THERMOPLASTIC ELASTOMERS MOLDABLE UNDER LOW SHEAR CONDITIONS
A thermoplastic elastomer compound of an acrylic-containing styrenic block copolymer and plasticizer oil have been found to be capable of sintering at a temperature ranging from about 180 C to about 200 C when the copolymer and the oil are in no more than a 2:1 weight ratio. The compound can be used in rotomolding or slush-molding equipment to make plastic articles having elastomeric properties.
1 . A thermoplastic elastomer compound, comprising:
(a) highly flowable acrylic-containing styrenic block copolymer;
(b) plasticizer oil; and optionally
(c) functional additives
wherein when the copolymer and the oil are present in no more than a 2:1 weight ratio the compound is capable of sintering at a temperature ranging from about 180° C. to about 200° C.
2 . The compound of claim 1 , further comprising polyolefin.
3 . The compound of claim 1 , wherein the acrylic-containing styrenic block copolymer has the following physical properties:
Hard content (wt %)
31
Specific gravity (g/cm 3 )
0.93
Hardness (JIS A)
74
100% modulus @ 25° C. (MPa)
3.5
Tensile strength* @ 25° C. (MPa)
29.5
Elongation @ 25° C. (%)
500
100% Modulus @ 80° C. (MPa)
2.1
Tensile Strength* @ 80° C. (MPa)
11.4
Elongation @ 80° C. (%)
600
Melt Flow Rate @ 230° C. and
5.6
2.16 kgf (g/10 min)
Solution Viscosity @ 10 wt % in
15
Toluene at 30° C. (mPa · s)
4 . The compound of claim 1 , further comprising additives selected from the group consisting of adhesion promoters; biocides (antibacterials, fungicides, and mildewcides), anti-fogging agents; anti-static agents; bonding, blowing and foaming agents; dispersants; fillers and extenders; fire and flame retardants and smoke suppresants; impact modifiers; initiators; lubricants; micas; pigments, colorants and dyes; oils and plasticizers; processing aids; release agents; silanes, titanates and zirconates; slip and anti-blocking agents; stabilizers; stearates; ultraviolet light absorbers; viscosity regulators; waxes; and combinations of them.
5 . The compound of claim 1 , wherein the compound further comprises styrene-ethylene-ethylene/propylene-styrene.
6 . The compound of claim 1 , wherein the compound is capable of sintering at a temperature ranging from about 180° C. to about 200° C. when in the form of pellets about 2-3 mm in size.
7 . A molded article, comprising a compound of claim 1 , wherein the article is preparable by rotomolding or slush-molding.
8 . A method of using the compound of claim 1 , wherein the method comprises the step of rotomolding or slush-molding the compound into an article at sintering temperatures ranging from about 180° C. to about 200° C.