CS257265B2 - Process for preparing block polyamide copolymer - Google Patents

Abstract

A method for preparing a block polyamide copolymer, which is carried out by mixing epsilon-caprolactam, a compound containing N-acyllactam functional groups selected from the group comprising adducts of polyethertriol with a molecular weight of 1,000 to 10,000, preferably 3,000 to 6,000 with a dihalide of an aliphatic or aromatic dicarboxylic acid and epsilon-caprolactam, at least one amine with a molecular weight of 60 to 10,000, preferably up to 6,000 selected from the group comprising aliphatic monomeric polyamines and aliphatic polymeric polyamines with a polyether or polyalkyleneimine skeleton, the multifunctionality of which is formed by at least two primary and/or secondary amino groups, the amount of the multifunctional amine being at least 0.02 equivalents of the sum of the primary and secondary amino groups, based on the equivalent of the N-acyllactam groups contained in the compound, and a catalyst anionic polymerization of lactams, whereby the mixing is carried out by mixing a compound with N-acyllactam groups with a part of caprolactam and an amine and catalyst with the rest of the caprolactam, after which both resulting premixes are mixed together

Description

The invention relates to a method for preparing polyamide materials with high impact strength, which consist of block copolymers containing polyamide and elastomeric segments. In particular, the invention relates to a method for preparing screened polyamide block copolymers.

Polyamide block copolymers can generally be formed by alternating blocks of polyamide segments, such as segments of elastomeric polymers, such as polyethers, polyesters, hydrocarbons or polysiloxanes. Polyamide block copolymers are generally produced by copolymerization of a lactam monomer and elastomeric polymers and can be linear or branched depending on the structure of the elastomeric polymer used. A more detailed review of the structure and methods of making a given type of polyamide block copolymer is provided in United States Patent No. 4,031,164 (Hendrick and Gabbert).

The properties of the polyamide segments and elastomeric polymer segments contained in the block copolymers affect, as stated in the above-mentioned patent of authors Hendrick and Gabbert, the properties of the resulting polymer. To obtain a material with a high modulus of elasticity, it is necessary to use polyamide segments of higher molecular weight and/or in a higher percentage by weight. Higher elongation and better impact properties can be achieved in the production of block polyamide copolymers by using a higher weight content and/or at a higher molecular weight of elastomeric polymers.

Influencing the properties of block polyamide copolymers in other ways would be advantageous.

This invention relates to the crosslinking of polyamide block copolymers using polyfunctional amines.

Crosslinked polyamide block copolymers are obtained according to the present invention by a reaction process in which the polyamide block copolymers are crosslinked by the action of polyfunctional amines.

This can be done, for example, by reacting compounds with acyl lactam functional groups with polyfunctional amines to obtain a crosslinked substance containing acyl lactam functional groups, which is subsequently or simultaneously reacted with a lactam monomer in the presence of an anionic lactam polymerization catalyst to form crosslinked polyamide block copolymers. The properties of the resulting block copolymers can be variable depending on the degree of crosslinking.

Specifically, polyamide block copolymers consist of alternating blocks of polyamide segments with the formula

O wherein X represents a 1,5-pentylene group and m is an integer greater than one, and segments of polyether elastomeric polymers. A more detailed description of such a block polyamide copolymer is given in United States Patent No. 4,031,164.

There are a number of methods for producing polyamide block copolymers. One general method involves the use of polyether elastomeric prepolymers, which provide elastomeric segments in the polyamide block copolymers, and the monomer caprolactam. The elastomeric prepolymer is prepared to contain a lactam initiator group, which polymerizes additional caprolactam to form polyamide segments. The lactam initiator group is an acyl lactam group, which is a known initiator of lactam polymerization.

The use of elastomeric polymers containing acyl lactam groups for the production of block polyamide copolymers is described in European Patent Application No. 67,695. The above compounds with acyl lactam functional groups can then be reacted with epsilon3

-caprolactam in the presence of a basic polymerization catalyst, kaltam, to form block polyamide copolymers.

As mentioned above, polyamide block copolymers exhibit properties imparted by the elastomeric polymer segments and the polyamide segments.

In the process according to the invention, when crosslinking block polyamide copolymers with multifunctional amines, the overall properties of the resulting polymer can be changed even while maintaining a constant molecular weight and a constant mass content of elastomeric polymers. Said crosslinking is achieved by the reaction between at least one compound with N-aceyllactam functional groups and at least one multifunctional amine and subsequent or simultaneous reaction with epsilon-caprolactam in the presence of an anionic lactam polymerization catalyst.

The subject of the invention is a method for preparing block polyamide copolymers, characterized in that epsilon-caprolactam, a compound containing N-acyllactam functional groups selected from the group comprising polyethertriol adducts with a molecular weight of 1,000 to 10,000, preferably 3,000 to 6,000, with a dihalide of an aliphatic or aromatic dicarboxylic acid and epsilon-caprolactam, at least one multifunctional amine with a molecular weight of 60 to 10,000, preferably up to 6,000, selected from the group comprising aliphatic monomeric polyamines and aliphatic polymeric polyamines with a polyether or polyalkyleneimine skeleton, the multifunctionality of which is formed by at least two primary and/or secondary amino groups, wherein the amount of the multifunctional amine is at least 0.02 equivalents of the sum of primary and secondary amino groups, based on the equivalent of N-acyllactam groups, and a catalyst. anionic polymerization of lactams, wherein the mixing is carried out by mixing, on the one hand, a compound with N-acyllactam groups with a part of caprolactam, and on the other hand, an amine and a catalyst with the rest of the caprolactam, after which both resulting premixes are mixed together.

The polyfunctional amines used in the process according to the invention preferably contain at least three primary or secondary amino groups. These are compounds which may have different molecular weights and different structures. All polyfunctional amines defined above which are capable of crosslinking compounds with acyllactam functional groups and/or polyamide block copolymers are suitable for the process according to the invention. The amine functional group may be located at the end of the organic compound, may be bound in a side chain or may be within the organic compound, as in the case where the amine group connects two chains. The polyfunctional amine must contain at least two amine functional groups which are primary or secondary. Tertiary amines are not reactive with respect to the acyllactam functional groups of the compound containing N-acyllactam groups and therefore do not cause crosslinking of the polyamide block copolymers according to the present invention. However, it is known from the prior art that typical commercial mixtures of polyfunctional amines may contain a range of polyfunctional amines consisting of primary, secondary and tertiary amines. A mixture of this type will be useful in the practice of the present invention if a sufficient amount of polyfunctional amines carry at least two and more preferably at least three primary or secondary amine groups which will react with the functional acyl lactam groups and thereby cause crosslinking of the alkyne with the acyl lactam functional groups and ultimately the block polyamide copolymers.

As mentioned above, various types of multifunctional amines of different molecular weights can be used in the process of the invention, as long as they are capable of crosslinking compounds with acyl lactam functional groups and/or polyamide block copolymers. The type of multifunctional amine used can affect the physical properties of the polyamide block copolymers prepared therefrom. Preferred multifunctional amines are polyamines with a polyether or polyethyleneimine backbone. The molecular weight of the polyamines is preferably at least 500. The term molecular weight as used in the description of the invention and in the following examples means the number average molecular weight, the determination of which is known in the art. Particularly preferred polyfunctional amines are polyoxyalkylene polyamines in which the alkylene group contains 2 to 4 carbon atoms, having a molecular weight in the range of 400 to 5,000. The most preferred polyfunctional amines are polyamines, which are generally prepared by the polymerization of alkylene imines, such as ethylene imine, and by the polymerization of organic diamines, such as alkylenediamines, resulting in polyamines containing interchain secondary and tertiary amino groups.

These preferred polyamines have molecular weights in the range of 60 to 10,000. Examples of these polyamines are polyethyleneimines, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and triethylediamine. Polyetheramines can be prepared from polymers which contain functional groups reactive with di- or polyfunctional amine monomers, such that the corresponding polyfunctional amines are formed by appropriate reaction. They can be obtained by reductive amination of polyols, cyanoethylation of polyols followed by hydrogenation or by reaction of 2 equivalents of diisocyanate with all hydroxyl groups of the polyols and reaction with water. Other methods of preparing these polyfunctional amines are known in the art.

The use of polyetheramines or other polyamines with a glass transition temperature below 20°C can have a significant effect on the ductility and impact properties of the polyamide block copolymers prepared therefrom, especially if the polyamine has a relatively high molecular weight.

The effect on these properties can be so great that the molar ratio of N-acyl lactam functional compounds to polyamines can be reduced without affecting the overall properties which are determined by the elastomeric polymer segments of the acyl lactam functional compounds.

The term N-acyllactam functional group refers to a derivative of a carboxylic acid and epsiloncaprolactam. The term N-acyllactam functionality refers to the number of acyllactam groups per molecule of a compound with N-acyllactam functional groups. These compounds with acyllactam functional groups can be prepared by any method known in the art. The compound containing N-aryllactam functional groups must be formed from such a polyether elastomer that the resulting polyamide block copolymer has a tensile recovery value of at least 50 percent. Tensile recovery is determined on a dry molded polymer sample that has been stretched 50 percent relative to its original length (1) and held in that state for ten minutes before the tension is released. Tens of minutes after the tension is released, the length (l _r ) of the sample is measured. The percent tensile recovery is

1.5 1 - 1L

--— x 100.

0.5 1

In order for the elastomeric polymer to provide the above tensile recovery, it is generally required that the polyamide block copolymer contain at least 50% by weight of elastomer. However, the amount of elastomeric polymer in the polyamide block copolymers of the invention is not limited to at least 50% by weight, as both lower and higher proportions in the range of 10 to 90% by weight also provide improved properties to the polyamide polymers.

As already mentioned, the compound with N-acyl lactam functional groups is derived from elastomeric polyether triols with a molecular weight of 1,000 to 10,000, preferably 3,000 to 6,000.

One of the preferred compounds with N-acyl lactam functional groups has the following general formula:

Z - /0 - A { Q ) _b / _n in which

Q represents the residue of epsilon-caprolactam,

Z represents a segment of the polyether elastomeric polymer defined above, «

A represents a group of the formula

O

AND

C - or

or a mixture thereof and preferably a group of formula - c - R 4 c b represents an integer equal to 1, 2 or 3;

R represents a hydrocarbon group and n is an integer greater than 1, preferably greater than 2 and more preferably equal to 3.

Compounds with N-acyllactam functional groups are prepared by reacting the above-defined polyether triols with dihalides of dicarboxylic acids of aliphatic or aromatic type, such as terephthalic or isophthalic acid halide (where R represents phenylene) in the presence of an acid acceptor and subsequent reaction with epsilon-caprolactam.

The crosslinked polyamide block copolymers of the invention are prepared under conditions in which the polyfunctional amines are reacted with the acyllactam groups of the N-acyllactam-functional compounds before or simultaneously with the polymerization of caprolactam. This results in the crosslinking of the N-acyllactam-functional compounds, which, after subsequent or simultaneous polymerization of caprolactam, provide the crosslinked polyamide block copolymers. In carrying out the process of the invention, one particular type of N-acyllactam-functional compound and/or one type of polyfunctional amine, or a mixture of the above-described N-acyllactam-functional compounds and/or a mixture of polyfunctional amines, may be used.

The resulting polyamide block copolymer will typically contain at least 10% by weight of caprolactam block polymer, preferably from 10 to 90% by weight, and more preferably from 60 to 80% by weight.

The reaction between the N-acyllactam-functional compound and the polyfunctional amine is usually carried out in the presence of caprolactam and a catalyst. The reaction conditions are selected such that the reaction between the polyfunctional amine and the acylactam-functional compound predominates over the polymerization of the caprolactam. This can be achieved by maintaining the reaction temperature below the optimum temperature for polymerization of the lactam in the mixing step, for example by maintaining the temperature below about 100°C and then increasing the reaction temperature to values above about 100°C, for example in the range of 110 to 150°C, to promote polymerization of the caprolactam. In a preferred embodiment, the reaction conditions are selected such that simultaneous reaction is possible, for example by increasing the temperature to 130 to 150°C immediately after mixing the reactants.

The amount of polyfunctional amine used in the process of the invention should be sufficient to improve the tensile properties and/or tear strength of the block polyamide copolymers. The amount required will depend largely on the molecular weight and functionality of the polyamine, with lower amounts being required for high molecular weight and high functionality. The polyamine is preferably present in an amount of at least 0.02 equivalents, more preferably at least 0.2 equivalents, and even more preferably 0.3 to 0.6 equivalents of amino groups (primary plus secondary) per equivalent of N-acyl lactam groups.

The resulting bond between the polyfunctional amine and the N-acyllactam group of a compound with N-acyllactam functional groups will likely be as follows:

⁰ 9 , “ *>

Elastomeric segment /vx NH-Y-C-X-C-Y-NH X^Elastomeric segment wherein X represents a polyfunctional amine residue and the bond is formed by the amine groups of the polyfunctional amine and the carboxyl group of the lactam residue. The polyfunctional amine from which the X group is derived, as mentioned above, may have amine groups located at the terminal position of the polymer molecule, in the side chains of the polymer or incorporated into the polymer as intrapolymeric groups.

A typical block polyamide copolymer, crosslinked with lactam functional groups, which was made from a preferred compound with an N-acylpolyfunctional amine, has the following general formula

I -{C-Y-NHt A-tNH-Y-Ct 0 Z-O-fC-Y-NHt

O

AT

-LetNH-Y-Ct X •fé-Y-NHť -A ^m 4 (NH

-Y-go

0-Z

OťC-Y-NHt A(NH-Y-Č+ m ₆ m _?

-N' in which Z and A have the meaning defined above,

X represents the residue of a polyfunctional amine as defined above,

Y represents a 1,5-pentylene group, p is an integer equal to or greater than 1 and in a preferred embodiment greater than 3, m, m ₃ , m ₂ , m^, m^, m^, mg and m? are integers equal to or greater than one, anan' are integers equal to or greater than one, in a preferred embodiment equal to or greater than two and in a more preferred embodiment equal to or greater than three.

As is clear from the above formula of crosslinked block polyamide copolymers, the reaction between the elastomeric segment with N-acyl lactam functional groups and the multifunctional amine results in the formation of amide bonds (λ^ NH-Y-CO-X-CO-X-CO-Y-NHZVZ) between the functionalized elastomeric segment and the multifunctional amine.

Examples of la2

The following examples demonstrate two methods of crosslinking elastomeric segments with N-acyllactam functional groups. Example 1 shows a method according to the present invention, in which it is started from the reaction of a polyol and a bisimide (or bis-acyllactam) to form elastomeric segments with acylactam functional groups, which are then reacted with a polyfunctional amine and then with monomeric caprolactam. Example 2 demonstrates a method according to the present invention, in which it is started from an elastomeric segment with N-acyllactam functional groups, which is crosslinked with a polyfunctional amine and subsequently reacted with caprolactam. Two examples 1' and 2' were carried out using exactly the same procedure and with the same materials, but without the polyfunctional amine, in order to compare the properties between the crosslinked polyamide block copolymer according to the invention and a polyamide block copolymer that has not undergone this crosslinking.

Example

A 500 milliliter (mL) flask was charged with 117 grams (g) of ethylene oxide-terminated polyoxypropylenetriol with a molecular weight (m.w.) of approximately 4,800, 26.3 g of N-adipoyl-bis-caprolactam, 5 g of caprolactam, and 1.5 g of Flectol H (antioxidant). The mixture was heated and stirred under vacuum at 133 Pa at 125°C for 30 minutes and then cooled to 85°C.

In a second flask, 225 g of caprolactam was dried by heating under vacuum until 25 ml of the substance had been distilled off. The caprolactam was then cooled to 75°C and 15 ml of a 3 molar ethylmagnesium bromide in diethyl ether solution were added. This flask was evacuated until completely degassed and 3.7 g of polyoxypropylenediamine (approximate m.p. 230) was added.

The contents of both flasks were simultaneously injected into a two-part closed mold lined with Teflon, which was preheated to 130 ° C. The two parts of the mold were separated by a 3.2 mm thick Teflon sealing insert. The components were injected into the mold through a Kenics static mixer, 6.35x152.4 mm, using a Zenith No. 5 gear pump at a rotation frequency of 200 min ^- '''.

After five minutes, the castings were removed from the mold. The resulting polyamide block copolymer contained 40% polyether.

Example 2

The N-acyl lactam functional compound was prepared by reacting ethylene oxide-terminated polyoxypropylene triol (approx. m.w. 4800), terephthalic acid chloride, and excess caprolactam in tetrahydrofuran at 40 °C in the presence of triethylamine (acting as an acid acceptor). The molar ratio of triol to terephthalic acid chloride used to prepare this functional compound was 2:5.

134 g of the above-described compound with N-acyl lactam functional groups and 43 g of caprolactam were placed in a 500 ml flask. The mixture was heated under vacuum at a heating nest temperature of 140 °C until 25 ml of caprolactam was distilled off and then cooled to 85 °C.

In the second flask, a 0.23 molar solution of bromorabnesium prolactam was prepared by adding 15 ml of a 3 molar solution of ethylmagnesium bromide in diethyl ether to 200 g of dry caprolactam. Then 2.12 ml (2.0 g) of polyoxypropylene diamine (approximately m.w. 230) was added. A 30% equivalent of primary and secondary amino groups of the polyfunctional amine was used compared to the equivalent of N-acyllactam groups of the compound containing N-acyllactam functional groups. The contents of both cells were injected into a mold as described in Example 1. After 5 minutes, a cast of a block polyamide copolymer containing 40% polyether was removed from the mold.

Comparative examples 1' and 2'

Two comparative examples 1' and 2' were carried out using the same procedure and using the same substances (without polyfunctional amine) as described above for the corresponding examples 1 and 2.

The polyamide block copolymers which were produced in the form of castings according to Examples 1 and 2 and Comparative Examples 1' and 2' were tested for various properties, essentially according to the following methods:

Tensile strength: ASTM 638 /units are megapascals (MPa)/

Tear strength: ASTM D1004 /units are newtons per meter (N/m)/

Tensile modulus: ASTM D638 /units are megapascals (MPa)/

Elongation: ASTM D638 /units %/

The results obtained in Examples 1 and 2 and in Comparative Examples 1' and 2' are shown below in Table I. As can be seen from Table X, the properties of the polyamide block copolymers were generally improved by sieving. The only property that was negatively affected by sieving was the flexural modulus. However, for certain applications this reduction is insignificant.

Table I

Tensile properties

Strength MPa Elongation % Recovery ⁴ % Bending modulus MPa Tearing strength N/m Comparative example 1' 23,098 320 78 69,639 71,273.026 Example 1 23,167 370 78 55,160 72,673.97 Comparative example 2' 24,615 320 - 115,146 73,549.56 Example 2 25,649 330 72 92,393 78,803.1

⁴ Tensile test recovery was determined after rupture

Examples 3 to 9

Examples 3 to 9 demonstrate the use of di- and tri-functional amines for crosslinking polyamide block copolymers in accordance with the process of the invention.

A premix solution of the N-acyl lactam functional compound was prepared by dosing 1,800 g of the N-acyl lactam functional elastomer segment prepared according to Example 2 into a flask together with 18 g of the antioxidant Flectol ODP. The mixture was heated with vigorous stirring for 1 hour at 100°C under a vacuum of 133 Pa to remove all moisture. The mixture was then cooled to 75°C and divided into 200g portions for Examples 3 to 9.

A premix of a 0.18 molar solution of caprolactam magnesium bromide in caprolactam (catalytic solution) was prepared by adding 60 ml of a 3 molar solution of ethyl magnesium bromide in diethyl ether to 1,000 g of molten dried caprolactam, followed by complete degassing at a vacuum of 133 Pa. Different types of multifunctional amines were added to the catalytic solution in amounts of

of which are listed under the individual examples in Table II below. Table II Catalyst solution/amine mixture 3 Eq. of amine (*) Example No. Used amine catalytic solution (g) Amine (g) 3 HMD ¹ 112.9 1.54 25 4 HMD 137.3 2.64 33 5 HMD 109.7 2.33 37.5 6 HMD 103.8 2.41 40 7 TAN ² 118.2 1.60 25 8 TAN 146.6 2.48 30 9 TAN 163.4 2.91 32

Hexane-1,6-diamine nonantriamine □

the percentage of equivalent amino groups (total of primary and secondary amino groups) based on one equivalent of N-acyllactam functional groups in each 200 g sample of a substance containing N-acyllactam functional groups.

-AND

The solution of the compound with N-acyl lactam functional groups and the catalyst solution containing the multifunctional amine were pumped into a vertical two-part mold lined with Teflon and preheated to 130 ° C. The mold parts were separated by a Teflon insert with a thickness of 3.17 mm. The solutions were introduced into the mold through a Kenicš static mixer, 6.35x152.4 mm by two Zenith No. 5 gear pumps at a speed of 200 min ^-1 .

The proportions of the components pumped were 2.57 ml of the N-acyl lactam functional compound solution per 1 ml of the catalyst solution. Curing of the polyamide block copolymers to a hard resin was completed in each example within 30 to 60 seconds.

The resulting properties found in Examples 3 to 9 are shown below in Table III. These properties were determined as described in Examples 1 and 2.

Table III

Example Tensile strength Ductility Recovery No. MPa <%> in motion 3 8,480 300 92 4 8,756 383 86 5 11,859 407 90 6 10,894 449 88 7 7,515 317 88 8 8 136 472 85 9 6,550 364 88

⁺ Tensile recovery was determined after rupture

Examples 10 to 16

Examples 10 to 16 demonstrate the dependence of the properties of amine-crosslinked polyamide block copolymers according to the invention on different molar contents of diamines and triamines.

Each example started from a premix solution of a compound with N-acyllactam functional groups. This premix was prepared by charging 1067 g of the compound with N-acyllactam functional groups, prepared according to Example 2, 158 g of caprolactam and 0.4 g of copper acetate, monohydrate, into a 21 liter flask. The mixture was dried by distilling off 25 ml of the substance under vacuum at 140 °C. The dried solution was kept at 100 °C under vacuum until use, when the vacuum was released to nitrogen.

For each of the examples, individual batches (200 g) of catalytic solution were prepared.

Each of these catalyst batches was prepared by charging a 500 ml flask with 193 g of caprolactam plus the amine type in the amounts given in Table IV below. The catalyst solution was dried by distilling off 25 ml of the substance under vacuum under an oil pump at a temperature of 140 °C. The temperature was adjusted to 125 °C and 32 g of catalyst concentrate was dissolved in each batch. This catalyst concentrate contained 1.05 mol/kg of caprolactam magnesium bromide in caprolactam. Each of the prepared catalyst solutions contained 0.16 mol/kg of caprolactam magnesium bromide. The catalyst solutions were maintained at 100 °C under vacuum until use, when the vacuum was released to nitrogen. Table IV below gives the types and amounts of amines used and the molar percentages of amino groups to acyl lactam groups.

and

Table IV

Example Amine used Equivalents of amine ³ (») g amine 10 none 0 0 11 PEI-6 ² 30 1.17 12 PEI-6 60 2.24 13 PEI-6 90 3.41 14 PEI-6 150 5.66 15 PEI-18 ³ 60 2.24 16 PEI-18 90 3.41

The equivalent of amino groups (sum of primary and secondary amino groups) per N-acyllactam functionality of a compound with N-acyllactam functional groups at a ratio of solution of compound with N-acyllactam functional groups to catalyst solution of 1:1.

PEI-6 = poly(ethyleneimine) with a molecular weight of 600. Of the amino groups, 25% are primary, 25% secondary and 25% tertiary.

PEI-18 = poly(ethyleneimine) with a molecular weight of 1,800. Distribution of amine groups as in PEI-6.

The solution of the compound with N-acyl lactam functional groups and the catalyst solution were simultaneously injected through a Kenics static mixer, 6.35 mm, into a vertical mold measuring 203x203x3.17 mm, which was preheated to 130 °C, by two Zenith No. 5 gear pumps at a speed of 200 min ³ . The resulting casts of block polyamide copolymer contained 40% polyoxypropylene.

The above castings according to Examples 10 to 16 were subjected to the property tests listed below in Table 5 according to the test methods listed in Examples 1 and 2 with an additional flexural recovery test carried out as follows:

Bend recovery - casting bent 180° over a 12.6 mm mandrel for 30 seconds. Recovery values were determined after 5 minutes. Units are %.

The results of these tests are shown in Table 5 below.

Table V

No. Amine Equiv. % Tensile strength MPa Elongation % Modulus of elasticity in tension MPa v Tearing strength N/m Bending recovery % 10 0 33,440 340 374,399 113,826.7 79 11 30 39,370 400 499,198 140,094.4 73 12 60 40,474 380 521,262 145,347.94 73 13 90 35,440 320 462,654 134,840.86 74 14 150 36,199 330 331,649 134,840.86 73 15 60 38,956 350 523,330 141,845.58 72 16 90 37,646 340 484,718 136,592.04 73

The elongation, tensile strength, tensile modulus and tear strength improved over the amino equivalent percentage range of about 30 to about 60%. Above 60%, these properties deteriorated but were still better than Example 10. Flexural recovery deteriorated with crosslinking, but this property is not critical for certain applications. The overall property profile improved.

Examples 17 to 20

Examples 17 to 20 demonstrate the properties of block polyamide copolymers crosslinked with polyethertriamine according to the invention, wherein the amount of compound with N-acyllactam functional groups was reduced according to the amount of polyethertriamine used. The elastomeric properties of the polyetheramine parts obtained compensated for the reduced amount of compound with N-acyllactam functional groups used in the production of the block polyamide copolymers.

The N-acyllactam functional compound was prepared as described in Example 2. Batches of the N-acyllactam functional compound in caprolactam solution were prepared for Examples 17 to 20. The corresponding amounts of N-acyllactam functional compound and caprolactam used for the solution in each example are shown in Table VI below.

Table VI

Example Compound with N-acyllactam Caprolactam ³ groups (g) (g)

17 132 43 18 124 51 19 131 44 20 i) 120 55

¹ The caprolactam batch includes an additional 25 g for distillation to dry the solution. The batch also includes 0.06% by weight of magnesium acetate, hydrate (antioxidant).

The catalyst solution in each of these examples was prepared as described in Examples 10 to 16. Each solution contained a final concentration of 0.16 moles of caprolactam magnesium bromide per kg of caprolactam solution. A polyfunctional amine was added to the catalyst solution, the type, amount, and percentage of equivalent of primary and secondary amino groups based on the equivalent of N-acyl lactam groups (amine equivalence) being given in Table VII below for each example.

Table VII

Example g caprolactam ³ Used amine Amine Equivalence % g amine g cat. of concentrate 17 191 T-403 ² 20 1.8 32 18 185 T-403 100 8.1 32 19 191 T-3000 ³ 4 2.5 32 20 176 T-3000 30 17.2 32

caprolactam includes 25 g extra for distillation o polyoxypropylenetriamine, approximate molecular weight 400 (Jeffamine T403) ³ polyoxypropylenetriamine, approximate molecular weight 300 (Jeffamine T-3000).

In all examples, the properties listed in Table VIII were tested according to the test methods previously described. The test results are summarized below for each example, along with the properties of Example 10, which are listed again for comparison.

Table VIII

Ex. Amine Equiv. % Tensile strength MPa Elongation % Modulus of elasticity in tension MPa Tearing strength N/m Bending recovery % 10 0 33,441 340 374,398 115,577.88 79 17 20 37,026 390 509,540 136,592.04 73 18 30 40,680 460 448,864 138,343.22 74 19 4 41,094 450 415,768 143,596.76 73 20 30 33,096 350 386,809 136,592.04 72

It is evident from the results shown in Table VIII that the block polyamide copolymers that have been crosslinked show significant improvements in properties. The above results also document the significant improvements obtained with the use of polyfunctional amines when the functionality of the amine is at least three (based on primary and secondary amino groups).

While the preferred embodiments have been described in the above examples, modifications and changes may be made thereto without departing from the scope of the invention. Accordingly, the foregoing description is intended to be illustrative only and not restrictive of the invention.

SUBJECT OF THE INVENTION

Claims (4)

OBJECT OF THE INVENTION A process for the preparation of a block polyamide copolymer, comprising mixing epsilon-caprolactam (I), a compound (II) containing N-acyllactam functional groups selected from the group consisting of polyethertriol adducts having a molecular weight of 1,000 to 10,000, preferably 3 000 to 6000 with an aliphatic or aromatic dicarboxylic acid dihalide and epsilon-caprolactam, at least one multifunctional amine (III) having a molecular weight of 60 to 10,000, preferably up to 6,000, selected from the group consisting of aliphatic monomeric polyamines and aliphatic polymeric polyamines with polyether or a polyalkyleneimine backbone, the functional of which comprises at least two primary and / or secondary amino groups, wherein the amount of the multifunctional amine (III) is at least 0.02 equivalent to the sum of the primary and secondary amino groups; based on the equivalent of the N-acyllactam groups contained in compound (II), and the catalyst (IV) of the anionic polymerization of lactams, the mixing being carried out by mixing compound (II) with N-acyllactam groups with a portion of caprolactam (I) and the amine (III) and the catalyst (IV) with the remainder of caprolactam (I), whereupon the two masterbatches are mixed together. 2. A process according to claim 1, wherein at least 0.2, preferably 0.3 to 0.6 equivalents of the sum of the primary and secondary amino groups of the amine (III) is used per equivalent of the N-acyl lactam functional groups of compound (II). . 3. The process of claims 1 and 2, wherein the mixing of the masterbatch, wherein the compound (II) is reacted with the N-acyllactam groups with the multifunctional amine (III), is carried out at a temperature below 110 ° C. the reaction mixture is polymerized at 110-150 ° C. 4. The process according to claim 1, wherein the reaction of compound (II) with the N-acyl lactam groups with the multifunctional amine (III) and the polymerization of caprolactam (I) are carried out simultaneously, mixing the premix and maintaining the resulting reaction mixture at 130. to 150 ° C. Severography, n. P., MOST