US3919137A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for making polyvinyl chloride processing aid involving cooling step in acrylate graft polymerization of polyvinyl chloride
Assignee: Stauffer Chemical Co
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Filing: 1973-05-21
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Granted: 1975-11-11
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Expires: 1993-05-21
Abstract
Abstract A process is disclosed for preparing a polyacrylate-modified polyvinyl chloride processing aid for polyvinyl chloride by sequentially polymerizing the vinyl chloride and the desired acrylate ester monomer. Thus, a conventional vinyl chloride suspension polymerization is conducted at a controlled rate of agitation and in the presence of a specified concentration of an alkyl, hydroxyalkyl or carboxyalkyl modified cellulose suspending agent and is then halted at or near its completion; unreacted vinyl chloride monomer is removed, the suspension of polyvinyl chloride particles is cooled, a minor proportion of an acrylate ester monomer, e.g., methyl methacrylate, is then added with a fresh supply of a free radical initiating catalyst to the cooled suspension, the cooling being sufficient to retard polymerization of the acrylate, and polymerization is then resumed by heating the suspension and continued until the acrylate ester monomer polymerizes in and/or on the particles of the previously polymerized polyvinyl chloride. The polyacrylate-modified PVC thereby recovered is an effective aid for processing conventional PVC, or it can be processed per se since it is suitable for calendering or extruding.
Inventors
- 👤 James N Dyer
- 👤 Arthur J Yu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 04:13
CPC Classifications
C; C08; C08F; C08F259/00; C08F259/02; C08F259/04
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
346 words
IN A PROCESS FOR THE PREPARATION OF A POLYACRYLATE-MODIFIED POLYVINYL CHLORIDE PROCESSING AID WHICH COMPRISES: (1) FIRST PREPARING PARTICLES OF POLYVINYL CHLORIDE IN THE 5-150 MICRON SIZE RANGE BY SUSPENSION POLYMERIZING VINYL CHLORIDE MONOMER IN THE PRESENCE OF FROM ABOUT 0.01 TO 5%, BY WEIGHT, OF THE VINYL CHLORIDE MONOMER, OF A SUSPENDING AGENT WITH AGITATION BEING APPLIED TO THE SYSTEM, (2) REMOVING UNREACTED VINYL CHLORIDE MONOMER FROM THE SYSTEM AFTER POLYMERIZATION OF THE VINYL CHLORIDE IS AT LEAST 60% COMPLETE, (3) ADDING TO THE SUSPENSION OF POLYVINYL CHLORIDE PARTICLES RESULTING FROM STEP (1) AN EFFECTIVE CONCENTRATION OF (A) A CHAIN TRANSFER AGENT, (B) AN ACRYLATE ESTER MONOMER SELECTED FROM THE GROUP CONSISTING OF METHYL METHACRYLATE AND MIXTURES OF METHYL METHACYLATE TOGETHER WITH FROM ABOUT 20 TO 0%, BY WEIGHT, OF ONE OR MORE ETHYLENICALLY UNSATURATED COMONOMERS AND (C) ANEFFECTIVE CONCENTRATION OF AT LEAST ONE FREE RADICAL INITIATING CATALYST WHICH IS SOLUBLE IN SAID ACRYLATE ESTER MONOMER, SAID ACRYLATE ESTER MONOMER BEING ADDED TO THE SYSTEM IN A TOTAL AMOUNT TO PROVIDE BETWEEN ABOUT 20-100% OF MONOMER, BY WEIGHT OF THE POLYVINYL CHLORIDE RESULTING FROM STEP (1), (4) SUSPENSION POLYMERIZING THE ACRYLATE ESTER MONOMER IN THE PRESENCE OF THE MIXTURE RESULTING FROM STEP (3) WHILE APPLYING AGITATION, AND, (5) RECOVERING THE PARTICLES OF POLYACRYLATEMODIFIED POLYVINYL CHLORIDE RESULTING FROM STEP (4), SAID PARTI-CLES OF POLYACRYLATE-MODIFIED POLYVINYL CHLORIDE COMPRISING OF PARTICLES OF POLYVINYL CHLORIDE HAVING POLYACRYLATE ESTER MOIETIES IN AND/OR ON SAID POLYVINYL CHLORIDE PARTICLES, THE IMPROVEMENTS WHICH COMPRISES UTILIZING AS SAID SUSPENDING AGENT IN STEP (1) AND ALKYL, HYDROXYALKYL OR CARBOXYALKYL CELLULOSE, AND IN STEP (3) COOLING SAID SUSPENSION OF POLYVINYL CHLORIDE PARTICLES TO A TEMPERATURE BELOW WHICH SUBSTANTIAL POLYMERIZATION OF SAID ACRYLATE ESTER MONOMER CAN BE INITIATED BY SAID FREE RADICAL INITIATING CATALYST PRIOR TO ADDING SAID ACRYLATE ESTER MONOMER AND SAID FREE RADICAL INITIATING CATALYST TO SAID SUSPENSION OF POLYVINYL CHLORIDE PARTICLE FOLLOWED BY ADDING SAID ACRYLATE MONOMER AND SAID CATALYST SEPARATELY TO SAID SUSPENSION FOLLOWED BY HEATING SAID SUSPENSION TO A TEMPERATURE ABOVE AT LEAST 45*C. TO INTITIATE POLYMERIZATION OF SAID ACRYLATE ESTER MONOMER.
Claim 2
Dependent Claim
346 words
IN A PROCESS FOR THE PREPARATION OF A POLYACRYLATE-MODIFIED POLYVINYL CHLORIDE PROCESSING AID WHICH COMPRISES: (1) FIRST PREPARING PARTICLES OF POLYVINYL CHLORIDE IN THE 5-150 MICRON SIZE RANGE BY SUSPENSION POLYMERIZING VINYL CHLORIDE MONOMER IN THE PRESENCE OF FROM ABOUT 0.01 TO 5%, BY WEIGHT, OF THE VINYL CHLORIDE MONOMER, OF A SUSPENDING AGENT WITH AGITATION BEING APPLIED TO THE SYSTEM, (2) REMOVING UNREACTED VINYL CHLORIDE MONOMER FROM THE SYSTEM AFTER POLYMERIZATION OF THE VINYL CHLORIDE IS AT LEAST 60% COMPLETE, (3) ADDING TO THE SUSPENSION OF POLYVINYL CHLORIDE PARTICLES RESULTING FROM STEP (1) AN EFFECTIVE CONCENTRATION OF (A) A CHAIN TRANSFER AGENT, (B) AN ACRYLATE ESTER MONOMER SELECTED FROM THE GROUP CONSISTING OF METHYL METHACRYLATE AND MIXTURES OF METHYL METHACYLATE TOGETHER WITH FROM ABOUT 20 TO 0%, BY WEIGHT, OF ONE OR MORE ETHYLENICALLY UNSATURATED COMONOMERS AND (C) ANEFFECTIVE CONCENTRATION OF AT LEAST ONE FREE RADICAL INITIATING CATALYST WHICH IS SOLUBLE IN SAID ACRYLATE ESTER MONOMER, SAID ACRYLATE ESTER MONOMER BEING ADDED TO THE SYSTEM IN A TOTAL AMOUNT TO PROVIDE BETWEEN ABOUT 20-100% OF MONOMER, BY WEIGHT OF THE POLYVINYL CHLORIDE RESULTING FROM STEP (1), (4) SUSPENSION POLYMERIZING THE ACRYLATE ESTER MONOMER IN THE PRESENCE OF THE MIXTURE RESULTING FROM STEP (3) WHILE APPLYING AGITATION, AND, (5) RECOVERING THE PARTICLES OF POLYACRYLATEMODIFIED POLYVINYL CHLORIDE RESULTING FROM STEP (4), SAID PARTI-CLES OF POLYACRYLATE-MODIFIED POLYVINYL CHLORIDE COMPRISING OF PARTICLES OF POLYVINYL CHLORIDE HAVING POLYACRYLATE ESTER MOIETIES IN AND/OR ON SAID POLYVINYL CHLORIDE PARTICLES, THE IMPROVEMENTS WHICH COMPRISES UTILIZING AS SAID SUSPENDING AGENT IN STEP (1) AND ALKYL, HYDROXYALKYL OR CARBOXYALKYL CELLULOSE, AND IN STEP (3) COOLING SAID SUSPENSION OF POLYVINYL CHLORIDE PARTICLES TO A TEMPERATURE BELOW WHICH SUBSTANTIAL POLYMERIZATION OF SAID ACRYLATE ESTER MONOMER CAN BE INITIATED BY SAID FREE RADICAL INITIATING CATALYST PRIOR TO ADDING SAID ACRYLATE ESTER MONOMER AND SAID FREE RADICAL INITIATING CATALYST TO SAID SUSPENSION OF POLYVINYL CHLORIDE PARTICLE FOLLOWED BY ADDING SAID ACRYLATE MONOMER AND SAID CATALYST SEPARATELY TO SAID SUSPENSION FOLLOWED BY HEATING SAID SUSPENSION TO A TEMPERATURE ABOVE AT LEAST 45*C. TO INTITIATE POLYMERIZATION OF SAID ACRYLATE ESTER MONOMER.
Claim 3
Dependent Claim
53 words
The process of claim 1 wherein said ethylenically unsaturated monomer which is introduced into the system in step (3) along with said methyl methacrylate, is selected from the group consisting of the C2-c3 alkyl methacrylates, the C1-C12 alkyl acrylates, the glycidyl esters of acrylic and methacrylic acid and mixtures of the latter monomers.
Claim 4
Dependent Claim
35 words
The process of claim 1, wherein the proportion of acrylate ester monomer which is introduced into the system in step (3) is from about 35-65%, by weight, of the polyvinyl chloride resulting from step (1).
Claim 5
Dependent Claim
22 words
The process of claim 1, wherein the acrylate ester monomer which is introduced into the system in step (3) comprises methyl methacrylate.
Claim 6
Dependent Claim
29 words
The process of claim 1, wherein the remaining vinyl chloride monomer is removed in step (2) after polymerization of the vinyl chloride in step (1) is about 80% complete.
Claim 7
Dependent Claim
49 words
The process of claim 1, wherein said chain transfer agent is selected from the group consisting of chlorinated aliphatic hydrocarbons; aromatic hydrocarbons; aldehydes; aliphatic and cyclic ketones; cyclic ethers; alkyl esters of aliphatic carboxylic acids; aliphatic alcohols; aliphatic carboxylic acids; cyclic hydrocarbons; mono- ci- and polymercaptans; and mixtures thereof.
Claim 8
Dependent Claim
12 words
The process of claim 6 wherein said chain transfer agent is mono-mercaptan.
Claim 9
Dependent Claim
13 words
The process of claim 7 wherein said chain transfer agent is lauryl mercaptan.
Claim 10
Dependent Claim
27 words
The process of claim 1 wherein the polyvinyl chloride resulting from step (1) has a particle size in the range of from about 25 to 80 microns.
Claim 11
Dependent Claim
48 words
The process of claim 1 wherein the particles of polyacrylate-modified polyvinyl chloride resulting from step (4) have a particle size in the range of from about 10 microns up to a maximum limit Such that no more than about 15%, by weight, are larger than about 150 microns.
Claim 12
Dependent Claim
33 words
The process of claim 10, wherein the particles of said polyacrylate-modified polyvinyl chloride processing aid resulting from step (4) have a particle size in the range of from about 40 to 150 microns.
Claim 13
Dependent Claim
37 words
The process of claim 1 wherein the polyacrylate-modified polyvinyl chloride processing aid resulting from step (4) has a Relative Viscosity of from about 1.50-2.80 when determined, at 25*C., with a 1% solution of the polymer in cyclohexanone.
Claim 14
Dependent Claim
30 words
The process of claim 1 wherein the acrylate ester monomer which is introduced into the system in step (3) comprises a mixture of methyl methacrylate and a C1-C12 alkyl acrylate.
Claim 15
Dependent Claim
13 words
The process of claim 13 wherein said C1-C12 alkyl acrylate comprises n-butyl acrylate.
Claim 16
Dependent Claim
38 words
The process of claim 14 wherein the acrylate ester monomer which is added to the system in step (3) comprises a mixture of about 84%, by weight, of methyl methacrylate and about 16%, by weight, of n-butyl acrylate.
Claim 17
Dependent Claim
49 words
The process of claim 1 wherein said particles resulting from step (4) comprise about 70%, by weight, of polyvinyl chloride and about 30%, by weight, of polyacrylate ester moieties which comprise a copolymer of about 84%, by weight, of methyl methacrylate and about 16%, by weight, of n-butyl acrylate.
Claim 18
Dependent Claim
25 words
The process of claim 1 wherein said suspending agent is selected from the group consisting of methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and carboxymethyl cellulose.
Claim 19
Dependent Claim
12 words
The process of claim 17 wherein said suspending agent is methyl cellulose.
Claim 20
Dependent Claim
25 words
The process of claim 1 where step (3) is conducted by cooling said suspension below a temperature of 45*C. and above a temperature of 0*C.
Claim 21
Dependent Claim
15 words
The process of claim 19 wherein said cooling temperature is below 45*C. and above 25*C.
Claim 22
Dependent Claim
28 words
The process of claim 1 wherein said free radical initiating agent is added first to said suspension after cooling followed by the subsequent addition of said methyl methacrylate.
Claim 23
Dependent Claim
49 words
The process of claim 1 wherein said suspending agent is methyl cellulose, said suspension is cooled to below 45*C. and above 25*C., and said free radical initiating catalyst is first added to said suspension of polyvinyl chloride particles after cooling followed by the subsequent addition of said methyl methacrylate.
Claim 24
Dependent Claim
9 words
The product resulting from the process of claim 1.
Claim 25
Dependent Claim
9 words
The product resulting from the process of claim 16.
Claim 26
Dependent Claim
9 words
The product resulting from the process of claim 21.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |