Boots – shoes – and leggings – Boots and shoes – Made of material other than leather
Reexamination Certificate
2002-09-30
2004-11-16
Tucker, Philip (Department: 1712)
Boots, shoes, and leggings
Boots and shoes
Made of material other than leather
C036S089000, C525S088000, C525S089000, C525S105000
Reexamination Certificate
active
06817114
ABSTRACT:
The present invention relates to styrene-butadiene-styrene compositions coupled with organic coupling agents carrying epoxy groups, and their use for various applications such as for example roofing, binders for road coverage or footwear compounds.
The bituminous compositions of the prior art, when used for roofing or waterproofing membranes suffer from major drawbacks; either the high temperature properties are improved at the expense of the low temperature properties, or if both ends of the temperature spectrum yield acceptable performances, the viscosity will be very; high, requiring that special equipment be used for handling the bituminous composition.
It is moreover well-known that the residue of the coupling agent remains in the copolymer formed and is thus capable of leaving toxic residues or other unwanted products in the polymers, which may be troublesome in certain uses. This phenomenon is particularly important with silicon tetrachloride (SiCl
4
) as coupling agent. Indeed, when SiCl
4
is used as coupling agent, it is noted that lithium chloride (LiCl) is formed as by-product. The presence of LiCl is detrimental to the optical properties of copolymers and favours the thermal ageing of these copolymers.
It is known to improve the physical properties of bituminous compositions by incorporating elastomeric bock copolymers generally represented by the formula (S-B)
n
Y wherein Y is the residue of a polyfunctional coupling agent, (S-B) represents a single arm constituted of a polydiene block B and a polyvinyl aromatic end block S. and n represents the number of arms (S-B).
The coupling agents can be selected from among polyvinyl aromatic compounds, polyepoxides, polyisocyanates, polyamines, polyaldehydes, polyhalides, polyanhydrides, polyketones, polyepoxyesters and polyesters. Combinations of different kinds of coupling agents may also be used.
Among the several polyfunctional agents of coupling available on the market, those of small residual toxicity have been preferred. For example, EP-B-344140 discloses the use of polyfunctional coupling agents of the general formula SiX
n
R
4−n
wherein X is a halogen, preferably Cl, R is an alkyl, cycloalkyl or aryl radical, preferably methyl, ethyl and/or phenyl and n is an integer from 2 to 4. The most frequently used coupling agent is SiCl
4
.
It is also known to use organic coupling agents carrying epoxy groups. Polymers of epoxidised hydrocarbons are used such as epoxidised liquid polybutadiene or epoxidised vegetable oils such as epoxidised soybean oil and epoxidised linseed oil. Each epoxy can be coupled to a chain. The number of coupling sites is undetermined and can vary according to the number of epoxy groups: it is at least 3 and preferably, it is from 4 to 6. However, the styrene-butadiene-styrene (S-B-S) compositions obtained with epoxidised triglyceride esters, sold under the name of Vikoflex, have never been used for commercial applications wherein good mechanical properties combined with low viscosity are required.
It is an object of the present invention to use organic coupling agents carrying epoxy groups in order to prepare products combining improved mechanical properties and low viscosity.
It is another object of the present invention to use organic coupling agents carring epoxy groups in order to provide improved roofing compositions.
It is a further object of the present invention to use organic coupling agents carrying epoxy groups in order to provide improved binders for road coverage applications.
It is yet a further object of the present invention to use organic coupling agents carrying epoxy groups in order to produce improved thermoplastic compounds.
The resinous thermoplastic block polymers used in the present invention are of the radially branched type with at least 3 arms. The arms of each branch are composed of substantially pure homopolymeric blocks of polymonovinylarene represented by S and polyconjugated diene represented by B.
Preferably, in the process of polymerisation used for preparing the products of the present invention, a block base copolymer is prepared by the following steps:
1) A first block of vinylaromatic monomer is polymerised to form a first block S.
2) The polymerisation is carried out at a temperature of from 20 to 60° C., for a period of about 20 minutes, in the presence of an organolithium compound as a catalyst, and in the presence of a solvent that is an inert hydrocarbon.
3) When all the vinylaromatic monomer has been polymerised, a monomer of a conjugated diene is introduced into the solution. This monomer starts reacting entirely at the living ends of the chains to give a block copolymer of the type S-B-Li, in which B represents the conjugated diene block.
The vinylaromatic compound which constitutes the block S of the block copolymer can be styrene, vinyltoluene, vinylxylene or vinylnaphtalene or a mixture thereof.
The conjugated dienes employed ordinarily are those of 4 to 12 carbon atoms per molecule, with those of 4 to 8 carbon atoms preferred for availability. Such monomers include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, piplerylene, 3-butyl-1,3-octadiene, 2-phenyl-1,3-butadiene, and the like. The monovinylarenes employed ordinarily contain 8 to 20, more conveniently 8 to 12 carbon atoms per molecule, including such as styrene, &agr;-methylstyrene, 1-vinyinaphtalene,2-vinyinaphtalene, as well as alkyl, cycloalkyl, aryl, alkaryl, and aralkyl derivatives thereof in which the total number of carbon atoms in the combined substituents generally is not greater than 12. Examples of sustituted monomers include 3-methylstyrene, 4-n-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 3-ethyl-4-benzylstyrene, 4-p-tolystyrene, or 4-(4-phenyl-n-butyl)styrene.
The catalyst is generally an alkyllithium, which may be branched such as those of secondary alkyl radicals, having 3 to 8 carbon atoms. However, n- and s-butyllithium are preferably used for reasons of ease of procurement and storage stability. The solvents used are generally paraffinic, cycloparaffinic and aromatic hydrocarbons and their mixtures. Examples are n-pentane, n-hexane, n-heptane, 2,2,4-trimethylpentane, cyclohexane, cyclopentane, benzene, toluene and xylene. A polar solvent, such as cyclic esters (THF) or acyclic ethers or tertiary amines, can be incorporated in order to obtain the formation of a specific polymeric microstructure, such as, for example, an increased amount of vinyl units, as well as random S/B blocks.
The peak molecular weight Mp of the base copolymer was measured by conventional Gel Permeation Chromatography (GPC) technique. The peak molecular weight Mp, so determined, varies within wide limits and is generally from 40000 to 120000 and preferably from 60000 to 80000, the polyvinylaromatic block representing from 15 to 45% by weight of the base copolymer. When this stage of the process has been reached, polymeric chains of the type S-B-Li have been formed.
The operating conditions for the GPC technique were as follows: the temperature was 23° C., the solvant was THF and there were 5 columns in series containing ultrastyragel with pore openings ranging from 500 to 1000000 A. The solvant debit was 1 ml/min and there was a U.V. detector in series with a refraction index detector. 200 microliters of the products to be analysed, at a concentration of 0.1% in THF, were injected. The internal standard was 0.01% of tertiobutyl hydroxy toluene (THB) and the calibration was achieved using the Mark and Houwink equation in which k=1.251E-4 and &agr;=0.717. The calculations were based upon the refraction index detector and the styrene percentage was defined by the U.V. detector.
The block base copolymer terminated by a lithium atom, called the living base polymer, is then reacted with at least one coupling agent comprising at least 3 epoxy groups per mole, preferably at a rate of 0.2 to 0.75 parts per hundred parts of the total polymers obtained by coupling.
The polyfunctional treating agent is added to the polymerisation mixture under reaction conditions sufficient to
Atofina Research S.A.
Aylward D.
Jackson William D.
Tucker Philip
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