POLYMERIC COMPOSITION

Abstract: A polymeric composition comprising an ethylene/vinyl acetate/carbon monoxide terpolymer and an organosilicon compound having in the molecule at least one hydrolyzable hydrocarbon-oxy group directly bonded to a silicon atom.

Description: This invention relates to a polymeric composition comprising an ethylene/vinyl acetate/carbon monoxide terpolymer and an organosilicon compound. More specifically, it relates to a polymeric composition comprising the aforesaid terpolymer and having improved processability, odor and heat stability. Generally, ethylenic polymers are nonpolar and have the defect of poor compatibility with other polymers. An ethylene/vinyl acetate/carbon monoxide terpolymer, however, has good compatibility with many polymers containing polar groups such as polyvinyl chloride, polyamides and cellulose derivatives because it has highly polar carbon monoxide units in the molecule (see, for example, U. S. Patent 3,780,140). In particular, the ethylene/vinyl acetate/ carbon monoxide terpolymer is used as a permanent plasticizer instead of conventional liquid plasticizers or as a modifier. The use of this terpolymer as a permanent plasticizer makes most of its characteristics, and can circumvent the changes with time of the rigidity of vinyl chloride resin compositions owing to volatilization or extraction of the liquid plasticizers, and the contamination of substrates by bleed-out of the liquid plasticizers from such vinyl chloride resin compositions, which are the defects of the conventional vinyl chloride resin compositions. Sheets and other articles fabricated from vinyl chloride resin compositions containing the above terpolymer are also used in fields where conventional vinyl chloride resin compositions cannot be satisfactorily applied, for example as pond liners for reservoirs of industrial waste water which require outdoor durability, and cover sheets of electrical appliances which require a high degree of freedom fro bleed-out. The above terpolymer or blends of this polymer with other synthetic resins such as vinyl chloride resins, however, have relatively poor heat stability at high temperatures during kneading or molding or during a crosslinking reaction with organic peroxides or by electron bean irradiation, and this causes the final products to have an irritating odor. This defect is commonly possessed by vinyl acetate-type polymers. Since vinyl acetate units in the above terpolymer are adjacent to carbon monoxide units, the reactivity of the vinyl acetate units is high, and they tend to liberate acetic acid at lower temperatures, and in turn impart an irritating oder to the final products. It is generally kn that such a defect is removed by adding magnesium oxide to the terpolymer or a polymer composition containing it, The addition of magnesium oxide is effective for preventing the occurrence of an irritating odor in the products, But during processing, the terpolymer or its composition has poor releasability from the roll surface or has reduced heat stability. For example, in a test of heating at 120 C for 400 hours which is used to evaluate the heat stability of a vehicle sheet, etc. the heat weight loss of a sheet of the terpolymer or its composition aining magnesium oxide has an increased heat weight loss and its discoloration is accelerated. In particular, the poor releasability of the molding compound from the roll surface is serious. Since this defect prevents smooth performance of the processing operation, it constitute a serious drawback in the kneading and molding process. Because the aforesaid problems are detrimental to the practical application of the ethylene/vinyl acetate/carbon monoxide terpolymer or a blend of it with another synthetic polymer, it has been strongly desired to improve the processability, odor and heat stability of the aforesaid terpolymer. It is an object of this invention therefore to provide a novel polymeric composition comprising the ethylene/vinyl acetate/carbon monoxide terpolymer. Another object of this invention is to provide a polymeric composition comprising the aforesaid terpolymer which has little or no irritating odor. Still anotehr object of this invention is to provide a polymeric composition comprising the aforesaid terpolymer and having excellent heat stability. Yet another object of this invention is to provide a polymeric composition comprising the aforesaid terpolymer and having excellent releasability from a roll surface during processing. A further object of this invention is to provide the use of a polymeric composition having the aforesaid properties as a plasticizer. A still further object of this invention is to provide a polyvinyl chloride composition containing the aforesaid polymeric composition as a plasticizer. Additional objects and advantages of this invention will become apparent from the following description. According to this invention, the above objects and advantages of this invention can be achieved by a polymeric composition comprising an ethylene/vinyl acetate/carbon monoxide terpolymer and an organosilicon compound having in the molecule at least one hydrolyzable hydrocarbon-oxy group directly bonded to a silicon atom. The ethylene/vinyl acetate/carbon monoxide terpolymer used in this invention is known per se, and can be produced, for example, by the method described in U. S. Patent No. 3,780,140. Preferably, the terpolymer used in this inven tion consists substantially of about 40 to about 80 % by weight of ethylene unfits, about 15 to about 60 % by weight of vinyl acetate units and about 5 to about 30 % by weight of carbon monoxide. More preferably, the terpolyumer consists substantailly of about 60 to about 70 % by weight of ethylene units, about 20 to about 35 * by weight of vinyl acetate units and about 5 to about 15 % by weight of carbon monoxide. The terpolymer used in this invention includes not only a copolymer composed only of ethylene, vinyl acetate and carbon monoxide, but also those which additionally contain, a small amount (for example, not more than 5 * by weight) of another monomer, for example (meth)acrylates such as ethyl (meth)acrylate, n-butyl acrylate and glycidyl methacrylate, vinyl esters of carboxylic acids, other than vinyl acetate, such as vinyl propionate, unsaturated carboxylic acids such as acrylic acids and nitriles such as acrylonitrile and methacrylonitrile. The organosilicon compound used in the composition of this invention should have at least one hydrolyzable hydrocarbon-oxy group directly bonded to a silicon atom in the molecule. In other words, if the hydrocarbon-oxy group is represented by RD-, the organo silicon compound used in this invention should have at least one, RO-Si moiety in the molecule. The hydrocarbonoxy group, is. for example, an alkyloxy or aryloxy group. The alkyl group in the alkyloxy group may be linear or branched and, nay be interrupted by an oxygen atom. Preferably, the alkyloxy group has I to 12 carbon atoms, and the aryloxy group has 6 to 18 carbon atoms. Ex ample of the alkyloxy group include methoxy, ethoxy, n-propoxy, io-propoxyr n-butoxy, iso-butoxy, secbutoxy, tert-butoxy, n-pentoxy, n-hexoxy, n-octoxy, n-nonanoxy and n-decylkoxy. Examples of he alkyloxy group tn which the alkyl group is interrupted by an oxygen atom are 2-methoxyethyloxy and 3-ethoxypropyloxy. Examples of the aryloxy group are phenoxy, methylphenoxy and naphthoxy groups. Especially preferably, the organosilicon compound has 2 to 4 hydrocarbon-oxy groups directly bonded to the same silicon atom in the molecule. Examples of the organosilicon compound are as follows: (A) Compounds of the following formula Si(ORr) 4 wherein the four g groups may be identical or different, and each represents an alkyl group which may be interrupted by an oxygen atom, or an aryl group. Specific examples include ortho-methyl silicate, orthoethyl silicate, ortho-n-propyl silicate, ortho-n-butyl silicate, ortho-isoamyl silicate and ortho-trimethyirnono- phenyl silicate. (B) 'Compounds of the following formula (R3nSi4OR2) 4-n 2 wherein n is 1, 2 or 3, R2 groups may be identical or different and each represents an alkyl group which may be interrupted by an oxygen atom, or an aryl group, and R3 groups may be identical or different and each repre sents an alkyl, alkenyl or aryl group. Specific examples include methyltrimethoxysilane, ethyltrimethoxysilane, phenyltrimethoxysilane, dimethyldimethoxysilane, diethyldiethoxysilane, diphenyldimethoxysilane, trimethylmonomethoxysilane and tri ethylmonoethoxys il ane. (C) Compounds of the following formula X-(CH2)-qSiRm5(OR4)3-m wherein R4 groups may be identical or differ ent and each represents an alkyl group which may be interrupted by an oxygen atom, or an aryl group, R5 reepresents an alkyl group having 1 to 8 carbon atoms, X represents an acryloxy, methacryloxy, glycidoxy or 3,4-epoxy cyclohexyl group or a substituted or unsubsti tuted amino group, q is 2 or 3, and m is 0 or 1. Preferably! these con-pounds have a boiling point of at least 200 o(;, and include, for example, gamma-meth- acryloxypropyltrimethoxysilane, gamma-glycidoxypropyltrimethoxysilane, gamma-glycidoxypropylmonomethyldiethoxysilane, N-(beta-aminoethyl)-gamma-aminopropyltrimethoxysilane, N-(beta-aminoethyl)-gamma-aminopropylmonomethyldimethoxysilane, gamma-aminopropyltriethoxysilane, N-phenyl-gamma-aminopropyltrimethoxysilane, and beta (3,4-epoxycyclohexyl)ethyltrimethoxysilane. (D) Compounds of the following formula CH2=CH-Si(OR5)3 wherein R5 groups nay be identical or differ ent, and each represents an alkyl group which nay be interrupted by an oxygen atom, or an ;y1 groups Specific examples include vinyl tris(beta-methoxyethoxy)- silane, vinyltrimethoxysilane and vinyltriethoxysilane. (E) Condensation products of the compounds (A) to (D) above which contain at least one alkoxy group in the molecule The organosilicon compound is used in a proportion of, for example, 0.2 to 10 parts by weight, preferably 1 to 5 parts by weight, per 100 parts by weight of the terpolymer. If the organosilicon compound is used in smaller proportions, the desired effect of inhibiting an irritating odor is difficult to obtain. If it is used in larger proportions, the resulting polymeric composition decreases in viscosity and its processability is reduced. Alternatively, the organosilicon compound tends to bleed out on the surface of the molded article and becomes sticky. The terpolymer is blended with other plastic resins having compatibility with it, such as halogenated polymers, polyamides and cellulose derivatives, particularly vinyl chloride resins, and are used as a permanent plasticizer for these synthetic resins. The polymeric composition of this invention can equally be used as a plasticizer. The present invention thus also provides a polymeric composition comprising the aforesaid terpolymer, the aforesaid organosilicon compound and another plastic resin having compatibility with the terpolymer. Vinyl chloride resins are especially preferred as the other plastic resin. Not only a homopolymer of vinyl chloride, but also copolymers of vinyl chloride with comonomers can be used as the vinyl chloride resins. Examples of the copolymer include alpha-olefins such as ethylene and propylene, vinyle esters such as vinyl acetate, unsaturated carboyxlic acid esters such as acrylic esters, vinyl ethers such as alkylvinyl ethers, other vinyl halides such as vinyl bromide and vinyl fluoride, and other compounds such as styrene, acrylonitrile and vinylidene chloride. As required, liquid plasticizers may be incorporated in the vinyl chloride resins. The polymeric composition containing the plastic resin may be prepared by simultaneously or successively dry-blening or melt-blending the aforesaid ingredients. In the case of successive blending, it is possible to prepare the polymeric composition of the invention consisting substantially of the terpolymer and the oragnosilicon compound and then blending it with the plastic resin. Irrespective of whether the blending is carried out successively or simultaneously, the resulting polymeric compositions show much the same properties. when the individual ingredients are dryblended, the organosilicon compound is easily meltblended uniformly when subsequently the aforesaid ter polymer with or without the other plastic resin is melted in a roll, an extruder, etc. Melt-blending of the individual, ingredients may be carried out in various types of, ers, rollers and kneaders such as a single screw extruder, a twinoscrew extruder or a Banbury mixer, There is no particular restriction on the sequence of ing these ingredients. the polymeric composition of this invention containing the plastic resin shows the following marked advantages. (1) A terpolymer composition prepared by adding magnesium oxide has poor releasability from the roll surface during kneading and molding. In contrast, the polymer position of this invention exhibits good releasability f; the roll surface. (2) then irritating odor of molded articles, such as filmy or sheets, from the terpolymer or a blend of it with ano,ther plastic polymer, described above, is due presumably to acetic acid which is generated by the heat decomposition of the vinyl acetate units of the terpolyner when it is heated at high temperatures, for instance during kneading or molding. It is believed that in the polymer composition of this inventon, acetic acid is captured by the organosilicon compound, and therefore, the final product does not have an irritating odor ascribable to acetic acid. (3) The terpolymer composition containing magnesium oxide gives a product having much reduced aging resistance, and the product undergoes accelerated discoloration and has a high weight loss. In contrast, the inclusion of the specific organosilicon compound in the polymer composition of this invention serves to obviate the reduction of the aging resistance of the product. Thus, the polymer composition of this invention shows improved releasability, processability, heat resistance and aging resistance and the freedom frg an irritating odor without particularly showing a sid effect by the addition of the organosilicon comp'oundq It is the general practice to improve the mechanical properties and anti-blocking property at high temperatures of the aforesaid terpolymer or a composi- tion comprising it and another plastic resin by cross- linking them with organic peroxides or by electron beam irradiation. At this time, too, the organosilicon compound in the polymeric composition of this invention can advantageously capture acetic acid liberated during the crosslinking reaction at high temperatures. The following examples illustrate ths ent invention in more detail. EXAMPLES 1 - 4 In each run, a polymer composition haying the following formulation was prepared and molded into a sheet. The properties of the composition and the sheet were evaiuated in accordance with the methods shown below. The results are shown in Table 1. (parts by weight) Polyvinyl chloride (average degree of polymerization 1000) 100 Ethylene/vinyl acetate/carbon monoxide terpolymer (ethylene units 66 weight %, vinyl acetate units 24 weight % and carbon monoxide units 10 weight %; melt index 35 g/10 minutes) 100 Organosilicon compound (see Table 1) 0.2 Ba-Zn stabilizer 2.5 Phosphite ester 0.5 Epoxidized soybean oil 5 Phenol it antioxidant 0.3 Methods of measurement and evaluation Roll releasability: The composition was kneaded at 165 C on a 6-inch roll, and the time which elapsed until the kneaded mixture could no longer be removed from the roll surface was measured. Longer periods of tiae indicate better releasability. Smoothness of the sheet surface: The roll sheet sampled 10 minutes after the initation of kneading was evaluated by visual observations Irritating odor: Five grams of the sheet was sealed up in a 200 ml glass bottle, and heated at 100 C for 4 hours. The bottle was then opened, and the presence of an irritating odor was examined. Discoloration (AE): The sheet was heated to 1200C for 1 week, and the degree of its discoloration was examined by using a color difference meter (Color Computer Model SM-2 made by Suga Testing Machine Co., Ltd.). Heat weight loss: The sheet was heated at 1200C for 480 hours, and then the change of the weight of the sheet was examined. COMPARATIVE EXAMPLE 1 The procedure of Examples 1 to 4 was repeated except that the organosilicon compound was not used. The results are shown in Table 1. COMPARATIVE EXAMPLE 2 The procedure of Examples 1 to 6 was repeated except that 1 part by weight of manganesium oxide was, used instead of the organosilicon compound. The results are also shown in Table 1. Table 1 EMI12.1 Example <SEP> (Ex.) <SEP> Smoothness <SEP> Heat <tb> or <SEP> Roll <SEP> re- <SEP> of <SEP> the <SEP> Irittat- <SEP> Discolor <SEP> weight <tb> Comparative <SEP> Organosilicon <SEP> compound <SEP> leasability <SEP> sheet <SEP> ing <SEP> odor <SEP> ation <SEP> loss <tb> Example <SEP> (CEx.) <SEP> (min.) <SEP> (#E) <SEP> (%) <tb> Ex. <SEP> 1 <SEP> ortho-ethyl <SEP> silicate <SEP> 60 <SEP> Good <SEP> No <SEP> 27 <SEP> 3.2 <tb> Ex. <SEP> 2 <SEP> ortho-isopropyl <SEP> silicate <SEP> 50 <SEP> Good <SEP> No <SEP> 25 <SEP> 3.6 <tb> Ex. <SEP> 3 <SEP> Ethyl <SEP> silicate <SEP> condensate <SEP> 50 <SEP> Good <SEP> No <SEP> 27 <SEP> 3.3 <tb> (40% <SEP> as <SEP> SiO2) <tb> Ex. <SEP> 4 <SEP> vinyl <SEP> tris(beta-methoxy- <SEP> 55 <SEP> Good <SEP> No <SEP> 25 <SEP> 3.6 <tb> ethoxy)silane <tb> CEx. <SEP> 1 <SEP> None <SEP> 60 <SEP> Good <SEP> Yes <SEP> 26 <SEP> 3.5 <tb> CEx. <SEP> 2 <SEP> MgO <SEP> 15 <SEP> Poor <SEP> No <SEP> 63 <SEP> 5.1 <tb> (blackening <tb> occurred) <tb> EXAMPLE 5 Compositions were prepared as in Example 1 by changing the amount of the ortho-ethyl silicate to 1, 2 and 5 parts by weight, respectively. Roll sheets obtained by roll kneading were evaluated for their surface stickiness and irritating odor. All of the sheets tested were found to be free from an irriating odor and stickiness. EXAMPLES 6-7 AND COMPARATIVE EXAMPLE 3 Two parts by weight of each of the organosilicon compounds shown in Table 2 was added to 100 parts by weight of the same ethylene/vinyl acetate/ carbon monoxide terpolymer as used in Examples 1 to 5, and the mixture was kneaded by a Brabender plastograph at a temperature of 160 0C and a rotor rotating speed of 50 rpm for 10 minutes. The resulting kneaded mixture was examined for an irritating odor. The rsults ate shown in Table 2. Table 2 EMI13.1 <tb> Example <SEP> Organosilicon <SEP> compound <SEP> Irritating <SEP> <tb> <SEP> odor <tb> <SEP> Methyl <SEP> silicate <SEP> con <tb> <SEP> 6 <SEP> densate <SEP> (SiO2 <SEP> content <SEP> No <tb> <SEP> 50 <SEP> %) <tb> <SEP> 7 <SEP> gamma-Glycidoxypropyl- <SEP> No <SEP> <tb> <SEP> trimethoxysilane <tb> Compa <tb> rative <SEP> (None) <SEP> Yes <tb> Ex. <SEP> 3 <tb>

Claims: What is claimed i52 1. A polymeric composition comprising an ethylene/vinyl acetate/carbon monoxide terpolymer and an organosilicon compound having in the molecule at least one hydrolyzable hydrocarbon-oxy group directly bonded to a silicon atom. 2. The composition of claim l which consists substantially of the terpolymer and the organosilicon compound. 3. The composition of claim 1 wherein the terpolymer consists substantially of about 40 to about 80 8 by weight of ethylene units, about 15 to about 60 % by weight of vinyl acetate units and about 5 to about 30 % by weight of carbon monoxide units. 4. The composition of claim 1 wherein the hydrocarbonoxy group of the organosilicon compound is an alkyloxy group in which the alkyl may be interrupted by an oxygen atom, or an aryloxy group. 5. The cotposition of claim 1 wherein the organosilicon compound has 2 to 4 hydrocarbon-oxy groups directly bonded to the same silicon atom in the molecule. 6. The composition of claim 1 wherein the organosilicon compound is a compound represented by the following formula S;{OR1)4 wherein the four R1 groups may be identical or different, and each represents an alkyl group which My be interrupted by an oxygen atom, or an aryl group. 7. The composition of claim l wherein the organosilicon compound is a compound represented by the following formula (R #nSi#ORê)4-n R2 wherein n is 1, 2 or 3, Rê groups may be identical or different and each represents an alkyl group which may be interrupted by an oxygen atom, or an aryl group, and R3 groups may be identical or different and each re presents an alkyl, alkenyl or aryl group. 8. The composition of claim 1 wherein the organosilicon compound is a compound represented by the following formula X+CH2XqSiRm(OR )3-m wherein R4 groups may be identical or differ ent and each represents an alkyl group which may be interrupted by an oxygen atom, or an aryl group, R5 reepresents an alkyl group having 1 to 8 carbon atoms, X represents an acryloxy, methacryloxy, glycidoxy or 3,4-epoxy- cyclohexyl group or a substituted or unsubsti- tuted amino group, q is 2 or 3, and m is 0 1. 9. The composition of claim 1 wherein the organo- silicon compound is a compound represented by the fol1QW- ing formula CH2=CH-Si(OR5)3 wherein R5 groups may be identical or differ ent, and each represents an alkyl group which may be interrupted by an oxygen atom, or an aryl group. 10. A polymeric composition comprising an ethylene/vinyl acetate/carbon monoxide terpolymer, an organosilicon compound having in the molecule at least one hydrolyzable hydrocarbon-oxy group directed bonded to a silicon atom, and another plastic polymer having compatibility with the terpolymer. 11. The cc-position of claim 1 wherein the other plastic polymer' is a vinyl chloride-type polymer. 12. The composition of claim 10 wherein the terpolymer consists substantially of about 40 to about 80 % by weight of ethylene units, about 15 to about 60 % by weight of vinyl acetate units and about 5 to about 30 % by weight of carbon monoxide units. 13. The composition of claim 10 wherein the hydrocarbon-oxy group of the organosilicon compound is an alkyloxy group in which the alkyl may be interrupted by an oxygen atom, or an aryloxy group. 14. The composition of claim 10 wherein the organosilicon compound has 2 to 4 hydrocarbon-oxy groups directly bonded to the saxe silicon atom in the molecule. 15. The composition of claim 10 wherein the organosilicon compound is a compound represented by the following formula SiXOR1)4 wherein the four R1 groups may be identical or different, and each represents an alkyl group which may be interrupted by an oxygen atom, or an aryl group. 16. The composition of claim 10 wherein the organosilicon compound is a compound represented by the following formula (R #nSi#ORê)4-n wherein n is 1, 2 or 3t R2 groups may be identical or different and each represents an alkyl group which may be interrupted by an oxygen atom, or an aryl group, and R3 groups may be identical or different and each represents an alkyl, alkenyl or aryl group. 17. The composition of claim 10 wherein the organosilicon compound is a compound represented by the following formula X#CH2#SiRm5(OR4)3-m wherein R4 groups may be identical or differ ent and each represents an alkyl group which may be interrupted by an oxygen atom, or an aryl group, R5 represents an alkyl group having 1 to 8 carbon atoms, X represents an acryloxy, methacryloxy, glycidoxy or 3,4-epoxy cyclohexyl group or a substituted or unsubsti tuted amino group, q is 2 or 3, and m is 0 or 1. 18. The composition of claim 10 wherein the organosilicon compound is a compound represented by the following formula CH =CH-Si(OR5 )3 2 wherein R5 groups may be identical or different, and each represents an alkyl group which may be interrupted by an oxygen atom, or an aryl group.

Inventors: TADA, SEIICHI
Applicants: DU PONT-MITSUI POLYCHEMICALS CO.,LTD.
Application year: 1985
Main classification: C08L23
IPC codes: C08L23, C08L33, C08L27, C08K5, C08L31, C08L51, C08L1, C08L73, C08L101, C08L65