JP2006509872A - Process for producing thermoplastic vulcanizates - Google Patents

Abstract

A process for producing a thermoplastic vulcanizate (TPV) in a reactor is provided. This process forms a mixture in which the silane-grafted elastic polymer component is dispersed in a thermoplastic matrix component. The mixture comprises: a) 25-60 parts by weight of elastic polymer component per 100 parts by weight of the matrix component and elastic polymer component; b) 40-75 parts by weight of matrix component per 100 parts by weight of the combination of matrix component and elastic polymer component; c) formed by mixing with a silane grafting agent in a reactor. The silane grafted elastic polymer component is crosslinked by adding a solid water generator to the reactor.

Description

  The present invention relates generally to a process for producing thermoplastic vulcanizates used, for example, in automotive applications and as a PVC replacement.

  Thermoplastic vulcanizates ("TPV") are generally known to be renewable materials having at least one partially or fully crosslinked rubber or elastomer component dispersed in a thermoplastic matrix component. Yes. Generally, the TPV is prepared by blending the matrix material and the elastomer component with the desired additives and a sulfur or peroxide cure package to promote at least partial crosslinking of the elastomer component. Blending is performed in a large scale mixer and grafting is performed using unsaturated functional groups in the polymer chain of the elastomer provided by units derived from a diene such as ethylidene norbornene.

  The mixer is continuous and the TPV is provided in the form of pellets. When a temperature above the softening point or melting point of the matrix component is reached, the TPV uses a complete knitting or melting of the TPV under conventional molding or shaping conditions for thermoplastics to convert continuous sheets and / or molded articles. Can be formed. TPV has the properties of a thermosetting elastomer and can be reworked in a closed mixer.

  In actual use, there are limitations to known procedures for manufacturing TPV and processing into shaped articles. For example, it is difficult to process polymers that do not have units derived from dienes. The overall process has many steps using TPV supplied by the TPV manufacturer from a limited grade directory, limiting the formulation's adaptation to specific end use requirements.

  For example, it is known to graft polyolefins with silanes in electrical applications and to cause moisture to crosslink after extrusion.

  Polymer Engineering and Science, June 1999, Vol. 39, No. 6, page 1087, discloses a TPV in which ethylene-octene is dispersed in a polypropylene matrix. Yes. In the first step, an ethylene-octene polymer is coated and grafting is caused by the formation of peroxides upon melting (see page 1092 of Polymer Engineering and Science). Properly coated polypropylene is added and blended in the second step. In the third step, water is injected to cause crosslinking. German patent DE 4402943 discloses a similar process.

  PCT Publication No. WO 98/23687 discloses a thermoplastic polymer blend composition containing a thermoplastic matrix resin phase substantially free of crosslinking and a dispersed silane-grafted elastomer phase.

  It is one object of the present invention to provide a simplified and / or flexible process by integrating blending and grafting and / or blending and curing.

  In one embodiment, a process for producing a thermoplastic vulcanizate (“TPV”) in a reactor is provided by the present invention. The process includes forming a mixture of a silane-grafted elastic polymer component dispersed in a thermoplastic matrix component and adding a solid water generator to cross-link the silane-grafted elastomer component. Including. The mixture comprises: a) 40-75 parts by weight of matrix component per 100 parts by weight of the matrix component and elastic polymer component, b) 25-60 parts by weight of elastic polymer component per 100 parts by weight of the combination of matrix component and elastic polymer component, and c ) Formed by mixing the silane grafting agent in the reactor.

  In another embodiment, the process comprises: a) a thermoplastic polymer component to form a continuous matrix phase, an elastic polymer component, and a silane grafting agent to form a phase dispersed in the matrix, and Blending an additive to promote silane grafting; and b) adding a solid water generating agent, wherein the water forming agent is silane grafted with the formulation formed in step a). Water is released while undergoing shear to crosslink the polymer.

In certain aspects of any of the embodiments described herein, the process has any combination of one or more of the following features.
a) a continuous matrix phase having a crystallinity of at least 40% as determined by DSC;
b) an elastic polymer component having a crystallinity of less than 40% as determined by DSC;
c) the process further comprises mixing a free radical generator in the reactor;
d) the free radical generator is a peroxide,
e) the process further comprises mixing the hydrolysis catalyst in a reactor;
f) The silane grafting agent, free radical generator, and hydrolysis catalyst are added as separate components to the reactor,
g) Silane grafting agent, free radical generator, and hydrolysis catalyst are added to the reactor as a mixture on the porous carrier polymer.
h) the porous carrier polymer is selected from the group consisting of polyethylene and polypropylene;
i) The silane grafting agent is vinyl alkoxysilane,
j) the vinylalkoxysilane is selected from the group consisting of vinylmethoxysilane and vinylethoxysilane;
k) The solid water generator is selected from the group consisting of metal oxide / carboxylic acid combinations, Epsom salts, Gruber salts, clays, water, talc, and combinations thereof.
l) the matrix component comprises at least one of polyolefins, polyamides, and polyesters;
m) The elastic polymer component comprises at least one of halobutyl rubber, ethylene-propylene rubber, ethylene-propylene-diene terpolymer rubber, natural rubber, synthetic rubber, amine functional synthetic rubber, and epoxy functional synthetic rubber. ,
n) The elastic polymer component is an ethylene interpolymer,
o) The process comprises mixing 25 to 35 parts by weight, or 30 parts by weight of the elastic polymer component and 65 to 75 parts by weight or 70 parts by weight of the matrix component per 100 parts by weight of the matrix component and elastic polymer component combination. including,
p) The reactor is a batch type compounding device,
q) The reactor is a continuous blender,
r) The reactor is connected to a die suitable for extruding the product in the reactor into the shaped product without the intervention of a pelletizing step.
s) the matrix component has a crystallinity of at least 40% as determined by DSC;
t) The elastic polymer component has a crystallinity of at most 40% as determined by DSC.
u) The crystallinity of the matrix component and the elastic polymer component differs by at least 10%, or at least 20%,
v) The matrix component and the elastic polymer component are blended and combined simultaneously with the silane grafting agent.

Thermoplastic matrix component The matrix component of TPV includes thermoplastics such as polyolefins, polyamides, and polyesters. Suitable polymers for the matrix component are polyolefin-based thermoplastic polymers made by polymerization of monoolefin monomers using high pressure, low pressure or medium pressure methods using conventional single site catalysts such as Ziegler Natta and / or metallocenes. Preferably, the thermoplastic matrix component, at least 95 wt% monoolefin monomers converted to repeat units having the formula _{CH 2 = C (CH 3)} -R or _CH 2 = CHR (wherein, R, H or 1 It is a polyolefin that is a monoolefin of 12 carbon atoms (a linear or branched alkyl group).

  Suitable polymers for the matrix component include ethylene and ethylene interpolymers containing α-olefins having 3 to 10 carbon atoms as cononomer, polypropylene, ethylene and α-olefins having 4 to 10 carbon atoms as cononomers. Propylene interpolymers containing such α-olefins, as well as mixtures of two or more are included. The ethylene-derived polymer can be either high density or low density. The term polypropylene is used to mean a homopolymer or copolymer or a mixture thereof. In general, the higher the melting point of the matrix component, the higher the temperature at which the TPV can be processed. The propylene polymer matrix component can be any propylene-based polymer, ie a polymer in which the majority of units are derived from propylene.

  In one embodiment, the matrix component is based on a propylene polymer, which can be a propylene homopolymer, copolymer or impact copolymer. Generally, the propylene polymer can have a melt flow rate (MFR) of 15 or greater, and optionally 25 or even 35 MFR. In general, the bending rate is at least 1000 MPa, or at least 1200 MPa, alternatively 1300 MPa. Polypropylene polymers can be made using multisite catalysts or single site catalysts such as metallocenes.

  In one embodiment, the matrix component is polypropylene with improved impact resistance. In this embodiment, the matrix component itself is a blend of a propylene polymer matrix with an uncrosslinked elastomer dispersed therein. In a particular aspect of this embodiment, the elastomer is a copolymer and is present in an amount less than 20 wt% based on the total weight of the polypropylene blend with improved impact resistance. In another particular aspect of this embodiment, the propylene polymer matrix component of the polypropylene with improved impact resistance is a polypropylene having a propylene content of at least 95 wt%, a weight average molecular weight of at least 70,000, It is highly stereoregular with tactic regularity or syndiotactic regularity.

  Polypropylene with improved impact resistance can be prepared as a reactor blend in which the propylene polymer portion and the elastomer portion are in different zones or in a single reaction zone, as is known in the art. Formed simultaneously by polymerization of propylene with another suitable olefin monomer. Alternatively, polypropylene with improved impact resistance can be formed by melt blending polypropylene and elastomer, each formed separately prior to blending. Generally, for economic reasons, polypropylene with improved impact resistance is prepared as a reactor blend, and for this reason, the elastomer content that generally improves impact resistance is greater than 20 wt% of the reactor blend. More typically, it does not exceed 12 wt% of the reactor blend. Further discussion of details of polypropylene with improved impact resistance can be found in US Pat. No. 4,521,566, which is fully incorporated herein by reference. Regardless of how a polypropylene with improved impact resistance is formed, this improved impact polypropylene generally has a propylene polymer of 80 wt% so that the propylene content of the blend is at least 80 wt%. ~ 90 wt% and 10 wt% to 20 wt% elastomer. The improved impact resistant polypropylene of the present invention has a 1% secant modulus of 60,000 psi to 130,000 psi and an MFR with an upper limit of 5.0 or 3 and a lower limit of 0.5.

  In one embodiment, the matrix component is a thermoplastic polyamide composition. These generally include crystalline or resinous, high molecular weight solid polymers, including copolymers and terpolymers having repeating polyamide units in the polymer chain. Polyamides can be prepared by polymerization of one or more ε-lactams such as caprolactam, pyrrolidone, lauryl lactam and aminoundecane lactam, or amino acids, or by condensation of dibasic acids with diamines. Both fiber forming grade nylon and molded grade nylon are suitable. Examples of such polyamides are polycaprolactam (nylon 6), polylauryl lactam (nylon 12), polyhexamethylene adipamide (nylon 6,6), polyhexamethylene-azeramide (nylon 6,9), polyhexa Made by polycondensation of methylene sebacamide (nylon 6,10), polyhexamethylene isophthalamide (nylon 6, IP) and 11-aminoundecanoic acid condensation product (nylon 11), and metaxylenediamine and adipic acid A partially aromatic polyamide. Furthermore, the polyamide can be reinforced with, for example, glass fibers or inorganic fillers or mixtures thereof. Pigments such as carbon black or iron oxide can also be added. Additional examples of polyamides include Kirk-Othmer, Encyclopedia of Chemical Technology, Vol. 10, p. 919, and Encyclopedia of Polymer Science and Technology (Encyclopedia of Technology). Polymer Science and Technology), Vol. 10, pages 392-414.

  The matrix component is present in an amount in the range of an upper limit of 80, or 75, or 70, or 65 parts by weight and a lower limit of 40 parts by weight per 100 parts by weight of the matrix component and elastic polymer component combination. The elastic polymer component is present in an amount in the range of 60 parts by weight upper limit and 35, 30, or 25, or 20 parts by weight upper limit per 100 parts by weight of the matrix component and elastic polymer component combination.

Elastic polymer component The elastic polymer component generally comprises a polymer having elastomeric properties. Examples include rubbers, elastomers, and plastomers. The polymer may have residual unsaturation or curable functional sites that can be reacted with the curing agent and at least partially crosslinked. Possible rubber components include halobutyl rubber, ethylene propylene (EP) rubber, ethylene-propylene-diene terpolymer (EPDM) rubber, natural rubber, and synthetic polyisoprene, polybutadiene rubber, styrene-butadiene rubber, butadiene-acrylic. Synthetic rubber such as Ronitol rubber is included. Amine- or epoxy-functional synthetic rubbers are also suitable. Examples of these include amine functionalized EPDM, epoxy functionalized natural rubber, and functionalized metallocene plastomers.

The elastic polymer component can be based on an ethylene interpolymer. That is, an ethylene-derived unit is a major component in terms of% by weight. Ethylene interpolymer upper limit is 0.915 g / cm ³ or 0.910 g / cm ^3, the lower limit may have a density in the range of 0.860 g / cm ^3. An ethylene interpolymer is a single site catalyst, for example, an organometallic compound with at least one ligand having a cyclopentadienyl anion structure through which the ligand coordinates to a transition metal cation It can be prepared using a catalyst having a transition metal component. Preferably, the interpolymer has a narrow molecular weight distribution and a narrow composition distribution.

Metallocene catalyzed ethylene interpolymers can be partially thermoplastic and partially elastomeric and are sometimes referred to as “plastomers”. The ethylene interpolymer may be a copolymer having from 85 mol% to 96 mol% ethylene derived units and from 4 mol% to 15 mol% α-olefin conomonomer derived units based on the total monomer content. α- olefin monomer is incorporated in an amount to provide for a density of ^{0.915g / cm 3 ~0.860g / cm 3} . The plastomer α-olefin conomonomer can be an acyclic monoolefin such as butene-1, pentene-1, hexene-1, octene-1, and 4-methyl-pentene-1.

  The elastomeric polymer component can be based on an ethylene-α-olefin-diene terpolymer. Incorporation of a specific amount of diene monomer provides an elastic polymer component with additional residual unsaturation that allows further functionalization and / or crosslinking reaction or coupling of the elastic polymer component in the final product. However, the present invention can be practiced to give satisfactory results when the elastomeric polymer component is an ethylene interpolymer substantially free of dienes.

Ethylene interpolymers can be characterized by one or more of the following points.
(A) a DSC melting point curve (second melt rundown) showing the occurrence of a single melting point peak occurring in the range of 40 ° C. to 110 ° C.,
(B) a weight average molecular weight value in the range of 70,000 to 130,000,
(C) a molecular weight distribution (Mw / Mn) value of 4.0 or less, or 3.5 or less,
(D) 1% secant modulus of 800 psi or less without exceeding 15,000.

The elastic polymer component can be EXACT ™ plastomer available from ExxonMobil Chemical Company, Baytown, Texas. EXACT ™ plastomer is a copolymer of ethylene and a C _{4 to} C ₈ α-olefin conomonomer and has a plastic-like molecular weight.

  The elastic polymer component can be an Engage ™ polymer. Engage ™ polymer is a metallocene catalyzed plastomer available from Dow Chemical Company, Midland, Michigan.

The elastic polymer component may include more than one polymer. For example, the elastomeric polymer component may include (a) an ethylene copolymer having a C _{4 to} C ₈ α-olefin comonomer and a plastic-like molecular weight, such as the EXACT ™ plastomer described above, and (b) ethylene-propylene-diene ( "EPDM") terpolymer may be included. The EPDM of (b) is present in the elastic polymer component in an amount within the range of 75 wt% or 70 wt% and the lower limit is 50 wt% or 60 wt% based on the total weight of the elastic polymer component, and the upper limit is 0.00. the lower limit in 90 g / cm ³ or 0.880 g / cm ³ can be a low crystallinity EPDM having a density of 0.860 g / cm ^3. Low crystallinity EPDM means that the EPDM has a heat of fusion of less than 10 J / g as determined by DSC. The low crystallinity EPDM can be Vistalon ™ 7500 available from ExxonMobil Chemical Company, Baytown, Texas. Vistalon ™ 7500 is a low crystallinity EPDM terpolymer with an ethylene content of 52.3 wt% and a heat of fusion of 0.6 J / g.

  Instead, the EPDM of component (b) is present in the elastic polymer component in an amount within the range of 60 wt% or 50 wt% upper limit and 20 wt% or 25 wt% lower limit, based on the total weight of the elastic polymer component. The crystallinity can be EPDM. High crystallinity EPDM means that the EPDM has an ethylene content greater than 70 wt% and a heat of fusion greater than 10 J / g as measured by DSC. The high crystallinity EPDM can be Vistalon ™ 1703P available from ExxonMobil Chemical Company, Baytown, Texas. Vistalon ™ 7500 is a high crystallinity EPDM with an ethylene content of 78% and a vinyl norbornene content of 0.9 wt%.

The rubber component is a halogenated copolymer of isomonoolefin and alkylstyrene as described in US Pat. Nos. 5,162,445 and 6,207,754, both of which are fully incorporated herein by reference. May further be included. The halogenated copolymer can be a copolymer of a C _{4 to} C ₇ isomonoolefin and an alkyl styrene. The isomonoolefin can be isobutylene, the alkylstyrene can be a halogenated methylstyrene, and the halogen can be bromine. The halogenated copolymer uses bromine in a normal alkane (eg, hexane or heptane) solution and utilizes a bisazo initiator, such as AIBN or VAZO52 (2,21-azobis (2,4 dimethylpentanenitrile)), It can be prepared by halogenating an isobutylene-alkylstyrene copolymer at 55 ° C-80 ° C for 4.5-30 minutes, followed by caustic quenching. The recovered polymer is then washed in basic wash water and water / isopropanol wash solution, recovered, stabilized and dried.

Crosslinking One common crosslinking method involves the use of peroxides to form carbon-carbon bonds to crosslink elastic polymer components. However, when the matrix component includes polypropylene, the peroxide degrades the polypropylene matrix in addition to crosslinking the elastic polymer component. It is therefore desirable to use chemical agents that significantly crosslink elastomeric components such as vinyl alkoxysilanes. Vinyltrimethoxysilane (VTMOS) and vinyltriethoxysilane (VTEOS) are specific examples of vinylalkoxysilane. Vinyl alkoxysilanes can be used with very small amounts of peroxide, i.e., a vinylalkoxysilane / peroxide ratio of 10/1 to 40/1. The peroxide can be chosen to be reactive at low temperatures during initial blending. Peroxide is used as a free radical generator for grafting vinylsilane molecules to the elastomer backbone, as shown below.

  The present invention can be practiced by adding the silane and optionally the free radical generator and the hydrolysis catalyst to the compounding equipment as separate components or as a mixture during the grafting stage.

  Silane can be fed to the compounding device via a solid carrier polymer that is compatible with the base polymer. Such a process is described in U.S. Pat. No. 5,112,919, which is fully incorporated herein by reference, which, in contrast to liquid silane, contains a silane crosslinker in the extruder. A process for adding a solid feed of is provided.

  Silane can be supplied to the blender as a “silane masterbatch”. As used herein, the term “silane masterbatch” refers to a mixture of vinylalkoxysilane, a small amount of free radical generator, and a hydrolysis catalyst on a solid carrier polymer. Two types of silane masterbatches are commercially available. One type is based on a porous polyethylene carrier and the other type is based on a porous polypropylene carrier. The polypropylene carrier can be homopolypropylene propylene, an impact copolymer of propylene, or a random copolymer of propylene. Polypropylene random copolymers are not preferred. This is because vinylsilanes graft onto ethylene bonds along the backbone of the polypropylene random copolymer and crosslink both the carrier as well as the elastomer.

  Engineering resins such as polyamides and polyesters can also be used as carriers to increase the high temperature resistance of TPV. Maleic anhydride grafted plastomer or maleic anhydride grafted EP rubber or EPDM can be used as a compatibilizer between the engineering resin and the elastomeric polymer component. Peroxides and vinyl silanes can also be used as carriers.

  When the silane grafting reaction is complete, the water generating agent releases water upon heating in the compounding device, preferably in the melting temperature range of the polymer, thereby allowing the occurrence of crosslinking. The water generating agent can be added to the reactor upon completion of the silane grafting reaction. Examples of water generating agents include Epsom salts, Gruber salts, clays, water, talc, metal oxide / carboxylic acid combinations, and combinations thereof. Examples of metal oxide / carboxylic acid combinations are zinc oxide / stearic acid, zinc oxide / isononanoic acid, and zinc oxide isooctanoic acid.

  Figures 1 and 2 illustrate weight loss-temperature thermogravimetric analysis for magnesium sulfate heptohydrate (Epsom salt) and sodium sulfate decahydrate (Glauber salt), respectively. These figures show that Epsom salt releases half of its hydrated water at 150-200 ° C. and Gruber salt releases half of its hydrated water at much lower temperatures. Figures 3-7 are for talc, hydrated clay (hydrous aluminum silicate), and some metal oxide / carboxylic acid combinations (zinc oxide / stearic acid, zinc oxide / isononanoic acid, and zinc oxide / isooctanoic acid). 2 illustrates a thermogravimetric analysis of weight loss-temperature.

  In the presence of water molecules, the OR group of the grafted vinylsilane molecule can be easily hydrolyzed to an OH group. The Si-OH group then undergoes a condensation reaction in the presence of a hydrolysis catalyst, such as dibutyltin dilaurate, to form a Si-O-Si bond. If not enough vinylsilane molecules are grafted onto the elastomer backbone, the Si-O-Si bond results in two-dimensional chain extension from the elastomer molecule. If enough vinylsilane molecules are grafted onto the elastomer backbone, a three-dimensional network can be formed and the elastomer is crosslinked. The crosslinking process described above is shown below.

  The present invention can be practiced without a subsequent vulcanization step. This is because the addition of a water generating agent to the compounding device allows the TPV to be crosslinked before exiting the mixing line. In the case of a batch mixer, after completing the grafting reaction, the feed ram is raised and the water generator is added. The mixing is then continued in the mixer until the vulcanization reaction is complete. Alternatively, a continuous mixer, such as an extruder, can be used as the compounding device. In the one pass process, the water generator is added to the extruder at a point downstream of the region where the silane grafting reaction occurs. In the two-pass process, silane grafting occurs in the first pass and the cross-linking reaction is completed by adding the water generator to the second pass of the same extruder.

  With appropriate process conditions, the degree of crosslinking, ie gel content, can be about the same for the entire compound. This is an advantage over processes where the compounded article is water treated after it emerges from the compounding line, so that the degree of crosslinking becomes dependent on the thickness of the article.

Other Raw Materials The TPV of the present invention can be improved by adding conventional raw materials known in the art. Such raw materials include particulate fillers, clays, pigments, reinforcing agents, stabilizers, antioxidants, flame retardants, tackifiers, plasticizers, waxes, process oils, lubricants, foaming agents, and extender oils. However, it is not limited to these. These additional raw materials can constitute up to about 50 weight percent of the total composition. One skilled in the art will appreciate that other additives can be used to enhance the properties of TPV.

Apparatus The TPV of the present invention can be prepared using any suitable batch mixing apparatus (eg, a Banbury mixer) or continuous apparatus (eg, a single screw or twin screw extruder).

  The present invention is illustrated in more detail below with reference to the following examples, which should not be construed as limiting the scope of the invention. Table 1 shows a list of test methods used in the examples.

In the following examples, Escorene ™ PP1105 is a propylene homopolymer having a melt flow rate of 35, a bending rate (MPa) of 1300, and a notched Izod impact strength (@ 23 ° C. KJ / m ² ) of 3.2. It is. Escorene ™ PP8191 has a density of 0.9 g / cm ³ , a melt flow rate of 1 dg / min, an ethylene cononomer content of 20 wt%, a 1% secant modulus of 62,500 psi and a DSC peak melting point of 141.6 ° C. Polypropylene with improved impact resistance. Capron ™ 73ZP is a polyamide-6 resin from Honeywell, Morristown, NJ. Ultamid 35 is a 6,66 polyamide from BASF, Freeport, Texas. Pebax 3533 is a soft polyamide made by Atofina Chemikel of Philadelphia, PA. Sunpar 150HT is a sun oil process oil from Marcus Hook, Pennsylvania. EXACT ™ 8201 has a melt index of 1.1 g / 10 min, a density of 0.882 g / cm ³ , a bending rate of 1% secant at 3300 psi, a Mooney viscosity (1 + 4 @ 125 ° C.) of 19, and a peak melting point of 66. It is an ethylene-octene copolymer at 7 ° C. and a melt flow rate of 2.5 g / 10 min. EXACT ™ 4033 has a density of 0.880 g / cm ³ , a melt index of 0.8 g / 10 min, a bending rate of 1% secant at 3300 psi, a Mooney viscosity (1 + 4 @ 125 ° C.) of 28, and a DSC peak melting point of 60 It is an ethylene-butene copolymer at 0C. Vistalon ™ 1703P is a high crystallinity EPDM containing about 0.9 wt% vinyl norbornene and 78 wt% ethylene. Vistalon ™ 3666 is an oil extended low crystallinity EPDM with a heat of fusion of 0 J / g. Vistalon ™ 9303 is another low crystallinity EPDM with a heat of fusion of 3.7 J / g. Exxpro ™ 89-1 is a brominated polymer derived from a copolymer of isobutylene and methylstyrene. Exxpro ™ 89-1 has a density of 0.93 g / cm 3, Mooney viscosity of 35 ML (1 + 8) @ 125 ° C. and bromine wt% of 1.2. Escorene ™, Exact ™, Vistalon ™ and Exxpro ™ are products available from ExxonMobil Chemical Company. Silane Masterbatch # 1 is the name XL-Pearl Y-15307, supplied by OSI Specialties of Crompton Corporation, Tarrytown, NJ, 70 wt% silane absorbed in 30 wt% porous polypropylene. Contains a mixture. The majority of this silane mixture is composed of VTMOS type silane with the addition of grafted peroxide and hydrolysis catalyst. Silane masterbatch # 2, also supplied by OSI Specialties, contains 50 wt% silane mixture absorbed in 50 wt% porous polypropylene. Most of the silane mixture is composed of VTMOS type silane. Silane masterbatch # 3, also supplied by OSI, contains 70 wt% silane mixture absorbed in 30 wt% porous polypropylene. Most of the silane mixture is composed of VTEOS type silane. A commercial supplier of porous carriers is Akrel Systems, Akzo Nobel Membrane GmbH, Obernberg, Germany.

Example 1 (Banbury mixer; Silane masterbatch # 1)
In Samples 1-5, various amounts of silane masterbatch # 1 (VTMOS type silane absorbed in a porous polypropylene carrier) were added to a 30/70 blend of Escorene ™ PP1105 / Exact ™ 8201, The mixture was melt mixed in a 00C size Banbury mixer to carry out the silane grafting reaction. A batch weight of 2270 g was used. After the silane grafting reaction was completed, as shown by the motor torque increase, the feed ram was raised and 0.2 parts of Epsom salt was added per 100 parts of resin. The ram was then lowered until another torque increase was observed. In order to prevent the material from being heated above 500 ° F., the mixer was shifted to a lower rotor speed to complete the crosslinking reaction.

Example 2 (Twin Screw Extruder; Silane Masterbatch # 1)
Samples 6-11 of Table 3 illustrate a TVG having a propylene homopolymer matrix component and an ethylene-based copolymer rubber component produced by a continuous mixer, as described in detail below. The same Escorene ™ PP1105 / Exact ™ 8201 resin mixture as described in Example 1 was melt blended together with a VTMOS masterbatch on a porous polypropylene carrier, first using a 30 mm ZSK twin screw extruder. To complete the silane grafting reaction. In the second pass, the melt blended formulation was compounded with the Epsom salt on the same ZSK extruder to complete the crosslinking reaction.

Example 3 (Banbury mixer; Silane masterbatch # 2)
In Samples 12-16, VTMOS masterbatches (1.5 parts to 3.5 parts per 100 parts resin) on various amounts of porous polyethylene carrier were added to Escorene ™ PP1105 / Exact ™ 8201 30 / 70 blends and this mixture was melt mixed in a Banbury 00C mixer to carry out the silane grafting reaction. A batch weight of 2270 grams was used. As indicated by the increase in motor torque, after the silane grafting reaction was completed, the feed ram was raised and 0.2 parts of Epsom salt was added per 100 parts of resin. The ram was then lowered until another torque increase was observed. In order to prevent the material from being heated above 500 ° F., the mixer was shifted to a lower rotor speed to complete the crosslinking reaction.

Example 4 (Twin Screw Extruder, Silane Masterbatch # 2)
Samples 17-24 of Table 5 illustrate TPVs having a propylene homopolymer matrix component and an ethylene-based copolymer rubber component produced by a continuous mixer, as described in detail below. The same Escorene ™ PP1105 / Exact ™ 8201 resin mixture as described in Example 1 was melt blended together with a VTMOS masterbatch on a porous polypropylene carrier, first using a 30 mm ZSK twin screw extruder. To complete the silane grafting reaction. In the second pass, the melt blended formulation is compounded with the Epsom salt on the same ZSK extruder to complete the crosslinking reaction.

Example 5 (Silane master batch # 3)
In samples 25-28, various amounts of vinylethoxysilane (VTEOS) masterbatch (0.5-2 parts per 100 parts resin) on a porous polyethylene carrier were added to Escorene ™ PP1105 / Exact ™ 8201. And the mixture was melt mixed in a Banbury 00C mixer to carry out the silane grafting reaction. A batch weight of 2270 grams was used. As indicated by the increase in motor torque, after the silane grafting reaction was completed, the feed ram was raised and 0.2 parts of Epsom salt was added per 100 parts of resin. The ram was then lowered until another torque increase was observed. In order to prevent the material from being heated above 500 ° F., the mixer was shifted to a lower rotor speed to complete the crosslinking reaction.

  The results show that the gel level achieved with VTEOS is much less than with the corresponding VTMOS shown in FIG.

Example 6
Samples 29-34 illustrate a TPV having a propylene homopolymer matrix component and a rubber component comprising a combination of a metallocene plastomer and a low crystallinity EPDM rubber. Each of these compositions showed only a polypropylene melting peak by DSC and no secondary low temperature peak was observed. In Sample 31 as well, Burgess clay served as both a water generant and a reinforcing agent, as shown by the higher tensile strength of the non-clay containing formulation.

Example 7
Samples 35-38 illustrate a TPV having a propylene homopolymer matrix component and a rubber component comprising a combination of a metallocene plastomer and a high crystallinity EPDM rubber. By replacing EXACT ™ 8201 in this embodiment with a high crystallinity EPDM such as Vistalon ™ 1703P (78 wt% ethylene and 36.5 J / g heat of fusion), as shown in Table 8, TPV Softness (bending rate and hardness) is improved. Based on the gel content results, it is clear that vinyl salin can be simultaneously grafted to both EXACT ™ 8201 and Vistalon ™ 1703P and crosslinked with the same type and amount of water generating agent (Epsom salt) .

  The compositions in Table 8 were produced by a two pass formulation using a 30 mm ZSK twin screw extruder. All ingredients were first blended together and fed to the extruder to complete the silane grafting reaction. In the second pass extrusion, Epsom salt was compounded with the material produced from the first pass to complete the crosslinking reaction. Samples 36-38 show that as more Vistalon ™ 1703P is used to replace the stiffener EXACT ™ 8201, the stiffness (bending rate) decreases as compared to Comparative Sample 35. Yes.

Example 8
In Samples 39-41, a vinyl methoxysilane (VTMOS) masterbatch on a porous polypropylene carrier is added to 2.2 parts per 100 parts of resin to a 27.6 / 64 blend of Escorene ™ PP7715E4 / EXACT ™ 8201. did. In each of samples 39-41, different metal oxide / carboxylic acid combinations were used.

Example 9
For Sample 42, 3 parts of VTMOS masterbatch on porous polypropylene carrier per 100 parts of resin was added to a 30/70 blend of Escorene ™ PP1105 / EXACT ™ 8201. In sample 43, 3 parts of VTMOS masterbatch on porous polypropylene carrier per 100 parts of resin was added to a 30/70 blend of Escorene ™ 7715 / EXACT ™ 8201. Escorene ™ 7715 is an impact copolymer having a polypropylene matrix in which uncrosslinked ethylene-propylene is dispersed.

Example 10
As shown in Table 11, the TPV composition comprises a polypropylene copolymer (Escorene ™ PP8191) with improved impact resistance as a matrix component, a metallocene plastomer (Exact ™ 4033) and a halogenated rubber ( And rubber component containing Exxpro ™ 89-1).

  In the presence of zinc oxide and zinc stearate, the plastomer can be grafted to the halogenated rubber. However, the zinc oxide / zinc stearate combination has no effect in crosslinking the plastomer itself. Extra amounts of zinc oxide and zinc stearate can be used to crosslink the halogenated rubber. Sample 44 shows that by replacing the plastomer with 5 parts of halogenated rubber, the resulting blend has a melt flow rate of 1 dg / min. Sample 45 is the same as Sample 44 except that 0.05 parts zinc oxide per 100 parts resin and 0.05 parts zinc stearate per 100 parts resin are added. The resulting composition showed a slight decrease in melt flow rate due to crosslinking of 5 parts of halogenated rubber. In sample 46, 12.5 parts of halogenated rubber was used to replace an equal amount of plastomer, and the melt flow rate was reduced to 0.1 dg / min, indicating an increase in the degree of crosslinking in the formulation.

Example 11
A 75 liter Banbury mixer was used to produce a TPV having the composition described in Table 12 below. Add EXACT ™ 8201, Escorene ™ PP1105, silane masterbatch, carbon black, and half of Cel-span to the empty barrel and maintain high and intermediate rotors to maintain a melt temperature of about 360 ° F. It was melted using both speeds. The ram was raised and the other half of Cel-span was added and the mixture was melted again. The ram was then raised and Burgess clay, Epsom salt, and AX-71 were added. After the maximum torque increase was observed, the ingredients were mixed for an additional 30 seconds. The total cycle time was about 4 minutes. The batch was then discharged into a downstairs hold mill at 335 ° F. The 4 "strip from the two roll machine was then continuously fed to the short barrel extruder to form a 3" continuous rope. The rope temperature was recorded to be 340 ° F. The extruded rope was supplied to the upper part of the inverted L-shaped calendar, and the melted rope was processed into a continuous thin sheet.

  Using the temperature distribution in Table 13 below, a 3.8 mil thick, 58 "wide sheet was produced at a production rate of 50 yards per minute.

  The properties of the sheet are shown in Table 14 below.

  A low voltage SEM micrograph of the rolled sheet is shown in FIG. Referring to FIG. 8, the white bumpy particles are cross-linked plastomers and the dark lines are the polypropylene matrix. The large and small embedded particles are carbon black or flame retardant.

Example 12
A size D Banbury mixer was used to produce a TPV having the composition described in Table 15 below. EXACT ™ 8201, Escorene ™ PP1105, and silane masterbatch are added to an empty barrel and melted using both high and intermediate rotor speeds to maintain a melt temperature of about 360 ° F. It was. The ram was raised and Burgess clay and Epsom salt were added. After the maximum torque increase was observed, the ingredients were mixed for an additional 30 seconds. Sunpar 150M was injected into the mixer to cool the melt temperature of the batch. The total cycle time was about 4 minutes. The batch was then discharged into a melt feed pellet extruder and the batch was processed into 1/8 "x 1/8" pellets.

  The pellets were then fed into the feed hopper of a Black Clawson sheet extruder to produce a continuous sheet 36 "wide by 10 mil thick under the conditions shown in Table 16.

  The sheet properties are shown in Table 17 below.

  Various trade names used herein are indicated by a (trademark) symbol, indicating that the name may be protected by certain trademark rights. Some such names may also be registered trademarks in various jurisdictions.

  All patents, test procedures, and other references cited herein, including priority documents, are to the extent that such disclosure is consistent with the present invention and to which such incorporation is permitted. The jurisdiction sword is fully incorporated by reference.

FIG. 3 is a graph of thermogravimetric analysis of weight loss-temperature for magnesium sulfate heptohydrate (epsom salt). Figure 2 is a graph of thermogravimetric analysis of weight loss-temperature for sodium sulfate decahydrate (Glauber salt). Figure 6 is a graph of thermogravimetric analysis of weight loss-temperature for talc. It is a graph of the thermogravimetric analysis of the weight loss-temperature about hydrated clay (hydrous aluminum silicate). Thermogravimetric analysis of weight loss-temperature for the zinc oxide / stearic acid combination. Thermogravimetric analysis of weight loss-temperature for the zinc oxide / isononanoic acid combination. Thermogravimetric analysis of weight loss-temperature for the zinc oxide / isooctanoic acid combination. It is a low voltage SEM micrograph of a rolled sheet.

Claims (36)

A process for producing a thermoplastic vulcanizate (TPV) in a reactor comprising:
a) in the reactor,
i) 25-60 parts by weight of elastic polymer component per 100 parts by weight of the combination of matrix component and elastic polymer component;
ii) 40-75 parts by weight of matrix component per 100 parts by weight of the combination of matrix component and elastic polymer component;
iii) mixing a silane grafting agent to form a mixture in which the silane-grafted elastic polymer component is dispersed in the thermoplastic matrix component;
b) adding a solid water generating agent to the reactor to crosslink the silane grafted elastic polymer component.   The process of claim 1, wherein step a) further comprises mixing a free radical generator in the reactor.   The process of claim 2 wherein the free radical generator is a peroxide.   The process of claim 1, wherein step a) further comprises mixing a hydrolysis catalyst in the reactor.   The process of claim 2, wherein step a) further comprises mixing a hydrolysis catalyst in the reactor.   The process of claim 5, wherein the silane grafting agent, free radical generator, and hydrolysis catalyst are added to the reactor as separate components.   6. The process of claim 5, wherein the silane grafting agent, free radical generator, and hydrolysis catalyst are added to the reactor as a mixture on the porous carrier polymer.   The process of claim 7, wherein the porous carrier polymer is selected from the group consisting of polyethylene and polypropylene.   The process of claim 1, wherein the silane grafting agent is vinyl alkoxysilane.   The process according to claim 9, wherein the vinylalkoxysilane is selected from the group consisting of vinylmethoxysilane and vinylethoxysilane.   The process of claim 1, wherein the solid water generator is selected from the group consisting of metal oxide / carboxylic acid combinations, Epsom salts, Gruber salts, clays, water, talc, and combinations thereof.   The process of claim 1, wherein the matrix component comprises at least one of a polyolefin, a polyamide, and a polyester.   The elastic polymer component comprises at least one of halobutyl rubber, ethylene-propylene rubber, ethylene-propylene-diene terpolymer rubber, natural rubber, synthetic rubber, amine-functionalized synthetic rubber, and epoxy-functionalized synthetic rubber. The process according to 1.   The process of claim 1 wherein the elastic polymer component is an ethylene interpolymer.   The process according to claim 1, wherein step a) comprises mixing 25 to 35 parts by weight of the elastic polymer component and 65 to 75 parts by weight of the matrix component per 100 parts by weight of the combination of the matrix component and the elastic polymer component.   The process of claim 1, wherein step a) comprises mixing 30 parts by weight of elastic polymer component and 70 parts by weight of matrix component per 100 parts by weight of the combination of matrix component and elastic polymer component.   The process of claim 1 wherein the reactor is a batch type compounding device.   The process of claim 1 wherein the reactor is a continuous compounding device.   The process of claim 1, wherein the reactor is connected to a die suitable for extruding the product in the reactor into a shaped article without intervention of a pelletizing step.   The process of claim 1, wherein the matrix component has a crystallinity of at least 40% as determined by DSC and the elastomeric polymer component has a crystallinity of at most 40% as determined by DSC.   21. The process of claim 20, wherein the crystallinity of the matrix component and the elastic polymer component differ by at least 10%.   21. The process of claim 20, wherein the crystallinity of the matrix component and the elastic polymer component differ by at least 20%.   The process of claim 1, wherein the matrix component and the elastomeric polymer component are blended and combined simultaneously with the silane grafting agent. A process for producing a thermoplastic vulcanizate (TPV) comprising:
A) a thermoplastic polymer component for forming a continuous matrix phase having a crystallinity of at least 40% as determined by DSC, an elastic polymer component having a crystallinity of less than 40% as determined by DSC, and a matrix Blending a silane grafting agent to form a phase dispersed therein and an additive to promote silane grafting;
B) adding a solid water generator, which releases water while the formulation formed in step A) is subjected to shear to crosslink the silane grafted polymer. Process.   25. The process of claim 24, wherein the polymer for the matrix phase and the polymer for the elastic polymer component are blended and combined simultaneously with the silane grafting agent and additives.   26. A process according to claim 24 or claim 25, wherein the silane grafting agent and additive are part of a masterbatch and preferably comprise a polymer compatible with the elastic polymer component as a solid carrier.   The solid water generator is a hydrolysis capable of reacting a compound containing absorbed or hydrated water that can be released upon heating up to the blending temperature, preferably releasing the water added with the silane grafting agent. A process according to any of the preceding claims containing both a catalyst or a compound.   A process according to any preceding claim wherein the ingredients are blended in a batch or continuously operated blending apparatus.   Process coagulation according to any of the preceding claims, wherein steps A and B are continuous without any intermediate pause in the blending or solidification of the polymer components.   A process according to any preceding claim, wherein the elastic polymer component is an ethylene interpolymer.   Process according to any of the preceding claims, wherein the crystallinity of the thermoplastic polymer component and the elastic polymer component differs by at least 10%, preferably 20%.   A process according to any of the preceding claims, wherein the elastic polymer component has a heat of fusion of less than 40 J / g, preferably less than 30 J / g.   In step A), the thermoplastic polymer component is 40 to 75 parts by weight, preferably 65 to 75 parts by weight, more preferably 70 parts by weight, and the elastic polymer component 25 to 60 parts by weight, preferably 25 to 35 parts by weight, more preferably 30 parts. A process according to any preceding claim wherein the parts by weight are blended.   A process according to any preceding claim, wherein the thermoplastic polymer component comprises at least one of polyolefins, polyamides, and polyesters.   A process according to any of the preceding claims, wherein the silane grafting agent is a vinylalkoxysilane, preferably vinylmethoxysilane or vinylethoxysilane.   A process according to any preceding claim, wherein the solid water generator is a metal oxide / carboxylic acid combination, an Epsom salt, a Grauber salt, clay, water, talc, or any combination thereof.

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