962 results about "Crystallization rate" patented technology

Gas barrier polyamide compositions exhibiting a low crystallization rate and good coinjection stretch blow moldability with polyethylene terephthalate (PET) to enable the fabrication of clear, high barrier multilayer PET bottles that have a long shelf life.

A semiconductor memory device with a dielectric structure and a method for fabricating the same are provided. The dielectric structure includes: a first dielectric layer having a dielectric constant of approximately 25 or higher; a second dielectric layer including a material having a crystallization rate lower than the first dielectric layer and formed over the first dielectric layer; and a third dielectric layer including a material substantially identical to that of the first dielectric layer and formed over the second dielectric layer.

The invention relates to a high performance polylactic acid composite material and a preparation method. The high performance polylactic acid composite material comprises the following components in parts by mass: 40-85 parts of polylactic acid, 10-40 parts of modified inorganic or natural fibres; 1-10 parts of organic modified natural minerals, 0.8-5 parts of sensitizing agents, 0.1-2 parts of heat stabilizers, 0.1-1 part of antioxygen and 0.1-1 part of lubricating agent. The inorganic or natural fibre reinforced polylactic acid is selected to improve the mechanics performance, silane coupling agents are adopted to carry out surface processing to improve the compatibility with the polylactic acid matrix; and organic modified natural minerals are selected to improve the crystallization rate of the polylactic acid, also improve the material performance, reduce energy source consumption, and reduce the cost of products. After heat processing is carried out, the heat resistance and the mechanics performance of the composite material are further improved through the radiation crosslinking of crystallized polylactic acid. The prepared polylactic acid composite material has excellent mechanical property and heat resistance, and can avoid the problem of property reduction caused by a single modification method. The method is simple. The composite material can be prepared through the traditional plastic processing methods. The invention is suitable for industrial production.

A coform nonwoven web that contains a matrix of meltblown fibers and an absorbent material is provided. The meltblown fibers are formed from a thermoplastic composition that contains at least one propylene/α-olefin copolymer of a certain monomer content, density, melt flow rate, etc. The selection of a specific type of propylene/α-olefin copolymer provides the resulting composition with improved thermal properties for forming a coform web. For example, the thermoplastic composition crystallizes at a relatively slow rate, thereby allowing the fibers to remain slightly tacky during formation. This tackiness may provide a variety of benefits, such as enhancing the ability of the meltblown fibers to adhere to the absorbent material during formation of the coform web. In certain embodiments, the coform web may also be imparted with texture using a three-dimensional forming surface. In such embodiments, the slow crystallization rate of the meltblown fibers may increase their ability to conform to the contours of the three-dimensional forming surface. Once the fibers crystallize, however, the meltblown fibers may achieve a degree of stiffness similar to conventional polypropylene, thereby allowing them to retain their three-dimensional shape and form a highly textured surface on the coform web.

The invention is applicable to the technical field of engineering plastic and provides a PET (polyethylene terephthalate) engineering plastic and a preparation method and application thereof. The PET engineering plastic comprises PET, compatilizer, bromine flame retardant, flame-retardant synergist, nucleating agent, nucleating synergist, oxidation inhibitor and glass fibers and the like. Crystallization density and crystallization rate of PET composite materials are increased and excellent tension, bending, impacting and thermal-deformation performances and excellent injection molding processing performances of the PET engineering plastic are realized by the aid of compounding of the nucleating agent, the nucleating synergist, the flame retardant and the flame retardant synergist. Flame retardant of the PET engineering plastic is improved by compounding of the flame retardant and the flame retardant synergist, tracking of the PET engineering plastic is suppressed or alleviated and CTI (comparative tracking index) value of the PET engineering plastic is increased.

Disclosed are certain novel polyester compositions particularly useful for shaping or forming into containers and similar shaped articles by thermoforming procedures. The polyester compositions comprise a thermoplastic polyester, an impact modifier and a polyester crystallization rate enhancing component selected from poly(tetramethylene terephthalate) homo- and co-polymers. The polyester compositions exhibit improved crystallization rates as compared to similar compositions not including impact modifier or compositions using other types of crystallization rate enhancing components such as polyolefin-based polymers.

The invention relates to a rapid crystallization polylactic acid composite material and a preparation technique thereof. The composite material comprises the following components in portion by weight: 59 to 98 portions of hypocrystalline poly-L-lactic acid, 1 to 40 portions of organic modified natural mineral, 1 to 20 portions of organic crystallization promoter, 0.1 to 1.0 portion of heat stabilizer, and 0.05 to 1.0 portion of lubricant. The sum of the mass percentage of the components is 100 percent. The preparation method for the material comprises the following steps: firstly preparing the modified natural mineral; then mixing the components according to the components of the composite material; agitating and mixing the raw materials evenly through a high-speed agitator; and adding the co-mixture into a twin screw extruder for extrusion and granulation. The method improves the crystallization rate of a polylactic acid matrix through the synergistic action of organized mineral and the crystallization promoter. Due to the addition of the organic crystallization promoter, the method strengthens the mechanical properties of the polylactic acid composite material, while simultaneously quickening the crystallization rate of polylactic acid, thereby avoiding the defect of greatly reducing the mechanical properties of the polylactic acid composite material caused by the addition of a single inorganic mineral nucleating agent. The price of adopted fillers is low; and the whole preparation method has a simple technological process and less consuming time of the technological process, and can realize the large-scale industrialized production.

The invention discloses an M-Sb-Se phase transition film material used for a phase transition storage and the ingredient thereof is (SbxSe(1-x))(1-y)My, wherein y is an atomic ratio of 0.2%-15%, x is the atomic ratio of 50%-95%, and doping elements of M comprise one or two elements out of tungsten, aluminum, indium, silver, copper, nickel, gallium, titanium , tin, oxygen and nitrogen. The M-Sb-Se phase transition film material of the invention has faster crystallization rate, faster read-write rate and better data holding property than the commonly used Ge2Sb2Te5 material and better thermal stability than SbSe binary material. Meanwhile, the material is free from element Te, thereby being environment friendly, and the material has good compatibility with CMOS technique.

The invention belongs to the technical field of a catalyst and an application thereof, and particularly relates to a nano MFI-type molecular sieve which is easy to separate and has high hydrothermal stability and a hierarchical pore channel structure, and a preparation method and application thereof. The method comprises the following steps: (1) selecting a prepared nano MFI-type molecular sieve suspension as a mother liquid; (2) adding a cationic flocculant into the mother liquid to assemble the nano molecular sieve; (3) putting the assembled nano molecular sieve into a reaction kettle for hydrothermal synthesis to obtain a nano molecular sieve compound with a block size of 100 nanometers to 100 microns. The nano molecular sieve compound is subjected to conventional filtering, washing, drying and roasting to obtain the nano MFI-type molecular sieve with a hierarchical pore channel structure. The nano MFI-type molecular sieve prepared by the method can be separated through a filtering operation and has the advantages of open intercrystalline pore channel structure, large pore volume, high crystallization rate and high hydrothermal stability; in a methanol-to-propylene reaction, the nano MFI-type molecular sieve shows higher propylene yield and stability than the nano MFI-type molecular sieve prepared by a conventional method.

The invention provides a method for preparing pure ammonium paratungstate (APT) from crude Na2WO4 solution containing NaOH, P, As, Si, Sn and other impurities. The method comprises the following steps of crystallizing tungsten into Na2WO4 crystals through concentration, separating NaOH from impurities, redissolving and acidifying the Na2WO4 crystals till the pH of the crystals is between 2.0 and 6.0, adsorbing the crystals by use of macroporous weak alkaline anion exchange resin, desorbing the crystals by use of NH4OH, obtaining (NH4)2WO4 solution, performing evaporation crystallization and obtaining the APT. Under the condition that the crystallization rate is between 88 and 90 percent, the P, the As and the Si contained in the APT are all less than 10*10. The method has the outstanding advantage of small amount of discharged wastewater (mainly liquid after exchange), namely the volume of the discharged liquid after the exchange is one third to one twenty-fifth of that of liquid before the exchange; in addition, the discharged liquid after the exchange contains no detrimental impurities and is easy to control.

The invention provides a synthesis method of an SSZ-13 molecular sieve. A USY molecular sieve or Beta molecular sieve with adsorbed N,N,N-trimethyl-1-adamantanamine cations is used as a structure guide agent to synthesize the SSZ-13 molecular sieve together with an aluminum source, a silicon source, an alkali source, water and mixed seeds, thereby greatly reducing the consumption of the expensive template N,N,N-trimethyl-1-adamantanamine cations in the traditional method, and obviously lowering the cost for synthesizing the SSZ-13 molecular sieve. The method can enhance the crystallization rate of the SSZ-13 molecular sieve and shorten the required crystallization time, and thus, is more beneficial to industrial production. The SSZ-13 molecular sieve synthesized by the method has high crystallinity and favorable hydrothermal stability; and the synthesized SSZ-13 molecular sieve can be used as an MTO (Methanol To Olefins) catalyst and can also be used as an automobile tail gas treatment catalyst support.

The invention belongs to the technical field of high polymer materials, and particularly relates to an exfoliated montmorillonite/maleic anhydride-styrene ionomer composite material as well as a preparation method and an application thereof. The preparation method disclosed by the invention comprises the following steps: by virtue of in-situ intercalation free-radical polymerization, enabling monomers to enter organic montmorillonite (MMT) sheet layers via a diffusion action and then polymerizing among the MMT sheet layers, and opening and exfoliating the MMT sheet layers by virtue of polymerization heat, so as to form an exfoliated montmorillonite and maleic anhydride-styrene copolymer composite material; and performing hydrolysis and salinization on the copolymer composite material to prepare the exfoliated montmorillonite and maleic anhydride-styrene ionomer composite material. The ionomer composite material can be used as a nucleating agent for PET (polyethylene terephthalate), and is capable of remarkably increasing the crystallization temperature and crystallization speed of the PET. The ionomer composite material is simple in preparation method, capable of adopting a one-time process of mixing-reaction extruding granulation with the PET, convenient to operate, high in benefits, low in cost, and suitable for industrialized production.

The invention relates to a fat composition used for chocolate coatings, a preparation method thereof, and the chocolate coatings and food containing the fat composition. The fat composition is rich in SSU (1, 2-di-saturated fatty acid-3-unsaturated fatty acid triglyceride), low in trans fatty acid content, low in content of saturated fatty acids, free of lauric acid and high in crystallization rate, and can be solidified into a stable form CBR (cocoa butter replacer) without temperature adjustment.

The invention belongs to the technical field of high polymer materials, and in particular relates to a polyethylene terephthalate nucleating agent and a preparation method thereof. The method comprises the following steps of: based on polystyrene-b-poly(styrene-alt-maleic anhydride) diblock copolymer as a raw material, hydrolyzing, salinizing and purifying to prepare an ionomer of the polystyrene-b-poly(styrene-alt-maleic anhydride) diblock copolymer. A polystyrene block can form microphase separation in molten polyethylene terephthalate (PET), and thus, a crystal nucleus is provided for PET crystallization; and moreover, a poly(styrene-alt-maleic anhydride) block and PET are well compatible with each other, so that crystallization surface energy can be reduced, and the crystallization temperature and crystallization speed of the PET can be increased. In addition, a plasticizer such as di-2-ethylhexy1 azelate is added while the nucleating agent is added, the movement velocity of a PET chain segment can be further increased, so that the growing speed of crystals is increased. The preparation method is simple, convenient to operate, high in benefit, low in cost and suitable for industrial production.