Organoclay (stearyl ammonium-modified montmollironite, C18-Mt) was treated with stearic acid (SA) by the following method.C18-Mt was mixed with SA in toluene and then toluene was evaporated.The amounts of SA treated were varied from 0.025-0.25g/g-C18-Mt (g per 1g of C18-Mt).The structure of C18-Mt treated with SA (C18-Mt(SA)) and the adsorption state of SA on C18-Mt were investigated using X-ray diffraction (XRD) and differential scanning calorimetry (DSC).The basal spacing of C18-Mt(SA) increased with increasing the amounts of SA added up to 0.15g/g-C18-Mt and became constant value.When the amount of SA added increased from 0 to 0.15g/g-C18-Mt, the basal spacing of C18-Mt(SA) increased from 2.1 to 3.0nm.The XRD results show that the SA added to C18-Mt was adsorbed into the C18-Mt interlayers.In the DSC curves of C18-Mt(SA), a melting peak of SA was appeared at ca. 69℃　when　the　amounts　of　SA　added　were　more　than　0.10g/g-C18-Mt.　　The　enthalpy　of　fusion　of　SA　increased　with　increasing　the　amounts　of　SA　added.　　The　DSC　results　indicate　that　an　excess　of　SA,　which　was　not　adsorbed　into　the　C18-Mt　interlayers,　was　adsorbed　onto　the　surface　of　C18-Mt(SA)　particles.　　C18-Mt(SA)　was　washed　with　toluene.　　Before　and　after　washing　with　toluene,　the　amounts　of　SA　on　C18-Mt　were　estimated　by　weight　loss　on　ignition.　　The　results　suggest　that　a　part　of　SA　was　strongly　adsorbed　into　the　C18-Mt　interlayers,　however　most　of　SA　was　physically　adsorbed　into　the　C18-Mt　interlayers　and　onto　the　surface　of　C18-Mt(SA)　particles.

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Plasma discharge treatment was conducted to the surface of low density poly(ethylene) (LDPE) sheet in oxygen atmosphere.The adhesive strength of LDPE with poly(ethylene terephthalate)(PET) was determined as a function of laminating temperature without using adhesive.It was found that the temperature showing maximum strength was present.This temperature also varied with the molecular weight of LDPE, and the tendency was similar to that of melting point.When we plotted the adhesive strength in the maximum temperature against MFR(melt flow rate), the strength showed maximum at a given MFR.In other words, the adhesive strength of LDPE with PET reached maximum in the LDPE having a given molecular weight.This result can be explained as follows.In the low molecular weight region, i.e., high MFR, the adhesive strength decreased with the increase of molecular weight, though the fracture was cohesive failure.In the high molecular weight region, the LDPE surface becomes difficult to attain sufficient adhesion for short time because of surface hardness, and the strength decreased with the increase of molecular weight.

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