DE1941228A1 - Polymer mixtures - Google Patents

Description

DR. W. SCHALK DIPL.-ING. P.WIRTH · Dl P L. -1 NC. G. DAN N EN BERG DR-V-SCHMIED-KOWARZIK DR. P. WEINHOLD DR. D. GUDEL

6 FRANKFURT AM MAIN

GR. ESCHENHEIMER «TRASSE 39 QY / KV

RC-1132-M28

Dart Industries Inc. 8 ^ -80 Beverly Boulevard Los Angeles Ca., 90 05 ^ / üSA

Polymerisatm ischun ^ en

The present invention relates to the reinforcement of thermoplastic I.

Resins, especially the reinforcement of nylon resin of the filled or unreinforced type or the unmodified resin by mixing with reinforcing agents to improve certain physical properties.

Nylon, the general name for certain polyamide resins, is primary available in about ^ to 6 main types, such as nylon 6/6, nylon 6, Nylon 6/10, nylon 11 and to some extent nylons 7, 8, 9 and 12. These

Resins are / produced by condensation of a diamine with an adipic acid, such as nylon 6/6 and nylon 6/10 (e.g. the reaction of hexamethylene diamine and adipic acid results in polyhexamethylene adipamide = nylon 6/6) ,

while others are made by polymerizing amino acids or derivatives, such as caprolactam (nylon 6). Similarly, nylon 11 was made by polymerizing 11-aminoundecanoic acid. For many years nylon resins have been used for a variety of purposes such as textiles and molding resins. Although the nylon resins generally known, for example Zähigk "ince and have stiffness (the resistance is a function of molecular weight and crystalline structure) _(could Izod Kerbschlagfeetigkeit certainly be improved; in fact, many

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Attempts have been made to make such improved nylon resins been. So are some published notched Izod impact strength values for Nylon 6/6, nylon 6 and nylon 6/10 4> 89 cmkg / cm, these values according to ASTM D-256 can be determined. From these values in the literature, according to the invention have been substantially confirmed, it can be seen that this is a property which can undoubtedly be improved.

The aim of the present invention is therefore to produce nylon preparations with improved physical properties.

Another goal is the production of a nylon preparation with improved Izod impact resistance by simply mixing.

The novel preparation according to the invention comprises a mixture of nylon in amounts of 50-95% by weight, with the remainder of 5-50% by weight consisting of an ionic copolymer. The ionic copolymers can be prepared by neutralizing at least 10 % of the acid groups in the ionic copolymers with metal ions. They are prepared by reaction of a d-olefin of the formula RCH = CH is _0, in which R is H or an alkyl group having 1-8 carbon atoms, with 1-25 mol # d a, ß-äthylenischfangesättigten carboxylic acid.

According to the invention, any nylon can be mixed with the ionic copolymers can be used in the proportions given above to improve the impact properties of the nylon. It is especially the peculiar ones nylon 6, 6/6 and 6/10 have been improved as shown in the following examples. Nylon resins are commercially available and are used in

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Manufactured by great Finns around the world. Particularly suitable types of nylon according to the invention are available under the trade names "Zytel", "Xylon" etc in trade; their impact properties can be changed by mixing with ionic copolymers are significantly improved.

The ionic copolymers which are suitable according to the invention as impact modifiers are compatible with the nylon; the method of making the blends is by melt blending the resins in any suitable apparatus. The ionic copolymers are relatively new, but can easily be prepared by known processes; see. eg, US Patent 3264 272. i

An ionic copolymer is used as the inventive component that modifies the impact properties and is composed of: a "fl (-olefin of the general formula RCH = CH _2. In which R stands for hydrogen or an alkyl radical with 1-8 carbon atoms, the olefin content of this copolymer at least 50 Mol- #, based on the copolymer, and a (, ß-ethylenically unsaturated carboxylic acid, the acid monomer content of the copolymer 1-25 Mol-5 &, based on the copolymer, and the copolymer has a melt index between 0.5 and about ** 0 and uniformly dispersed in the copolymer a metal ion with '

an ionized valence of 1 to 3, where at least 10 $ (preferably 30 %) of the monovalent carboxylic acid copolymer is neutralized by this metal ion and is present in the ionic state. The ^ olefins used in the copolymer are, for example, ethylene, propylene, butene-1, pentene-1, hexene-1, heptene-1, 3-methylbutene-1, 4-methylpentene-1, etc. The concentration of the polymerize d. -Olefins in the copolymer is at least 50 Mol- #, preferably more than 80

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The second component of the ionic copolymer is derived from a ' dl »ß-Ä thy le nisci / unsaturated carboxylic acid, preferably with 3-8 carbon atoms. Such monomers are, for example, acrylic acid ». Methacrylic acid, ethacrylic acid, itaconic acid, maleic acid, fumaric acid, Manchester of these dicarboxylic acid, such as methyl hydrogen maleate, methyl hydrogen fumarate, ethyl hydrogen fumarate and maleic anhydride. Although maleic anhydride is not regarded as a carboxylic acid since it does not have a hydrogen atom bonded to the carboxyl groups, it can be regarded as an acid because of its chemical reactivity, which is that of an acid. Other odß-mono-ethylenically unsaturated anhydrides of carboxylic acids can also be used.

The base copolymers which are used to form the ionic copolymers according to the invention can be prepared in various ways. For example, the copolymers can be obtained by copolymerizing a mixture of the olefin and the carboxylic acid monomer. This process is preferred for the copolymers of ethylene used in the process according to the invention. These processes for the production of ethylene / carboxylic acid copolymers are described in the literature. In a preferred process, a mixture of the two monomers is placed in a polymerization zone, such as a pipe or a tube at high pressure, ie 50-3000 atm., And a high temperature of 150-30O ⁰ C. held autoclave together with a free radical-forming polymerization initiator, such as a peroxide, introduced.

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The formation of the. ionic copolymers suitable as plastics The copolymers used are preferably of high molecular weight, as described in US Pat. No. 3,355,319 and the British Patent specification 1 011 981, the corresponding passages of which are hereby incorporated into the present application, is specified in detail. The mole

The molecular weight of the copolymers suitable as base resins is most appropriately defined by the melt index, which is a measure of the viscosity (cf. the description in ASTM D-1238-57T) _O The melt index of the sand used to form the ionic copolymers that are suitable as plastics Iiisehpolymerisate preferably lies between 0.1-1000 g / 10 min, preferably between 1.0-100 g / 10 min _e

The preferred master copolymers of the present invention, however, are by direct copolymerization of ethylene with a monocarboxylic acid comonomers obtain.

The ionic copolymers according to the invention are made by reacting the Copolymers with ionizable metal compounds that give an ionic attraction obtained.

This ionic attraction results in the formation of a network, which in the solid *

Condition occurs. In the molten state and under the shear forces that occur during the production of the melt, the ionic crosslinks of these polymers are broken, however, and the polymers show processability the melt, which is practically the same as that of the base polymer. When the melt cools down and when it is not used during manufacture occurring shear forces are the networks due to their

Q Q 9 8 0 8/1 7 7 Q

ionic nature formed again, and the solidified copolymer shows again the properties of a cross-linked material.

The change in properties due to the reaction with the metal, ie a "neutralization" of the Qundmischpolymerisates in the ionic copolymer, is significantly influenced by the degree of neutralization and therefore the number of ionic crosslinks and the type of crosslinking that occurs. Although the improvement in solid state properties is obtained even with a small percentage of neutralized acid groups, a marked improvement becomes only neutralization. from $ 5 »preferably $ 10, established acid groups. In general, it has been found that copolymers with molecular weights, measured as a melt index of 1-5 g / 10 min and a monocarboxylic acid concentration of 5-10 %, after neutralization of 50-80 %, show optimum properties in the solid state. The degree of neutralization can be reduced if the molecular weight of the base copolymer increases or if the acid content of the base copolymer is increased without there being any significant change in the properties in the solid state.

The metal ions suitable for forming the ionic copolymers are is described in more detail in U.S. Patent 3,355,32-9 which also describes the manufacture the ionic copolymers teaches. The metal ions can be divided into two Categories are divided into metal ions without complex formation and metal ions with complete formation. / For metal ions without complex formation, the corresponds to Valence of the ion of the valence of the metal. ^ These metal ions are made up of the commonly known and used metal salts containing the metal ions with complex formation are those in which the metal is attached to more than one species is bound by salt groups, of which at least one is ionized and at least one is not ionized. Since the formation of the ionic copolymers

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e-—

- 7 only requires an ionized valence state, it can be seen that.

such metal ions with complex formation are also suitable sand »

The metal ions without complex formation that are used to produce the ionic copolymers suitable sand, include for the ö (-> olefin / monocarboxylic acid copolymers mono-, di- and trivalent ions of metals in groups I, II, III, IV-A and VII of the Periodic Table of the Elements (see "Handbook of Chemistry and Physics ", Chemical Rubber Publishing Com-. 3?" ed., page 392). Monovalent metal ions without complexing the metals in the specified Groups are also used to form the ionic copolymers with copolymers of olefins and ethylenically unsaturated dicarbon

+ + + + suitable for acids. Suitable monovalent metal ions are Na, K, Li, Cs,

+ + + 24 2+ 24 *

Ag, Hg and Cu. Common divalent metal ions are Be, Mg, Ca.

Sr ²⁺ , Ba ²⁺ , € u ²⁺ , Cd ²⁺ , ¹ Hg ²⁺ , Sh ²⁺ , Pb ²⁺ , Fe ²⁺ , Co ²⁺ , Ni ²⁺ and Zn ²⁺ . Suitable trivalent metal ions are Al, Sc ^, Fe * ^ and Y.

The amount of ions used or the degree of neutralization will vary with the degree of change in properties in the solid state desired and the degree of change in melt property desired. Usually the concentration of the metal ions should be at least such that the metal ion neutralizes at least 10 pounds of the carboxylic acid groups in order to achieve a noticeable change in the properties. As mentioned above, the degree of neutralization for optimal properties varies with the acid concentration and the molecular weight of the interpolymer. However, it is usually expedient to neutralize at least 30% of the acid groups. The degree of neutralization can be measured in various ways, such as by IR analysis, whereby the degree of neutralization can be calculated from the changes in the absorption bands. Another method consists in titrating a solution of the ionic copolymer with a strong base. In general

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mine the added metal ion reacts stoichiometrically with the carboxylic acid in the polymer up to neutralizations of 90 % . To AEEN neutralization to terminate, small excesses of crosslinking agent are necessary. However, a large excess of crosslinking agent does not further contribute to the properties of the ionic copolymer, since after ionic crosslinking of all carboxylic acid groups no further crosslinks are formed.

The ionic copolymer is crosslinked by adding it a metal compound to the base copolymer. The metal compound used must have at least one valency equivalent to that in water practically ionized group is saturated.

According to US Pat. No. 3,355,319, the crosslinking takes place under conditions a homogeneous, uniform distribution of the crosslinking agent in the base copolymer allow. No particular reaction condition is critical except that the condition requires removal of the hydrogen salt radical reaction product should allow, which is preferably done by volatilization. Since the homogeneous distribution of the crosslinking agent and the necessary volatilization of the hydrogen-salt radical reaction product Difficult at room temperature will generally be elevated temperatures applied. The networking takes place in particular either by melting of the polymer with the crosslinking metal compound, which is preferably is used in solution, or by adding the crosslinking agent, directly or in solution, to form a solution of the basic copolymer, whereupon, after the reaction, the polymer obtained is precipitated and separated off will. Of these methods, the first is essential because of its alien nature Simplicity preferred. It goes without saying, however, that this is applied in detail Procedure is not critical as long as it meets the special requirements above. The course of neutralization, i.e. that

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Degree to which the metal ion is ionically crosslinked with the carboxylate ion and the carboxylate hydrogen reacts with the anion of the metal compound and has been removed can easily be measured by IR spectroscopy of the non-ionized and ionized carboxylate groups can be followed.

In the above patent (USP 3,355,319) there are sufficient examples for the production of ionic copolymers} and commercially available ionic copolymers are sold as "Surljm ^11" by duPont de Nemours & Co.

The preparations according to the invention can be prepared by using nylon, λ

ionic copolymer and other filler components, e.g. by melting in a common device, such as a Banbury mixer, etc., together mixes a uniform mixture. The components can also be dry together are mixed, whereupon a melt is produced by extrusion or injection molding. In the injection molding of dry mixtures should be a pre-plasticization in a screw device or another Method that achieves good mixing can be used.

The ionic copolymer component of the preparation according to the invention is prepared by copolymerizing the g ( -olefin and the carboxylic acid, i

preferably according to the method of British patent specification 9 ^ 3 380 »which results in a random distribution of the acid groups in the copolymer chain. The ionic copolymer acts in the solid state, as if it were crosslinked, and in the molten state, as if it were not crosslinked. As stated, the preferred neutralization range is between 30-100% by weight of the acid groups present. Since polyvalent, basic salt-forming metal ions can be used, up to 150 $ of the amount of such a metal ion which is theoretically required for a 100% neutralization can be used

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- ίο -

will. The ionic copolymers and their preparation are described in more detail in Canadian patents 67b 595 and 713 63I.

In the preferred embodiment of the present invention, the ionic copolymer and nylon mixed in the melt; The ionic copolymer is used in amounts of 10-30% by weight, preferably 15-25 Weight .- ^, of the final preparation, which in the simplest case only consists of the ionic copolymer and nylon is used. Where other inert fillers such as glass fiber, asbestos, metal sulfides, etc., are used, these are α for calculating the total amount of ionic mixed poly morisates excluded from the final weight of the preparation in the preparation, i.e. the percentage always relates to the two components. Where the nylon contains glass fibers, the amount incorporated is between 5-60% by weight, preferably 15-40 wt. #, Glass fibers based on the nylon. The nylon resins can also be used with glass fibers and molybdenum disulfide or "Teflon" (polytetrafluoroethylene) in amounts between 5-40 # of the latter compounds in the glass-reinforced Nylon or each alone can be reinforced without the glass reinforcement. Also, they can be fortified with asbestos in amounts of $ 5-50.

^ The most effective improvement in the impact properties of nylon or polyamide. material surprisingly arose from the use of ionorae using divalent metals as neutralization preparations.

In particular, it was found that ionic copolymers with the metals zinc or calcium gave exceptional results, although ionic copolymers with monovalent metals, such as sodium, also gave an improvement. The ionic copolymers particularly suitable according to the invention were the materials "Surlyn A Type 1555" (Na-Ion) and "Surlyn A Type 1557" (Zn-Ion) at concentrations of 20-25 %,

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- 11 -

The following examples were used to measure the physical properties the following ASTM procedures were used:

Tensile strenght; kg / cm D-638

Strain; # D 638

Flexural strength; kg / cm D 790

Heat set temperature; ⁰ C. D 6k8

Izod impact strength; cmkg / cm D 256

Water absorption j # D 570

spec. Weight D 792

The following examples illustrate the present invention without it to restrict.

• i

In Table 2 is the effect on tensile strength, Izod impact strength and Heat resistance temperature after mixing the nylon with ionic copolymers shown. It is emphasized that increasing the Izod impact value for the nylon was unexpected because blends of nylon with other high impact plastics, such as polyethylene, are not nylon resins per se with high impact strength compared to the ionic copolymers containing materials. This is shown in Table 1 through comparisons of the results from mixing the specified polyolefins and copolymers of the given polyolefins and from mixing ionic Copolymers.

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- 12 Table 1

Tensile strength * Izod impact strength kg / ent cmkg / cm,.

high-density polyethylene, crystalline polypropylene
Ethylene / acrylonitrile copolymer

Ethylene / vinyl acetate mixed polymer ("Elvax" from DuPont)
"Surlyn A 1555"

"Suriyn A 155?"

1:90 weight ratio made of high-gray, dense polyethylene and nylon 6/6
10:90 wt. -Mixture of ethylene / vinyl acetate copolymer and nylon 6/6

20:80 weight mixture of ethylene / vinyl acetate copolymer and nylon 6/6

25:75 weight blend of crystalline polypropylene and nylon 6/6

20:80 wt. Blend of "Surlyn A 1557" and nylon 6/6

280 322

196 280 273

707 735

602

539 616

25:75 mix off
Nylon 6/6

A 1557 "and

81.5

does not break

59.7 ^ .65.2

6.52

3.26 15.2 , 19.0

The above table shows the unpredictability of the results according to the invention. In this case, the specified polyolefins and the copolymers were added to nylon 6/6 in different percentages from $ 5 to $ 20, but there was no noticeable improvement in the impact strength. strength. In contrast, it is noted that the ionic copolymer according to the invention achieved a very high improvement in the Izod impact strength. example 1

A number of nylon resins were melt blended with "Surlyn A 1557", by keeping the specified mixed polymer quantities at about 204-206 C, which depended on the type of nylon and the amount of "Surtyn" into an extruder introduced and available as test sticks. The results are in the table 2 listed.

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nylon ionic. - 13 - , Izod impact strength. Heat resistance kind: $ Table 2 cmkg / cDi temperature; C. Verse. 6/6 0 Tensile strength 4.89 82 No. 6/6 5 kg / cm ^ 6.52 78 1 6/6 10 826 8.69 77 CM 6/6 15th 756 9.23 - 3 6/6 20th 700 15.2 - 4th 6/6 25th 687 i9, o; 71 5 6th 25th 620 17.9 61 6th 6/10. 25th 630 17.4 6i. "; ' 7th "Surlyn A type 1557 " 476 8th i s ρ i el 2 490 + = (Zn ion) B e

Table 3 shows blends of nylon 6/6 with "Surlyn A Type 1555" (Na-Ion), prepared according to Example 1; the improvements in Izod impact properties were not as marked as when the metal crosslinking agent was a divalent salt.

Table 3

Vers. Nylon-ionic tensile strength. Izoci impact strength Heat resistance no. art mixed polymer kg / cm2 cmkg / cm temperature; ⁰ C.

9 ⁺ 6/6 5 721 7.6 82

1O ⁺ 6/6 10 644 8.69 78

11 6/6 21 567 10.3 67

+ = the dry mixture was immediately deformed in screw devices.

Example -3

Table 4 shows further mixtures according to the invention with diapered, inert ones Glass fibers made by incorporating the glass into a molten one Mixture of nylon and "Surlyn A 1557" ·

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Table 4-

Attempt no.

6/6

6/6

6/10 6/10

Nylon art

Bath composition

$ Nylon

% "Surlyn»

$> added glass

Tensile strenght; kg / cm ο olzod impact strength; cmkg / cm

O ₀ heat set temperature at gkg / cm ² ; ⁰ C.

~ "* The connections from Trials 1, 3 and 5 were commercially available, glass-reinforced nylons with the
ο trade name "NYLAPIL".

100 75 100 75 100 75 0 25th 0 25th 0 25th 30th 30th 30th 30th 3Q 30th 1400 1001 1470 1127 1330 1106 13.6 25.5 16.3 29.3 18.5 28.8 257 237 216 ■ ' 204- 216 193

The above data adequately show that resulting from the incorporation according to the invention Ionic copolymers achieved improvements. The one with glass Filled nylons can also contain other additives such as lubricants, e.g. molybdenum disulphide, and polytetrafluoroethylene or just molybdenum disulphide or polytetrafluoroethylene without glass. They can also contain asbestos instead of glass. ·

The typical values for nylon 6/6 for tensile strength are 826 kg / cm ι Izod impact strength 4.9 cm kg / cm and heat resistance temperature 66 C; for nylon 6 the tensile strength is 630 kg / cm, the izod impact strength is 4.9 cmkg / cm and the heat resistance temperature is 50 ° Ci and for nylon 6 / I0 the tensile strength is 595 kg / cm, the izod impact strength is 4.9 cmkg / cm and heat resistance temperature 57 ° C

OQ98O'8 / 1770

Claims (1)

Claims , O mixture »consisting of an intimate mixture of nylon and an ionic copolymer in a nylon amount of 50-95 wt .- ^, where the The remainder of 5-50 wt .- # consists of the ionic copolymer. , 2. Mixture according to claim 1, characterized in that the nylon is nylon 6, nylon 6/6, or nylon 6/10. . 3 · - Mixture according to claims .1 and 2, characterized in that it consists of 70-90 wt .- # nylon and 10-30 wt .- # of an ionic copolymer consists. Ί · .- Mixture according to claim 1 to 3 »characterized in that ^ that the ionic Copolymer has been neutralized by a divalent metal salt, preferably zinc. 5. Mixture according to claims 1 to 4, consisting of a mixture of nylon in an amount of 50-95% by weight and the remaining 5-50% by weight of an ionic copolymer produced by neutralizing at least 10% of the acid groups of a copolymer with MefaüLlionen, the copolymer being derived from units of an o (-01ef ins of the formula RQl = CH ₂ , in which R is hydrogen or an alkyl group with 1-8 carbon atoms, and 1.0-25 mol # units of one oi-ß-ethylenically unsaturated carboxylic acid. 6.- Mixture according to claim 5, characterized in that the g (-β-ethylenically unsaturated carboxylic acid is acrylic, methacrylic, maleic, fumaric acid, a monoalkylaaleate ester, monoalkyl fumarate ester, maleic anhydride or fumaric anhydride. 009808/1770 • - 17 -. · 7 - mixture of claim 1 to 6, consisting of an intimate mixture aas nylon and an ionic copolymer nylon in a amount between 50-95 wt .- $, and the remaining 5-50 wt -j> of the ionic interpolymer "nobel the nylon resin. is reinforced with $ 5-60 fiberglass. 8, - Mixture according to claim 1 to 6, consisting of an intimate mixture of nylon and an ionic copolymer in an amount of nylon between 50-95 wt .- # and the remaining 5-50 wt .- # of the ionic copolymer, the nylon resin with 15- ^ 0 # glass fibers and 5-30 % molybdenum disulfide is reinforced. '" 9. Mixture according to claim 8, characterized in that instead of molybdenum disulfide, polytetrafluoroethylene is used. 10.- Mixture according to claim 1 to 6, consisting of an intimate mixture of nylon and an ionic copolymer in an amount of nylon between 50-95 wt .- # and the remaining 5-50 $ of the ionic copolymer, the nylon resin with 5- $ 30 molybdenum disulfide is filled. 11 ..- mixture according to claim 10, characterized in that instead of molybdenum disulfide polytetrafluoroethylene is used. "'i 12. ~ Mixture according to claim 1 to: &, consisting of an intimate mixture of nylon and an ionic copolymer in <an amount of nylon of 50-95 wt. <- # and the remaining 5-50 % of the ionic copolymer, the nylon resin with 5-50 wt. 5δ asbestos is reinforced. . The patent attorney: 009808/177 0