DD201603A5 - MIXES OF AN ACRYLIC POLYMER AND A STRIKE INTERPOLYMER - Google Patents

Abstract

The invention relates to mixtures of an acrylic polymer and an impact-resistant interpolymer for the production of weather-resistant and impact-resistant articles, such as building boards and ornaments, exterior vehicle parts, garden furniture u.a. The aim of the invention is to improve the physical properties, in particular the impact resistance of the polymers. According to the invention, the novel blends are comprised of an acrylic polymer such as polymethyl methacrylate and an impact-resistant interpolymer consisting of crosslinked acrylic or methacrylic rubber, crosslinked styrene-acrylonitrile and uncrosslinked styrene-acrylonitrile polymer components. The interpolymer contains about 5 to 50% by weight of the (meth) acrylic component, from about 5 to about 35% by weight of the crosslinked styrene-acrylonitrile component and from about 15 to about 90% by weight of the uncrosslinked styrene-acrylonitrile component. the mass ratio of acrylic resin and interpolymer is between about 60:40 and about 20:80. The blends have better impact resistance compared to the impact strength of the acrylic polymer and have better strength, hardness and stiffness than the interpolymer component.

Description

Berlin, the. 02/26/1982

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Mixtures of an acrylic polymer and an impact-resistant interpolymer

Field of application of the invention

The present invention relates to mixtures of a. Acrylic polymer such as polymethyl methacrylate resin and an impact-resistant interpolymer * The resulting mixtures can be used to make weather-resistant, impact-resistant articles.

Characteristic of the known technical solutions

Acrylic polymers such as Polymethyljjiethacrylatharze have good optical quality, excellent weather resistance and good tensile and flexural strength. For for a variety of applications use, such as building boards, headstones, automotive exterior parts, garden furniture, für'Schwimmbecken parts, but so on * The impact resistance of unmodified acrylic resins is very low and includes the use of ^one such resins for certain Ven ^ ending purposes where a higher degree of impact resistance is required

Recently, it was disclosed in US Patent, 3,655,325 for R, P. Fellmann u _# a. proposed various thermoplastic polymers (including acrylic resins, see column 8,

Lines 11 to 13) and.ei.o impact-resistant three-stage acrylic

to be mixed elastically. This prior art description states that the choice of the third phase of the interpolymer is critical, and it will

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suggested that if the impact properties were to be altered, the third step would have to be a methacrylate or acrylate (see column 5, lines 55 to 70),

Interpolymers, which consist of crosslinked (meth) acrylate, crosslinked styrene-acrylonitrii- and uncrosslinked styrene-acrylonitrile polymer components . This type of interpolymer is described in more detail in US Pat. No. 3,944,631 to A, 3, Yu ₄ and others. It has been described in the prior art that it is a suitable additive for polycarbonate resins (US Pat. No. Hr. 4,148,842 for A * 0. Qu et al.), For blends of chlorinated vinyl chloride polymer and vinyl chloride polymer (US Pat , 4 ISO for P. force u, a.) and (for Vinylchlofidpolymere US Patent No. ₄ 4158 is 2S5).

Object of the invention

The aim of the invention is to provide novel weather-resistant and impact-resistant mixtures of an acrylic polymer and an impact-resistant interpolymer.

Explanation of the essence of the invention

The invention has for its object to achieve the desired properties by selecting a suitable interpolymer and a suitable mixing ratio between acrylic polymer and interpolymer,

According to the invention, the novel mixtures contain:

(1) an acrylic resin and (2) an impact resistant interpolymer comprising crosslinked (meth) acrylate _i crosslinked styrene

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Acrylonitrile and uncrosslinked styrene-methacrylate polymer components «

As used herein, the term "acrylic resin" means those acrylic resins made by the polymerization of acrylic ester monomers. Details of the structure of these polymeric materials as "ie on the process for their 8ildung can be found in a number of publications such as Modern Plastics Encyclopedia (Edition 1977-1978), page 9 to 10; Handbook of Plastics and Elastomers, C.A., Harper, Ed. McGraw-Hill, Inc. 1975, pages 1-71 to 1-75; and Polymers and Resins by B, Goiding, Van iMostrand Co ,,. 1959, page to 452 * Representative polymers belonging to this class of acrylic resins or plastics include: polyethyl methacrylate, polyethyl acrylate and polybutyl acrylate. Copolymers of these acrylic esters with minor amounts of one or more copolymerizable monomers should also be able to be included, z, 3. the copolymer of methyl methacrylate with styrene and acrylonitrile. Commercially available acrylic resins include those sold under the following trademarks: LUCITE and PLEXIGLAS,

By the term "impact resistant interpolymer consisting of crosslinked (meth) acrylate, crosslinked styrene-acrylonitrile and uncrosslinked styrene-acrylonitrile components", the type of interpolymer compositions disclosed in US Pat. No. 3,944,631 to A, J, Qu, a. is to be understood. These interpolymer compositions are formed by the following type of sequential three-stage polymerization reaction:

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1, emulsion polymerization of a monomer charge (herein, for purposes of the invention referred to as "(meth) acrylate") of at least one C -, - C alkyl acrylate _{in t} C_-C ₂₂ alkyl methacrylate or compatible mixtures thereof ~, a. aqueous polymerization medium in the presence of an effective amount of a suitable di- or polyethylenically-unsaturated crosslinking agent for such type of monomer, wherein the C 1 -C 4 -alkyl acrylates are the preferred (meth) acrylate monomers for use in this step;

2-, emulsion polymerisation of a monomer charge of styrene and acrylonitrile in an aqueous polymerisation medium, also in the presence of an effective amount of a tetraethylenated di- or polyether-saturated crosslinking agent for such monomers, this polymerization being carried out in the presence of the product of step 1 such that the crosslinked (meth) acrylate and crosslinked styrene-acrylonitrile components form an interpolymar in which the respective phases surround and interpenetrate one another; and

3. either emulsion or suspension polymerization of a monomer charge of styrene and acrylonitrile without crosslinking agent in the presence of the product recovered in step 2. If desired, steps i and 2 may be reversed in the process described above.

This product, which is used as the impact-resistant interpolymer component in the invention blends, generally consists of from about 5 to about 50 parts by weight of the (meth) acrylate component _i described above from about 5 to about 35 parts by weight the crosslinked styrene-acrylo-

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nitrile component and from about 15 to about .90% by weight of the uncrosslinked styrene-acrylonitrile component. It has low graft polymerization between the styrene-acrylonitrile copolymer components and the crosslinked (meth) acrylate polymer component. on. Further details of this type of polymer composition are disclosed in U.S. Patent 3,944,531 to-A. j. Qu et .. a », which is incorporated herein by reference.

The blends of the present invention may be formulated in weight ratios of acrylic resin to interpolymer additive of from about 75:25 to about 5:95, depending on the exact physical properties required in the final product. A preferred range is between 50:40 and 20:80, blending can be done using one of the well-known Polymerrnischtechniken, such as the two-vValzsn- or Branburymischenj single or Men-rfäch Schneckenextrudieren or after another arbitrary method-, sufficient heat (e.g., 3, 175 to 300 ⁰ C, preferably 200 to 250 ^° C) and shear developed for the respective polymer ingredients (acrylic resin and interpolymer additive) _{: to} obtain a satisfactory blend in accordance with the invention,

The blends of the invention may also contain any conventional functional additives normally used in acrylic polymer compositions, such as fillers, dyes ,. Lubricants, flame retardants and the like *

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Au sführungsbeispiel

The present invention will be further illustrated by the following examples.

Example 1

In this example, the impact, hardness, tensile and flexural strength properties are illustrated by a series of blends of a commercially available polymethylmethacrylate (PMMA) _t LUCITE 147K and the impact resistant interpolymer (abbreviated "interpolymer") described above. The interpolymer contained 32 mass-xS crosslinked polybutyl acrylate 10 _mass} ^ crosslinked styrene-Acrylonitrii and 58 mass fö uncrosslinked styrene-acrylonitrile *

Sample Nos. 2 to 5 listed below were mixed at temperatures of 221 to 232 C at 90 rpm in a conventional extruder using a single stage screw with a compression ratio of 2: 1 by extrusion. Sample Nos. 1 and No. were control samples.

Sample composition (mass ^)

1 iOO '% interpolymer

2'20 ^ o PMMA / 80 % interpolymer

3 40 % PMMA / 60 % interpolymer

4 50 % PMMA / 50 % interpolymer

5 6Q. % -B * MA / ACL% interpolymer

6 100 % PMMA .__

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The samples Ur, 1 to 5 were then dried by power at 90 C and injection-molded at 190 to 200 C with a mold temperature set at 54 C (on a transfer molding machine with a capacity of 24 g). The windrow speed had been set to "slow", the area returned moderately, and the injection pressure setting was "34". The cycle had an injection life of 10 s and a screw return time of 20 s »

The generated test panels were tested and the following physical properties were determined;

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Impact strength cone test (1) Izod test (2)

Sample % PMMA (J / m) ; (J / m)

> 6410 641

^ 6410 395

5230 176

2030 S3

1180 64

A 800 21

(1) The test is carried out by dropping a 1.8-legged arrow with a tip diameter of 1.60 cm from different heights onto 0.32 cm thick injection-molded plates over a pad with a diameter of 2.22 cm carried out. The average Bruch energy τ / urde calculated afterwards

(2) AS ^{1 in} D-256, Method A, using 0.32 cm thick specimen.

0 laod-siechs elkerbs chlag- Hit hard.3- 20 examination (3) examination (4) 40 (J / m) (J / m) 50 2355 435 Sample % PMMA 60 1484 174 1 100 769 202 2 475 80 3 406 61 4 176 27 5 6

(3) ASTM D-256, Method B using 0.52 cm thick specimens.

(4) ASTM D-1822, Specimen Type L.

These results show that in the samples i? R. 2 to 5 by an increase in the amount of interpolymer (and a corresponding reduction in the amount of polymethyl methacrylate) a susaia

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compound mixture with improved impact resistance is achieved.

Barcol. Hardness (5) Sample % PMMiI Immediately Hach 10 s

1 0 48 28

2 20 60 43

3 40 66 55

4 50 75; 66

5 60 80 70

6 100 92 87

(5) Tested on a Barcol Impressor hardness tester (model Mr. QYZJ 935) after the test in the. Manual, published by Barber-Boleman Co. ,, Rockford, 111., proposed methodology. ,

These values indicate that the presence of poly (methyl methacrylate) contributes to the hardness of the mixture,

Zugfestickeitseigenschaften

Tensile strength Elongation at break (6) at Hießen (6)

sample % PH3 & L (Lapa)

0 32.4 120 20 42.7 120 40 49.6 130 50 55.1 120 60 59.9 98 100 HA. Ha. fkörpj sr type 1.

The gatekeeper of. Poly methyl methacrylate contributes to the strength of the mixture in "Uferte von Probe Hr. 6 were not considered reliable as the clamping area was cracked due to the brittleness of the specimens.

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5lege own sehf iren

% PMMA Bending strength (7) Bending modulus (7) sample 0 (MPa) (GPa) 1 . 20 52.7 1.59 2 40 59.6 2.07 3 50  81.3 2.56 4 50 90.9 2, 54 5 100 99.9 2.72 5 131.6 3, 36

(7) ASTM D-790, Method i _t Procedure B.

Higher flexural strength and a higher modulus (stiffness) are achieved as the percentage of polyethyl ethylacrylate in the blends is increased.

Example 2

This example shows the influence of mixing conditions such as. Melting temperature and mixing shear on the measured by the Izod impact strength impact strength of a mixture of 70% by mass impact-resistant interpolymer and 30% by weight of polymethyl methacrylate (LUCITE brand, 40), the respective blends were in 250 g portions in one

TM Small Batch Mixer (the PREP MIXER), melt plastified under the conditions described below. The mixing time was varied inversely to the rpm values in order to keep the number of total revolutions constant.

Sample RPM Total Mixing Time Equilibrium

(min) Melting temperature ( ⁰ C)

1 '50 ~ .7 205

2 50 7 232

3 50 7 258

232 53 0 2 _% _

4 25 14 235

5 75. , 4.6 250

Gieichgewichts-Torque Izod Impact Test Cm-R) (J / m)

1 15200 112

2 7000 80

3 3600 75

4 4600 85

5 6700 96

These values indicate that in a high shear gassy blending process, as used in the above test, excessively severe temperature conditions during mixing may be responsible for the. Izod impact strength of the mixture may be detrimental "However, a change in the rate of soher, this effect could not be determined if the Gesamtanaah1 revolutions was kept constant"

Example 5 «

In this example, the ultraviolet light-induced discoloration of mixtures according to the invention, including those stained with titanium dioxide, is tested.

Samples were prepared by mixing the ingredients at 200 ° C and 50 rpm for a period of min in a small batch mixer and then pressing to form homogeneous test panels which also contained six parts by weight of rutile TiQ 2 pigment per hundred parts by weight of sample , The samples were used as described below for a period of time in a high intensity (30 watt) germicidal lamp apparatus 3j2 cm from the lamp, and at the end of that time, the iraryvariance was compared to an unexposed control specimen from the same sample measured by a Hunter-Color-Meter,

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More values denote a less discolored specimen.

Parabolic Changes to an Unexposed Specimen (1)

Sample 1 day 4 days 5

19.2

18.1

100% interpolymer 15.7 17.4 20 fa PMMA / 80 % Inter- polymer ^ ⁰² 12 _t 2 -. 50 % PMM4 / 50 % Inter polymer ² 9.9 13.2 50% PMMA / 50 % Inter- polymer " ²²¹ ' 1O ₁ O 12.9 50 % PMM / 50 % Inter- polymer ³⁰ ^ 9.6 13.3

TiOp was added to Interpolyraer's physis before mixing with PMM4.

TiOp was added to the PMMÄ-Pnase before "blending with the interpolymer"

TiOp became after mixing of interpolymer and PiMa. eye passed.

(1) Measured by means of a HUI-TTEHLAB color difference meter (Model No. D 25D2) in accordance with ASTM D-1.925, these values indicate the color change (A 3) rather than the units of the Y-index, as assumed by the above method. '.

These values indicate that the ultraviolet lightfastness of the mixture is improved over discoloration by the polymethyl methacrylate and that the phase to which the TiO 2 pigment is added does not significantly affect the blend's Ultimate O.sub.2 resistance.

Example 4 ·:.

In this example, the influence of the processing conditions

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to the impact resistance properties of a mixture of 70% by weight impact-resistant interpolymer and 30% by weight poly (methyl methacrylate) brand LUCITE 147K

The blends were made by extrusion at various barrel housings ranging from 177 to 265 ° C and various screw speeds (40 to 120 rpm). * A 1: 1, 1 inch diameter single stage screw was used * The extruded test specimens were then injection molded at 200 to 220 ° C in a mold of 54 ° C. The injection molding machine described in Example 1 was used. No back pressure was applied to the melt and the cycle time was 30 seconds in total.

Sample screw velocity spray housing temperature

(Rpm) ( ⁰ C)

177

199 221 221 221

221

221 .243 265

Izod impact test

1 80 2 80 3 '40 4 60 5 80 6 100 7 '120 8th 80 9 '30 obe Cone drop test (3 / m) _ 1 '_ · --- 2510 2 3200 3 2830

123

128 123

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4 3680 139

5 4320 166

6 4380. 155

7 4010 187.

8 3790 187

9 3260 187

Sample Izod Exchange Exam

P / m) (kD / m ² )

1 481 114

2 908. 105

3 '. 491 124

4 - 561 122

5 587 120

6,539,111

7 '705 130

S 833 132

  9,732,120

The same test methods were used as in the corresponding tests in Example 1.

These values show that the general trend in the tested under extrusion conditions mixtures intended to suggest that the impact strength at moderately high temperatures and screw speeds is optimal and that the mixture due to insufficient values of temperature and 8 _c approximation can not develop their full potential of impact strength.

Example 5

in this example, the gloss and color characteristics of a 50% wet impact copolymer and

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50 mass / ö. Polymethyl methacrylate (trademark LUCITE 147 described existing mixture, which contains still further 6 parts by mass i0o ~ ^au ^ hundred parts by mass Interpolyraer and polymethylmethacrylate.

The test specimens from the mixture were added by compression molding

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188 ° C to a thickness of 0.08 cm, after the mixture had been mixed at 220 ⁰ G, and 30 U / min in a small Gb.grgerunischer made, The molded specimens were in a. -ÄEiiDHSS OMSTSE subjected to xenon arc accelerated aging at 50 % relative humidity, all. 2 hours 18 · minutes were sprayed with fasser «. In the table, the data on changes in the color of the sample over time compared to a commercially available impact resistant Acirjlsorte be included with a different chemical composition.

Color change in comparison to a test specimen not placed there (1)

Hours Inter-polymer / PMIA mixture. Commercial acrylic

46 0.8 '0.7

209 "1.2 0.7

378 1.0 1.0

515 x 1.1 1.0

682 1> 1 1 »2

851 .1,4 1,3

1014 .1,1 1,6

1301 ... 1.3 1.9

2052 '1.4 1.8

(1) Measured by a color difference meter HDMiEHLAB (Model 2Tr.24D2) in accordance with ASTM D-1925> only these values express the color changes (ΔS) rather than the units of the asperity index adopted in the above standard method.

These data show that the mixture has color retention properties equivalent to commercial AcryMaterial.

.-- " 60 ° gloss loss (%) (2)

Hours of interpolymer / PMEA mixing; Commercial acrylic

46 1 0

209 5 .6

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373 10 10

515 12 12

682. 15 15 ·

851 19 21

1014 26 38

1301 28 SO

2052 '· 39? 6

(2) Measured with a glossmeter from GiEDIJSR (GLOSSGLED SISIEM 60) in accordance with ASTM D-523

These data indicate that the gloss of the commercial acrylic is greater after more than one thousand hours of exposure under the test conditions described.

While some embodiments of the invention are illustrated in the foregoing examples, they are not to be considered as limiting the scope of the invention as defined in the following claims.

Claims (9)

invention claim A weather-resistant, impact-resistant mixture, characterized in that it consists of: (1) an acrylic resin and. (2) an impact-resistant interpolymer consisting of crosslinked (meth) acrylate, crosslinked styrene-acrylonitrile and uncrosslinked styrene-acrylonitrile polymer components, 2. Mixture according to item 1, characterized in that the interpolymer about 5 to about 50% by mass of the (meth) acrylic component ,. from about 5 to about 35% by weight of the crosslinked styrene-Acrylonitrilkomponente and from about 15 to 90 mass% ^ etna ^it contains uncrosslinked styrene-Acrylonit rilkomponente. 3. Mixture according to item 1 or 2, characterized in that the mass ratio of acrylic resin and interpolymer is between about 75:25 and about 5:95, The mixture according to item 1 or 2 _{t is} characterized in that the mass ratio of acrylic resin and interpolymer is between about 60:40 and about 20:80. 5 * Mixture according to item 1 or 2, characterized in that the (meth) acrylate component of the crosslinked C ₀ -C. Alkyl acrylates selected from crosslinked C ₀ -C ₀₀ -alkyl-methacrylates and compatible mixtures thereof. Compound according to item 1 or 2, characterized in that the (meth) acrylate component is a crosslinked C 1 -C -alkyl acrylate . 26.2.1982 Y ^ AP C 08 G / 232 530/2 530 2 - ^ - ^{594S4 / 18} 7 * Mixture according to item 1 or 2 _3, characterized in that the acrylic resin is polymethylmethacrylate * 8 «Mixture according to item 1 or 2, characterized in that the acrylic resin is polymethyl methacrylate and the (-meth) acrylate component is cross-linked sutyl acrylate * 9, blend of item 1 or 2, characterized in that the weight ratio of acrylic resin and interpolymer is between about 60:40 and about 20:80, and the interpolymer is from about 5 to about 50 weight% of a crosslinked polybutyl acrylate component * of about 5 to and including 35 mass% of the crosslinked styrene-acrylonitrile component and from about 15 to about 90 mass% of the uncrosslinked styrene-acrylonitrile component.