JPH08217949A - Abs composition resistant to impact and stress whitening - Google Patents

Abstract

PURPOSE: To provide a resin polymer having a suitable balance between three properties, i.e., impact resistance, resistance to whitening upon bending stress and melt viscosity.

CONSTITUTION: Two ABS polymer components different from each other in particle diameter of rubber stock portion are blended. One of the ABS components has a large butadiene stock particle diameter of 2,500 to 3,000 Å, while the other ABS component has a small SBR/ACN stock particle diameter of 700 Å, and the wt. ratio of both the components is (50:50) to (90:10). A specific example of the former ABS is Blendex (R) 131 modifier sold by GE Specialty Chemicals, while a specific example of the latter ABS is Blendex (R) 424 modifier manufactured by GE Specialty Chemicals. The blend is suitable for extruding, injection molding, and calendering and useful for the production of ABS films having a standard thickness.

COPYRIGHT: (C)1996,JPO

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to high impact polymers. Furthermore, it relates to a polymer having a low bending stress whitening property.

[0002]

2. Description of the Prior Art It is difficult to obtain a polymer having a desirable balance of impact resistance and low bending stress whitening property. Improving one of these polymer properties, namely impact resistance or bending stress whitening, often compromises the other property.

[0003]

Accordingly, it would be desirable to have a polymer which has a desirable balance of impact resistance and bending stress whitening. Such polymers are extruded and / or calendered into thin packaging films and / or laminate films that are subject to severe impact during service life and, for aesthetic reasons, require minimal bend whitening. It is useful for production by. One example of such an application is the outer surface of a travel bag or suitcase.

[0004]

SUMMARY OF THE INVENTION The present invention, in one aspect, is impact resistant (6.0 ft-lbs / at room temperature 1/4 "Izod method).
of more than a) and bending stress whitening properties, each having a sufficient amount and size, each having a plurality of acrylonitrile-butadiene-containing different basic particle sizes.
It is a compound of styrene (ABS) polymer for packaging film or laminating film. The ratio of one ABS component to the other ABS component is impact resistance, bending whitening property, and melt viscosity (when measured with a Brabender No. 5 head at a roller blade of 180 ° C and 30 RPM of 2800 to 3000
MKgm. Or at 100 sec ^-1 when measured at 200 ° C using 0.041 "15/1 orifice by capillary rheometry.
It can be fine-tuned to achieve the desired balance of tripartite (3.68 × 10 ^{4 to} 6.20 × 10 ³ poise). The term "ABS component" as used herein refers to ABS polymer in polymerized form.

In another aspect, the present invention provides a room temperature (23
℃ ± 2 ℃) impact resistance and low temperature (-18 ℃ ± 2 ℃) impact resistance and the bending stress whitening properties to achieve the desired balance, each has a sufficient amount and dimensions, respectively different backbone A standard thin ABS film (0.007-0.015 inch) blend of a plurality of ABS polymers with particle sizes. The ratio of one ABS component to the other ABS component can be fine-tuned to obtain the desired balance of impact resistance, bend whitening, and melt viscosity.

[0006] In a third aspect, the present invention provides GE Specialty Chemicals, Inc.
Impact resistance like Blendex® 131 Modifier for sale (7.0 ft-lbs / i room temperature 1/8 "Notched Izod method)
n) General-purpose (suitable for extrusion, injection molding, calendering) blend of ABS and transparent ABS with low bending stress whitening property such as Blendex (registered trademark) 424 modifier sold by GE Specialty Chemicals. It is a thing. The ratio of one ABS component to the other ABS component can be fine-tuned to obtain the desired balance of impact resistance, bend whitening, and melt viscosity.

In a fourth aspect, the present invention is a blend of ABS polymers with different base particle sizes that provides the melt viscosity required for calendering large area sheets.

[0008]

Detailed Description of the Invention: The ABS polymers of the present invention comprise a two-phase system. This two-phase system comprises a polybutadiene or polybutadiene / styrene rubber backbone with a styrene-acrylonitrile (SAN) copolymer attached thereto. This backbone is commonly referred to as the "graft phase" because the SAN physically binds or grafts to the rubber through a chemical reaction that occurs simultaneously with the polymerization of the SAN copolymer. SAN not grafted to rubber backbone
The part is commonly referred to as the "free hard phase". The graft phase is
It is dispersed throughout the hard phase SAN to form a polymer continuous phase. The rubber interface is a surface that forms a boundary between the graft phase and the hard phase. The graft-bonded SAN acts at this interface as a compatibilizer between the rubber and the rigid SAN, preventing these two otherwise immiscible phases from separating.

A first ABS polymer component suitable for use in the ABS formulation of the present invention is A / B /, where A is acrylonitrile, B is butadiene and S is styrene.
It has a composition of 17-22 / 30-37 / 40-48 in the order of S. All ratios mentioned herein are weight percentages unless otherwise stated. The composition of ABS is A / B / S, preferably 19
-21 / 32-36 / 40-46, more preferably 19-20 / 31-35 /
43-45, optimally 20/35/45. A suitable polybutadiene backbone contains divinylbenzene (DVB) in an amount of 0 to 1 part by weight and a particle size of 2700 to 3500 (angstroms).
A preferred polybutadiene backbone contains DVB in an amount of 0 to 0.75 parts by weight and a particle size of 2700 to 3100 (angstrom). A more preferred polybutadiene backbone contains DVB in an amount of 0 to 0.5 parts by weight and a particle size of 2900 to 3100 (angstrom).
The optimal polybutadiene backbone does not contain DVB and the particle size is
It is from 2800 to 3050 (Angstrom). A suitable styrene / acrylonitrile (S / AN) ratio is 7.1 to 1.8 / 1.0, preferably 5.5 to 1.5 / 1.0, more preferably 6 to 1.7.
/ 1.0. The optimum S / AN ratio is 2.25 / 1 and the number average molecular weight ( _Mn ) of the free hard part is 47,000. Suitably, of the total polymer, the graft phase (polybutadiene + grafted SAN) is 38-50% and the free hard phase (non-grafted SAN) is 62-60%.
Preferably, the graft phase is 41-49% of the total polymer
The free hard phase is 57-59%. More preferably, the graft phase is 44-47% of the total polymer and the free hard phase is
55-56%. Optimally, 46% grafted phase and 54% free hard phase of the total polymer. Suitably, 18-20% of the total SAN is graft bonded to the polybutadiene, preferably 15-17% of the total SAN, more preferably 12-14% and optimally 11%. It is graft bonded to polybutadiene. The suitable number average molecular weight (M _n ) of the graft-bonded SAN is 28,000 to 38,000, preferably 3
It is 2,000 to 38,000, more preferably 34,000 to 37,000, and most preferably 36,000. Blendex® 131 modifier is
It is an example of the above ABS and is commercially available from GE Specialty Chemicals. Blendex® 131 modifier or equivalent ABS polymer is blended with semi-rigid polyvinyl chloride (PVC), suitably about 36-60% by weight of the total composition, preferably about 35%. ~ 55% by weight, more preferably about 38-53% by weight, optimally about 40%
Used in an amount of ~ 50% by weight.

A second ABS suitable for use in the present invention.
The polymer component is 7 to 12/45 in the order of A / B / S / DVB.
-80 / 25-90 / 0-95, preferably 8-11 /
50-75 / 28-50 / 0-75, more preferably 9-10 / 54-65
/ 29 to 35/1 to 15, optimally 9.93 / 57.85 / 30.93 /
It has a composition of 1.3. This polymer is suitably 75-30
% Backbone and 45-15% SAN, preferably
70-35% backbone and 40-20% SAN, more preferably
68-40% backbone and 37-25% SAN, optimally 65%
Comprises the backbone of SAN and 35% SAN. The composition of the above 65% polybutadiene / styrene / acrylonitrile / divinylbenzene backbone is A / B / S / DVB in order.
2.93 / 57.85 / 2.93 / 1.3 with a particle size of 700 (angstrom
-Mu). This backbone is graft-bonded to 22.9 parts of 35% SAN, and is usually a "high rubber graft modifier".
Called. The M _n of the graft-bonded SAN is suitably 10,000-40,000, preferably 20,000-35,000, more preferably 25,000-33,000, optimally 30,000. Suitably, the S / AN ratio is 4.75 / 1 and the _{Mn of} free rigid SAN is 1
At 5,000, it accounts for 20% of all polymers. Preferably S /
The AN ratio is 4.6 / 1, _{Mn of} free hard SAN is 25,000,
It accounts for 15% of the total polymer. More preferably, the S / AN ratio is 4.4 / 1 and the _{Mn of the} free rigid SAN is 40,000, accounting for 10-0% of the total polymer. Optimally, the S / AN ratio is 4 /
1. _{Mn of} free hard SAN is 35,000,
It accounts for 12.1%. Blendex (R) 424 modifier is an example of ABS as described above and is available from GE Specialty
Commercially available from Chemicals. Blendex® 424 modifier or equivalent ABS polymer is suitably used in an amount of about 4.0 to 9.0 parts per 100 parts of resin (phr: parts per h).
undred resin), preferably about 4.2 to 8.8 phr, more preferably about 4.5 to 8.5 phr. Optimally
Blendex® 424 modifier or equivalent ABS polymer is a hard, transparent, calendered, low bend whitening P
Used in VC packing films in amounts of approximately 5-8 phr.

Two exemplary commercial ABS polymers described above,
The compositions of the Blendex® 131 modifier and the Blendex® 424 modifier are summarized in Table 1.

[0012]

[Table 1] Table 1 Composition (% by weight) Molecular weight S / ACN% Acrylonitrile butadiene Styrene Divinyl benzene Blendex 131 Total polymer 20 35 45 ---- ---- Hard phase 16.62 --37.39 --4.7 × 10 ⁴ 2.25 / 1 54.0 Graft phase 3.38 35 7.61 --3.6 × 10 ⁴ 2.25 / 1 46.0 Core --35 --------- Core particle size distribution --2800 ------- -(Angstrom) 3050 Blendex 424 All polymers 9.93 57.85 30.93 1.3 ---- --Hard phase 2.4 --9.6 --3.5 × 10 ⁴ 4/1 12.0 Graft phase 7.53 57.85 21.33 1.3 3.0 × 10 ⁴ 4 / 1 88.0 Basic 2.93 57.85 2.93 1.3 ---- --Basic particle size distribution --700 ---- -----(Ongstrom) Blendex (registered trademark) 131 Modifier and Blendex (registered trademark) ) Suitable ABS polymer compositions such as 424 modifiers are suitable for use in Banbury mixers and Mill / Farre.
l) Blending is carried out using conventional melt mixing equipment such as continuous mixers, single-screw and twin-screw extruders. A suitable ratio of the two ABS polymer components of the present invention that can be used in achieving the desired balance of impact resistance and crease stress whitening is a component with a large butadiene backbone particle size / small SBR / A.
The order of components including the CN basic particle size is 75/25 to 80/25, preferably 60/40 to 85/15, and more preferably 55/45 to 88.
/ 12, optimally 50/50 to 90/10. Depending on the choice, the polymer system may be protected by antioxidants and surface metal removal lubricants (ext.
ernal metal release lubricant) is added.

Table 2 shows the two exemplary commercial ABS polymers described above, Blendex® 131 modifier and Blendex.
Includes impact resistance, processability, and bend whitening data for the ™ 424 modifier.

[0014]

[Table 2] Table 2 A B C D E F G Blendex 131 50.0 70 75 80 85 90 100 Blendex 424 50.0 30 25 20 15 10 0 Weston ODPP ^* 1.0 -------------------- ------------------------------> Ethylene bustier limit wax 0.5 ------------- --------------------------------> ^* Weston ODPP is an antioxidant impact resistant 1/4 "RT notch Toisotte 2.9 3.53 3.42 3.54 3.98 4.54 7.32 (ft-lbs / in) RT Gona-Donna Spear Method 0.4 0.94 0.89 1.01 0.98 1.14 1.70 (in-lbs / mil, 20mil film) Brabender Torque Rheometer (180 ℃, 60RPM, No .5 head, 45g) Time (min) Torque (MKgm) 5 --2371 --2306 --2435 2671 15 --2229 --2306 --2252 2707 25 --2337 --2370 --2409 2865 35 --2427 --2422 --2534 2828 45 --2502 --2527 --2610 3249 55 --2546 --2585 --2674 3522 Capillary rheometer viscosity (190 ° C, 0.041 orifice, 15/1, L / D) Shear rate (sec ^-1 ) (Poise × 10 ⁴ ) 100 4.172 4.211 4.139 4.218 500 1.229 1.253 1. 245 1.204 1000 0.726 0.743 0.7419 0.702 Sample A exhibits remarkably low fold whitening, but too low impact resistance for film applications, and Sample B is the opposite combination of impact resistance / fold whitening. Excellent in impact resistance but maximum in bending whitening.Samples A and G respectively correspond to the limits of impact resistance and bending stress whitening.B to F between these two samples. These two properties change in a stepwise manner, as illustrated in Example 1. Samples C, D, and E have impact resistance and bend whitening in the proper range, while at the same time being suitable for extrusion and calendering. Enters the melt viscosity range. These samples can also be used in injection molding applications.

The samples included in Table 2 were prepared by melt mixing for 3 minutes at 325 ° F in a 1000 cc laboratory Banbury mixer. The melt was placed in a 325 ° F. two roll mill, rolled into 0.125 inch sheets and then cut into pieces for granulation. The granulated material was injection molded into 1/8 inch and 1/4 inch impact specimens for impact resistance testing. The particles were also extruded into a 25 mil thick, 3 inch wide film for impact resistance testing by the Gardner Dart Method.

The ABS formulations referenced above were prepared from resins synthesized by emulsion polymerization. In order to protect the resin from oxidation during the melt-mixing stage and to remove metals to improve the melt flow during injection molding and extrusion, this resin is mixed with phosphorous acid antioxidant (Weston TNPP) and ethylene for lubrication Bistearimide wax was added. These additives were added to the formulation based on the number of parts relative to 100 parts resin.

For commercial purposes, the formulation that achieves the most desirable balance of impact resistance, bend whitening and viscosity properties is the Blendex 131 / Blendex 424 80/20 ratio of each modifier. . This sample shows Blendex 131 Modifier 8
00g, 200g Blendex 424 modifier, 2g Weston® TNPP, and ethylene bis-stearimide wax 5
and g are melt mixed in a Banbury mixer. Other optional ingredients such as pigments or additional lubricants can be added if desired. After melt blending in a Banbury mixer, the blend can be processed by either calendering, extrusion or injection molding.

In summary, the present invention discloses a blend of ABS polymers, each having a different particle size, with the desired balance of impact resistance, flexural stress whitening, and melt viscosity. . These compositions have a standard thickness of A
It is useful as a BS film.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Larry Bee Simmons Box 2460, Washington, USA, West Virginia, Box 2460, RT3 (no address)

Claims (6)

[Claims] 1. An ABS composition comprising a plurality of ABS polymers each having an amount and size sufficient to produce the desired balance of impact resistance and stress whitening properties, each ABS polymer having a different base particle size. 2. The composition of claim 1 having a desirable balance of impact resistance and stress whitening properties at room and low temperatures. 3. An SBR / AC in which one ABS component has a large butadiene backbone particle size and the other ABS component is small.
The composition of claim 1 having an N-basic particle size. 4. The large butadiene backbone particle size is 2500
4. The composition of claim 3, which is ˜3000 (angstrom) and has a small SBR / ACN backbone particle size of 700 (angstrom). 5. The two ABS components are an ABS component having a large butadiene basic particle size / a small SBR / A.
50/50 to 90 in terms of the ratio of ABS components with CN basic particle size
5. The composition of claim 4, each present at / 10. 6. The composition of claim 1, wherein each backbone particle size is selected to produce a desired melt viscosity for calendering large area sheets.