FR2508050A1 - PROCESS FOR IMPROVING THE SURFACE PROPERTIES OF PVC RESIN FIBERED ARTICLES BY MEANS OF LOW TEMPERATURE PLASMA - Google Patents

Abstract

THE INVENTION RELATES TO A PROCESS FOR IMPROVING THE SURFACE PROPERTIES OF AN ARTICLE FURNISHED IN PVC RESIN, CHARACTERIZED IN THAT IT INCLUDES THE FOLLOWING STEPS: A. THE SURFACE OF THE SHAPED ARTICLE IS EXPOSED TO LOW TEMPERATURE PLASMA SHAPED IN A GASEOUS ATMOSPHERE CONTAINING AN ORGANIC NITROGEN COMPOUND, AND B. THE SURFACE OF THE SHAPED ARTICLE IS EXPOSED TO LOW TEMPERATURE PLASMA SHAPED IN A GASEOUS ATMOSPHERE CONTAINING AN ORGANIC DERIVATIVE OF SILICONE, AFTER OR BEFORE STAGE A.

Description

-1 2508050

  The present invention relates to a method for improving the surface properties of shaped articles made of vinyl chloride resin. The invention is more particularly intended to confer on articles

  shaped vinyl chloride resin a permanent anti-static effect

  by treating the surface of the article with a low temperature plasma.

  It is well known that shaped articles made of chlorine-based resin

  Vinyl resins (PVC resins) are very sensitive to electrostatic charges.

  This causes some disadvantages, that is to say that their appearance deteriorates rapidly by the deposition of dust and dirt.

  and that the human body in contact with their surfaces undergoes the sensation of

  due to an electric shock caused by the accumulated static charge,

  accompanied sometimes by the appearance of sparks.

  To prevent the formation of an electrostatic charge

  static electricity on the surface of a shaped article of PVC resin, certain processes are known in which the surface of the article is

  coated with an antistatic agent, or such agent is incorporated into the composition

  The first method is suitable for obtaining an instantaneous antistatic effect, but is not without problems since the duration of the antistatic effect is short and the surface thus coated is sometimes sticky and causes The second method, by incorporating an antistatic agent into the body of the shaped article, is, of course, superior to the first with respect to the duration of the antistatic effect obtained, but the effectiveness of the antistatic agent incorporated is relatively low As a result of an increase

  of the antistatic agent incorporated in the resin, in order to obtain an ef-

  enough, the surface of the article becomes sticky, causing the appearance of

  of film, blocking phenomena and other disadvantages, in addition to a decrease in the workability of the resinous composition, a lower resistance of the shaped article to heat and a unpleasant surface of the article, di to color effects

and the appearance of spots.

  Also known is a method for improving the hydrophilic character of the surface of a shaped article of PVC resin, with the aim of reducing the

  electrostatic charge, by treating the surface with a low temperature plasma

  -2- eradication of a mineral gas such as helium, argon, nitrogen, oxygen,

  carbon monoxide and the like, although this method of treating

  Static does not give great satisfaction because of its low efficiency.

  The invention is therefore intended to provide a new

  improved method for imparting to the surface of a PVC resin shaped article a long lasting improved antistatic effect by modifying the properties of the surface by a low temperature plasma treatment without negatively influencing the excellent irerent properties.

to resin articles.

  The present method comprises treating the surface of the PVC resin shaped article with a low temperature plasma in two stages, in one of the steps the surface of the article is exposed to the low temperature plasma of a compound. organic nitrogen-containing and in the other the

  surface is exposed to the low temperature plasma of an organo-silicone.

  It has been found that the object of the present invention can be achieved by two-stage treatment with a low temperature plasma,

  This is probably due to the fact that it is

  facing an extremely fine modified layer thanks to plasma treatment,

  this layer being firmly bonded to the body of the resin article, and the

  the formation of this modified layer being greater than in

  very different types of polymer resins, so that the effect of

  plasma can be more clearly highlighted.

  The present process will be described in more detail below.

  In one of the two stages of low temperature plasma treatment, the surface of the resin article is exposed to the low temperature plasma created in an atmosphere formed by the vapor or gas of an organic compound containing The latter can be a

  amine, an amide or a diamine, respectively represented by the

following general mules:

I_ 2 4 _ -N 5 7 -R 8 N-R 9

  R N-R, R C-N-R and R -N-R-N-R 13 II 6 110 he

R OR R

  In these formulas R 1 and R 3 are each a substituted or unsubstituted monovalent hydrocarbon group, R, R, R, R, R, R and R are each a hydrogen atom or a monovalent hydrocarbon group.

  substituted or unsubstituted and R is a divalent hydrocarbon group

stituted or unsubstituted.

  Among these amines and amides include for example the following

  methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine,

  thylamine, triethylamine, n-propylamine, di-n-propylamine, tri-n-propylamine, n-butylamine, n-amylamine, n-hexylamine,

  laurylamine, ethylenediamine, trimethylenediamine, hexamethylene,

  diamine, ethanolamine, diethanolamine, allylamine, aniline, alanine

  nine, N-methylaniline, allyldimethylamine, 2-aminoethyl ether,

  1-dimethylamino-2-chloroethane, cyclopropylamine, cyclohexyl-

  amine, ethylene imine, 1-methylethylene imine, N, N-dimethyl-

  formamide, formamide, capronamide, aminoacetal, benzylamine, piperidine, pyrrolidine, morpholine, and the like and their derivatives These nitrogen-containing organic compounds may be used

  in combination of two or more types as needed.

  In the other of the two stages of treatment with low plasma

  temperature, the surface of the resin article is exposed to the plasma of

  temperature in a gas or vapor of an organosilane of the general formula: HR Si X ab 4-ab or a hydrolytic condensation product of such a compound In this general formula, R is a monovalent hydrocarbon group such as an alkyl group, for example methyl, ethyl, propyl or butyl, an alkenyl group, for example vinyl or allyl, an alkynyl group, for example ethynyl, propinyl or butynyl, or an aryl group, for example phenyl or naphthyl, and substituted groups obtained by replacing a portion of the hydrogen atoms in the hydrocarbon groups mentioned above by substitution atoms, for example halogen atoms, or by substitution groups such as nitrile groups. symbol X in the formula indicates a halogen atom such as chlorine or bromine, or an alkoxy group such as methoxy, ethoxy and butoxy The suffixes a and b in the formula denote, the first a number in tier 0, 1, 2, 3 or 4

  and the second is 0, 1 or 2 under the condition that a + b is not greater than 4.

  Among these organosilanes, mention may be made in particular of the following:

  trimethylchlorosilane, trimethylmethoxysilane, trimethyl-

  ethoxysilane, vinyl dimethyl chlorosilane, vinyl dimethyl methox-

  silane, vinyl-dimethyl ethoxysilane, ethynyl dimethyl methoxysilane,

  Ethynyl dimethyl chlorosilane, methyl-chloromethyl-methoxy-chloro

  silane, triethyl methoxysilane, dimethyl chloromethyl ethoxysilane, dimethyl chloromethyl chlorosilane, dimethyl phenyl methoxysilane,

  2-chlorothymethyl dimethylchlorosilane, 2-chloroethyl dimethyl-

  methoxysilane, methyl-dichlorosilane, dimethyl-dimethoxysilane,

  diethyl dimethoxysilane, dimethyl diethoxysilane, vinyl methyl

  dichlorosilane, vinyl-methyl-dimethoxysilane, 2-chloro-ethyl-methyl-

  dimethoxysilane, vinyl methyl diethoxysilane, chloromethyl methyl

  dichlorosilane, methyl-phenyl dimethoxysilane, chloromethyl-methyl

  dimethoxysilane, methyl-trimethoxysilane, methyl-triethoxysilane,

  vinyl trimethoxysilane, phenyltrimethoxysilane, chloromethyltrimine

  thoxysilane, 2-chloro-ethyl-trimethoxysilane, tetramethoxysilane,

  tetraethoxysilane, and similar compounds Although the silanes mentioned above

  do not have other halogen atoms than chlorine, other types of halogen atoms such as bromine can replace atoms

chlorine or alkoxy groups.

  In addition, silanes corresponding to the formulas R 4 Si, R 35 i H,

  RH If X 2, H If X 3 and R 2 H If X can be used also in the definition

  These silanes can be used in combination with the formula given above.

  combination of two or more as needed.

  The choice of organosilicone used in the treatment with

  mna, according to the present process, is not limited to those mentioned above, but it can be replaced by a hydrolytic condensation product hydrolysable silane or, in other words, an organopolysiloxane

  examples of such organopolysiloxanes are: divinyl tetramethyl disil

  oxane, di (chloromethyl) tetramethyl di siloxane, diethynyl tetramethyl

  Disiloxane, tetramethyl-disiloxane, and similar compounds Other types of organopolysiloxanes may of course be suitable, provided that the compound is not a high polymer, and can give a sufficiently high vapor pressure to provide the pressure of the atmosphere of

low temperature plasma.

  -5- The vinyl chloride resin of which the article is made

  shaped to which the process of the invention refers may be a homogeneous resin

  polyvinyl chloride polymer or also a primary copolymer resin

  composed of vinyl chloride Comonomers copolymerized with vinyl chloride to form copolymers are for example

  vinyl esters such as vinyl acetate, vinyl ethers, acyl

  acrylics and methacrylics and their esters, maleic and fumaric acids and their esters, maleic anhydride, vinyl derivatives

  such as styrene, vinylidene halides, acrylonitrile, metha-

  crylonitrile and olefins such as ethylene and propylene.

  The vinyl chloride-based resin

  shaped keys can receive all kinds of additives and agents Rigidity and

  the flexibility of the shaped articles are influenced, for example, by mixing

  resin with a plasticizer Structural plasticisers can be used.

  various chemical substances, for example phthalic acid esters such as dioctyl phthalate, dibutyl phthalate and butylbenzyl phthalate, dibasic aliphatic acid esters such as dioctyl adipate and dibutyl sebacate, pentaerythritol, glycol esters such as ethylene glycol dibenzoate, fatty acid esters such as methylacetyl ricinoleate, tricresyl and triphenyl phosphates, epoxidized oils such as epoxidized soybean oil and epoxidized linseed oil , the

  esters of citric acid such as acetyl tributyl citrates and acetyl

  trioctyl and polyesters such as trialkyl-trimellitates, pyromellitate Z 5 of tetra-n-octyl and polypropylene adipate, etc.

  Additives used to improve slip power and stability

  of the resinous composition are, for example, the metal salts of carboxylic acids, such as calcium, zinc, lead,

  barium and cadmium, inorganic lead compounds such as tribasic sulphate

  lead and dibasic phosphite from plomnb, organic tin derivatives such as dibutyltin dilaurate, n-octyltin maleate and di-n-octyltin mercaptide, esters such as butyl stearate

  amides of carboxylic acids such as ethylene bistearyl amine,

  medium molecular weight fats and polyethylene esters and waxes

  lene. Other types of conventional additives may also be used, including, for example, fillers, agents for improving thermal stability, antioxidants, ultraviolet light absorbers, anti-static agents, and anticondensation, pigments, dyes, crosslinking aids, etc. It is also possible that the resinous composition of which the shaped articles are made is a mixture of polymers comprising a

  vinyl chloride-based resin with a highly polymeric rubber

  For example, copolymers of ethylene and vinyl acetate, co-polymers

  polymers of acrylonitrile and butadiene, copolymers of styrene and acrylonitrile, copolymers of methyl methacrylate, styrene and butadiene, copolymers of acrylonitrile, styrene and butadiene, urethane elastomers, resins polyamides, terpolymers

  of ethylene, propylene and a diene monomer, poly-

  butadiene modified with epoxy, etc. When mixed with a PVC resin the proportion of these rubbery polymers is preferably not

  greater than 50 parts by weight with respect to the PVC resin.

  The process for the manufacture of shaped articles from the above-described vinyl chloride resinous composition is not

  not limited to particular processes, but may be selected from

  such as extrusion or injection molding, calendering, insufflation, die-casting, etc. There is no

  more particular limitations with regard to the shape of the articles.

  The present process has the object of imparting a long lasting antistatic effect to the surface of the above-described PVC resin article by modifying the surface properties of the article by means of a plasma treatment. This plasma treatment is essentially carried out during a process in which the PVC resin is introduced into a chamber for the formation of a low temperature plasma, the pressure in the chamber being maintained at a maximum of 13.3 mbar by passing a gas formed by one or other of the nitrogenous organic compounds or organosilicones described above, a low temperature plasma is produced in the chamber where the pressure is maintained at the pressure at which the surface of the shaped article is exposed to the low temperature plasma, the gas of the plasma atmosphere is then replaced by the other of the two gases, which is passed through bedroom of the plasma while maintaining the pressure at maximum 13, 3 mbar and finally one creates again a plasma of low temperature in this second

  plasma gas to expose the surface of the shaped article.

  In the two-stage plasma treatment described above, it is irrelevant to employ either one of the two plasma gases, the first one, ie the nitrogenous organic compound or the organophosphorus. silicone, although it is

  it is preferable that the first plasma treatment be performed in the

  mosphere of the nitrogenous organic compound and the second in the atmosphere of

  organosilicone to give the present process a more secure effect.

  The change from one plasma gas to another can be done in any suitable way For example we put the plasma chamber

  after the completion of the first vacuum plasma treatment in elimi -

  the gaseous nitrated organic compound, and then the organosilicone is introduced

  view of the second plasma treatment It is also possible to replace

  place one of the plasma gases continuously through the other by gradually lowering

  the rate of flow of the nitrogenous organic compound into the atmosphere of the first plasma treatment, while simultaneously initiating the introduction of the organosilicone by gradually increasing its flow rate to form the atmosphere of the second treatment with the plasma to finally stop completely the introduction of nitrogenous organic gas which has the effect of obtaining the plasma atmosphere of pure organosilicone, while the plasma is created continuously in the atmosphere whose composition is modified in continuous, starting from the nitrogenous organic compound

  pure and resulting in pure organosilicone through stages

  intermediaries where the two are mixed It is also possible to introduce

  an inert gas or other active gas into the plasma chamber after

  the completion of the first stage of plasma treatment and prior to

  second stage stage to expose the surface of the shaped article to the low temperature plasma of such a third gas The effect of the two stage plasma treatment according to the invention can sometimes be improved

  subjecting the shaped article after the plasma treatment to one

  temperature, irradiation with ultraviolet light or

  by the additional plasma in the atmosphere of a mineral gas.

8 22508050

  The two-stage plasma treatment according to the invention may also comprise the variant of diluting the plasma gas, that is to say the

  nitrogenous organic compound or organosilicone, with a rare gas, for example

  helium, argon or similar gas, with a mineral gas such as nitrogen, oxygen, air, hydrogen, water vapor, carbon dioxide, carbon monoxide and the like, or an organic gas other than the compound

  organic nitrogen and organosilicone In the case where the plasma gas is di-

  when read with such a mineral gas, the partial pressures of the nitrogenous organic compound or of the organosilicone and of the mineral gas are preferably included

  respectively between 1.3 and 13.3 mbar and between 1.3 and 13.3 mbar.

  In this way additional results are achieved by conferring

  molded sheets with improved wetting, printing and adhesion properties and other similar surface properties, in addition to

  better anti-static effect or lower surface resistivity.

  In the plasma treatment method described above, the pressure of the plasma atmosphere in the plasma chamber must be equal to or less than 13.3 mbar or, preferably, be between

  6, 6 10 and 1, 33 mbar, because it does not obtain sufficient effect by a treat-

  by the plasma in an atmosphere with a pressure greater than 13.3 mbar, ie the antistatic effect of the surface treated by the

  plasma decreases rapidly with increasing surface resistivity

  which accompanies the increase in gaseous pressure in the atmos-

  The influence of the gas pressure was totally unexpected in the context of the knowledge of the

  conventional plasma polymerization and plasma treatment.

  The electrical parameters of the plasma formation are an electrical power supply of the electrodes of between 10 and kw, at a frequency of between 10 kHz and 100 MHz. The type of the electrodes is not limiting and electrodes can be used. interior

  or external Electrode-free plasma discharges are also suitable for

  The low temperature plasma is produced either by incandescent discharge or corona discharge, without any particular difference in efficacy being seen between these treatments. The overall duration of plasma treatment in two stages is usually between a few seconds and several tens of minutes so

  to obtain a sufficient effect, although this duration also depends on the

  electrical power supplied by the electrodes, and other conditions.

  Hereinafter, the present process will be described in more detail by means of nonlimiting examples. In these examples, the effect obtained through the treatment of

  Plasma according to the process of the invention is evaluated in three ways.

  the following: by raising the distance at which the surface charged by the static electricity of a resin sheet attracts cigarette ashes,

  by measuring the surface resistivity of the resin sheet and measuring

  the friction-induced load tension of the resin sheet.

  The test methods for determining these properties are as follows: The pulling distance of the cigarette ash: a sample of resin sheet is rubbed ten times with a dry cotton cloth, and is then brought closer to cigarette ash disposed on a table to determine the distance at which the ashes are attracted by the electrostatic charge-bearing resin sheet Measurement is made at 250 ° C

  and at a relative humidity of 60%.

  Surface Resistivity: This measurement is made on the resin sheet using an instrument made by Toa Denpa Kogyo Co.

  The friction load voltage: the measurement is carried out with an ap-

  rotary table for the measurement of static electricity made by Koa Shokai Co. by rubbing the test sample with a cotton cloth rotating at 750 rpm under a weight of 200 g and the value of the tension charge is read after 1 min and after 180 min counted from the end of the

friction.

Example 1

  A resinous composition comprising 100 parts by weight of a PVC resin, 3 parts by weight of a stabilizer containing zinc and lead, 50 parts by weight of dioctyl phthalate and 2 parts by weight of an epoxidized soybean oil is kneaded in a ball mill for 10 minutes at 170 ° C and shaped by pressure molding at 1750 C to give a sheet

with a thickness of 0.5 mm.

  The resin sheet is placed in the plasma chamber of an apparatus to create a plasma, the pressure in the chamber being, after a vacuum of 1.3 104 mbar, maintained at 0.4 mbar by the introduction continuous flow of gaseous ethylamine and a low temperature plasma is created in the chamber by the dissipation of an electric power of 1 k W at the high frequency of 13, 56 M Hz, and the resin sheet is exposed for 1 min The sheet thus treated receives n 1. The same procedure is repeated except that the gaseous ethylamine is replaced by trimethylchlorosilane gas, and the duration of the treatment

  is extended to 3 minutes The sheet thus obtained receives the n 2.

  In addition, the procedure for the treatment of sheet No. 1 is followed by placing under vacuum 1.3 mbar of the plasma chamber.

  in which then trimethyl-chlorosilane, which is

  zeux up to a pressure of 0.5 mbar, then creates in the chamber a low temperature plasma by the dissipation of an electric power of 500 W at a frequency of 13, 56 M Hz, which is exposed to the surface of the

  resin sheet during 3 man The sheet thus obtained receives the n 3.

  The results of the tests carried out with the resin sheet before the plasma treatment, as well as those obtained with the treated sheets

  n s 1 to 3, are recorded in Table I attached.

Example 2

  A resinous composition comprising 100 parts by weight of a

  PVC resin, 3 parts by weight of a mercaptide stabilizer of

  butyltin and 0.1 part by weight of a polyethylene wax as a lubricant is kneaded in a ball mill for 10 minutes at 180 ° C and shaped

  die-cast at 185 ° C. to give a sheet of 1 mm thick

sor.

  This resin sheet is placed in the plasma chamber and after having put it under a vacuum of 1.3 104 mbar, the pressure is maintained at 0.11 mbar by continuously introducing diethylamine gas, and the

  plasma of low temperature in the chamber by the dissipation of a

  electrical power of 700 W at a frequency of 13.56 M Hz at which the resin sheet is exposed for 2 min. Then the plasma chamber is re-opened under a vacuum of 1.3 mbar, and then introduced continuously. vinyl methyl dimethoxysilane in the chamber to a pressure of 0.13 mbar, where a low temperature plasma is created by means of an electrical power of 1 kW at a frequency of 13.56 MHz. to which the resin sheet

  is exposed for 1 man The thus obtained resin sheet receives the n 4.

  The results of the test conducted with the resin sheet No. 4 before and after the plasma treatment are shown in Table I.

Example 3

  A resinous composition comprising 100 parts by weight of a PVC resin, 1.5 parts by weight of dibutyltin maleate, 1 part by weight of calcium stearate, 0.5 part by weight of zinc stearate and 1 part by weight of calcium stearate. stearic acid is kneaded in a ball mill for 10 minutes at 180 ° C. and shaped by pressure molding at 185 ° C. for

  give a sheet of 1 mm thick.

  The resin sheet is placed in the plasma chamber, in the

  -4 which, after putting it under a vacuum of 1.3 10 mbar, is maintained

  a pressure of 0.2 mbar by successively introducing

  thylamine and argon so that the partial pressures are

  of 0, 13 mbar and 0.07 mbar. A low temperature plasma is created in this atmosphere by means of an electric power of

  W at a frequency of 13.56 M Hz at which the surface of the film is exposed.

  The resin sheet thus obtained receives the n 5.

  The above experimental procedure is repeated except that the methyl-

  gaseous amine is replaced by trimethylmethoxysilane, and the duration of the plasma treatment is decreased up to 3 minutes The resin sheet

thus obtained receives the n 6.

  In addition, the same resin sheet is processed by the plasma of

  low temperature in exactly the same way as described for the treatment

  The film chamber containing the film is placed under a vacuum of 1.3 × 10 -4 mbar. Thereafter, air and trimethyl-methoxysilane gas are introduced in such a way that the pressures

  partial air and trimethyl methoxysilane gas are established.

  at 0, 07 and 0.4 mbar respectively. A low temperature plasma is created in this atmosphere using an electric power of 400 W at a frequency of 13.56 M Hz at which the surface of the resin sheet is exposed.

  for 3 minutes The resin sheet thus obtained receives NO 7.

  The results of the examination of the superficial properties of resin leaf 12 before treatment and treated leaves ns 5, 6 and 7 are shown in Table I.

Example 4

  A resin sheet prepared as described in Example 2,

  It is placed in the plasma chamber and, after having placed it under a vacuum of 1.3 mbar, the pressure is maintained at 0.07 mbar.

  continuously passing gaseous allylamine A low-temperature plasma

  The temperature is created in the chamber by means of an electrical power of 3 kW at a frequency of 110 kHz at which the surface of the resin sheet is

exposed for 30 s.

  The thus treated sheet is kept in the open air for 24 hours at 50.degree. C. and then placed again in the plasma chamber which is placed under a vacuum of 1.3 mbar.

  the nitrogen and tetramethoxysilane gases so that the partial pressures

  the two gases are each set at 0, 13 mbar A bass plasma

  temperature is created in this atmosphere by means of an electric power

  2 k W at a frequency of 110 kHz, at which the surface of the resin sheet is exposed for 30 s The results of the examination of the surface properties of the sheet thus obtained, which receives the NO 8, are recorded. the

Table I.

Example 5

  A resinous composition comprising 100 parts by weight of a

  copolymer resin of vinyl chloride and vinyl acetate in a

  weight of 84/16, 1 part by weight of an epoxidized soybean oil, 1 part by weight of dibutyltin mercaptide, 0.5 part by weight of calcium stearate and 0.1 part by weight of carbon black, is kneaded for 10

  min at 180 ° C, and shaped by pressure molding at 180 ° C to give

  a plate 5 mm thick.

  This resin plate is placed in the plasma chamber put

  under a vacuum of 1, 3 mbar, then continuously introduced ethylene-

  gas diamine in the plasma chamber such that the pressure is maintained at 0.07 mbar A low temperature plasma is created in

  this atmosphere by means of an electrical power of 3 k W at a frequency of

  110 kHz, at which the surface of the resin plate is exposed.

5 minutes.

13 2508050

  The plasma treatment above is followed by a decrease

  gradual increase in the rate of introduction of gaseous ethylenediainine accom-

  accompanied by a simultaneous introduction of vinyl-dimethyl-chlorosilane gas at a gradually increasing rate to compensate for the decrease in ethylenediamine while maintaining the constant pressure at 0.07 mbar, so that after 3 minutes the gaseous atmosphere in the plasma chamber is

  consisting of pure silane at a pressure of 0.07 mbar in this atmosphere.

  Once again, a low temperature plasma is created and the surface of the resin plate is exposed for 5 minutes under the same conditions.

Only in the first stage of plasma treatment.

  The results of the examination of the surface properties of the resin plate, which receives No. 9, as well as those obtained with the resin plate before the treatment, are shown in Table I.

TABLE I

  Exemption Echa'n Distance ResistivityPension load per pie NO bushing NO d T raction superf friction, volts, after cigarette ash 1 minute 180 minutes no 6 0132 0480 treated 6 71 50 40 1 O 3 x 109 300 3600 2 O 5 x 109 100 2800 3 O 2 x 10 830 120 traitno 6 9 x 10 147 600 10 000 4 O 4 x 108 80 190 treated 6 7 x 101 7 100 9 900 3 5 O 5 x 109 600 5900 6 O 6 x 109 200 4100 7 O 5 x 108 60 160 4 8 O 7 x 109 150 210 no 5 013340 10 treated 3 x 030910 9 0 2 x 109 90 150 -

Claims (8)

  1 Method for improving the surface properties of an article   formed of PVC resin, characterized in that it comprises the following stages:   (a) exposing the surface of the shaped article to the low temperature plasma formed in a gaseous atmosphere containing a nitrogenous organic compound, and b) exposing the surface of the formed article to the low temperature plasma formed in a gaseous atmosphere. containing an organic derivative of   silicone, after or before stage a).   Process according to Claim 1, characterized in that the compound   Nitrated organic salt is an organic amine represented by the general formula iew R -N-R,   wherein R is a substituted or unsubstituted hydrocarbon group and   R and R are each a hydrogen atom or a hydrocarbon group   novalent substituted or unsubstituted.   3. Process according to claim 1, characterized in that the compound   The organic nitrogen is an amide represented by the general formula 4 _ 5 R C -N-R   where R is a substituted or unsubstituted monovalent hydrocarbon group   substituted and R and R are each a hydrogen atom or a hydrogen group   substituted or unsubstituted monovalent carbide.   4. Process according to claim 1, characterized in that the compound   organic nitrogen is a diamine represented by the general formula R -N-R 8-N-R 9 h o lu R R   wherein R is a substituted or unsubstituted monovalent hydrocarbon group, R, R and R are each a hydrogen atom or a group   substituted or unsubstituted monovalent hydrocarbon and R is a hy-   substituted or unsubstituted bivalent hydrocarbon.   16- Process according to claim I characterized in that the organosilicone is a compound represented by the general formula RH Si X bab 4-ab 'wherein R is a substituted or unsubstituted monovalent hydrocarbon group, X is a halogen atom or a alkoxy group, a is the number 0, 1, 2, 3 or 4 and b is the number O, 1 or 2, provided that a + b is not greater than 4,   or a hydrolytic condensation product of such a compound.   Process according to Claim 1, characterized in that the atmosphere   gas contains the nitrogenous organic compound under a particular pressure   between 1.3 and 13.3 mbar and a mineral gas   partial pressure of between 1.3 and 13.3 mbar.   Process according to Claim 1, characterized in that the atmosphere   gas contains the organosilicone under a partial pressure   between 1, 3 and 13.3 mbar and a mineral gas under a pressure of   from 1.3 to 13.3 mbar.   Process according to Claim 1, characterized in that stage a) precedes stage b)