IL24692A - Thermoplastic polymeric compositions - Google Patents

Description

Thermoplastic polymeric compositions EDISOH invention relates to thermoplastic polymeric compositions and is especially concerned with such tions which are based on graft A thermoplastic polymeric composition in accordance with the invention includes from 1 to 99 by weight of a graft copolymer obtained by polymerization in aqueous emulsion of a vinyl vinylidene monomers mixture on an aqueous latex of a synthetic or natural and from 99 to by weight of a graft copolymer obtained by the polymerization of vinyl and or vinylidene monomers mixture containing a synthetic or natural elastomer dissolved Compositions in accordance with the invention have in general good physical properties and in particular a high resistance to impact even at low an excellent stiffness and are also highly stable to It has surprisingly found that with an equal quantity of which may polybutadiene or other dienic conjugated hydrocarbons polymers or present in the polymeric a product is obtained which has a much higher resilience than a graft copolymer prepared from rubber aqueous latex used alone or mixed with one or more resinous copolymers so as to give the same final rubber Also it has surprisingly been found that with the same quantity of rubber present in the polymeric a product in accordance with the invention is obtained which is characterised by a better percentage elongation and stability to light than an emulsion graft copolymer used alone or in admixture with one or more At the same time it has been noted that the other properties of a composition according to the invention do not appear to be adversely affected compared with those properties of an emulsion graft copolymer used or in an admixture with one or more resinous copolymers so as to give the same final rubber The emulsion graft copolymer used in a composition of the invention may be prepared for example by any of the methods to those skilled in the It is preferred to use a vinyl vinylidene monomers mixture constituted by a monomer and an The monomers mixture is in emulsion onto a synthetic rubber aqueous latex preferably containing a high percentage of a monomer may be styrene d derivatives of styrene substituted in the vinyl group in the aromatic group such for example as ethylstyrenes and and Mixtures of two or more monomers may also be The monomer may example be acrylonitrile vinylidene cyanide and alkylic esters of acrylic and methacrylic Also two or more of these monomers may be used in a dienic hydrocarbon may be an aliphatic or aliphatic possibly having two conjugated double Examples are chloroprene and may be used alone or as ery good compositions are obtained by using 4 polymerized in aqueous emulsion on an aqueous latex of a synthetic elastomer containing at least and preferably more than of For every 100 parts of monomers from 30 to 200 parts of synthetic elastomer are generally Particularly suitable graft copolymers are prepared in an emulsion containing roms 15 to by weight of 10 to by weight of and 50 to by weight of styrene graft copolymer obtained by the polymerization of a vinyl vinylidene mixture in which a synthetic or natural rubber has been may be pared in the manner described in Patent Specieification The synthetic or natural rubber is homogeneously dissolved in a mixture of a monomer and an acr the solution of the rubber in the monomer is polymerized first in the absence of thereafter in the presence of water and a suitable suspending until an almost complete conversion has been Good results are obtained by using monomer mixtures containing from 20 to 40 parts by weight of acrylonitrile and from 60 to 80 parts by weight of In such mixtures from to by weight of synthetic rubber as compared with the total weight monomers and rubber are homogeneously The rubber preferably used is a synthetic elastomer constituted by pol This The nature of the graft copolymers used in the thermoplastic polymeric compositions in accordance the and their relative proportions may varied within a broad range so as to give the desired properties to the polymeric compositions More particularly the two copolymers and their ratio can be to give the composition desired Further with the impact resistance remaining substantially the nature and the ratio between the two copolymers make it possible to select other properties of the polymeric raising of the two does not require any special since it is possible to follow known According to one preferred embodiment of the the two graft in the form of powder or are mixed cold in a rotating drum During the mixing even the normal which are commonly for and are added to the mixture thus obtained is then fed to an extruder in which thorough mixing takes followed by product so obtained ean then be moulded by extrusion or infection after possibly adding further external She invention will now be illustrated by the following in which all proportions are by weight unless otherwise resinous copolymer was prepared based on styrene and as a comparison steel autoclave resistant to internally lined a vitreous material and provided a stirrer and temperature control 100 Parts of water were a mixture of 100 parts of monomers mixture having the following percentage added styrene acrylonitrile a catalyst consisting of in amounts of in respect to monomers mixture was started bringing autoclave contents to a temperature of in a period of 50 a suspending agent consisting of parts of a partially alkaline product of polymethylmethacrylate wife of hydrolysis grade and having in a aqueous solutio a viscosity of 200 centipoises at was duced in the autoclave and the brought to She temperature of the autoclave contents increased continuously from C to 140 C in Then the contents were cooled to about and steam distilled to eliminate unconverted contents of the autoclave tere cooled and beads dischargedj and the copolymer thus obtained were centrifugedj and extruded under copolymer obtained had the following styrene acrylonitrile It had the properties listed in the following Table I Property Result Method of ermination Resilience with 2 D 256 Yielding load cm Breaking load 750 638 Modulus of elasticity under traction i D 658 638 stress under flection Modulus of elasticit flection D 790 Rockwell scale 110 D Preparation of Resinous A res nous copolymer prepared from and as a Into a stainless steel as described 100 parts water were introduced and a 100 parts of a monomer having the following were added to the acrylonitrile a catalyst consisting of butylperoxide in an amount of with respect to the mixture was Also an amount of with respect to the monomers mixture was added as a was started by bringing the autoelave contents to a She reaction heated 2 hours at a temperature and during the next hours the temperature was increased to 110 reaction mass was kept at this temperature for a further 2 By operating ia this way a copolyme obtained whose composition She copolymer had following properties listed in Sable gable Resilience Izod at x with s Yielding load Elongation Maximum stress under flection Modulus of elasticity under flection hardness scale 109 These properties and those of other products to described all determined by the same standards as given in Sable Into a autoclave were introduced at room temperature 170 of an emulsion of a latex containing of a suitably pol as sold by Firestone as PSS and 278 g of g of a mixture containing of monomer and of acr lohitrile g of potassium of sodium g of the condensation product of formaldehyde and the sodium salt of an alkylnaphthalenesulphonic acid and g of as a buffer e separately This reaction mixture was allowed to polymerize a period of 6 first at and then at a gradually increasing temperature up to An as obtained and this was coagulated by the addition of a saline filtered obtain the precipitate and the precipitate The graft copolymer as obtained had the following percentages of chemically combined and it had the following properties listed Table Table III Izod Resilience t C x l Eg 13 Yielding load 160 Breaking load 160 of elasticity traction Elongation 80 stress under flection 250 Modulus of elasticit under flection 9 Preparation of a gra suspension In the manner described in Patent Specification three different quantities of a polybutadiene rubber 100 of sold by Firestone were finely ground and added to three different quantities of a mixture containing 47 of styrene and of ground rubber was added with stirring in quantities of and with respect to the total quantity of the monomers see thus obtained mixture was in each case brought to a temperature of 70oC and maintained 5 Any undissolved rubber particles were then filtered off from the solution of styrene Then acrylonitrile was added in such an amount that the styrene acrylonitrile mixture had the following percentage compositions acrylonitrile styrene Together with the acrylonitrile9 were added a polymerization catalyst consisting of part of and part of consisting of mixture so obtained was heated for about 3 hours at a temperature of Next the mixture of partially monomers was transferred to a polymerization autoclave containing 100 parts of previously and heated at a temperature of and a suspending system was added consisting of part of partially hydrolyzed polymethacrylate having a 7 The autoclave contents cooled to about and steasa distilled to eliminate unconverted A copolymer was obtained in the of beads which eentrifuged and by hot air at product was then extruded under vacuum at a temperature of e compositions of the copolymer products and their physical properties in relation to quantities of rubber employed are below in Styrene contents Acrylonltrile contents contents Butadiene contents Izod Resilience iead at 25 C with Izod o Resilience lead at 0 C with Resilience at with HDT Yielding load Breaking load Modulus of elasticity under traction Elongation Maximum stress under flection Modulus of elasticity under flection Rockwell hardness scale L 12 Preparation of a graft suspension as described in Patent Specification and starting from a mixture consisting of i acrylonitrile in which had been dissolved various quantities of graft copolymers of styrene and acrylonitrile on diene were obtained whose compositions and physical properties in relation to the amount of rubber employed are summarized below in fable content Acrylonitrile content Butadiene content at cm cm with Izod 0 Resilience C with Resilience at with Yielding load Breaking load Modulus of elasticity under traction Elongation Maximum stress under flection Modulus of elasticity under flection 3 Rockwell hardness scale 14 Method of of the previously prepared graft copolymers The two components of the blends in the form of small particles or were introduced into a rotating drum mixer at room Then the following additives were mineral wax 0 to antioxidant to dye and pigments to and a thorough mixing took place for 15 She mixture so obtained was extruded under vacuum from a screw extruder in which an even more thorough mixing took 2 Properties of blends of graft Several blends were prepared from a copolymer prepared as in Example and a tetrapolymer prepared as in Example The suspension used contained of rubber and was admixed with varying quantities of the the blends contained from 0 to of rubber The properties of the blends are indicated below in Table Properties Copolymer of Example Total amount of Suspension copolymer 0 100 Amount of rubber in the suspension copolyiaer 0 Izod 0 Resilience at with Izod 0 Resilience at 0 C Resilience at with 102 Yielding load cm 649 2 Breaking 750 537 Modulus of elasticity under traction Elongation Maximum stress under flection Modulus of elastioity under flection Rockwell hardness scale 110 101 Example Several blended mixtures of graft copolymers were prepared from an emulsion graft copolymer prepared as in Example tilth a suspension graft copolymer prepared as in Example The suspension graft copolymer used had of rubber and it was blended with various quantities of the emulsion graft copolymer so as to have blends containing total rubber quantities varying from 0 to The properties of the resulting blended mixture are indicated in Properties Copolymer of Example Total amount of rubber in the blends 0 Suspension copolymer 0 Amount of rubber in the suspension copolymer 0 Resilience at with Izod 0 j Resilience 0 0 cm with Izod Resilience at cm cm with 102 Yielding load Breaking load 750 Modulus of elasticity under traction Elongation Maximum stress under flection Modulus of elasticity under flection Rockwell hardness scale 110 Example 4 Operating in the manner described in connection with Examples 2 and a suspension graft copolymer was employed which contained of rubber together with various quantities of an emulsion graft copolymer so as to give blended mixtures containing rubber in total quantities of 0 to The properties of the blended mixtures are indicated below in fable As it can be the data relative to the first of Sables refer to the resinous copolymer the preparation and the ties of have been indicated in Example Properties Copolymer of Example Total of rubber in the mixtures 0 Suspension copolymer 0 100 of rubber in the suspension copolymer 0 Izod Resilience at with 2 Izod Q Resilience load at with Izod Resilience at C with 102 Yielding load 462 Breaking load 750 455 Modulus of elasticity under traction Elongation Maximum stress under flection 712 Modulus of elasticity under flection Rockwell hardness scale L 110 Several mixtures of graft copolymers were blended an emulsion graft copolymer prepared as in Example and a suspension graf copolymer prepared as in Example Suspension graft copolymers having and of rubber were used together with various quantities of the emulsion graft copolymer to give mixtures containing total quantities of rubber of to The properties of these mixtures are indicated in Tables and As it can be seen the data relative to the first column of Tables and XI refer to the resinous copolymer the preparation and the properties of which indicated in Example Properties Copolymer of Example Total amount of rubber 0 2 Suspension oopolymer 0 100 Total amount of rubber in the suspension oopolymer 0 2 Izod Resilience at with 2 Izod 0 Resilience at cm cm with 2 Izod 0 Resilience at C with 2 95 93 Yielding load 585 Breaking load 810 545 Modulus of elasticity under traction Elongation Maximum stress under flection Modulus of elasticity under flection Rockwell hardness scale L 109 105 A L Properties Copolymer of Example Total amount of rubber 0 Suspension copolymer 0 100 Total amount of rubber in the suspension copolymer 0 at with o Resilience at with Izod Resilience load at with 95 Yielding load 530 Breaking load 810 495 Modulus of elasticity under traction Elongation Maximum stress under flection 910 Modulus of elasticity under flection Rockwell hardness scale L 109 102 XI Properties Copolymer of Example lb Total amount of rubber 0 Suspension copolymer 0 100 Total amount of rubber in the suspension copolymer 0 Resilience at with Izod Resilience at 00 with Izod Resilience load at with Yield load 468 Breaking load 810 442 Modulus of elasticity under traction Elongation 12 Maximum stress under flection 773 Modulus of elasticity under flection cm Rockwell hardness scale L 109 96 Example 6 In order to demonstrate the properties of the compositions of this the following fables XII and XIII are set out characteristics of such blended ma erials when varying the total rubber present consequently the of the gra copolyme i The polymeric compositions set out in III and XIII were obtained by mixing an emulsion graft copolymer prepared as in lc with a resinous copolymer prepared as in Examples la and Properties Copolymer o Example Total amount of rubber 0 Emulsion graft copolymer 0 Resilience at C with Resilience at with Izod Resilience load at with 102 Yelding load Breaking load 750 Modulus of elasticity under traction Elongation Maximum stress under flection Modulus of elasticity under Rockwell hardness scale L 110 Properties Copolymer of Example lb Total amount of rubber 0 Emulsion graft copolymer 0 Izod Resilience at 0 with Resilience load at 0 C with Izod o Resilience at with Yielding load Breaking load 810 Modulus of elasticity under traction Elongation Maximum stress under flection 2 Modulus of elasticity under flection Rockwell hardness scale L 109 comparing the properties listed in fable XII with those in it can be seen that with th same quantity of rubber present in the meric compositions under the thermoplastic polymeric according to the present present a greater resistance to impact and a higher elongation value while the other properties are not Similar results as seen by comparing Table Sables X and 28 insufficientOCRQuality

Claims (2)

1. * Thermoplastic polymeric compositions containing from 1 to 99% by weight a graft copolymer (A) produced by the polymerization in aqueous emulsion of a mixture of a styrene-type monomer with an acrylonitrile-type monomer on an aqueous latex of a synthetic elastomer? and from 99 to 1$ by weight of a graft copolymer (B) produced by the polymerisation of a mixture of a styrene-type monomer and an acrylonitrile-type monomer containing a dissolved synthetic or natural elastomer. 2i Compositions as claimed in Claim 1, containing the an copolymer (A) in/amount of from 1 to 50$ by weight, and the copolymer (B) in an amount of from 99 to 5 % by weight. 3. Compositions as claimed in Claim 1 or 2, containing a high percentage of a dienic hydrocarbon as the synthetic elastomer. .· 4. Compositions as claimed in Claim 3» wherein a copolymer (A) is used which has been produced by the polymerization in aqueous emulsion of a st ene and/or ÷ a-methyl-styrene monomer with acrylonitrile on an aqueous latex of a synthetic elastomer containing at least 70% by weight of butadiene. 5. Compositions as claimed in Claim 4, wherein a copolymer (A) is used in whose preparation the ratio by weight of monomers to synthetic elastomer has been from 0.5 to 3.3. - 29 ■=■ 24692/ 6i Compositions as claimed in any of Claims 1 to 5i wherein a copolymer (A) is used which has been prepared from 30 to 60 parts by weight of styrene, 10 to 25 parts by weight of acr lonitrile and 15 to 60 parts by weight of butadiene. 7.* Compositions as claimed in any of Claims 1 to 6, wherein a copolymer (B) is used which has been prepared by polymerizing, first in the absence ofwater and thereafter in the presence of water, a mixture of styrene-type monomers with acrylonitrile-?type monomers containing dissolved natural or synthetic rubber in proportions from 0.5 to 30Λ, calculated on the aggregate weight of the monomers and rubber. 8. Compositions as claimed in any of Claims 1 to 7, wherein a copolymer (B) is used in whose preparation, poly-butadiene has been used as the dissolved synthetic elastomer 9. Compositions as claimed in any of Claims 1 to 8, wherein a copolymer (B) is used which has been produced by polymerizing a mixture of 20 to 40 parts by weight of acrylo nitrile with 80 to 60 parts by weight of styrene and/or a-methylstyrene containing 0.5 to 15 parts by weight of dissolved pol butadiene. 10. Compositions as claimed in Claim 9, wherein a copolymer (B) is used in whose production the polymerization has been conducted initially in the absence of ¾ater and then in the aqueous suspension. - 30 - 24692/3 11. Thermoplastic polymeric eoiapositions in accordance with Claim 1, substantially as described herein,with reference to the Examples. 1

2. Objects moulded from compositions as claimed in an preceding Claim. For the Applicants RG/rb