is represented by the formula Z / O - A (X) _{b / n} wherein the Z segment is a polyether, a polyester containing polyether segments or hydrocarbon segments, a hydrocarbon, a polysiloxane or combinations thereof, wherein A is selected from the following group is selected O OOOO Il il It 11 ti - C - R frC} _b ; -C -, - CC-, - SO ₂ - and -POR ₁ -; and wherein b is an integer of _1, 2 or 3, R _{1 is selected} from the group consisting of alkyl, aryl, aralkyl, alkyloxy, aryloxy, aralkyloxy and halo groups, R is a hydrocarbon or polyether group having a relative Molecular weight of about 300 or less, η is an integer of one or more, and X is halogen. 10. The composition according to claim 9, characterized in that the lactam of the Magnesiumdilactams from the 2-pyrollidone, ε-caprolactam and laurolactam comprehensive group is selected. A composition according to claim 10, characterized in that the halogen of the functional acid halide material is chlorine. Composition according to Claim 10, characterized in that the group A 0 is O, the Z-segment being a "" C-R