阅读说明：本技术 烯烃多嵌段共聚物/硅氧橡胶组合物和由其形成的泡沫 (Olefin multi-block copolymer/silicone rubber composition and foam formed therefrom ) 是由 禹海洋 胡小链 陈红宇 K·G·库默 于 2017-12-28 设计创作，主要内容包括：一种组合物,其包括至少以下组分：A)烯烃多嵌段共聚物；和B)包括侧链乙烯基且任选地包括末端乙烯基的硅氧橡胶。(A composition comprising at least the following components: A) an olefin multi-block copolymer; and B) silicone rubbers comprising pendant vinyl groups and optionally terminal vinyl groups.)

1. A composition comprising at least the following components:

A) an olefin multi-block copolymer; and

B) silicone rubbers comprising pendant vinyl groups and optionally terminal vinyl groups.

2. The composition of claim 1 wherein the silicone rubber has a weight average molecular weight (Mw) of 200,000 g/mole or more.

3. The composition of claim 1 or 2, wherein the silicone rubber comprises one or more structures selected from i), and optionally one or more structures selected from ii):

i)-O-[Si(R)(CH＝CH₂)]-[Si(R')(R”)]-O-, wherein R, R 'and R "are each independently alkyl, and further C1-C6 alkyl, and wherein R, R' and R" may all be the same alkyl;

ii)H₂C＝CH-[Si(R^IV)(R^V)]-O-wherein R^IVAnd R^VEach independently is alkyl, and further is C1-C6 alkyl, and wherein R is^IVAnd R^VMay be the same alkyl group.

4. The composition of any preceding claim, wherein the silicone rubber comprises pendant vinyl groups and terminal vinyl groups.

5. The composition of any of the preceding claims wherein the olefin/α -olefin block copolymer has a density from 0.866g/cc to 0.887 g/cc.

6. The composition of any of the preceding claims wherein the olefin/α -olefin block copolymer has a melt index (I2) of 0.5 to 5.0 grams/10 minutes (190 ℃ and 2.16 kg).

7. The composition of any of the preceding claims, wherein the olefin multi-block copolymer is an ethylene/α -olefin multi-block copolymer.

8. The composition of any of the preceding claims, wherein the composition comprises from 10 wt% to 30 wt% of component B, based on the weight of component a and component B.

9. An article comprising at least one component formed from the composition of any of the preceding claims.

10. The article of claim 9, wherein the article is a foam.

Background

Olefin Block Copolymer (OBC) may be used to form a lightweight midsole. For use as a monocomponent foam, the polymer composition should have good abrasion resistance and good wet skid resistance (wet cof (coefficient of friction)). While polydimethylsiloxane may be used to improve abrasion resistance, wet COF is generally reduced, resulting in poor wet skid resistance. Foamable compositions and/or other elastomeric compositions are described in the following references: US6767931, US2011/0178195, US2015/0166755, US2016/0160037, KR1075070B1 (abstract), US7671106, US6013217, US2012/0322905, JP3665446B2 (abstract), CN105670199A (abstract), CN103709581B (abstract). However, there is a need for a new polymer composition that provides good abrasion resistance and good wet COF. There is a further need for such compositions having good mechanical properties such as compression set, resilience and tensile strength. The following invention has met these needs.

Disclosure of Invention

A composition comprising at least the following components:

A) an olefin multi-block copolymer;

B) silicone rubbers comprising pendant vinyl groups and optionally terminal vinyl groups.

Drawings

Fig. 1 depicts a schematic of different samples cut from Bun foam.

Fig. 2 depicts SEM images of comparative example 2 (leftmost), comparative example 3 (middle), and inventive example 1 (rightmost).

Detailed Description

OBC/silicone rubber compositions have found use in single base foam applications. It has been found that these compositions provide an excellent crosslinking mechanism during foaming and produce foams with good (low DIN) abrasion resistance without significant reduction in wet COF. These compositions were also found to have good mechanical properties such as compression set, resilience and tensile strength. Furthermore, the addition of silicone rubber may contribute to the processability of the composition when used in injection foaming applications.

As discussed above, the present invention provides a composition comprising at least the following components:

A) an olefin multi-block copolymer;

B) silicone rubbers comprising pendant vinyl groups and optionally terminal vinyl groups.

The inventive compositions may comprise a combination of two or more embodiments as described herein.

The components of the inventive compositions may comprise a combination of two or more embodiments as described herein.

In one embodiment, or a combination of two or more embodiments described herein, the silicone rubber has a weight average molecular weight (Mw) of 200,000 g/mole or more, or 250,000 g/mole or more, or 300,000 g/mole or more, or 350,000 g/mole or more, or 400,000 g/mole or more, or 450,000 g/mole or more, or 500,000 g/mole or more.

In one embodiment, or a combination of two or more embodiments described herein, the silicone rubber comprises one or more structures selected from the following i), and optionally one or more structures selected from ii):

i)-O-[Si(R)(CH＝CH₂)]-[Si(R')(R”)]-O-, wherein R, R 'and R "are each independently alkyl, and more C1-C6 alkyl, and wherein R, R' and R" may all be the same alkyl;

ii)H₂C＝CH-[Si(R^IV)(R^V)]-O-wherein R^IVAnd R^VEach independently is alkyl, and is more C1-C6 alkyl, and wherein R is^IVAnd R^VCan beThe same alkyl group. Here, structure i) represents an internal group of the silicone rubber polymer molecule, which internal group is bonded to an additional part of the polymer molecule at the respective oxygen end group. Structure ii) represents the end group of the silicone rubber polymer molecule, which is bonded to the additional part of the polymer molecule at the oxygen end group.

In one embodiment, or a combination of two or more embodiments described herein, the silicone rubber comprises a pendant vinyl group and a terminal vinyl group.

In one embodiment, or a combination of two or more embodiments described herein, the silicone rubber comprises a structure selected from iii):

iii)wherein p is 1 to 20 and q is 2000 to 20000. Here, structure i) shows examples of pendant vinyl groups and terminal vinyl groups. In structure iii) above, the pendant vinyl groups can be randomly distributed throughout the polymer chain.

In one embodiment, or a combination of two or more embodiments described herein, the silicone rubber has a viscosity of 10 or more at 25 ≧ C⁶cSt。

In one embodiment, or a combination of two or more embodiments described herein, the total vinyl groups (CH) of the silicone rubber, based on the weight of the silicone rubber, and as determined by 1H NMR₂CH) content of more than or equal to 0.10 mol%.

In one embodiment, or a combination of two or more embodiments described herein, the silicone rubber further comprises the following structure iv):

iv)wherein m is 1 to 20000 and n is 1 to 20000; r1, R2, R3, R4 are each independently alkyl groups, and R1, R2, R3, R4 may be the same alkyl group.

The silicone rubber may comprise a combination of two or more embodiments as described herein.

In one embodiment, or a combination of two or more embodiments described herein, the olefin/α -olefin block copolymer has a density from 0.866g/cc to 0.887g/cc, or from 0.868g/cc to 0.885g/cc, or from 0.870g/cc to 0.880g/cc, or from 0.872g/cc to 0.880g/cc, or from 0.874g/cc to 0.880g/cc (1cc 1cm ═ 1 cm-³)。

In one embodiment, or a combination of two or more embodiments described herein, the olefin/α -olefin block copolymer has a melt index (I2) from 0.5 to 5.0 grams/10 minutes, or from 1.0 to 4.0 grams/10 minutes, or from 1.0 to 3.0 grams/10 minutes, or from 1.0 to 2.0 grams/10 minutes (190 ℃ and 2.16 kg).

In one embodiment, the olefin multi-block copolymer has a melting temperature (Tm) of 100 ℃ to 135 ℃, more preferably 110 ℃ to 130 ℃, and even more preferably 115 ℃ to 125 DEG C

In one embodiment, the olefin multi-block copolymer is an ethylene/α -olefin multi-block copolymer in yet another embodiment, the α -olefin is a C3-C8 α -olefin, and more specifically a C4-C8 α -olefin.

The olefin multi-block copolymer may comprise a combination of two or more embodiments as described herein.

In one embodiment, or a combination of two or more embodiments described herein, the composition includes 70 wt% or more, or 75 wt% or more, or 80 wt% or more, or 85 wt% or more, or 90 wt% or more of component A based on the weight of component A and component B.

In one embodiment, or a combination of two or more embodiments described herein, the composition comprises 10 to 30 wt%, or 15 to 20 wt%, of component B, based on the weight of component a and component B.

In one embodiment, or a combination of two or more embodiments described herein, the composition comprises 60 wt% or more, or 65 wt% or more, or 70 wt% or more, or 75 wt% or more, or 80 wt% or more, 85 wt% or more, or 90 wt% or more of component A and component B, based on the weight of the composition.

In one embodiment, or a combination of two or more embodiments described herein, the composition further comprises a filler. For example, inorganic fillers (e.g., calcium carbonate, talc, silica).

In one embodiment, or a combination of two or more embodiments described herein, the composition further comprises brominated butyl rubber.

In one embodiment, or a combination of two or more embodiments described herein, the composition further comprises an ethylene-based polymer in yet another embodiment, the propylene-based polymer is L DPE.

In one embodiment, or a combination of two or more embodiments described herein, the composition further comprises a crosslinking agent (e.g., a peroxide or triallyl isocyanurate).

In one embodiment, or a combination of two or more embodiments described herein, the composition further comprises a blowing agent, such as modified azodicarbonamide, benzenesulfonylhydrazide, dinitrosopentamethylenetetramine, sodium bicarbonate, or ammonium carbonate.

In one embodiment, or a combination of two or more embodiments described herein, the composition includes one or more blowing agent activators (e.g., zinc oxide, zinc stearate).

In one embodiment, or a combination of two or more embodiments described herein, the amount of component a present in the composition is greater than the amount of component B present in the composition.

In one embodiment, or a combination of two or more embodiments described herein, the composition has an abrasion DIN value of 220mm or less³Or less than or equal to 210mm³Or less than or equal to 200mm³. In one embodiment, the composition has an abrasion DIN value of 190mm or less³Or less than or equal to 180mm³Or less than or equal to 170mm³Or less than or equal to 160mm³Or less than or equal to 150mm³. In one embodiment, or a combination of two or more embodiments described herein, the composition has an abrasion DIN value of 120mm³To 200mm³Or 120mm³To 180mm³Or 120mm³To 160mm³。

In one embodiment, the composition has a wet COF value of 0.500 or more, or 0.510 or more, or 0.520 or more. In one embodiment, or a combination of two or more embodiments described herein, the composition has a wet COF value of 0.530 or 0.540 or 0.550 or 0.560 or 0.570 or 0.580 or 0.590 or 0.600. In one embodiment, or a combination of two or more embodiments described herein, the composition has a wet COF value of from 0.500 to 0.610, or from 0.520 to 0.610, or from 0.530 to 0.610, or from 0.540 to 0.610, or from 0.550 to 0.610.

In one embodiment, or a combination of two or more embodiments described herein, the composition has a resiliency ≧ 66% or ≧ 68%. In one embodiment, or a combination of two or more embodiments described herein, the composition has a resiliency of from 65% to 70%.

In one embodiment, or a combination of two or more embodiments described herein, the composition has a tensile strength ≧ 2.50MPa, or ≧ 2.60MPa, or ≧ 2.70 MPa. In one embodiment, or a combination of two or more embodiments described herein, the composition has a tensile strength of from 2.50MPa to 3.20MPa, or from 2.60MPa to 3.20MPa, or from 2.70MPa to 3.20 MPa. 1

In one embodiment, or a combination of two or more embodiments described herein, the composition has a compression set value of 26% or less, or 24% or less, or 22% or less. In one embodiment, or a combination of two or more embodiments described herein, the composition has a compression set value of 20% to 26%, or 20% to 24%, or 20% to 22%.

In one embodiment, or a combination of two or more embodiments described herein, the resilience of the composition>60％、DIN<200mm³And a wet COF>0.55。

In one embodiment, or a combination of two or more embodiments described herein, the composition comprises ≦ 1.00 wt% or ≦ 0.50 wt%, or ≦ 0.20 wt%, or ≦ 0.10 wt%, or ≦ 0.05 wt% of the styrenic block copolymer or terpolymer (e.g., SES, SBS, SEP, etc.), based on the weight of the composition. In one embodiment, or a combination of two or more embodiments described herein, the composition does not include a styrenic block copolymer or terpolymer (e.g., SES, SBS, SEP, etc.).

In one embodiment, or a combination of two or more embodiments described herein, the composition comprises ≦ 1.00 wt% polystyrene, or ≦ 0.50 wt%, or ≦ 0.20 wt%, or ≦ 0.10 wt%, or ≦ 0.05 wt% polystyrene based on the weight of the composition. In one embodiment, the composition does not comprise polystyrene.

In one embodiment, the composition includes 50 wt.% or less, or 40 wt.% or less, or 30 wt.% or less, or 20 wt.% or less, or 10 wt.% or less EVA based on the weight of the composition.

In one embodiment, or a combination of two or more embodiments described herein, the composition comprises ≦ 1.00 wt% EVA, or ≦ 0.50 wt%, or ≦ 0.20 wt%, or ≦ 0.10 wt%, or ≦ 0.05 wt% EVA, based on the weight of the composition. In one embodiment, the composition does not include EVA.

In one embodiment, or a combination of two or more embodiments described herein, the composition comprises ≦ 1.00 wt% or ≦ 0.50 wt% or ≦ 0.20 wt% or ≦ 0.10 wt% or ≦ 0.05 wt% polyamide based on the weight of the composition. In one embodiment, the composition does not include a polyamide.

The inventive compositions may comprise a combination of two or more embodiments as described herein.

Also provided is an article comprising at least one component formed from a composition of one or more of the compositions described herein. In yet another embodiment, the article is a foam, and a more unitary foam. In one embodiment, the foam has a density of 0.20 to 0.30g/cc, or 0.22 to 0.28g/cc, or 0.24 to 0.26 g/cc.

The article may comprise a combination of two or more embodiments as described herein.

Olefin multi-block copolymers

The composition of the present invention comprises an olefin multi-block copolymer or an olefin block copolymer. As used herein, an "olefin block copolymer" (OBC) is a multi-block orSegmented copolymers, and comprise two or more chemically distinct regions or segments (referred to as "blocks") joined in a linear fashion, i.e., polymers comprising chemically differentiated units joined end-to-end with respect to polymerized ethylene functionality rather than in a pendant or grafted fashion. In certain embodiments, the blocks differ in the following respects: the amount or type of comonomer incorporated therein, the density, the amount of crystallinity, the crystallite size of the polymers that can be attributed to such compositions, the type or degree of tacticity (in-line or in-line), regioregularity or regioirregularity, the amount of branching (including long chain branching or hyper-branching), homogeneity, or any other chemical or physical property. Due to the unique process for making the copolymers, the olefin block copolymers are made from polydispersity index (PDI or M)_w/M_n) Is characterized by a unique distribution of block lengths and/or a distribution of block numbers. More specifically, when produced in a continuous process, embodiments of the OBC may have PDI in the range of 1.7 to 8; or 1.7 to 3.5; or 1.7 to 2.5; or 1.8 to 2.5; or 1.8 to 2.1. When produced in a batch or semi-batch process, embodiments of the OBC may have PDI in the range of 1.0 to 2.9; or 1.3 to 2.5; or 1.4 to 2.0; or 1.4 to 1.8.

Ethylene/α -olefin multi-block copolymer further comprises ethylene and a copolymerizable α -olefin comonomer in polymerized form, characterized by multiple (i.e., two or more) blocks or segments of two or more polymerized monomer units that differ in chemical or physical properties (block interpolymer), and is a multi-block copolymer.

(AB)_n，

Wherein n is an integer of at least 1, preferably greater than 1, such as 2,3,4, 5, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100 or more, "a" represents a hard block or segment; and "B" represents a soft block or segment. A and B are connected in a linear fashion, not in a branched or star fashion. "hard" segment refers to a block of polymerized units in which ethylene is present in an amount greater than 95 weight percent in some embodiments, and greater than 98 weight percent in other embodiments. Stated differently, the comonomer content in the hard segment is less than 5 weight percent of the total weight of the hard segment in some embodiments, and less than 2 weight percent of the total weight of the hard segment in other embodiments. In some embodiments, the hard segments comprise all or substantially all of ethylene.

On the other hand, a "soft" segment refers to a block of polymerized units, wherein the comonomer content is greater than 5 weight percent, in some embodiments greater than 8 weight percent, in various other embodiments greater than 10 weight percent, or greater than 15 weight percent of the total weight of the soft segment. In some embodiments, the comonomer content in the soft segment can be greater than 20 wt.%, in various other embodiments greater than 25 wt.%, greater than 30 wt.%, greater than 35 wt.%, greater than 40 wt.%, greater than 45 wt.%, greater than 50 wt.%, or greater than 60 wt.%.

Because the distinct distinguishable segments or blocks formed from two or more monomers are linked into a single polymer chain, the polymers cannot be completely fractionated using standard selective extraction techniques. For example, polymers containing relatively crystalline regions (high density segments) and relatively amorphous regions (low density segments) cannot be selectively extracted or fractionated using different solvents. In an embodiment, the amount of polymer extractable using the dialkyl ether or alkane solvent is less than 10%, or less than 7%, or less than 5%, or less than 2% of the total polymer weight.

Additionally, the PDI of the OBC disclosed herein conforms to the Schulz-Flory distribution rather than the Poissonidistribution (Poissondistribution). The OBCs of the present invention are made by the polymerization process described in U.S. patent No. 7,858,706 and U.S. patent No. 7,608,668, which produces a product having a polydisperse block distribution as well as a polydisperse block size distribution. This results in the formation of OBC products with distinguishable physical properties. The theoretical benefits of polydisperse block distributions have been modeled and discussed previously in Potemkin, physical Review E (1998)57(6), pages 6902-6912 and Dobrynin, journal of chemi-physical (J.chem. Phyvs.) 107(21), pages 9234-9238.

In yet another embodiment, the ethylene/α -olefin multi-block copolymer has a density of from 0.86 to 0.89g/cc, more preferably from 0.87 to 0.88g/cc (1cc ═ 1 cm)³)。

In one embodiment, an ethylene/α -olefin multi-block copolymer is defined as having (a) a Mw/Mn from 1.7 to 3.5, at least one melting point, Tm, in degrees celsius, and a density, d, in grams/cubic centimeter, wherein the numerical values of Tm and d correspond to the relationship:

Tm>-2002.9+4538.5(d)-2422.2(d)²。

in one embodiment, an ethylene/α -olefin multi-block copolymer is defined as having (a) a Mw/Mn from 1.7 to 3.5, at least one melting point, Tm, in degrees celsius, and a density, d, in grams/cubic centimeter, wherein the numerical values of Tm and d correspond to the relationship:

Tm>-2002.9+4538.5(d)-2422.2(d)²，

wherein d is 0.866g/cc, or 0.87g/cc to 0.89g/cc, or 0.91g/cc, or 0.93g/cc, and Tm is 113 ℃, or 115 ℃, or 117 ℃, or 118 ℃ to 120 ℃, or 125 ℃, or 130 ℃.

In one embodiment, the ethylene/α -olefin multi-block copolymer is defined as having (B) a Mw/Mn from 1.7 to 3.5 and is characterized by a heat of fusion, Δ H in J/g, and a delta, Δ T in degrees celsius, defined as the temperature difference between the tallest DSC peak and the tallest crystallography classification ("CRYSTAF") peak, wherein the numerical values of Δ T and Δ H have the following relationships:

for Δ H greater than zero and up to 130J/g, Δ T > -0.1299(Δ H) +62.81,

aiming at the conditions that the delta H is more than 130J/g and the delta T is more than or equal to 48 ℃,

wherein the CRYSTAF peak is determined using at least 5 percent of the cumulative polymer, and if less than 5 percent of the polymer has a distinguishable CRYSTAF peak, then the CRYSTAF temperature is 30 ℃.

In one embodiment, an ethylene/α -olefin multi-block copolymer is defined as having (C) an elastic recovery, Re, in percent measured at 300% strain and 1 cycle with a compression molded ethylene/α -olefin interpolymer film, and having a density, d, in grams/cubic centimeter, wherein the numerical values of Re and d satisfy the following relationship when the ethylene/α -olefin interpolymer is substantially free of a crosslinked phase:

Re>1481-1629(d)。

in an embodiment, an ethylene/α -olefin multi-block copolymer is defined as having (D) a molecular weight fraction that elutes between 40 ℃ and 130 ℃ when fractionated using TREF, characterized in that the fraction has a molar comonomer content that is at least 5% higher than the molar comonomer content of a comparable random ethylene interpolymer fraction that elutes between the same temperatures, wherein the comparable random ethylene interpolymer has the same comonomer and has a melt index, density, and molar comonomer content (based on the entire polymer) within 10% of the melt index, density, and molar comonomer content of the ethylene/α -olefin interpolymer.

In one embodiment, the ethylene/α -olefin multi-block copolymer is defined as having (E) a storage modulus G '(25 ℃) at 25 ℃, and a storage modulus G' (100 ℃) at 100 ℃, wherein the ratio of G '(25 ℃) to G' (100 ℃) is in the range of about 1:1 to about 9: 1.

In one embodiment, the ethylene/α -olefin multi-block copolymer is defined as having (F) a molecular fraction that elutes between 40 ℃ and 130 ℃ when fractionated using TREF, characterized in that the fraction has a block index of at least 0.5 and up to about 1 and a molecular weight distribution, Mw/Mn, greater than about 1.3. in yet another embodiment, the ethylene/α -olefin multi-block copolymer has a molecular weight distribution, Mw/Mn, less than or equal to about 3.5.

In one embodiment, the ethylene/α -olefin multi-block copolymer is defined as having (G) an average block index greater than zero and up to about 1.0, and a molecular weight distribution, Mw/Mn, greater than about 1.3.

The ethylene/α -olefin multi-block copolymer can have any combination of properties (A) - (G) described above.

Non-limiting examples of suitable comonomers include linear/branched α -olefins having from 3 to 30 carbon atoms, such as propene, 1-butene, 1-pentene, 3-methyl-l-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene and 1-eicosene, cycloolefins having from 3 to 30 or 3 to 20 carbon atoms, such as cyclopentene, cycloheptene, norbornene, 5-methyl-2-norborene, tetracyclododecene and 2-methyl-1, 4,5, 8-dimethano-1, 2,3,4,4a,5,8,8 a-octahydronaphthalene, dienes and polyolefins, such as butadiene, isoprene, 4-methyl-1, 3-pentadiene, 1, 4-pentadiene, 1, 5-hexadiene, 1, 4-hexadiene, 1,3, 7-dimethyl-1, 3-octadiene, 1, 7-octadiene, 1, 6-difluorophenylenediene, 1, 7-octadiene, 7-diphenylethylene and 1, 7-bis (1, 7-and 7-phenylenediene.

In one embodiment, the comonomer in the ethylene/α -olefin multi-block copolymer is selected from propylene, butene, hexene or octene.

In one embodiment, the ethylene/α -olefin multi-block copolymer does not include styrene.

In yet another embodiment, the ethylene/octene multi-block copolymer has a density of from 0.86 to 0.89g/cc (1cc ═ 1 cm)³)。

In one embodiment, the soft segment of the ethylene/octene multi-block copolymer comprises from 5 mol%, or 7 mol%, or 9 mol%, or 11 mol%, or 13 mol%, or 15 mol% to 18 mol%, or 20 mol% units derived from octene. The ethylene/octene multi-block copolymer has a density of from 0.866g/cc to 0.887 g/cc. The ethylene/octene multi-block copolymer has a Melt Index (MI) of 0.5 g/10 min, or 5.0 g/10 min, or 10 g/10 min, or 15 g/10 min to 20 g/10 min, or 25 g/10 min, or 30 g/10 min.

In one embodiment, the OBC is an ethylene/octene multi-block copolymer having one, some, or all of the following properties: a density of from 0.866g/cc to 0.880g/cc, a melt index of from 0.5 g/10 minutes to 10 g/10 minutes, and a melt temperature of from 100 ℃ to 130 ℃ or from 110 ℃ to 125 ℃.

Olefin multi-Block Copolymers are available from Dow Chemical Company under The trade name INFUSE Olefin Block Copolymers.

The ethylene/α -olefin multi-block copolymer can include a combination of two or more embodiments as described herein.

Additive agent

The composition of the invention may comprise one or more additives. Additives include, but are not limited to, antioxidants, ultraviolet absorbers, antistatic agents, pigments, viscosity modifiers, anti-adhesion agents, mold release agents, fillers, coefficient of friction (COF) modifiers, induction heating particles, odor modifiers/adsorbents, and any combination thereof.

In one embodiment, the composition comprises the following, by weight of the composition: 50 to 95 weight percent of an olefin multi-block copolymer, 5 to 50 weight percent of a silicone rubber, 0 to 10 weight percent of a brominated butyl rubber, 0.1 to 10 weight percent of a crosslinking agent, 0.1 to 10 weight percent of a blowing agent, 0 to 5 weight percent of one or more activators, and 0 to 10 weight percent of an inorganic filler.

Summary of some embodiments

1) A composition comprising at least the following components:

A) an olefin multi-block copolymer;

B) silicone rubbers comprising pendant vinyl groups and optionally terminal vinyl groups.

2) The composition of claim 1, wherein the silicone rubber has a weight average molecular weight (Mw) of 200,000 g/mole or more, or 250,000 g/mole or more, or 300,000 g/mole or more, or 350,000 g/mole or more, or 400,000 g/mole or more, or 450,000 g/mole or more, or 500,000 g/mole or more.

3) The composition according to claim 1 or 2, the silicone rubber comprising one or more structures selected from the following i), and optionally one or more structures selected from ii):

i)-O-[Si(R)(CH＝CH₂)]-[Si(R')(R”)]-O-, wherein R, R 'and R "are each independently alkyl, and more C1-C6 alkyl, and wherein R, R' and R" may all be the same alkyl;

ii)H₂C＝CH-[Si(R^IV)(R^V)]-O-wherein R^IVAnd R^VEach independently is alkyl, and is more C1-C6 alkyl, and wherein R is^IVAnd R^VMay be the same alkyl group. Here, structure i) represents an internal group of the silicone rubber polymer molecule, which internal group is bonded to an additional part of the polymer molecule at the respective oxygen end group. Structure ii) represents the end group of the silicone rubber polymer molecule, which is bonded to the additional part of the polymer molecule at the oxygen end group.

4) The composition of any of claims 1-3, wherein the silicone rubber comprises pendant vinyl groups and terminal vinyl groups.

5) The composition of any of claims 1-4, wherein the silicone rubber comprises a structure selected from the group consisting of iii):

iii)wherein p is 1 to 20 and q is 2000 to 20000. Here, structure i) shows examples of pendant vinyl groups and terminal vinyl groups. In structure iii) above, the pendant vinyl groups can be randomly distributed throughout the polymer chain.

6) The composition as described in any one of 1 to 5, wherein the viscosity of the silicone rubber at 25 ℃ is not less than 10⁶cSt。

7) The composition of any of claims 1-6, wherein the total vinyl groups (CH) of the silicone rubber, based on the weight of the silicone rubber, and as determined by 1H NMR₂CH) content of more than or equal to 0.10 mol%.

8) The composition of any of claims 1-7, wherein the silicone rubber further comprises the following structure iv):

iv)wherein m is 1 to 20000 and n is 1 to 20000; r1, R2, R3. R4 are each independently alkyl, and R1, R2, R3, R4 may be the same alkyl.

9) The composition of any of claims 1-8, wherein the olefin/α -olefin block copolymer has a density from 0.866g/cc to 0.887g/cc, or from 0.868g/cc to 0.885g/cc, or from 0.870g/cc to 0.880g/cc, or from 0.872g/cc to 0.880g/cc, or from 0.874g/cc to 0.880g/cc (1cc ═ 1 cm%³)。

10) The composition of any of claims 1-9, wherein the olefin/α -olefin block copolymer has a melt index (I2) of 0.5 to 5.0 grams/10 minutes, or 1.0 to 4.0 grams/10 minutes, or 1.0 to 3.0 grams/10 minutes, or 1.0 to 2.0 grams/10 minutes (190 ℃ and 2.16 kg).

11) The composition according to any one of claims 1 to 10, wherein the olefin multi-block copolymer has a melting temperature (Tm) of from 100 ℃ to 135 ℃, more preferably from 110 ℃ to 130 ℃, more preferably from 115 ℃ to 125 DEG C

12) The composition of any of claims 1-11, wherein the olefin multi-block copolymer is an ethylene/α -olefin multi-block copolymer in yet another embodiment, the α -olefin is a C3-C8 α -olefin, and more C4-C8 α -olefin.

13) The composition of any of claims 1-12, wherein the composition comprises 70 wt% or more, or 75 wt% or more, or 80 wt% or more, or 85 wt% or more, or 90 wt% or more of component A based on the weight of component A and component B.

14) The composition of any of claims 1-13, wherein the composition comprises 10 to 30 wt%, or 15 to 20 wt%, of component B, based on the weight of component a and component B.

15) The composition according to any one of claims 1 to 14, wherein the composition comprises 60% by weight or more, or 65% by weight or more, or 70% by weight or more, or 75% by weight or more, or 80% by weight or more, 85% by weight or more, or 90% by weight or more of component A and component B, based on the weight of the composition.

16) The composition of any of claims 1-15, wherein the composition further comprises a filler. For example, inorganic fillers (e.g., calcium carbonate, talc, silica).

17) The composition of any of claims 1-16, wherein the composition further comprises bromobutyl rubber.

18) The composition of any of claims 1-17, wherein the composition further comprises an ethylene-based polymer in yet another embodiment, the propylene-based polymer is L DPE.

19) The composition of any of claims 1-18, wherein the composition further comprises a crosslinking agent (e.g., a peroxide or triallyl isocyanurate).

20) The composition of any of claims 1-19, wherein the composition further comprises a blowing agent, such as modified azodicarbonamide, benzenesulfonylhydrazide, dinitrosopentamethylenetetramine, sodium bicarbonate, or ammonium carbonate.

21) The composition of any of claims 1-20, wherein the composition comprises one or more blowing agent activators (e.g., zinc oxide, zinc stearate).

22) The composition of any of claims 1-21, wherein component a is present in the composition in an amount greater than the amount of component B present in the composition.

23) The composition as claimed in any of claims 1 to 22, wherein the composition has an abrasion DIN value of 220mm or less³Or less than or equal to 210mm³Or less than or equal to 200mm³. In one embodiment, the composition has an abrasion DIN value of 190mm or less³Or less than or equal to 180mm³Or less than or equal to 170mm³Or less than or equal to 160mm³Or less than or equal to 150mm³。

24) The composition as claimed in any of claims 1 to 23, wherein the composition has an abrasion DIN value of 120mm³To 200mm³Or 120mm³To 180mm³Or 120mm³To 160mm³。

25) The composition according to any of claims 1 to 24, wherein the composition has a wet COF value of 0.500 or more, or 0.510 or more, or 0.520 or more.

26) The composition according to any of claims 1 to 25, wherein the composition has a wet COF value of 0.530 or more, or 0.540 or more, or 0.550 or more, or 0.560 or more, or 0.570 or more, or 0.580 or more, or 0.590 or more, or 0.600 or more.

27) The composition of any of claims 1-26, wherein the composition has a wet COF value of from 0.500 to 0.610, or from 0.520 to 0.610, or from 0.530 to 0.610, or from 0.540 to 0.610, or from 0.550 to 0.610.

28) The composition according to any of claims 1 to 27, wherein the composition has a resilience of 66% or more, or 68% or more.

29) The composition of any of claims 1-28, wherein the composition has a resiliency of from 65% to 70%.

30) The composition according to any of claims 1 to 29, wherein the tensile strength of the composition is 2.50MPa or more, or 2.60MPa or more, or 2.70MPa or more.

31) The composition of any of claims 1-30, wherein the composition has a tensile strength of 2.50MPa to 3.20MPa, or 2.60MPa to 3.20MPa, or 2.70MPa to 3.20 MPa.

32) The composition of any of claims 1-31, wherein the composition has a compression set value of 26% or less, or 24% or less, or 22% or less.

33) The composition of any of claims 1-32, wherein the composition has a compression set value of from 20% to 26%, or from 20% to 24%, or from 20% to 22%.

34) The composition of any of claims 1 to 33, wherein the composition has a resilience>60％、DIN<200mm³And a wet COF>0.55。

35) The composition of any of claims 1-34, wherein the composition comprises ≦ 1.00 wt%, or ≦ 0.50 wt%, or ≦ 0.20 wt%, or ≦ 0.10 wt%, or ≦ 0.05 wt% of the styrenic block copolymer or terpolymer (e.g., SES, SBS, SEP, etc.), based on the weight of the composition.

36) The composition of any of claims 1-35, wherein the composition does not comprise a styrenic block copolymer or terpolymer (e.g., SES, SBS, SEP, etc.).

37) The composition of any of claims 1-36, wherein the composition comprises less than or equal to 1.00 wt%, or less than or equal to 0.50 wt%, or less than or equal to 0.20 wt%, or less than or equal to 0.10 wt%, or less than or equal to 0.05 wt% polystyrene, based on the weight of the composition.

38) The composition of any of claims 1-37, wherein the composition does not comprise polystyrene.

39) The composition of any of claims 1-38, wherein the composition comprises less than or equal to 50 wt%, or less than or equal to 40 wt%, or less than or equal to 30 wt%, or less than or equal to 20 wt%, or less than or equal to 10 wt% EVA, based on the weight of the composition.

40) The composition of any of claims 1-39, wherein the composition comprises ≦ 1.00 wt%, or ≦ 0.50 wt%, or ≦ 0.20 wt%, or ≦ 0.10 wt%, or ≦ 0.05 wt% EVA, based on the weight of the composition.

41) The composition of any of claims 1-40, wherein the composition does not comprise EVA.

42) The composition of any of claims 1-41, wherein the composition comprises less than or equal to 1.00 wt%, or less than or equal to 0.50 wt%, or less than or equal to 0.20 wt%, or less than or equal to 0.10 wt%, or less than or equal to 0.05 wt% of the polyamide, based on the weight of the composition.

43) The composition of any of claims 1-42, wherein the composition does not comprise a polyamide.

44) The composition of any of claims 1-43, wherein the silicone rubber is not liquid at room temperature (23 ℃).

45) The composition of any of claims 1-44, wherein the silicone rubber is a solid at room temperature (23 ℃).

46) An article comprising at least one component formed from the composition of any one of claims 1-45.

47) The article of manufacture of 46, wherein the article is a foam, and more mono-basic foam.

48) The article of manufacture of claim 46, wherein the foam has a density of 0.20 to 0.30g/cc, or 0.22 to 0.28g/cc, or 0.24 to 0.26 g/cc.

Definition of

Unless stated to the contrary, implied from the context, or customary in the art, all parts and percentages are by weight and all test methods are current as of the filing date of this disclosure.

As used herein, the term "composition" includes materials comprising the composition, as well as reaction products and decomposition products formed from the materials of the composition.

The term "comprises" and its derivatives are not intended to exclude the presence of any additional component, step or procedure, whether or not the same is disclosed herein. To avoid any doubt, all compositions claimed herein through use of the term "comprising" may include any additional additive, adjuvant, or compound, whether polymeric or otherwise, unless stated to the contrary. In contrast, the term "consisting essentially of … …" excludes from any subsequently listed range any other components, steps or procedures other than those not important to operability. The term "consisting of … …" excludes any component, step, or procedure not specifically recited or recited.

As used herein, the term "polymer" refers to a polymeric compound prepared by polymerizing monomers of the same or different types. The generic term polymer thus embraces the term homopolymer (employed to refer to polymers prepared from only one type of monomer, with the understanding that trace amounts of impurities can be incorporated into the polymer structure), and the term interpolymer as defined below. Trace impurities may be incorporated into and/or within the polymer.

As used herein, the term "interpolymer" refers to a polymer prepared by the polymerization of at least two different types of monomers. The generic term interpolymer thus encompasses copolymers (often used to refer to polymers prepared from two different types of monomers), and polymers prepared from more than two different types of monomers.

As used herein, the term "olefin-based polymer" refers to a polymer that includes, in polymerized form, a majority amount of an olefin monomer, such as ethylene or propylene (based on the weight of the polymer), and optionally may include one or more comonomers.

As used herein, the term "ethylene-based polymer" refers to a polymer that includes a majority weight percent of polymerized ethylene monomer (based on the total weight of the polymer), and optionally may include at least one polymerized comonomer.

As used herein, the term "ethylene/α -olefin interpolymer" refers to an interpolymer that comprises, in polymerized form, a majority amount of ethylene monomer (based on the weight of the interpolymer), and at least one α -olefin.

As used herein, the term "ethylene/α -olefin copolymer" refers to a copolymer that includes, in polymerized form, a majority amount of ethylene monomer (based on the weight of the copolymer), and α -olefin as the only two monomer types.

As used herein, the term "propylene-based polymer" refers to a polymer that includes, in polymerized form, a majority amount of propylene monomer (based on the total weight of the polymer), and optionally may include at least one polymerized comonomer.

Test method

GPC-silicone rubber

The chromatographic apparatus consisted of a Waters 2695 separation module equipped with a vacuum degasser and a Waters 2414 refractive index detector, separation was performed using STYRAGE L guard column (30mm × 4.6.6 mm), followed by three STYRAGE L HR columns (300mm × 7.8.8 mm) (molecular weight separation range 100 to 4,000,000), analysis was performed using certified grade toluene flowing at 1.0 ml/min as the eluent, and both column and detector were heated to 45 ℃, samples were prepared by weighing about 0.025g of pure sample into a 12m L glass vial and diluted with about 5m L toluene (0.5% wt/v), after filtration through a 0.45 μm PTFE filter, the sample solution was transferred into a glass autosampler vial, injection volume of 100 μ L was used, and data was collected for 38 min.

¹Identification of the Total vinyl level of H NMR-Silicone products

For silicone rubbers (e.g., RBB-2008-50 and SRB # 1):

the sample (0.05g) was dissolved in about 2.75g CDCl3 in a 10mm NMR tube at 50 ℃ on a Brooks AVANCE 400MHz spectrometer equipped with a Brooks (Bruker) Dual DU L high temperature CryoProbe and a sample temperature of 50 ℃¹H NMR. Two experiments were performed to obtain spectra, a control spectrum to quantify total polymer protons, and a double presaturation experiment, which suppresses strong polymer backbone peaks and enables high sensitivity spectra for quantification of unsaturation. With ZG pulses, 8 scans, 1.64s, relaxation delay (D)₁) Control was performed for 30 s. With modified pulse sequence, 100 scans, DS 4, AQ 1.64s, Pre-saturation time (D)₁)1s, relaxation delay (D)₁₃) Double pre-saturation experiments were performed for 30 s.

For silicone rubber blends (e.g., SPB #2)

Test samples were prepared by adding 0.05g of sample to 2.75g by weight of 50/50 o-dichlorobenzene-d 4/perchloroethylene with 0.001M Cr (AcAc)3 in a 10mm NMR tube, on a BrookDual DU L high temperature CryoProbe equipped BrookWAVE 400MHz spectrometer with a sample temperature of 120 ℃¹H NMR. Two experiments were performed to obtain spectra, a control spectrum to quantify total polymer protons, and a double presaturation experiment, which suppresses strong polymer backbone peaks and enables high sensitivity spectra for end-group quantification. With ZG pulses, 16 scans, 1.64s, relaxation delay (D)₁)14s control was performed. With modified pulse sequence, 200 scans, DS 4, AQ 1.64s, Pre-saturation time (D)₁)1s, relaxation delay (D)₁₃)13s double pre-saturation experiments were performed.

²⁹Si NMR-confirmation of the Presence of side-chain vinyl groups

About 0.85g of the sample was dissolved in about 1.5g of a solution containing 0.025M Cr (AcAc) in a 10mm NMR tube at 50 deg.C₃CDCl as a relaxant₃In (1). Performed on a Brooks AVANCEIII 400MHz spectrometer equipped with a Brooks 10mm PABBO probe and a sample temperature of 50 ℃²⁹Si NMR. Spectra were performed with a ZGIG pulse sequence, 8000 to 10,000 scans and 16s relaxation delay. Reference value of PDMS backbone Si unit is-22 ppm. Si attached to the terminal vinyl group was observed at-4 ppm, while Si having a side chain vinyl group was observed at-36 ppm.

SEM analysis

Method of cutting foam samples the samples were carefully cut using a single-edged blade to obtain SEM images. The samples were coated twice with a conductive coating to ensure good image quality. The samples were then placed in a Nova 630 SEM and viewed through an ETD detector at an accelerated voltage of 5KV detector.

Density of foam

Each Bun foam sample was weighed to the nearest 0.1 grams and the foam volume was determined by measuring the length, width and thickness to the nearest 0.01 cm. Density was calculated based on weight and volume. The sample cut from the Bun foam is shown in FIG. 1.

Rebound of falling ball (rebound resilience)

An 5/8 "diameter steel ball was dropped from a height of 500mm onto a Bun foam slab cut vertically from the Bun foam so that the slab had both an upper skin and a lower skin. % springback was calculated as { [ "springback height (mm)"/500 (mm) ]. times.100 }.

Asker C hardness

Hardness is the average of five readings (5 second delay) measured on the surface of a sample according to ASTM D2240.

Mechanical Properties

Bun foam skins and foam layers were provided for ASTM D638 (tensile, type 4) and ASTM D624 (tear, type C) mechanical property testing, each crosshead speed was 20 inches/minute the sample thickness was about 3mm the tear strength was measured by using a test specimen with the dimensions 6 inches (length) × 1 inches (width) × 0.4 inches (thickness) and a notch depth of 1 to 1.5 inches and at a test speed of 2 inches/minute.

DIN abrasion test (drum method):

DIN abrasion volume loss (in mm) was measured according to ASTM D5963 under a load of 10N, and using the rotation mode (method B, drum 40rpm), 40m abrasion during this test³In units). For each foam formulation, a rectangular flat sheet (peeled on one surface, about 10mm thick) was cut from Bun foam and this flat sheet was die cut into disks, each disk having the following dimensions: with a diameter of 16mm and a thickness of about 10 mm. The DIN abrasion volume loss was calculated according to the following formula:

wherein:

DIN: in mm³In terms of the loss in abrasion per unit,

Δm_t: weight loss in mg of test specimen

ρ_t: in mg/mm³Is the density of the test sample in units,

Δm_s: weight of standard rubber in mgAnd (4) loss.

The average is reported based on three test samples.

Wet COF

The wet COF was measured at a tensile distance of 230mm under a load of 2.7kg and a tensile speed of 100 mm/min according to ASTM D1894 (see fig. 1 a). In this test, frosted glass (flat) was used as the substrate, and deionized water was uniformly dispersed on the glass surface to form a thin water film. For each foam formulation, a rectangular flat sheet (peeled on one surface, about 7mm thick) was cut from Bun foam and this flat sheet was die cut into disks, each disk having the following dimensions: about 12.7mm in diameter and about 7mm in thickness). The disc was fixed to a slide plate using double-sided tape so that the surface of the skin was exposed and in contact with the glass plane. The maximum force Fm (kgf) during the stretch distance was recorded and the wet COF was calculated as (Fm)/(2.7kgf) and the average wet COF of the three test samples was recorded.

Density-polymer samples

Polymer samples were prepared according to ASTM D1928. Measurements were made within one hour of sample pressing using ASTM D792, method B.

Melt index

The melt index (or I2, I) of an ethylene-based polymer or OBC or a composition of the invention is measured according to ASTM D1238, Condition 190 ℃/2.16kg₂Or MI) and reported in grams eluted per 10 minutes.

DSC Standard method

The crystallinity of the ethylene-based polymer (PE or OBC) samples and the propylene-based polymer (PP) samples was measured using Differential Scanning Calorimetry (DSC). About five to eight milligrams of sample were weighed and placed in a DSC pan. The lid is pressed onto the pan to ensure a closed atmosphere. The sample pan was placed in a DSC unit, and the ethylene-based polymer sample was then heated to a temperature of 180 ℃ (230 ℃ for the propylene-based polymer sample) at a rate of about 10 degrees celsius per minute. The sample was held at this temperature for three minutes. The sample was then cooled at a rate of 10 degrees Celsius/min to-60 degrees Celsius for the ethylene-based polymer sample (for the propylene-based polymer sample-40 ℃) and held isothermally at this temperature for three minutes. The sample was then heated at a rate of 10 degrees celsius/minute until completely melted (second heating). By comparing the heat of fusion (H) determined from the second heating curve_f) Divided by the theoretical heat of fusion of 292J/g for the ethylene-based polymer sample (165J/g for the propylene-based polymer sample) and this amount is multiplied by 100 (e.g., the percent crystallinity ═ H for the ethylene-based polymer sample (H_f/292J/g) × 100, and for the propylene-based polymer sample, the% crystallinity is calculated as (Hf/165J/g) × 100).

The second heating profile obtained from DSC, as described above (peak T), unless otherwise stated_m) Determination of the melting Point (T) of the respective polymers_m). From the first cooling curve (peak T)_c) Determination of the crystallization temperature (T)_c)。

Compression set

Compression set was measured at 50 ℃ according to ASTM D395. For each foam formulation, a rectangular flat sheet (peeled on one surface, about 19.5mm thick) was cut from Bun foam and this flat sheet was die cut into disks (button samples), each disk having the following dimensions: 29mm (+ -0.5 mm) in diameter and about 19.5mm (+ -0.5 mm) in thickness. The samples of each button were examined for gaps, uneven thickness and non-uniformity and the selected button was tested (without those defects). Two specimens of each sample were compression set at the specified temperature and the average result for the two specimens was reported. The button sample was placed in a compression device having two metal plates that could be pressed together and locked in place at 50% of the original height of the button sample. The compression apparatus with the compressed sample was then placed in an oven and equilibrated at the appropriate temperature for the indicated time (6 hours at 50 ℃). In this test, the stress is released at the test temperature and the thickness of the sample is measured after a 30 minute equilibration period at room temperature. Compression set is a measure of the degree of recovery of the sample after compression and is calculated according to the equation CS ═ H0-H2)/(H0-H1; where H0 is the original thickness of the sample, H1 is the thickness of the spacer used, and H2 is the final thickness of the sample after removal of the compressive force.

Expansion ratio

The expansion ratio of the Bun foam was calculated via the following formula:

ER＝L₁/L₀

l therein₀Is the length of the die, and L₁Is the length of Bun foam after stabilization (overnight) at room temperature.

Some embodiments of the present disclosure will now be described in detail in the following examples.

Experiment of

Material

INFUSE 9100: olefin block copolymer (ethylene/octene multi-block copolymer), density 0.877g/cm³(ASTM D792), MI 1.0 grams/10 minutes (ASTM D1238 at 190 ℃/2.16 kg), shore a (shore a) 75(ASTM D2240).

Taismox 7360M: ethylene-vinyl acetate copolymer, density 0.941g/cm³(ASTM D792), MI 2.5 grams/10 minutes (ASTM D1238 at 190 ℃/2.16 kg), shore a-86 (ASTM D2240), 21 wt% VA content by weight of the copolymer.

E L VAX 265 ethylene vinyl acetate copolymer, density 0.951g/cm³(ASTM D792), MI 3.0 grams/10 minutes (ASTM D1238 at 190 ℃/2.16 kg), shore a 83(ASTM D2240), 28 wt% VA content by weight of the copolymer.

E L VAX 40L-03 ethylene-vinyl acetate copolymer, density 0.967g/cm³(ASTM D792), MI 3.0 grams/10 minutes (ASTM D1238 at 190 ℃/2.16 kg), shore a 65(ASTM D2240), 40 wt% VA content by weight of the copolymer.

RBB 2008-50: silicone rubber-satisfies the features of component B of claim 1.

SRB # 1: silicone rubber base # 1; mw about 100000 g/mol; terminal vinyl groups on PDMS only, silica content of 29.7 wt% based on the weight of silicone rubber; vinyl (1H NMR) content of 0.3 mol%, based on the weight of the silicone rubber. The vinyl group can be identified by 1H NMR. Use of²⁹Si NMR to confirm the presence of the side chain vinyl group and quantify the level of the side chain vinyl group.

SPB #2 Silicone rubber blend #2, ultra high molecular weight siloxane polymer (silicone rubber) dispersed in low density polyethylene (L DPE), at a level of 50 wt% siloxane polymer based on the weight of the blend.

BIIR 2030: brominated butyl rubber; density 0.93g/cm³(ASTM D792); 32MU munic (Mooney) at 125 ℃; bromine content was 1.8 wt% based on the weight of the rubber.

L UPEROX DC40P dicumyl peroxide (DCP) from Akema (Arkema) having an active peroxide content of about 40 wt%.

L UPEROX DC40P-SP2 is a scorch preventive DCP from Acoma having an active peroxide content of about 40 wt%.

AC 9000: azodicarbonamide type foaming agents. ZnO: and (3) zinc oxide. ZnSt: and (3) zinc stearate. ATOMITE: calcium carbonate.

A. Formulations

The formulations (compositions) are shown in table 1.

Table 1: formulations

EVA*：EVA 7360M/EVA 265/EVA 40L-03(30/30/40，wt/wt/wt)

Formulation preparation and sample preparation

Each formulation listed in table 1 was prepared by using the same method. Using the CE-1 formulation as an example, the polymer, here only INFUSE 9100(914 g), was added to a "1.5 liter" BANBURY mixer. Then, after the polymer components had melted (about 5 minutes at 120 ℃), ZnO, ZnSt and CaCO3 were added. Finally, the blowing agent and peroxide are added and mixed for an additional 3 to 5 minutes at about 120 ℃ (temperature not exceeding 130 ℃) for a total mixing time of 15 minutes to form a mixed formulation.

The mixed formulation was added to a two roll mill to form a roll-milled blanket (approximately 5mm thick). the blanket was cut into squares several squares weighing 420 grams total were placed into a preheated Bun foam mold (7 inches × 7 inches × 0.5.5 inches). preheating was carried out at 120 ℃ (no pressure) for 9 minutes, at 120 ℃ and 10 tons of force for 4 minutesThe sample was transferred to a foaming press and heated at 180 ℃ and 4 tons force (100 kg/cm)²Pressure) for 10 minutes. Once the pressure had been released, Bun foam was quickly released from the tray and placed in a ventilation hood over several non-stick pieces. The Bun foam was cooled overnight and then cut into slices for testing.

The Bun foam was trimmed to a plaque of "6 inch × 6 inch" using a vertical band saw.the density, hardness and resilience of the form trimmed flat sheet (with skin on both surfaces) was measured.the trimmed flat sheet was then cut to the desired thickness (thickness about 3mm) using a laboratory scale horizontal band saw.sheets (some containing skin layers and some not including skin layers) were used to measure tensile strength and tear properties.typically, the remaining intermediate foam layer of the trimmed Bun foam was used to measure the shrink resistance of the foam.other portions of the Bun foam were cut into sheets of different thickness for specific tests, for example, 7mm thickness for wet COF test, 10mm thickness for DIN abrasion test, 10mm thickness for split tear test, and 19.5mm thickness for compression set test.

B. Results and discussion

Table 2 below lists foam (single substrate) properties including expansion ratio, foam density with skin, hardness, mechanical properties, DIN abrasion and wet COF for the inventive and comparative examples.

Table 2 properties of comparative and inventive examples (with skin)

Two epidermal surfaces (whole plate). An epidermal surface or epidermal sample.

SEM morphologies comparing examples 2 and 3 and inventive example 1 at the same magnification are shown in fig. 1 below. It has been found that the foam formed by inventive example 1 (single base foam) provides much smaller cell sizes than the foams formed by comparative examples 2 and 3, respectively, and that such much smaller cell sizes provide improved tensile strength.

For comparative example 1 and comparative examples 2 and 3, abrasion resistance can be improved (reduced) by adding conventional PDMS while wet COF is significantly reduced. However, by comparing inventive example 1 and comparative example 2, we can find that the foam formed from inventive example 1 provides better (worse) abrasion resistance than the foam formed from comparative example 2 at similar foam hardness and wet COF. Further, by comparing inventive example 1 and comparative example 3, it was found that the foam formed from inventive example 1 provided a higher wet COF than the foam formed from comparative example 3 for similar foam hardness and abrasion resistance. Thus, inventive example 1 provides a better balance of wear and traction than comparative examples 2 and 3. In addition, higher resilience and higher tensile strength were obtained in the foam formed by the inventive example (single-base foam).

By comparing inventive example 1 and comparative example 4, it has been found that the foam formed from inventive example 1 (a single base foam) provides better abrasion resistance (lower value), better wet skid resistance (higher wet COF), lower compression set, and higher resiliency than the foam formed from comparative example 4 (EVA/silicone rubber) at similar expansion ratios and foam densities.

By comparing inventive example 1 and comparative example 5, it has been found that foams formed from inventive example 1 (silicone rubber with higher molecular weight) provide higher wet COF values and higher resilience, while maintaining better (lower) abrasion resistance, at similar foam hardness and foam density.

By comparing inventive example 1 and comparative examples 3 and 5, it has been found that high molecular weight and side chain vinyl groups (or high vinyl content) are required in the molecular structure of silicone rubber to obtain higher wet COF values. By comparing inventive example 1 and inventive example 2, it has been found that brominated butyl rubber (BIIR 2030) can be effectively used to increase the COF of OBC/silicone rubber syntactic foams.

It has also been found that silicone rubbers having high molecular weight (. gtoreq.200,000 g/mole) and pendant vinyl groups (vinyl content. gtoreq.0.04 wt%) provide better (lower) abrasion resistance while providing high moisture COF values. In addition, higher resilience and higher tensile strength can be obtained from the composition of the present invention. Single base foams based on such OBC/silicone rubber compositions provide better (lower) abrasion resistance, better wet skid resistance (higher COF) and higher resilience than EVA/silicone rubber compositions at similar expansion ratios and foam densities. Incorporation of bromobutyl rubber (BIIR) can be effective in increasing the wet COF of the OBC/silicone rubber compositions of the present invention.