Silane-vulcanised thermoplastic elastomers

Description of the invention

The present invention relates to a thermoplastic vulcanizate composition comprising thermoplastic silane vulcanized elastomers and a method of making a thermoplastic vulcanizate.

Thermoplastic elastomers (TPE) have the performance characteristics of conventional thermosetting rubbers, but can be melted repeatedly and therefore can be processed on thermoplastics processing equipment. Most TPEs consist of two phases: one containing a rubber material (elastomer) which is insoluble in the other phase, which is a flowable thermoplastic material. The rubber material acts as the dispersed phase and the thermoplastic material as the continuous phase.

Although vulcanization of the rubber in TPE is not generally necessary, the use of vulcanization techniques is desirable for better chemical resistance, better mechanical properties, or better control of phase separation. Such TPE blends that use a vulcanization reaction and method to effect phase separation into discrete domains are called thermoplastic vulcanizates (TPV). Vulcanization of only the rubber phase is essential for maintaining their thermoplastic character. For a detailed detailed description and review of TPV technology, see, for example, S. Abdou-Sabet, RC Puydak, and CP Rader in Rubber Chemistry and Technology, Vol. 69, pp. 476-493, 1996.

Moreover, it has been found that the mechanical properties of TPV improve with increasing degree of vulcanization of the rubber phase and with the opposite particle size of the rubber domains. Dynamic vulcanization (which consists in very thorough mixing of the mix of miscible polymers and then adding to this mixture with simultaneous mixing of the vulcanization system) is used to produce a highly dispersed and highly vulcanized rubber phase from a homogeneous mixture of polymers.

For thermodynamic and hydrodynamic reasons, it is preferable that the viscosity of the polymer increases during vulcanization, since the particles tend to agglomerate during phase separation. Moreover, if phase inversion may occur during vulcanization, it has a beneficial effect on the formation of fibrous rubber domains which impart the desired mechanical properties. However, it has been found advantageous to select a vulcanization mechanism that only partially encompasses the thermoplastic phase and not until the thermoplastic nature of the TPV has disappeared, but only to obtain better adhesion and miscibility of the polymers.

The choice of vulcanization method and the chemicals used therein depends on the process requirements, for example the reaction rate at processing temperature; miscibility with elastomer; side reactions with the thermoplastic; yield (number of cross-links produced by each molecule of vulcanizing substance); no adverse reactions; toxicity and hazards; color and smell.

An example of such TPVs is the EPDM / PP rubber disclosed in US Patent No. 3,130,535. EPDM is mixed very thoroughly with PP in a closed mixer and the peroxide is introduced to cure the EPDM. Excess peroxide and / or too high processing temperature and / or excessively reactive polymers cause degradation of the PP phase and / or its premature vulcanization. In contrast, an insufficient amount of peroxide and / or a too low processing temperature and / or a weakly reactive EPDM result in insufficient vulcanization.

The disadvantage of TPV based on polyolefins is the inability to paint them without preliminary surface preparation. It is disclosed in US Patent No. 4,311,628 that other crosslinkers can be used, for example, dimethyloloctylphenol resin and sulfur. Better mechanical properties can be obtained, but the drawback of both of these systems is too strong a smell and / or yellowing of the materials obtained, and the difficulty of controlling the sulfur vulcanization reaction.

EP 0324434 discloses the use of silane grafted polymers in the thermoplastic phase. After mixing, the material is molded and allowed to react with atmospheric moisture. In this way, a more elastomeric material can be obtained after water curing. However, such a water-vulcanized article does not contain a thermoplastic elastomer and cannot be recycled. To remove this limitation, EP 0409542 discloses the blending of EPR (ethylene propylene rubber) or EPDM with a crystalline thermoplastic ethylene-propylene copolymer, with an organofunctional silane and a free radical donor. The silane is grafted onto the resin with a free-radical donor, and vulcanization occurs by reacting the silane with water.

PL 196 185 B1

A refinement of the above methods is disclosed in EP 0510559, in which EPR or EPDM was first grafted, then mixed with thermoplastic PP and a water-containing vulcanization additive. The same process has been disclosed using ultra-low-density polyethylene or ultra-low-density polyethylene (VLDPE or ULDPE) in order to reduce the cost of raw materials and lower the mixing temperature. See also German Patent No. 4402943. It is also proposed to simultaneously introduce a dry mixture of the PP component and the PE component with the silane and the free radical generator, and in the next step to introduce water and prepare a condensation catalyst. However, introducing water into the extruder at a temperature well above the boiling point of water is very difficult. Moreover, the amount of water is so small that it is necessary to use complicated equipment which does not correspond to the subject matter of the invention.

U.S. Patent 4,146,529 to Yamamoto et al. Discloses the reaction of acid-modified polypropylene with an amino- or epoxysilane, but the purpose of the reaction is to use alkoxy groups to bind them to the fillers and react with ungrafted acid anhydride to reduce the amount of odorless and non-volatile products produced. and not for vulcanization by reacting alkoxy functional groups with one another. The purpose of these blends is to couple mineral fillers, not to produce thermoplastic vulcanizates, or, in the absence of a filler, to promote the reaction of an amino- or epoxysilane with a free, volatile, ungrafted acid or acid anhydride.

German Patent Specification No. 196 29 429 discloses, inter alia, the use of premixtures containing vinylsilanes, aminosilane and unsaturated acid anhydrides, which are suitably used for the vulcanization of polyolefins.

Figures 1-5 show the physical properties of the TPVs produced in the examples.

The present invention relates to the preparation of TPV using polymers, carboxylic acid anhydride and an aminosilane.

The object of the present invention is to produce new TPVs with a wide range of properties, cheap TPV, TPV for painting, to enable the production of TPV in conventional mixers without the need for additional expensive equipment, to avoid the use of large amounts of vulcanization agents (e.g. organometallic compounds or peroxides) in the production of TPV and production of durable TPV mixtures.

According to the invention, a thermoplastic vulcanizate composition having a gel content of 10 to 50% by weight, comprising a dispersed rubber phase and a continuous thermoplastic phase, is characterized in that the dispersed rubber phase comprises the crosslinked reaction product (a) of a first polymer selected from the group consisting of ethylene-α-copolymers. olefins, especially ethylene propylene copolymer, ethylene propylene diene terpolymer, butyl rubber, natural rubber, chlorinated polyethylene, silicone rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, ethylene-vinyl acetate copolymer, ethylene-butyl acrylate copolymer, ethylene-methacrylate copolymer, ethylene-ethyl acrylate copolymer, low-density ethylene-olefin copolymer, a-olefin copolymer ultra-low-density polyethylene, high-density polyethylene and nitrile rubber;

(b) a carboxylic acid anhydride grafted onto or copolymerized with the first polymer; and (c) an aminosilane; and the thermoplastic continuous phase is selected from the group consisting of polypropylene, polyethylene, especially high-density polyethylene, polystyrene, acrylonitrile butadiene styrene terpolymer, styrene acrylonitrile copolymer, poly (methyl methacrylate), thermoplastic polyesters, polyethylene terephthalate, polyethylene terephthalate, polyethylene terephthalate .

Preferably, the acid anhydride is grafted onto the polymer in the presence of a free radical donor.

Preferably the acid anhydride is a comonomer in the first polymer.

Preferably the aminosilane comprises a primary amine.

Preferably the composition comprises at least two different aminosilanes.

Preferably the composition comprises at least two different acid anhydrides.

The method of producing a thermoplastic vulcanizate according to the invention is characterized in that it comprises

(A) mixing the first polymer grafted onto or copolymerized with a carboxylic acid anhydride with a second polymer, the first polymer being selected from the group consisting of ethylene-alpha-olefin copolymers, especially ethylene propylene copolymer, ethylene propylene terpolymer and diene, butyl rubber (BR); natural rubber, chlorinated polyethylene, silicone rubber; isoprene rubber, butadiene rubber, styrene-butadiene rubber, ethylene-vinyl acetate copolymer, ethylene-butyl acrylate copolymer, ethylene-methacrylate copolymer, ethylene-ethyl acrylate copolymer, copolymers of ethylene with low-density polyolefylenes, very linear low-density polyethylene, and nitrile rubber, and the second polymer is selected from the group consisting of polypropylene, polyethylene, especially high-density polyethylene, polystyrene, acrylonitrile styrene butadiene terpolymer (ABS); styrene acrylonitrile copolymer, poly (methyl methacrylate), thermoplastic polyesters, polyethylene terephthalate, polybutylene terephthalate, and polycarbonate;

(b) reacting the mixture of (a) with an amino silane; and (c) vulcanizing the product of step (b) to form a thermoplastic vulcanizate.

Preferably, the first polymer is grafted onto the unsaturated carboxylic acid anhydride in the presence of a free radical donor.

Preferably, the two polymers are mixed with each other prior to acid anhydride grafting.

Preferably, the first polymer is an unsaturated carboxylic acid anhydride copolymer.

Preferably, the two polymers are mixed together after the first polymer has been grafted onto the carboxylic acid anhydride.

Preferably, the two polymers are reacted and mixed together in one step in a mixer-type extruder.

TPVs are a mixture of:

(a) the first polymer (rubber phase);

(b) a crystalline or partially crystalline thermoplastic polymer (thermoplastic phase);

(c) a carboxylic acid anhydride incorporated as a comonomer into component (a) or grafted onto component (a); and (d) an aminosilane;

which undergoes vulcanization.

A. Polymers

Suitable components of the rubbery polyolefin phase are (a) any polymer that can be reacted to form a carboxylic acid anhydride-containing polymer, i.e. a polymer such as, for example, ethylene propylene copolymer (EPR); ethylene propylene diene terpolymer (EPDM); butyl rubber (BR); natural rubber (NR); chlorinated polyethylenes (CPE); silicone rubber; iso-prene rubber (IR); butadiene rubber (BR); styrene butadiene rubber (SBR); ethylene vinyl acetate (EVA); ethylene butyl acrylate (EBA) copolymer, ethylene methacrylate copolymer (EMA), ethylene ethyl acrylate copolymer (EEA), ethylene-olefin copolymers [for example Exact and Engage, LLDPE (linear low density polyethylene)], high density polyethylene (HDPE) and nitrile rubber (NBR). Polypropylene is not suitable for this phase because it degrades during vulcanization; however, if the polypropylene is an acid anhydride grafted copolymer or copolymer of polypropylene, it may be used. The polymer is preferably an ethylene polymer or copolymer containing at least 50% ethylene (as monomer), and more preferably at least 70% of the monomers are ethylene.

Suitable thermoplastic polymers (b) are: polypropylene (PP); polyethylene, especially high-density polyethylene (PE); polystyrene (PS); acrylonitrile butadiene styrene terpolymer (ABS); styrene acrylonitrile (SAN) copolymer; poly (methyl methacrylate) (PMMA); thermoplastic polyesters (PET, PBT); polycarbonate (PC) and polyamide (PA).

Such polymers can be produced by any means known in the art, including bulk phase, slurry phase, gas phase, solvent phase, interface polymerization; in radical, ionic, metal-initiated polymerization (e.g. metallocene and Ziegler-Natta polymerization), in polycondensation, in polyaddition, or combinations of these methods.

The same polymers can be present in both phases, the acid anhydride is pre-introduced into one part of the polymer and this pre-reacted polymer acts as the rubber phase in the TPV. This pre-introduction allows the use of an acid anhydride

As a comonomer in the polymer or pre-reaction of the acid anhydride with the polymer. In either of these two cases, it is not necessary to introduce the acid anhydride separately since it is present in the polymer. Due to the complexity of this process, it is preferred that the two polymers are different polymers.

There is also a third possibility that the polymer of the rubber phase and the polymer of the thermoplastic phase may be the same polymer and the acid anhydride is incorporated into the polymer as a whole. In the case where a silane is introduced, part of the polymer forms the rubbery phase, while another part does not react (due to the relatively small amounts of anhydride and silane). It is important that the correct degree of phase separation is achieved between the rubber and thermoplastic phases when carrying out the process. Such a method is not necessarily for the production of TPV, since the required phase is not necessarily obtained without the process being significantly complicated, which is not preferred.

In the case of two different polymers, the polymer more reactive with the acid anhydride is grafted with the acid anhydride and is the rubber phase in the TPV.

The polymer to be the rubber phase should be extrudable and should be grafted with an acid anhydride.

The melting point of the thermoplastic phase should be below the decomposition temperature of the aminosilane as well as below the decomposition temperature of the acid anhydride (unless the acid anhydride is a comonomer in the polymer).

The polymers can have monomodal, bimodal or polymodal molecular weight distributions. The melt flow rate of the polymers melt may correspond to any speed known in the art for forming thermoplastics and rubbers.

B. Carboxylic acid anhydrides

Any carboxylic acid anhydrides that can be grafted by any mechanism on the polymer used as the rubber phase can be used. For grafting it is preferred that there is unsaturation in the polymer or more preferably in the acid anhydride. The unsaturation of the carboxylic acid anhydride can be internal or external to the ring structure, if present, as long as it allows reaction with the polymer. The carboxylic acid anhydride may contain halogens. Mixtures of different carboxylic acid anhydrides can be used. The following compounds can be mentioned as examples of unsaturated carboxylic acid anhydrides: isobutenyl succinic anhydride, (+/-) - 2-octene-1-ylsuccinic acid anhydride, itaconic acid anhydride, 2-dodecen-1-ylsuccinic acid anhydride, cis-1,2,3,6-tetrahydrophthalic anhydride, acid anhydride cis-5-norbornene-2,3-dicarboxylic acid, endobicyclo [2.2.2] oct-5-ene-2,3-dicarboxylic acid anhydride, methyl-5-norbornene-2,3-carboxylic acid anhydride, exo- 3,6-epoxy-1,2,3,6-tetrahydrophthalic, maleic anhydride, citraconic acid anhydride, 2,3-dimethyl maleic acid anhydride, 1-cyclopentene-1,2-dicarboxylic acid anhydride, 3,4,5,6-tetrahydrophthalic acid anhydride, bromomaleic acid anhydride and dichloromaleic acid anhydride.

These acid anhydrides may exist as a comonomer in the rubber phase polymer or may be grafted onto the rubber phase polymer.

The amount of acid anhydride used is from 0.01 to 1.0% by weight, based on the total amount of polymer.

C. Aminosilanes

The aminosilanes used in the present invention contain at least one hydrolysable group, for example an alkoxy, acetoxy or halogen group, preferably an alkoxy group. Preferably, there are at least two hydrolysable groups which can undergo a condensation cross-linking reaction whereby the resulting compound can be vulcanized. A mixture of different aminosilanes can also be used.

The amine should have a sufficient reaction rate with the acid anhydride. In general, tertiary amines do not react properly with acid anhydride and their use should be avoided. The amino group can bridge with the silicon atom via the branched group and reduce the yellowing of the resulting blend.

The silane can be represented by the formula YNHBSi (OR) a (X) 3-a in which a has a value from 1 to 3, preferably a is equal to 3, Y is hydrogen, alkyl, alkenyl, hydroxyalkyl, alkylaryl, alkylsilyl, alkylamino. In the C (= O) OR group or in the C (= O) NR group, R is an acyl, alkyl or alkylaryl group, X may be an R group or halogen. B means bivalent Gru6

The bridging group which is preferably an alkylene group and which may be branched (for example neohexylene) or cyclic. B may contain heteroatomic bridges, for example an ether bond. B is preferably a propylene group. R is preferably a methyl or ethyl group. Methoxy silanes provide better vulcanization properties than ethoxy silanes. Y is preferably an aminoalkyl group, hydrogen or an alkyl group. Y is more preferably hydrogen or a primary aminoalkyl group (e.g. aminoethyl). X is preferably Cl and a methyl group, more preferably X is a methyl group. As examples of silanes, g-aminopropyltrimethoxysilane (Silquest® A-1110 from Witco Corp., Greenwich, CT, USA); g-aminopropyltriethoxysilane (Silquest A-1100); g-aminopropylmethyldiethoxysilane; 4-amino-3,3-dimethylbutyltriethoxysilane, 4-amino-3,3-dimethylbutylmethyldiethoxysilane, Nb- (aminoethyl) -g-aminopropyltrimethoxysilane (Silquest A-1120); H2NCH2CH2NHCH2CH2NH (CH2) 3Si (OCH3) 3 (Silquest A-1130) and Nb- (aminoethyl) -g-aminopropylmethyldimethoxysilane (Silquest A-2120). Other suitable aminosilanes are the following compounds: 3- (N-allylamino) propyltrimethoxysilane, 4-amino-butyltriethoxysilane, 4-aminobutyltrimethoxysilane, (aminoethylaminomethyl) phenethyltrimethoxysilane, aminophenyltrimethoxysilane, 3- (1,3-aminopropenyl) dimethyl). , bis [(3-trimethoxysilyl) propyl] ethylene diamine, N-methylaminopropyltrimethoxysilane, bis- (g-tri-ethoxysilylpropyl) amine (Silquest A-1170) and N-phenyl-g-aminopropyl trimethoxysilane (Silquest Y-9669).

When the aminosilane is a latent aminosilane, i.e., ureidosilane or carbamate silane, the mixing temperature should be sufficient to cleave the appropriate blocking group from the amine and should allow the amine to react with the acid anhydride functional group, so it should be in the range from about 150 ° C to about 230 ° C. ° C. Examples of such latent aminosilanes include tert-butyl-N- (3-trimethoxysilylpropyl) carbamate, ureidopropyltriethoxysilane, and ureidopropyltrimethoxysilane. Other carbamate silanes that can be used are disclosed in US Patent No. 5,220,047, which is hereby incorporated by reference. To avoid additional deblocking difficulties, preferably a latent aminosilane is not used as the aminosilane.

The aminosilane should be used in an amount of 250 to 25,000 ppm, based on the weight of both polymers. It should also preferably be used in a molar ratio to the acid anhydride of from about 0.1 to about 10, preferably in a ratio of from about 0.9 to about 1.1, and more preferably in a ratio of about 1: 1.

The silane can be applied to a carrier such as a porous polymer, silica, titanium dioxide or carbon black, which can be easily incorporated into the polymer during the mixing step. Examples of such materials include Accurel polyolefin (Akzo Nobel), Stamypol polyolefin (DSM) and Valtec polyolefin (Montell), Spherilene polyolefin (Montell), Aerosil silica (Degussa), Micro-Cel E (Manville) and Ensaco 350G carbon black (MMM Carbon).

E. Any additions

A free radical donor is needed if the carboxylic anhydride is grafted onto the polymer by a free radical mechanism, but not if the acid anhydride is grafted by a different mechanism, or if it is a polymer comonomer. Suitable free radical catalysts can be selected from the group of water or oil soluble peroxides such as hydrogen peroxide, ammonium persulfate, potassium persulfate; from the group of various organic peroxide catalysts such as dialkyl peroxides, for example diisopropyl peroxide, dilauryl peroxide, di-tert-butyl peroxide, di (2-tert-butylperoxyisopropyl) benzene; 3, -3,5-trimethyl-1,1-di (tert-butylperoxy) cyclohexane; 2,5-dimethyl-2,5-di (tert-butylperoxyhexane, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyn-3; dicumyl peroxide, alkyl hydroperoxides such as tert-butyl hydroperoxide, hydroperoxide tert-amyl, cumyl hydroperoxide, diacyl peroxides such as acetyl peroxide, lauroyl peroxide, benzoyl peroxide, peroxyesters such as ethyl peroxybenzoate and azo compounds such as 2-azobis (isobutyronitrile).

The free radical donor may be present in a molar ratio of 1/100 to 1/1, based on the moles of the acid anhydride.

Standard additives such as stabilizers (UV, light or anti-aging stabilizers), antioxidants, metal deactivators, processing aids, waxes, fillers (silica, TiO2, CaCO3, Mg (OH) 2, carbon black and the like) can be incorporated into the TPV. dyes. Additionally, blowing agents can be incorporated into the polymers, thanks to which the polymer forms a foam during extrusion. Examples of blowing agents include volatile hydrocarbons, hydrofluorocarbons and chlorofluorocarbons. A known blowing agent such as azocarbamide or sodium bicarbonate (i.e. sodium bicarbonate) decomposes at elevated temperatures to form gaseous products. All these methods are chemical foaming methods. Foams can also be produced by injecting a liquid or gaseous blowing agent into the polymer melt. As examples, mention may be made of butane, CO2, nitrogen, water, helium and the like. The amount of such a foaming agent should be in the range from 0.1 to 50% by weight, based on the polymers.

Manufacturing method

The first reaction grafts the carboxylic acid anhydride (most preferably by a free radical mechanism) onto the rubber phase of the polymer. Said reaction may be performed on both polymers, or on one of the two separate polymers, although it is preferred to perform it on both polymers. As mentioned above, this step can advantageously be carried out by introducing a carboxylic acid anhydride as comonomer of the rubber phase polymer (in this case no radical donor is needed). The polymer should be grafted or copolymerized with the carboxylic acid anhydride before reacting with the aminosilane because the reaction product of the carboxylic acid anhydride with the aminosilane has a low grafting efficiency. Prior reaction of the carboxylic acid anhydride with the aminosilane would produce a semi-amide which may have poorer grafting properties. In that case, vulcanization would not occur. In contrast, the partial degradation of the polymer and / or the plasticizing effect of the semi-amide may result in an increase in the melt flow index (MFI).

It is preferable to introduce a free radical donor with the acid anhydride during the grafting step to graft the acid anhydride onto the rubber phase polymer.

If, during grafting, the second thermoplastic polymer is absent, it must be mixed with the graft rubber polymer phase before introducing the aminosilane; the disadvantage of such a method is obtaining TPV with worse mechanical properties.

The second step is the introduction of the aminosilane into the rubber-phase grafted polymer blend with the thermoplastic polymer. No need to add water and / or catalyst. There is a very fast reaction between the aminosilane and the grafted acid anhydride. The reaction of the grafted acid anhydride moiety with g-aminopropylsilane can be represented by the formula:

<img file="PL196185B1_D0001.tif" />

The reaction between the silane and the grafted acid anhydride moiety should be fast to obtain the vulcanizable material and faster than the reaction between the alkoxy groups

PL 196 185 B1 and an acid anhydride. The delayed reaction could occur simultaneously with vulcanization of the alkoxy moieties, which would prevent vulcanization. The reaction between the amino group and the acid anhydride is very fast when using, for example, primary amino groups. The reaction can be slowed down by using secondary amine groups. Furthermore, this step should be carried out at elevated temperature, for example 50 ° C to 200 ° C, depending on the polymer blend. The polymer blend is preferably in a molten state when the aminosilane is introduced into the polymer.

After the aminosilane has been seeded onto one polymer, it must be cured to form a gel phase of the vulcanized polymer. Separate moisture vulcanization is not required. A condensation catalyst may be used to accelerate the vulcanization step, although a semiamide should be sufficient catalyst. This vulcanization should take place in 1 to 10 minutes at an elevated temperature of 60 ° C to 200 ° C.

It should be noted that the total amount of additives is only 0.4% by weight of the total blend, which is about 5 times less than the amount needed for peroxide or vinyl silane vulcanization. This is a double benefit: reducing overall costs and reducing the amount of volatile peroxides that pose a risk to the environment.

During and after vulcanization, all components should be thoroughly mixed in a closed mixer. The mixer may be an extruder (single screw extruder, twin screw extruder and the like), a Buss Ko-Kneader type mixer or a regular closed type mixer. The mixing conditions depend on the polymers and the degree of vulcanization.

Properties

The product is a thermoplastic vulcanizate with excellent mechanical properties. The vulcanized materials contain a significant amount of gel and have clearly lower MFI values ​​than the starting polymers, which should improve creep resistance, increase tensile strength and result in materials with a hardness greater than that of non-vulcanized polymer blends. The end product has elastic properties (i.e., elongation at break greater than 400%) and can be melt processed by methods used in thermoplastic processing. The preferred gel content in the final product (i.e. rubber content) is from 10 to 50% by weight, more preferably from 25 to 35% by weight. Modules in stretching and when bending in the machine direction and in the transverse direction are better, as well as the material impact strength.

TPV is paintable and has better oil resistance. TPV can be used, for example, as adhesives and sealants, cable insulations, pipes, profiles, pressed and foam products, plates and the like.

Aminosilane-modified rubber phase polymers are usually better miscible with the thermoplastic polymer, resulting in a more durable TPV.

Examples

All silanes used are discussed above, except for Silquest A-186 [g- (3,4-epoxycyclohexyl) -ethyltrimethoxysilane], Silquest A-187 (g-glycidoxypropyltrimethoxysilane) and Silquest A-189 (g-mercaptopropyltrimethoxysilane). Mixer: Brabender, 50 cm head³ with Banbury knives. Mixing parameters: Brabender, 50 cm head³temperature 190 ° C, 120 rpm. All percentages are by weight unless otherwise stated.

Method I: Total amount of components in the blend - 55 g. All components except Valtec HL003 polypropylene homopolymer (+ 5% silane) were loaded into the Brabender head. After 5 minutes (Brabender torque recorded), Valtec HL003 (+ 5% silane) was applied to the Brabender head. The time and peak torque value of the Brabender were recorded as an index of vulcanization. The blend was removed from the Brabender when the Brabender torque had dropped to the starting level and when homogenization had been achieved (after about 10 minutes). In the press, a 1.5 mm thick sample was pressed at a temperature of 210 ° C and a pressure of 2 MPa.

Method II: The same procedure was used as in method I, but all ingredients were introduced simultaneously into the Brabender head. Mix production time - 15 minutes. In the press, a 1.5 mm thick sample was pressed at a temperature of 210 ° C under a pressure of 2 MPa for 200 seconds.

Examples I to III are given to show that a wide range of properties can be obtained depending on the type of polymers. The weight percentages of material applied to another material are based on the weight of the carrier and the weight of the material underneath the carrier.

PL 196 185 B1

Example I.

Blend: 75% very low density polyethylene Engage 8452 [DuPont Dow Elastomers, Melt Flow Index (190 ° C / 2.16 kg): 3 g / 10 min; density: 0.875 g / cm³], 17% Valtec HL003 polypropylene homopolymer [Montell Spheripol® porous granules, melt flow index (230 ° C / 2.16 kg): 0.7 g / 10 min, density: 0.900 g / cm³], 1% Valtec HL003 [+ 5% saturated Interox DHBP (2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, Peroxid-Chemie, Munich], 2% Valtec HL003 (+ 5% saturated anhydride maleic acid), 5% Valtec HL003 (+ 5% saturated A-1100).

Method I. Maleic anhydride was absorbed into the polymer by melting the anhydride (mp 53 ° C), mixing with the polymer and subsequent cooling.

Example II.

Blend: 75% Nordel 2722 rubber, ethylene, propylene and diene monomer (DuPont Dow Elastomers: density: 0.88 g / cm³, Mooney ML 1 + 4 viscosity at 121 ° C: 28), 17% Valtec HL003, 1% Valtec HL003 (+ 5% saturated Interox DHBP), 2% Valtec HL003 (+ 5% saturated maleic anhydride), 5% Valtec HL003 (+ 5% saturated A-1100). Method I.

Example III.

Blend: 75% very low density polyethylene Engage 8442.00 [DuPont Dow Elastomers, Melt Flow Index (190 ° C / 2.16 kg): 1.0 g / 10 min; density: 0.857 g / cm³], 17% Valtec HL003, 1% Valtec HL003 (+ 5% saturated Interox DHBP), 2% Valtec HL003 (+ 5% saturated maleic anhydride), 5% Valtec HL003 (+ 5% saturated A-1100). Method I.

Examples 4 to 7 show the effect of the process and ingredients.

Example IV (comparative):

Mixture: 75 Engage 8452, 25 Valtec HL003. Method II.

Example V (comparative):

Blend: 75 Engage 8452, 22% Valtec HL003, 1% Valtec HL003 (+ 5% saturated Interox DHBP), 2% Valtec HL003 (+ 5% saturated maleic anhydride). Method I.

Examples dVI (comparative):

Blend: 75% Engage 8452, 17% Valtec HL003, 1% Valtec HL003 (+ 5% saturated Interox DHBP), 2% Valtec HL003 (+ 5% saturated maleic anhydride), 5% Valtec HL003 (+ 5% saturated A- 1100). Method II.

Example VII (comparative).

Blend: 75% Engage 8452, 17% Valtec HL003, 1% Valtec HL003 (+ 5% saturated Interox DHBP), 2% Valtec HL003 (+ 5% saturated maleic anhydride), 5% Valtec HL003 (+ 5% saturated hexadecylamine) . Method I.

Examples VIII - XVII show the effect of changing the silane type. Examples XV-XVII are comparative examples. All silanes were introduced as a masterbatch based on Valtec HL003 at a concentration of 5% by weight. The mixtures were prepared using method I.

Physical properties

The physical properties were measured according to the following standards:

Elongation and tensile strength at break ISO 37 (50 mm / min)

MFI ISO 1972-1, No. 18 T

Shore A hardness ISO 868

ISO 6427 gel content

Torque torque meter on a Brabender mixer

Results

Change of silanes

Table 1 shows the properties of the materials obtained by the procedures mentioned in the experimental section. The comparative examples include: Example 4 a neat blend containing Engage 8452 (PE) and Valtec HL003 (PP); Example V - blend containing Engage, Valtec, peroxide and maleic anhydride; Example VI - a blend containing Engage, Valtec, peroxide, maleic anhydride and A-1100 but all ingredients were mixed together; and Example 7 - a blend containing Engage, Valtec, peroxide, maleic anhydride, and hexadecylamine.

PL 196 185 B1

Example IV gives the properties of the pure polymer blend, Example V evaluates the effect of the silane alone, Example VI shows the effect of the processing conditions and Comparative Example VII indicates the necessity of using silane in the mixture.

Table 1. Properties of mixtures

<td>Example no</td><td>Gel content,%</td><td>It will endure. tensile strength, MPa</td><td>Elongation, %</td><td>MFI (190 ° C, 5 kg), [g / 10 min]</td><td>Hardness Shore AND</td><td>Moment twisting, Nm</td>

<td>AND</td><td> 35</td><td> 23</td><td> 810</td><td> 1,80</td><td> 88,00</td><td> 13</td>

<td>II</td><td> 36</td><td> 8</td><td> 400</td><td> 0,90</td><td> 85,00</td><td> 10</td>

<td>III</td><td> 32</td><td> 32</td><td> 800</td><td> 0,60</td><td> 74,00</td><td> 12</td>

<td>IV (see)</td><td> 1</td><td> 14,53</td><td> 1005</td><td> 6,00</td><td> 83,00</td><td> 5</td>

<td>V (see)</td><td> 2</td><td> 16,13</td><td> 909</td><td> 7,71</td><td> 84,50</td><td> 4</td>

<td>VI (see)</td><td> 1</td><td> 15,00</td><td> 750</td><td> 7,50</td><td> 83,00</td><td> 5</td>

<td>VII (see)</td><td> 0</td><td> 20,94</td><td> 922</td><td> 6,75</td><td> 87.10</td><td> 4</td>

<td>VIII (A-1100)</td><td> 30</td><td> 18,13</td><td> 739</td><td> 0,46</td><td> 88,00</td><td> 12</td>

<td>IX (A-1110)</td><td> 32</td><td> 20,00</td><td> 762</td><td> 0,20</td><td> 87,30</td><td> 14</td>

<td>X (A-1120)</td><td> 31</td><td> 16,51</td><td> 756</td><td> 0,65</td><td> 88,00</td><td> 13</td>

<td>XI (A-1130)</td><td> 30</td><td> 19,30</td><td> 840</td><td> 0,70</td><td> 87,40</td><td> 13</td>

<td>XII (A-1170)</td><td> 20</td><td> 19,04</td><td> 932</td><td> 0,62</td><td> 87,10</td><td> 7</td>

<td>XIII (A-2120)</td><td> 27</td><td> 17,88</td><td> 810</td><td> 0,65</td><td> 86,30</td><td> 13</td>

<td>XIV (Y-9669)</td><td> 1</td><td> 23,53</td><td> 861</td><td> 1,91</td><td> 82,50</td><td> 5</td>

<td>XV (A-186)</td><td> 3</td><td> 23,03</td><td> 895</td><td> 4,68</td><td> 84,30</td><td> 4</td>

<td>XVI (A-187)</td><td> 1</td><td> 17,63</td><td> 877</td><td> 4,28</td><td> 85,00</td><td> 5</td>

<td>XVII (A-189)</td><td> 2</td><td> 20,17</td><td> 934</td><td> 4,40</td><td> 84,50</td><td> 5</td>

Figure 1 shows the gel contents when using different silanes.

Figure 2 shows the highest torque during compounding.

Figures 1 and 2 show that the peak torque increase during compounding is related to the vulcanization reaction. It can be seen that all primary amines (Silquest A-1100, A-1110, A-1120, A-1130 and A-2120) cause direct vulcanization when mixed with the polymer blend after grafting the maleic anhydride.

On the other hand, mixing all the materials at the same time (Comparative Example VI) did not result in significant vulcanization. Small variations in the degree of vulcanization compared to the A-1100 silane may be due to either different molar amounts, different numbers and / or different types of alkoxy groups and the number of amine functional groups per molecule. Thus, the material obtained with the A-1170 secondary aminosilane shows a relatively high degree of vulcanization, while the Y-9669 secondary aminosilane does not produce significant vulcanization. It was noted that since the molecular weight of A-1170 is much greater than the molecular weight of the other silanes used, and all experiments were conducted with equal weight amounts of silane,

This molar amount of A-1170 is less than the molar amount of the other silanes and at equivalent molar amounts it caused increased gel formation. The latter also applies to the other tested silanes as well as to the case where hexadecylamine was used instead of silane.

The data of Figures 3-5 show that for all cases where vulcanization has occurred, a significant change in material properties is observed compared to a mixture of the two polymers alone. The melt flow index decreases to about 1/10, and in the case of A-1110 silane even to 1/30 of its initial value. The materials are thus much harder, with higher tensile strength at break and lower elongation at break. These changes in properties are consistent with the relative degree of vulcanization of these mixtures.

As for the other silanes used, the properties of the materials obtained cannot be attributed to the high degree of vulcanization. However, all silanes result in a reduction in MFI which indicates the presence of chain elongation. This is evident when comparing all comparative examples, especially comparative example V (maleic peroxide and anhydride only), where even some degradation occurs. It should be noted that a high MFI value was also obtained when the A-1100 silane was mixed simultaneously with the other ingredients.

Replacing the aminosilane with hexadecylamine (Comparative Example VII) also produces a material with better mechanical properties and higher hardness. The improvement in performance is likely due to the attachment of long side chains ("comb polymers) to the polymer backbone as vulcanization is not possible. Thus, no TPV was obtained (no gel content).

Examples XVIII - XXI.

Change of aminosilanes

TPV was produced by the method described above. The same molar amount of aminosilanes was used in all runs. Silane A and Silane B had the following formulas:

<img file="PL196185B1_D0002.tif" />

<td></td><td>Example XVIII (A-1100)</td><td>Example XIX (silane A)</td><td>Example XX (silane B)</td><td>Example XXI (A-1170)</td>

<td>Composition:</td><td>parts</td><td>parts</td><td>parts</td><td>parts</td>

<td> 1</td><td> 2</td><td> 3</td><td> 4</td><td> 5</td>

<td>Engage 8452</td><td> 75,0</td><td> 75,0</td><td> 75,0</td><td> 75,0</td>

<td>Valtec HL003</td><td> 17,0</td><td> 17,0</td><td> 17,0</td><td> 17,0</td>

<td>Valtec HL003 + 5% DHBP</td><td> 1,0</td><td> 1,0</td><td> 1,0</td><td> 1,0</td>

PL 196 185 B1 cont. table

<td> 1</td><td> 2</td><td> 3</td><td> 4</td><td> 5</td>

<td>Valtec HL003 + 5% anhydride maleic</td><td> 2,0</td><td> 2,0</td><td> 2,0</td><td> 2,0</td>

<td>Valtec HL003 + 5% silane</td><td> 5,0</td><td> 5,0</td><td> 4,64</td><td> 7,72</td>

<td>Gel content,%</td><td> 26,0</td><td> 25,0</td><td> 8,0</td><td> 23,0</td>

<td>Appearance (according to the Gardner scale)</td><td> 3,0</td><td> 2,0</td><td> 1,0</td><td> 1-2</td>

<td>Relative adhesion (hot applied)</td><td>Okay</td><td>Okay</td><td>Okay</td><td>perfect</td>

Silanes A, B and A-1170 gave products slightly less yellow than the product obtained with A-1100. The use of A-1170 as a vulcanizing substance produced materials with much better adhesive properties compared to other samples.

Application of foams - examples XXII-XXV.

The use of TPV products for applying foams was evaluated in Examples XXII and XXIII and compared to compositions reacted with peroxide only and with maleic anhydride (Example XXIV), or only with peroxide (Example XXV), respectively. The materials, except for the use of azodicarbonamide as foaming agent, were reacted at 180 ° C in a Brabender mixer (other TPV manufacturing parameters - as above). After 10 min. the composition was cooled to 160 ° C and the foaming agent was introduced. In Example 23, the aminosilane was introduced after the foaming agent had been added. After mixing for 3 minutes, the test plates were prepared in the following conditions: 170 ° C / 10 MPa / 100 seconds. The plates were foamed in an oven at 200 ° C for 3 to 5 minutes. The following compositions were used:

<td>Composition</td><td>Parts</td><td>Example XXII</td><td>Example Xxiii</td><td>Example Xxiv</td><td>Example Xxv</td>

<td>1) Engage 8452</td><td> 75</td><td>X</td><td>X</td><td>X</td><td>X</td>

<td>2) Valtec HL003</td><td> 17</td><td>X</td><td>X</td><td>X</td><td>X</td>

<td>3) Valtec HL003 + 5% DHBP</td><td> 1</td><td>X</td><td>X</td><td>X</td><td>X</td>

<td>4) Valtec HL003 + 5% MAH</td><td> 2</td><td>X</td><td>X</td><td>X</td><td></td>

<td>5) Valtec HL003 + 5% A-1100</td><td> 5</td><td>X</td><td>X</td><td></td><td></td>

<td>6) GCS2 AC blowing agent</td><td> 15</td><td>X</td><td>X</td><td>X</td><td>X</td>

<td>Stability of the alloy during foaming¹</td><td></td><td>Okay</td><td>Okay</td><td>moderately</td><td>bad</td>

<td>Gel content,%</td><td></td><td> 26</td><td> 33</td><td> 1</td><td> 1</td>

<td> (² = after foaming)</td><td></td><td> (33²)</td><td> (31²)</td><td> (1²)</td><td> (1²)</td>

¹ the appearance of the foam structure

The foam resistance was sufficient to withstand the azodicarbonamide decomposition temperature (temperature 200 ° C in a few minutes). The shaped piece kept its original dimensions and did not stick to the substrate. On the other hand, non-vulcanized samples changed dimensions during foaming, which deteriorated the cell structure and caused adhesion to the substrate surface. It seems that the order of loading (the silane before the azodicarbonamide or after the azodicarbonamide) did not significantly affect the appearance of the foam or the amount of gel.

PL 196 185 B1

Examples XXVI-XXIX. Single polymer TPV.

The general procedure was the same as above, but only one polymer was used in Examples XXVII-XXIX: in Example XXVII - polyethylene, in Example XXVIII - HDPE Lupolen 5031L from Elenac, MFI (190 ° C, 2.16 kg) = 6.5, density 0.952, in Example XXIX - polypropylene.

<td>Example</td><td>Xxvi</td><td>Xxvii</td><td>XXVIIII</td><td>Xxiv</td>

<td></td><td>parts</td><td>parts</td><td>parts</td><td>parts</td>

<td>Engage 8452</td><td> 37,5</td><td> 46,0</td><td> 0,0</td><td> 0,0</td>

<td>Lupolen HDPE</td><td> 0,0</td><td> 0,0</td><td> 46,0</td><td> 0,0</td>

<td>Valtec HL003</td><td> 8,5</td><td> 0,0</td><td> 0,0</td><td> 46,0</td>

<td>5% DHBP on Valtec HL003</td><td> 0,5</td><td> 0,5</td><td> 0,5</td><td> 0,5</td>

<td>5% MAH dissolved in MeOH on Valtec HL003</td><td> 1,5</td><td> 1,5</td><td> 1,5</td><td> 1,5</td>

<td>Valtec HL003, 5% A-1100 on Valtec HL003</td><td> 2,5</td><td> 2,5</td><td> 2,5</td><td> 2,5</td>

<td>Gel content,%</td><td> 24,0</td><td> 19,0</td><td> 20,0</td><td> 0,0</td>

The grafted maleic anhydride / aminosilane system can be used to vulcanize the Engage resin itself as well as the HPDE itself, but will not gel when used in polypropylene.