Patent Publication Number: US-4840839-A

Title: Thermoplastic mass passed between rollers

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a thermoplastic mass passed between rollers, particularly useful for water and soundproofing. 
     2. Description of the prior Art 
     The preparation of sheet-like materials of chlorinated polyethylene (CPE) alone or blended with chlorosulphonated polyethylene to obtain a thermoplastic mass having characteristics more resembling those of a rubber, with the excellent properties of the CPE rather than those of a modified asphalt, is well known, as disclosed in British pat. Nos. 1,250,756, 1,475,924 and 1,531,872, U.S. Pat. No. 3,753,938, European pat. No. 031,235 and German pat. No. 2545,914. They are basically blends of a high polymer content with an asphalt base having a high softening point and low penetration. This asphalt base must be strongly aromatic with a low saturate content, to achieve homogenous blends usable in facilities similar to a rubber plant and to obtain high quality sheets which may be better handled in application than the pure products. 
     SUMMARY OF THE INVENTION 
     The invention consists of preparing easily handleable masses having a low CPE content, which is achieved by extending the CPE in oils and/or plasticizers and adding a high percentage of filler. If it is wanted to modify any of the properties of this mass, such as, for example, the heat stability thereof, additives known hereinafter as &#34;hardeners&#34; may be included therein. 
    
    
     The thermoplastic mass passed between rollers of the invention is characterised in that it is formed by a mixture, the essential components of which are: from 4 to 60% in weight of an oil having a saturate content, as determined by ASTM D 2007, below 15% in weight and preferably below 10%, with a high aromatic content; from 1 to 50% in weight of chlorinated polyethylene, having a chlorine content lying between 20 and 95% in weight; and from 20 to 90% in weight of fillers, constituted by finely divided powder of a product chosen from the group comprising calcium carbonate, silica, slate, talc, barium sulphate and others commonly used in the plastics industry or mixtures thereof. 
     According to a further feature of the invention, the mass includes colouring, stabilizing, lubricating, fire-proofing, anti-oxidant agents and other additives generally used in good practice. 
     As an alternative according to the invention, said oil is at least partly substituted by ethylbenzene, dibutyl phthalate or plasticizers commonly used to plasticize polyvinyl chloride; also, said chlorinated polyethylene is partly substituted by chlorosulphonated polyethylene. 
     In a further development of the invention hardeners with some degree of crystallinity are included in the mass and preferably said hardeners are selected from the group formed by polyolefins, copolymers and terpolymers thereof, polystyrenes, polybutenes and polyvinyl chloride. 
     The most appropriate oils are the strongly aromatic ones, preferably those obtained by furfural extraction or by any other dearomatization treatment, such as the extacts obtained with phenol, N-methylpyrrolidone, etc. Basically, these oils should have a low saturate content, less than 10% and a high aromatic content, as determined by ASTM D2007. These oils are very compatible with the CPE alone or mixed with chlorosulphonated polyethylene. Other oils, such as the alkylbenzenes, which are generally more expensive or less effective and the traditional plasticizers, mainly those used for PVC, may also be used. 
     The present invention contemplates the plasticization or extension of halogenated and sulfphahalogenated polyethylene derivatives, with a halogen content lying between 20% and 95%, mainly the types of CPE available on the market. 
     To the polymer which has been plasticized or extended with the appropriate oil, a high percentage of fillers, may be added to suppress the initial take of the polymer-oil mixture. As fillers, as said above, the regular ones in the plastics industry may be, such as calcium carbonate, powdered slate, talc, barium sulphate, etc in finely divided powder form. 
     To modify any of the properties of the oil-polymerfiller mixture and, particularly, to improve its temperature resistance, a number of products may be added thereto acting as what will be called &#34;hardeners&#34;, among which there are to be found, for example, the high and low density polyolefins, the copolymers and terpolymers thereof, the polybutenes, PVC, the most interesting being those having a certain degree of crystallinity. 
     To the mixture resulting from the use of the above mentioned products, additives proper to good practice with this type of polymers may be added, such as lubricants, antioxidants, stabilizers, etc. 
     The mixture may also be coloured and have the fire-proofing properties proper to the halogenated derivatives improved by adding to the mixture synergetic fire-proofing products such as antimony oxides, hydrated aluminium oxides, chloroparaffins, etc. 
     A mixture prepared by the above processes may be rolled or extruded, but generally it may be fed through the rollers of construction inferior to that of a calender. Normally, for sound proofing purposes, a reinforcement is not required although it is attached to a sheet of felt or the like, but a reinforcement is desirable for waterproofing purposes and the mass of the invention is applied to one or both sides mainly of a fabric, a non-woven fabric, etc., but also any traditional reinforcement may be used in such sheets, such as glass fibre blankets or fabrics, raffias, paper, etc. 
     To facilitate the understanding of the foregoing ideas, these are summarised hereinafter in form of a Table of schematic examples of compositions according to the invention which, in view of their merely illustrative nature, should be deemed to be devoid of any limitation with respect to the scope of legal protection being applied for. The Table also gives properties of said compositions. 
     The thermoplastic masses described hereinafter were prepared by first mixing the oil with the filler and the good practice additives and the &#34;hardeners&#34; in a Werner type double Z or loop type open mixer, while holding the temperature of the mass metween 80° and 120° C. Thereafter the CPE was added and the temperature was raised to above 130°, while being kept below 200° C. 
     
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          EXAMPLE                                                         
          I   II III                                                      
                    IV  V   VI VII                                        
                                  VIII                                    
                                      IX                                  
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FORMULATION                                                               
Oil.sup.(1)                                                               
          1000                                                            
              1000                                                        
                 -- 2000                                                  
                        1000                                              
                            1000                                          
                               1000                                       
                                  1000                                    
                                      1000                                
Alkylbenzene                                                              
          250 -- -- --  --  -- -- --  --                                  
Filler (CO.sub.3 Ca)                                                      
          3000                                                            
              1000                                                        
                 1500                                                     
                    3000                                                  
                        3000                                              
                            3000                                          
                               6000                                       
                                  3000                                    
                                      4000                                
PE        100 -- -- 400 --  100                                           
                               50 100 500                                 
CPE       400 500                                                         
                 1000                                                     
                    400 400 3000                                          
                               50 400 200                                 
Dibutylphthalate                                                          
          --  -- 1000                                                     
                    --  --  -- -- --  --                                  
PROPERTIES                                                                
Penetration ASTM                                                          
          42  64 51 61  40  21 75 36  34                                  
D-5 mm/10                                                                 
Fragility ASTM                                                            
          -35 -25                                                         
                 -30                                                      
                    -29 --  -30                                           
                               -5 -20 -12                                 
D-228 °C.                                                          
Elongation UEA tc                                                         
          L 647                                                           
              -- -- L 676                                                 
                        L 874                                             
                            -- -- L 941                                   
                                      L 791                               
%         T 675                                                           
              -- -- T 736                                                 
                        T 1148                                            
                            -- -- T 1071                                  
                                      T 745                               
Tensile strength                                                          
UEA tc    L 3,5                                                           
              -- -- L 15                                                  
                        L 9 -- -- L 4,5                                   
                                      L 1,7                               
kg/5 cm   T 4,1                                                           
              -- -- T 12                                                  
                        T 6 -- -- T 5 T 1,7                               
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 .sup.(1) The oil has a composition determined by ASTM D2007 of: saturates
 7%, aromatics 81% and polar solvents 12%.