MXPA97010393A - Improved pvc foam compositions - Google Patents

Abstract

The density of rigid foamed articles made by the thermal decomposition of a blowing agent in a vinyl chloride polymer is reduced by the use of an organotin mercaptoalkylcarboxylate, alone, or in combination with an organotin halide or carboxylate which activate the blowing agent. Sulfides made fromásaid organotin mercaptoalylcarboxylate are also superior activators of the blowing agent.

Description

- * "IMPROVED COMPOSITIONS OF PVC FOAM Background of the Invention This invention relates to the preparation of polymers vinyl chloride. It relates more particularly to combinations of compounds of certain organotin products which are higher activators for blowing or blowing agents, used in the preparation of cellular vinyl chloride polymers. 10 An important utility for vinyl chloride resins is found in the preparation of rigid foam articles. The articles are manufactured by known methods, such as the extrusion of a mixture of the resin and additives with a suitable blowing agent and choosing the temperature of the process, in such a way that it is above the decomposition temperature of the blowing agent. The bubbles of the gas emitted by the blowing agent are trapped inside the melted resin, thereby forming a cellular structure that is useful commercially for items such as pipes, structural ways and decorative moldings. Generally the polymer melts at a temperature between 150 ° and 200 ° C and it is necessary to include a stabilizer in the formula with the purpose of eliminating or at least minimizing the heat-induced discoloration of the vinyl chloride polymer from another way would present itself at these temperatures. Also, when the decomposition temperature of the blowing agent is much higher than the processing temperature, the activators are used to hasten the decomposition of the blowing agent and / or to lower the temperature of the decomposition.

/ **. The combination of a blowing agent and an activator 10 increases both the degree and the proportion of the decomposition of the blowing agent. The greater volume that results from the gas generated is desirable, since it reduces the amount of blowing agent required.

It is well known that a variety of organotin compound compounds, particularly dibutyltin derived from mercaptocarboxylic acid esters, will impart useful levels of thermal stability for vinyl chloride polymers. The German Patents Nos. 2,133,372 and 2,047,969 disclose the use of mercatscarboxylic acid esters of organotin products in foamed polyvinyl chloride. These compounds stabilize well but do not effectively activate blowing agents such as azobisformamide. The carboxylates of organotin products such as dibutyltin maleate, dibutyltin dilaurate and dibutyltin maleatehal esters are disclosed in Japanese Patent No. 6264/67 as being useful in flexible, ie plasticized foams, polymer foams. Although these compounds of organotin products activate the azodicarbonamides, they are poor thermal stabilizers for the polymer. In this way it can be observed that esters of mercaptocarboxylic acid of organotin impart good thermal stability but poor blowing agent activation, while organostannic carboxylates offer good activation but poor thermal stability with a result of lack of control of appropriate melt viscosity.

In addition to mercaptocarboxylic acid esters-dictiltin, dimethyltin-, dibutyltin-, and other compounds which are effective thermal stabilizers for vinyl chloride polymers but poor blowing agent activators are the bisulfides (dialkyltin-o-ercaptocarboxylic acid ester) such as bisulfides (dibutyltin-isooctylmercaptoacetate) bisulfide (acid ester of monalkyltin-dimersaptocarboxylic acid), sulfides such as bis (monobutyltin-di-isooctylmercaptoacetate), sulfides (monoalkyltin-dimercaptocarboxylic acid ester) sulphides (dialkyltin.mercaptocarboxylic acid esters) for example, sulfides (monobutylitinisooctylmercaptoacetate) (dibultin-isooctylmercaptoacetate) and -Tris-mercaptocarboxylic monoalkyltin acid ester, for example, monobutyltin tris (isooctylmercaptoacetate). The organotin carboxylates that are good blowing agents but poor thermal stabilizers are the __ monoalkiltin tris (half esters of dicarboxylic acid) such as onobultiltin tris (dodecyl maléate), dicarboxylic acid dialkiltin compounds such as dibutyltin axelate and dialkiltin monocarboxylic derivative acid, for example, dibutyltin bis (fatty acid carboxylate of resin oil) and dibutyltin bis (benzote) . The tin mercaptides of the so-called reverse esters are also known to be good stabilizers for vinyl chloride polymers and good activators for blowing agents. The reverse esters are called This is because they are the products of the reaction between the mercapto alcohols and carboxylic acids instead of the alcohols and mercapto carboxylic acids. The preparation of the corresponding esters and mercaptides, for example, dibutyltin bis- (mercaptoethyl laurate) and their use as stabilizers for the vinyl chloride polymers are taught in U.S. Patent No. 2,870,182, which it is incorporated herein by reference. The sulfides that are made by the reaction between an inverse ester, an organotin chloride and an alkali metal sulfide in an aqueous alkaline solution and their use as stabilizers for the vinyl chloride polymers are described in U.S. Pat. 4,062,881, which is also incorporated herein by reference. Sulfides that can be described as a mixture of the reaction products are also good activators for the blowing agents. Sulfide structures as taught by the '881 patent are somewhat controversial, because of a postulated equilibrium between them but it is believed to include bis [(monoorganotin) -bis (mercaptoalkylcarboxylate)] monosulfides and polysulfides] monosulfides and polysulfides bis [(diorganotin) -mono (mercaptoalkylcarboxylate)], and products that arise during equilibrium reactions between mono and polysulfides. The chemical and patent literature contains a number of examples demonstrating that members of different classes of organotin compounds can react with both under certain conditions to yield products containing one or more tin atoms wherein at least a portion of the Tin atoms bind to different combinations of 5 radicals than they were before being mixed.

D orkin et al. Disclose in U.S. Patent No. 3,953,385 that organostannic carboxylates provide only a marginal improvement "-10 in the activation of a blowing agent when combined with the mercaptocarboxylic acid esters of organostannic described herein In contrast to what is described, we have found that a combination of organotin carboxylates and a mixture of sulphides The organostannic agents described above are unexpectedly good activators for the blowing agents, as well as excellent stabilizers for the vinyl chloride polymers. We have also found that organotin chlorides work well by themselves or in combination with the organotin carboxylates as activators for blowing agents such as azobiscarbonamides, 5-phenyl tetrazole and benzene sulfonylhydrazide.

Compendium of the Invention An object of this invention is to provide more effective activators for the blowing agents in the preparation 5 of fluffy vinyl chloride polymers.

Another object of this invention is to provide foamed polyvinyl chloride articles having reduced r * - * density and contain reduced amounts of 10 by-products of blowing agents and blowing agent activators.

These and other objects that will be more apparent from the following description of the invention are achieved by the composition consisting essentially of: a vinyl chloride polymer, a blowing agent, at least one stabilizer selected from the group containing: (A) an organostannic mercaptide of a mercaptoalkyl carboxylate having the formula: R1 (4-y) Sn [SR2OC (= 0) R3] and I wherein R1 is a radical alkyl having from 1 to 8 carbon atoms; R: is a radical alkylene having from 2 to 18 carbon atoms, R3 is hydrogen, a radical hydrocarbyl, a hydroxyhydrocarbyl radical, or R (4) C (= 0) 0R (5), wherein R (4) is (CH2) P, phenylene, or -CH = CH-, and R (5) is a hydrocarbyl radical, p is 0 or an integer from 1 to 8 and y is any number from 1 to 3, and; (B) a sulfur of an organotinic ercaptide of Formula I; and optionally, at least one organotin salt that has the formula: wherein R 'is an alkaline radical having from 1 to 18 carbon atoms, X is a halogen of atomic weight of 35 to 127 or a carboxylate ion, and x is from 1 to 3.

The sulfide can be made by mixing an alkaline aqueous solution, a mercaptoalkyl carboxylate, an alkali metal sulfide or an alkaline earth metal sulfide or ammonium sulfide and an organotin halide having the formula: R (ß) (4-z) SnHalz II where R (6) is an alkaline group of 1 to 18 carbon atoms, Hal is a halogen having an atomic weight of 35 to 127, preferably chloride and z is any number from 1 to 3.

Alternatively, the sulfide can be made by mixing a monolakyl sulphide or dialkiltin with an organotin mercaptide of Formula I, and by other processes well known in the stabilizing art. It is believed that the sulfide includes monosulfides and polysulfides bis [bis (monoorganotin) -bis (mercaptoalkylcarboxylate)], monosulfides and polysufides bis [(diorganotin) -mono) mercaptoalkylcarboxylate]] and products that arise during equilibrium reactions between polysulfides and monosulfides, including monoalkylrin tris (mercaptoalkylcarboxylates), diacyltin bias (mercaptoalkylcarbosylates, and mono- and di-argotin mono- and polysulfides.) The sulfide can be further described epte by the formula: R H: [R (8) or -? - Sn-S-Z- [OC (= O) R (9)] m] n Sq IV wherein R (7) is a hydrocarbyl radical; R (8) is a hydrocarbyl radical or -S-Z- (0C (-0) R (9)) m; Z is an alkylene or radial hydroxyalkylene of at least 2 carbon atoms; R (9) is hydrogen, a hydrocarbyl radical, a hydroxyhydrocarbyl radical, or R (10) C (= 0) OR (11), wherein R (10) is (CH 2) P, phenylene or -CH = CH -, and R (ll), wherein R (ll) is a hydrocarbyl radical; m is an integer from 1 to 3, n is from 1 to 2, p is 0 or an integer from 1 to 8, q is from 1 to 10, and the valence of z is m + 1; with the requirement that it includes products that arise from a balance between the halves of -SnR (7), -SnR (8), and -SnS-Z (OC (= 0) R (9)) m as previously described.

This invention does not include the use of an organotin sulfide (mercaptoalkylcarboxylate) containing more than 80% by weight of a monoorganotin sulfide -bis- (mercaptoalkylcarboxylate) as a blowing agent activator in the vinyl chloride polymer composition when a Organostannic salt of the Formula II is not present in the composition.

Detailed Description of the Invention As used herein, a hydrocarbon radical has from 1 to 20 carbon atoms and includes alkyl, cycloalkyl, aryl, arylene, alkaryl, aralkyl and alkenyl radicals having up to 3 ethylenic double bonds.

The vinyl chloride polymers are made from monomers consisting of vinyl chloride alone or a mixture having preferably monomers of at least 70% by weight based on the total weight of the vinyl chloride monomer. They are elified by vinyl chloride copolymers with from about 1 to about 30% of an ethynylically copolymerizable unsaturated material such as vinyl acetate., vinyl butyrate, vinylbenzoate, vinylidene chloride, diethyl fumarate, diethyl mealate, other salts and alkyl meleates, vinyl propionate, methyl acrylate, 2-ethylhexyl acrylate, butyl acrylate and other acrylates of alkyl, methyl methacrylate, ethyl methacrylate, butyl methacrylate and other alkyl methacrylates, alpha methyl chloroacrylate, X 'styrene, trichlorethylene, vinyl ethers such as vinyl ethyl ether, vinyl chloroethyl ether and vinyl phenyl ether, vinyl ketones such as methyl ketone vinyl and ketone of vinyl phenyl, l-fluoro-2-chloroethylene, acrylonitrile, chloroacrylonitrile, allylidene diacetate and chlorallilidene diacetate. Typical copolymers include vinyl acetate-vinyl chloride (96: 4 commercially available as VYNW), vinyl acetate-vinyl chloride (87: 13), vinyl acetate-vinyl chloride anhydride (86) : 13: 1) vinylidene chloride-vinyl chloride (95: 5); vinyl diethyl chloride fumarate (95: 5), and 2-ethylhexyl chloride acrylate (80: 20) Of course, the vinyl chloride polymers constitute the main portion of the compositions of this invention. In this way, from about 70% to about 95% by weight of the total weight of the non-foaming compositions of this invention are quantified.

The blowing agent may be any or a mixture of those commonly used for foamed PVC pipe, including azobisformamide, 5-phenyl tetrazole, benzene sulfonyl hydrazide. The formula for azobisformamide is: 0 0 Azobisformamide is available under the registered trademark of CELOGEN AZRV. The blowing agent concentration is suitable for about 0.1 and 5.0%, but preferably from about 0.2 to about 3% by weight of the total composition prior to foam formation.

R 'in the organotin salt is preferably an alkaline group having from 1 to 8 carbon atoms, more preferably a single carbon atom, and when X is halogen it is preferably chloride and x is preferably from 2 to 3. When used, the portion of the organotin halide in the non-foaming compositions of this invention is from about 5 to about 15% by weight of the thermal stabilizer used in the vinyl chloride polymer composition of this invention. When X is a carboxylate ion, it preferably has from 1 to 20 carbon atoms and is exemplified by ions of acetic, propionic, butytic, caprylic, caproic, decanoic, lauric, stearic, oleic and banzoic acids. When used, the amount of organotin carboxylate is from about 10 to about 80% of the weight of the thermal stabilizer used in the vinyl chloride polymer composition of this invention.

The organotin halides can be prepared by methods well known in the art, such as those disclosed in U.S. Patent Nos. 3,745,183, 3,857,868, and 4,134,878. They are exemplified by methyltin trichloride, dimethyltin dichloride, trioctyltin chloride, dibutyltin dibromide, diphenyltin dichloride and dibenziltin dichloride.

The organotin carboxylates can be prepared by well known conventional methods such as by the reaction of an organotinhalide with carboxylic acid in the presence of a base in water or the reaction of an organotin oxide with carboxylic acid. They are exemplified by monobutyltin tris (docecylmaleate), dimethyltin azelate, diethyltin dilaurate, monobutyltin tri-tallate, and dimethyltin dibenzoate.

The amount of the stabilizer in the non-foaming compositions of this invention is from about 0.1 to about 10%, preferably from about 0.5 to about 5% by weight.They can be incorporated into the compositions by mixing in a grinder or suitable mixer by any of the other well-known methods that provide the uniform distribution of the stabilizers throughout the composition.RTM.10 In the stabilizer (A), R1 is preferably an alkaline group having from 1 to 4 carbon atoms, R2 is preferably an alkylene group having from 2 to 8 carbon atoms, R3 is preferably an alkali group which has from 1 to 7 carbon atoms or a group of phenyl, and y is preferably from 1 to 2. The reverse esters are commonly made from a mixture of chlororgan moorgano- and diorganotin; it is preferred in this invention to use a mixture containing from about 70 to 90, more preferably about 80 weight percent of the dimethyltin chloride to promote the formation of a fraction of the reverse esters having approximately the same proportion of mono- and di-guanotin bis (mercaptoalkylcarboxylates). It has been found that reverse esters having such a high concentration of half diorganotin are higher activators of the blowing agents without the need for a second activator such as organotin halides and organotin carboxylates. The stabilizer therefore comprises a The mixture of mercaptides for some of which the value of y in Formula I is w and for others the value of y is 3. It is preferred that the amount of mercaptides for which y is 2 is from about 70 to about 90% , preferably about 80% of the total weight of the mixture.

As noted above, the preparation of the mercaptoalkyl carboxylate esters and the corresponding tin mercaptides, for example, dibutyltin bis- (mercaptoethyl laurate) is disclosed in the U.S. Patent. No.2,870,182. The sulfides can be prepared by any of the various well known methods such as those disclosed in US Patent No. 4,062,881.

In this manner, methyltin trichuride, methyltin tribromide, methyltin triiodide, ethyltin trichloride, butyltin trichloride, butyltin tribromide, butyltin triiodide, sec. Butyltin triochloride, octyltin trichloride, benzyltin trichloride, dimethyltin dichloride, dimethyltin dibroraide dimethylide diiodide, dipropyltin dichloride, methyl butyl dichloride, dibensiltin dichloride dioctyltin dichloride, dipropyltin dichloride, dibromazine dibroma, dioctyltin diiodide, diioctyltin dichloride, dibenzitin dichloride, fentiltin trichloride, diphenyltin p-tolyltin dichloride trichloride, di-p-toltin dichloride, cislopentyltin trichloride, oleyltin trichloride, dioleyltin dichloride vinyltin trichloride, dialliltin dichloride, aliltin trichloride, eicosaniltin trichloride.

As for the mercaptoalkanol ester, for example, esters of mercaptoetherol, 2-thioglycerin, 3-thiglycerin, e-thiopropanol, 2-thipropanol, 4-thiobutanol, -thiooctadecane, 9-thiononanol, 8-thiooctanol, 6- * - thiohexanol with acids such as formic acid, acetic acid, propionic acid, bupric acid, pivalic acid, valeric acid, misic acid, palmitic acid, 2-ethylhexanoic acid, stearic acid, acidic acid, acid Oleic acid, linoleic acid, linolenic acid, carotonic acid, methacrylic acid, acrylic acid, p-t-butylbenzoic acid, enanthic acid, p-n-butylbenzoiso acid, carboxylic acid cyclohexane, phenylacetic acid, riciloleic acid, hydrogenated ricinoleic acid, phenylpropionic acid. By assumption that mixtures of acids can be used, ^ _. liquid resin acids, palmitic acid-stearic acid mixtures ranging from 60: 40 to 40: 60, soybean oil acids, cottonseed oil acids, hydrogenated cottonseed oil acids, acids 5 peanut oil, coconut oil acid, corn oil acids, castor oil acids, hydrogenated castor oil acids, shortening acids, etc. The media-ester models of polycarboxylic acids are monomethyl sulfate, monoethyl malonate, monopropyl malonate, monobutyl malonate, monooctyl malonate, mono-2-ethylhexyl maleate, monostearyl maleate, monoethyl fumarate, oxalate of mono methyl, monoethyl oleate, monoethyl malonate, monobutyl malonate, monoispropyl succinate, monomethyl sucinate, Monomethyl glutarate, moetyl aspartate, monomethyl glutarate, monoethyl adipate, monomethyl azelate, monomethyl ftalate, moetyl phthalate, monoethyl phthalate, monoisooctyl phthalate, monoethyl teraphthalate. 20 Mercapto ester models that can be used in the preparation of the tin compound include: 2-mercaptoethyl acetate, 2-mercaptoethyl propylate, 2-mercaptoethyl butyrate, 2-mercaptoethyl valerate, 2-mercaptoetyl pivalate, caproate of 2-mercaptoethyl, 2-mercaptoethyl caprilate, 2-mercaptoethyl decanoate pelargonate 2-mercaptoethyl laurate 2-mercaptoethyl laurate 2-mercaptoethyl eesanate 2-mercaptoethyl palmitate 2-mercaptoethyl ester 2-mercaptoethyl ricinoleate 2-mercaptoethyl oleate -mercaptoethyl linoleate of 2-mercaptoethyl linolenate tállate of 2-mercaptoethyl ester of cottonseed oil acids of 2-mercaptoethyl ester of pork lard of 2-mercaptoethyl ester of coconut oil of 2-mercaptoethyl benzonate of 2-mercaptoethyl crotonate of 2-mercaptoethyl cinnamate of 2-mercaptoethyl phenyl acetate of 2-mercaptoethyl phenyl propionate of 2-mercaptoethyl methyl meleate of 2-mercaptoethyl fuma ethyl rate of methyl 2-mercaptoethyl 2-mercaptoethyl butyl oxalate methyl oxalate 2-mercaptoethyl ethyl malonate 2-mercaptoethyl ethyl 2-mercaptoethyl methyl 2-mercaptoethyl azelate sucrose 2-mercaptoethyl azelate hexate 2-mercaptoethyl ftalate methyl 2-mercaptoethyl pelargonate 3-mercaptoethyl enatate 3-mercaptoethyl stearate 3-mercaptoethyl 3-mercaptoethyl oleate ricinoleate 3-mercaptoethyl ethyl meleate 3-mercaptoethyl benzonate 3-mercaptoethyl acetate 6-mercaptoethyl acetate 7 - mercaptoethyl propionate of 7- mercaptoetyl 8-mercaptoethyl acetate enanthate of 8-mercaptoethyl 18-mercaptoethyl enanthate acetate of 18-mercaptoethyl In Formula IV for sulfur, R (7) and R (8) are preferably alkyl groups having 1 to 8 carbon atoms, more preferably 1, Z is preferably an alkyl radical having from 2 to 8 carbon atoms, R (9) is preferably an alkyl radical having from 1 to 17 carbon atoms, n is preferably 1, and q is preferably 1 to 4 and more preferably 1 to 2.

In addition to the blowing agent thermal activator stabilizer compositions described in the above specification and the appended claims, the vinyl chloride polymer compositions of this invention may contain additives in order to increase the oxidation resistance, retardation of Flame and impact resistance of the polymer. Pigments, fillers, dyes, ultraviolet light absorbing agents and the like may also be present. Aids for the conventional process such as lubricating and acrylic resins can also be found.

Acrylic resins are used in the compositions of this invention as process aids to improve elasticity and melt resistance, and to avoid collapse of the cellular structure during the process. The amount of asrylic resin is from about 2 to about 15 parts percent of vinyl chloride polymer parts. The molecular weight of the resin can be in the range of 300,000 to 1,500,000, but those with higher molecular weights are preferred; resins having a molecular weight of 1,000,000 and higher are particularly preferred. Examples of acrylic process aids include those sold by Rohm & Haas under the registered trademark ACRYL0ID and the products numbers K-175 and K-400.

Among the antioxidants suitable for use in the present polymer compositions are the phenols, in particular those in which the positions adjacent to the carbon atom carrying the hydroxyl radical contain alkyl radicals as substitutes. Phenols are preferred in which this alkyl radical is sterically bulky, for example, a butyl radical of terriari.

A small amount, generally not more than 0.1%, of a metal releasing agent, such as an oxidized polyethylene, may also be included.

The effect of the blowing agent activator is independent of whether it is added to the vinyl chloride polymer as an aqueous solution, as part of a stabilizer package or as part of a lubricant package. A variety of conventional molding and extrusion techniques can be used to form rigid, cellular vinyl chloride polymers of this invention in a pipe or in any desired profile or sheet.

The following examples illustrate this invention more specifically. Unless otherwise indicated, all parts and percentages of these examples and through this specification are by weight. ABF is an abbreviation of azobisformamide.

Example 1 Formulas A and B of the PVC pipe were processed in a 3/4 inch Brabender extruder having a length of 25/1 of diameter ratio and right flight screw having a compression ratio of 2/1 and a 5 mm nozzle hole. The profile of the temperature (° C) was: Zone 1 170 Zone 2 180 Zone 3 190 Nozzle 170 Formulas A and B are the same, except for the sum of monomethyltin trichloride in B as shown in the following table. The results of the extrusion also. They are given in the table. 5 TABLE 1 FORMULA A B PVC 100.00 parts 100.00 parts 'I, CaC? 3 5.00 phr 5.00 phr 10 Ti? 2 1.00"1.00" Ca estereate 0.75"0.75" AC-629 * 0.08"0.08" Paraffin wax 1.30"1.30" Azobisformamide 0.35 M 0.35"15 Monomethyltin tris sulphide ( tap of mercaptoethyl) 0.70"0.70" 20 monomethyltin trichloride 0.00"0.05" * brand for oxidized polyethylene Extrusion results RPM 50 50 Torque m.mg 2514 2512 Proportion gm / hr 3400 3400 5 Fusing temperature (° C) 205 205 Foam density gm / cc 0.74 0.70 Examples 2-4 - «10 The formulas of the PVC pipe 2-4, as well as the Control 1 were processed in a 3/4 inch Brabender extruder having a length of 25/1 of diameter ratio and a screw of direct flight that has a compression ratio of 4/1 and a nozzle orifice of 5 mm. He temperature profile (° C) was: Zone 1 150 Zone 2 160 Zone 3 175 Mouthpiece 170 The formulas as well as the extrusion results are shown in the following table.

TABLE 2 FORMULA * * Cont 1 PVC 100.00 100.00 100.00 100.00 Acrylic resin K-400 6.00 6.00 6.00 6.00 K-175 0.50 0.50 0.50 0.50 CaC? 3 5.00 5.00 5.00 5.00 Ti? 2 1.00 1.00 1.00 1.00 Ca estereate 1.00 1.00 1.00 1.00 AC-629 0.1 0.1 0.10 0.10 Paraffin wax 0.50 0.50 0.50 0.50 Azobisformamide 0.15 0.15 0.15 0.15 Monomethyltin tris sulphide (tarantol de raersapto-etil) 1.50 1.50 1.50 1.50 Monomethyltin trichloride 0.00 0.40 0.20 0.20 * * Additive quantities in parts per hundred part of resin (phr) Extrusion results RPM 45 45 45 45 Torsion m. gm. 8650 7025 7950 7450 Proportion gm / hr 48.6 45.9 44.8 44.9 Melting temperature (° C) 215 215 212 211 Foam density gm / cc 0.96 0.85 0.91 0.91 EXAMPLE 5 / Cont. 2 and Examples Comp. 1 and 2 The PVC pipe formulas shown in Table 3 were processed in a 3/4-inch Brabender extruder having a diameter ratio length of 25/1 and a direct compression screw of 4-inch compression ratio. / 1 and a 5 mm nozzle hole. The results of the extrusion are also given in the table. The temperature profile (° C) was: Zone 1 150 Zone 2 160 Zone 3 175 Mouthpiece 170 TABLE 3 FORMULA ** Cont 2 CE 1 CE 2 PVC 100.00 100.00 100.00 100.00 Acrylic resin K-400 6.00 6.00 6.00 6.00 K-175 0.50 0.50 0.50 0.50 CaC03 5.00 5.00 5.00 5.00 > «! - > TÍ02 1.00 1.00 1.00 1.00 Ca estereate 1.00 1.00 1.00 1.00 RHEOLUBE 164 0.50 0.50 0.50 0.50 AC-629 0.1 0.1 0.10 0.10 Azobisformamide 0.15 0.15 0.15 0.15 monomethyltin tris sulphide (mercaptoethyl toluene) 1.50 1.20 monomethyltin 20 trichloride --- 1.50 - 1.20 dimethyltin ditallate - 0.30 0.30 * * additive quantities in parts per hundred part of resin (phr) Extrusion results RPM 45 45 45 45 45 Torsion m. gm. 8700 6800 7450 6575 7900 Proportion gm / hr 44. 1 46.8 43.4 43.9 43.3 Melting temperature (° C) 209 206 206 204 203 Foam density gm / sc 0.56 0.53 0.53 0.52 or .50 EXAMPLE 9-15 and Cont rol 2 The PVC pipe formulas shown in Table 5 were processed in a 3/4 inch Brabender extruder having a diameter ratio length of 25/1 and a direct compression screw of 4 compression ratio. / 1 and a 5 mm nozzle hole. The results of the extrusion are also given in the table. The temperature profile (° C) was: Zone 1 150 Zone 2 160 Zone 3 175 Mouthpiece 170 TABLE 5 FORMULA * 'Cor.t 2 9 10 11 PVC 100.00 100.00 100.00 100.00 Acrylic resin K-400 6.00 6.00 6.00 6.00 K-175 0.50 0.50 0.50 0.50 CaC? 3 5.00 5.00 5.00 5.00 TÍ02 1.00 1.00 1.00 1.00 Ca estereate 1.00 1.00 1.00 1.00 AC-629 0.1 0.1 0.10 0.10 Paraffin wax 0.5 0.5 0.5 0.5 Azobisformamide 0.35 0.35 0.35 0.35 Dimethyltin bis (mercaptoethyl) sulphide 1.50 Monomethyltin tris sulphide (mercapto ethyltallate) 1.50 Monomethyltin bis (mercapto ethyltallate) 1.50 Dimethyltin (mercaptoethyl ethyllate) 1.50 Ditallate dimethyltin * * additive quantities in parts per hundred part resin (phr) TABLE 5 (Cont.) FORMULA ** 12 13 14 15 PVC 100.00 100.00 100.00 100.00 Acrylic resin K-400 6.00 6.00 6.00 6.00 K-175 0.50 0.50 0.50 0.50 CaC? 3 5.00 0.50 0.50 0.50 TÍ02 1.00 1.00 1.00 1.00 Ca estereate 1.00 1.00 1.00 1.00 AC-629 0.1 0.1 0.10 0.10 Paraffin wax 0.5 0.5 0.5 0.5 Azobisformamide 0.35 0.35 0.35 0.35 Dimethyltin bis (mercaptoethyl) sulphide 1.20 Monometiltin tris sulphide (mercapto ethyltallate) 1.20 Monomethyltin bis (mercapto - "10 ethyltallate) 1.20 Dimethyltin (mercaptoethyltalate) 1.20 Ditallate of 15 dimethyliltin 0.30 0.30 0.30 0.30 * * additive quantities in parts per hundred part resin (phr) Extrusion results RPM 45 45 45 45 Torsion m. gm. 8700 8625 8825 8200 Proportion gm / hr 44.1 46.0 46.9 46.1 Melting temperature (° C) 209 205 206 204 Foam density gm / cc 0.56 0.63 0.55 0.51 Extrusion results (Cont. RPM 45 45 45 45 Torsion m. gm. 7525 7900 7525 7225 Proportion gm / hr 43.8 44.3 44.8 44.0 Melting temperature (° C) 204 206 205 205 Density of the esr 3urna gm / cc 0.52 0.58 0.55 0.49

Claims (27)

1. A composition consisting essentially of: a vinyl chloride polymer, a blowing agent, at least one stabilizer selected from the group containing: (A) an organostannic mercaptide of a mercaptoalkyl carboxylate having the formula: R1 (4-y) Sn [SR2OC (= 0) R3] and wherein R1 is a radical alkyl having from 1 to 8 carbon atoms; R2 is a radical alkylene having from 2 to 18 carbon atoms, R3 is hydrogen, a radical hydrocarbyl, a hydroxyhydrocarbyl radical, or R (4) C (= 0) OR (5), wherein R (4) is ( CH2) P, phenylene, or -CH = CH-, and R (5) is a hydrocarbyl radical, p is 0 or an integer from 1 to 8 and y is any number from 1 to 3, and; (B) a sulfur of an organotin mercaptide of Formula I; and optionally, at least one organostannic salt having the formula: R '(4-x) SnXx 5 wherein R' is an alkaline radical having from 1 to 18 carbon atoms, X is a halogen of atomic weight of 35 to 127 or a carboxylate ion, and x is from 1 to 3; with the requirement of J that when this organostannic salt is not in the In the composition, the composition is free of organostannic mercaptoalkylcrboxylate sulfide containing more than about 80% by weight of monoorganotin sulfide bis (mercaptoalkylcarboxylate).

2. The composition of claim 1, wherein X is a carboxylate ion having 1 to 20 carbon atoms and x is preferably 2 to 3.

3. The composition of claim 1, wherein R 1 is an alkaline group having from 1 to 4 carbon atoms, R 2 is an alkylene group having from 2 to 8 carbon atoms, R 3 is an alkaline group having 1 to 4 carbon atoms; to 17 carbon atoms or a group of phenyl, and y is 2 to 34. The composition of claim 1, wherein the sulfide has the formula: R (7)

[R (8) or -? - Sn-S-Z- [OC (= 0) R (9)]] n Sq wherein R (7) is a hydrocarbyl radical; R (8) is a hydrocarbyl radical or -S-Z- (OC (= 0) R (9)) m; Z is an alkylene or radial hydroxyalkylene of at least 2 carbon atoms; R (9) is hydrogen, a hydrocarbyl radical, a hydroxyhydrocarbyl radical, or R (10) C (= O) OR (II), wherein R (10) is (CH2) P, phenylene or -CH = CH -, and R (ll), wherein R (ll) is a hydrocarbyl radical; m is an integer from 1 to 3, n is from 1 to 2, p is 0 or an integer from 1 to 8, q is from 1 to 10, and the valence of z is m + 1; with the requirement that it includes products that arise from a balance between the halves of -SnR (7), -SnR (8), and -SnS-Z (OC (= 0) R (9)) m, including organotin sulfides oligomeric

5. The composition of claim 4, wherein R (7) and R (8) are alkaline groups having from 1 to 8 carbon atoms, Z is an alkylene radical having from 2 to 8 carbon atoms, R (9) ) is an alkaline radical having 1 to 17 carbon atoms, n is 1, and q is 1 to 4.

6. It is the composition of claim 4, wherein q is from 1 to 2.

7. The composition of claim 1, wherein stabilizer A comprises a mixture of organotin (organotin) mercaptides of mercaptoalkyl carboxylates, where y is 2 and y is 3 and the amount of mercaptides in which y is 2, is about 70 to about 90% of the total weight of the mixture.

8. The composition of claim 2, wherein the amount of mercaptides in which y s 2, is from about 80 to about 85% of the total weight of the mixture.

9. The composition of claim 8, wherein R1 is an alkaline group having from 1 to 4 carbon atoms, R2 is an alkylene group having from 2 to 8 carbon atoms, R3 is an alkaline group having from 1 to 17 carbon atoms or a group of phenyl, and y is 2 to 3.

10. A method for foaming a vinyl chloride polymer comprising heating a mixture consisting essentially of the polymer, a blowing agent, at least one stabilizer selected from the group consisting of: (A) an organostannic mercaptide of a carboxylate of mercaptoalkyl that has the formula: R1 (4-y) Sn [SR20C (= 0) R3] and wherein R1 is a radical alkyl having from 1 to 8 carbon atoms; R2 is a radical alkylene having from 2 to 18 carbon atoms, R3 is hydrogen, a radical hydrocarbyl, a hydroxyhydrocarbyl radical, or R (4) C (= 0) OR (5), wherein R (4) is ( CH2) p, phenylene, or -CH = CH-, and R (5) is a hydrocarbyl radical, p is 0 or an integer from 1 to 8 and y is any number from 1 to 3, and; (B) a sulfur of an organotin mercaptide of Formula I; and optionally, at least one organotin salt that has the formula: wherein R 'is an alkaline radical having from 1 to 18 carbon atoms, X is a halogen of atomic weight of 35 to 127 or a carboxylate ion, and x is from 1 to 3; with the requirement that when this organotin salt is not in the composition, the composition is free of organostannic mercaptoalkylcrboxylate sulfide containing more than about 80% by weight of monoorganotin sulfide bis (mercaptoalkylcarboxylate).

11. The method of claim 10, wherein X is a carboxylate ion having 1 to 20 carbon atoms and x is preferably 1 to 2.

12. The method of claim 10, wherein R1 is an alkaline group having from 1 to 4 carbon atoms, R2 is an alkylene group having from 2 to 8 carbon atoms, R3 is an alkaline group having from 1 to 17 carbon atoms or a group of phenyl, and y is 2 to 3.

13. The method of claim 10, wherein the sulfide has the formula: R (7) [R (8) or -? - Sn-S-Z- [OC (= 0) R (9)] m] n Sq wherein R (7) is a hydrocarbyl radical; R (8) is a hydrocarbyl radical or -S-Z- (OC (= 0) R (9)) m; Z is an alkylene or radial hydroxyalkylene of at least 2 carbon atoms; R (9) is hydrogen, a hydrocarbyl radical, a hydroxyhydrocarbyl radical, or R (10) C (= 0) OR (11), wherein R (10) is (CH 2) p, phenylene or -CH = CH -, and R (ll), wherein R (ll) is a hydrocarbyl radical; m is an integer from 1 to 3, n is from 1 to 2, p is 0 or an integer from 1 to 8, q is from 1 to 10, and the valence of z is m + 1; with the requirement that it includes products that arise from a balance between the halves of -SnR (7), -SnR (8), and -SnS-Z (OC (= 0) R (9)) m, including organotin sulfides oligomeric

14. The method of claim 13, R (7) and R (8) are alkaline groups having from 1 to 8 carbon atoms, Z is an alkylene radical having from 2 to 8 carbon atoms, R (9) is an alkaline radical having from 1 to 17 carbon atoms, n is 1, and q is from 1 to 4.

15. The method of claim 13, wherein q is from 1 to 2.

16. The method of claim 10, wherein X is a chloride ion.

17. The method of claim 11, wherein the organotin carboxylate comprises a mixture wherein x is from 2 to 3.

18. The method of claim 16, wherein the organotin (organotin) chloride comprises a mixture wherein x is from 2 to 3.

19. A rigid, cellular composition consisting essentially of a vinyl chloride polymer, a blowing agent, at least one stabilizer selected from the group containing: (A) an organostannic mercaptide of a mercaptoalkyl carboxylate having the formula: R1 (4-y) Sn [SR2OC (= 0) R3] and wherein R1 is a radical alkyl having from 1 to 8 carbon atoms; R2 is a radical alkylene having from 2 to 18 carbon atoms, R3 is hydrogen, a radical hydrocarbyl, a hydroxyhydrocarbyl radical, or R (4) C (= 0) 0R (5), wherein R (4) is ( CH2) p, phenylene, or -CH = CH-, and R (5) is a hydrocarbyl radical, p is 0 or an integer from 1 to 8 and y is any number from 1 to 3, and; (B) a sulfur of an organotin mercaptide of Formula I; and optionally, at least one organotin salt that has the formula: R '(4-x) SnXx wherein R 'is an alkaline radical having from 1 to 18 carbon atoms, X is a halogen of atomic weight of 35 to 127 or a carboxylate ion, and x is from 1 to 3; with the requirement that when this organotin salt is not in the composition, the composition is free of organostannic mercaptoalkylcrboxylate sulfide containing more than about 80% by weight of monoorganotin sulfide bis (mercaptoalkylcarboxylate).

20. The composition of claim 20, wherein X is a carboxylate ion having 1 to 20 carbon atoms and x is preferably 2 to 3.

21. The composition of claim 20, wherein wherein R1 is an alkaline group having from 1 to 4 carbon atoms, Rz is an alkylene group having from 2 to 8 carbon atoms, R3 is an alkali group having from 1 to 17 carbon atoms or a group of phenyl, and y is 2 to 3.

22. The method of claim 19, wherein the sulfide has the formula: R (7) [R (8) or -? - Sn-S-Z- [OC (= 0) R (9)] m] n Sq wherein R (7) is a hydrocarbyl radical; R (8) is a hydrocarbon radical or -S-Z- (0C (= 0) R (9)) m; Z is an alkylene or radial hydroxyalkylene of at least 2 carbon atoms; R (9) is hydrogen, a hydrocarbyl radical, a hydroxyhydrocarbyl radical, or R (10) C (= 0) OR (11), wherein R (10) is (CH2) P, phenylene or -CH-CH -, and R { 11), wherein R (ll) is a hydrocarbyl radical; m is an integer of 1 ai 3, n is 1 to 2, p is O or an integer from 1 to 8, q is from 1 to 10, and the valence of z is m + 1; with the requirement that it includes products that arise from a balance between the halves of -SnR (7), -SnR (8), and -SnS-Z (OC (= 0) R (9)) m, including organotin sulfides oligomeric

23. The method of claim 22, R (7) and R (8) are alkaline groups having from 1 to 8 carbon atoms, Z is an alkylene radical having from 2 to 8 carbon atoms, R (9) is an alkaline radical having from 1 to 17 carbon atoms, n is 1, and q is from 1 to 4.

24. The composition of claim 22, wherein q is from 1 to 2.

25. The composition of claim 19, wherein X is a chloride ion.

26. The composition of claim 20, wherein the organotin carboxylate (organotin) comprises a mixture wherein x is from 2 to 3.

27. The composition of claim 25, wherein the organotin (organotin) chloride comprises a mixture wherein x is from 2 to 3.