219 results about "Expandable microsphere" patented technology

The invention belongs to the technical field of automobile parts, and particularly discloses a GMT composite material automobile roof and a preparation method thereof. The GMT composite material automobile roof comprises a GMT composite board layer, a hot melt adhesive layer and a fabric layer, and is characterized in that the GMT composite board layer comprises the following components in parts by weight; comprising the following raw materials: 90-100 parts of composite fiber felt, 22-30 parts of modified bamboo fiber, 3-5 parts of tea tree oil, 1-2 parts of sodium tripolyphosphate, 2-4 parts of beta-glycerophosphate disodium, 0.5-0.8 part of lecithin, 15-20 parts of modified talcum powder, 4-6 parts of an expandable microsphere foaming agent and 190-200 parts of deionized water. The GMT composite material automobile ceiling prepared in the invention has excellent mechanical strength, durability and aging resistance, can provide mechanical protection for parts, and prolongs the service life of the automobile ceiling.

To provide a pressure sensitive adhesive sheet including thermo-expandable microspheres capable of exhibiting a releasing property by heating, the pressure sensitive adhesive sheet preventing changes in thickness and in surface roughness even under a high temperature when no separation is required.SOLUTION: A pressure sensitive adhesive sheet includes a substrate, a resin layer and a first adhesive layer in this order. The first adhesive layer includes thermo-expandable microspheres. The pressure sensitive adhesive sheet satisfies a relation Tf≥Tgas-10 by a thickness deformation initiation temperature Tf(°C) by a TMA analysis and a gasification initiation temperature Tgas(°C) by an EGA / MS analysis of the thermo-expandable microspheres.SELECTED DRAWING: Figure 1

The invention belongs to an electromagnetic shielding foam material, and relates to a thermal expansion microsphere, a preparation method thereof and an electromagnetic shielding-thermal management foam material, and the thermal expansion microsphere sequentially comprises a microsphere core, a middle layer and an outer layer from inside to outside; the preparation method comprises the following steps: mixing and emulsifying the component A and the component B in a high-speed shearing emulsifying machine to obtain a suspended emulsion, transferring the suspended emulsion into a high-pressure reaction kettle, polymerizing for 15-20 hours at 50-70 DEG C under the condition of nitrogen protection, heating to 90-110 DEG C, polymerizing for 2-4 hours, cooling and decompressing after the reaction is completed, and sequentially performing suction filtration, washing and drying on the product to obtain the high-performance polyurethane elastomer. Thermal expansion microspheres are prepared; the electromagnetic shielding-thermal management foam material is prepared from the thermal expansion microspheres through a thermal expansion foaming process. After being expanded, the thermal expansion microspheres have high stability and unique in-situ interface chemical bonding capability; the preparation method is simple; the application range is wide.

The invention discloses a thermal visbreaking pressure-sensitive adhesive tape and a preparation method thereof.The adhesive tape comprises a release layer, a thermal visbreaking layer and a base material layer which are sequentially arranged in a stacked mode, and the thermal visbreaking layer is obtained by coating thermal visbreaking glue and then curing the thermal visbreaking glue; the heat-reduced adhesive comprises the following raw material components in parts by weight: 90-120 parts of acrylate copolymer resin, 5-15 parts of modified resin, 0.01-1 part of a curing agent, 2-10 parts of modified thermal expansion microspheres and 20-60 parts of a solvent. The modified thermal expansion microspheres are specially modified, so that the compatibility and weather resistance of the modified thermal expansion microspheres in an acrylate pressure-sensitive adhesive can be improved, and the thermal viscosity-reducing adhesive prepared by adding the modified thermal expansion microspheres into an acrylate copolymer resin has excellent normal-temperature adhesive force which is not inferior to normal adhesive tape adhesion; and after the adhesive tape particles are expanded at a proper temperature, controllable viscosity reduction and even viscosity loss requirements can be met, and no residual adhesive is generated on the surface of an adhered object.

To provide an adhesive sheet containing an adhesive layer with thermally expandable microspheres, while being capable of forming a highly smooth adhesive layer and less likely to hinder the expandability of the adherend.SOLUTION: According to an embodiment, an adhesive sheet comprises a substrate, a resin layer, and an adhesive layer in this order, where the adhesive layer comprises thermally expandable microspheres, the resin layer comprises a base polymer, and the base polymer has a glass transition temperature Tg of -35°C to 20°C.SELECTED DRAWING: Figure 1

The present invention provides an adhesive sheet which contains thermally expandable microspheres and can exhibit releasability by heating, and in which a change in thickness and a change in surface roughness are suppressed even at high temperatures at which release of the adhesive sheet is not required.　An adhesive sheet according to one embodiment of the present invention is sequentially provided with a base material, a resin layer, and a first adhesive layer in this order. The first adhesive layer contains thermally expandable microspheres. The thickness deformation starting temperature Tf (°C) of the adhesive sheet as determined by TMA analysis and the gasification starting temperature Tgas (°C) of the thermally expandable microspheres as determined by EGA / MS analysis satisfy the relational expression Tf ≥ Tgas -10.

The present application provides a preparation method for a thermally expandable microsphere containing hydrophilic organic-modified colloidal silicon dioxide. In the preparation method, hydrophilic organic-modified colloidal silicon dioxide is mixed with a mixture of a monomer material capable of polymerizing to form a thermoplastic polymer shell and at least one foaming agent to form an emulsion, and the emulsion is polymerized to form the thermally expandable microsphere. Surface-modified colloidal silicon dioxide with hydrophilic organic group in the present application has good salt tolerance stability, can be stabilized in brine and is beneficial to the preparation of the thermally expandable microsphere; and the prepared microsphere has a narrow particle size distribution, can be easily dispersed in water and an organic system, and has good wettability. The application also relates to a thermally expandable microsphere and use thereof.

Thermally expandable microspheres comprise a polymeric shell surrounding a hollow core, wherein the hollow core comprises a blowing agent, and the polymeric shell comprises isolated lignin.

The invention relates to the technical field of polymer microspheres, in particular to a thermal expansion microsphere and a preparation method and application thereof. The thermal expansion microsphere comprises a polymer shell and an inner core coated in the shell, the inner core comprises a foaming agent, and the thermal expansion microsphere is characterized in that the polymer shell is formed by polymerization reaction of a monofunctional monomer and a cross-linking agent under the initiation of an initiator; wherein the difference value between the 10-hour half-life period temperature of the initiator and the peak exothermic temperature of the cross-linking agent is 60-81 DEG C. By controlling the decomposition activity of the initiator and the reaction activity of the cross-linking agent to be matched in a specific temperature difference range, construction of a uniform cross-linked network between shell polymer chain segments is achieved, and the obtained thermal expansion microspheres have a wide expansion temperature range, good heat resistance, stable expansion behavior and high expansion rate.

The present invention relates to a one-component thermosetting epoxy resin composition, comprising an epoxy resin A having on average more than one epoxide group per molecule, a latent hardener for epoxy resins, at least one heat-expandable microsphere HEM1 with a mean particle size D (0.5) between 2.5 – 22.5 μm and at least one heat-expandable microsphere HEM2 with a mean particle size D (0.5) between 25 - 75 μm. The epoxy resin adhesive is notable for a reduced difference in expansion volumes at 140 °C vs. 200 °C for 30 min, especially after storage at elevated temperatures and humidity.

The invention relates to the technical field of heat-conducting interface materials and bonding glue materials, in particular to organic silicon detachable heat-conducting bonding glue and a preparation method thereof.The bonding glue comprises a component A and a component B. The component A comprises, by mass, 4-6% of vinyl silicone oil, 0.2-0.5% of a coupling agent, 0.1-1.5% of a dispersing agent, 0.3-0.4% of a catalyst and 88-94% of aluminum oxide filler; 1 to 3.6 percent of expandable microspheres; the component B is prepared from 4 to 6 percent of vinyl silicone oil, 0.2 to 0.5 percent of a coupling agent, 0.1 to 1.5 percent of a dispersing agent, 0.01 to 0.05 percent of an inhibitor, 0.8 to 1.2 percent of hydrogen-containing silicone oil, 88 to 94 percent of aluminum oxide filler and 1 to 3.6 percent of expandable microspheres. The obtained heat-conducting adhesive is high in heat conductivity coefficient and shear strength, and can be quickly cured and disassembled.

The invention discloses a preparation process of secondary foaming type water-based synthetic leather, and relates to the technical field of polymer foaming materials, the preparation process comprises the following steps: 1) epoxy modified thermal expansion microspheres; 2) side chain amino modified polyurethane; 3) preparing foaming slurry; 4) preparing the synthetic leather; firstly, thermal expansion microspheres are epoxidized, waterborne polyurethane is grafted with side chain amino protected by t-butyloxycarboryl, the crosslinking degree is improved through triphenylmethane triisocyanate, and then the waterborne polyurethane is mixed with the epoxy modified thermal expansion microspheres; after the first time of foaming by a mechanical means, in the step 4), t-butyloxycarboryl is heated and dissociated, CO2 gas is generated, active amino is released, the t-butyloxycarboryl is crosslinked with epoxy of the thermal expansion microspheres, meanwhile, the thermal expansion microspheres are expanded, and chemical foaming, namely second time of foaming, is achieved. Through cooperation of mechanical and chemical secondary foaming processes, the problems that traditional water-based leather is hard in hand feeling, bubbles are prone to collapse and the performance is single are solved, and the comprehensive performance is remarkably improved compared with the prior art.

The invention discloses a preparation method of stable modified silica sol in an acidic system, which comprises the following steps: under the action of a zwitterionic polymer, directly grafting a silane coupling agent treated by amino acid on the surfaces of silica particles, so that the grafting rate of the coupling agent on the surfaces of the small-particle-size silica particles in the acidic system is effectively improved; meanwhile, the silane coupling agent treated by the amino acid can also reduce agglomeration among silicon dioxide particles, so that the acid stability of the silicon dioxide particles is improved. The thermal expansion microspheres prepared by the method are low in deslagging rate and good in stability.

The invention discloses a method for synthesizing thermal expansion microspheres by a controlled free radical polymerization method and a product thereof. The method comprises the following steps: mixing a nitrile monomer, an acrylate monomer, an initiator, a cross-linking agent, a foaming agent and an RAFT reagent to form an oil phase, emulsifying and dispersing the oil phase and a water phase containing inorganic salt and a dispersing agent, and carrying out polymerization reaction under the protection of nitrogen by adopting an optimized two-stage temperature control process (55 DEG C / 20h to 65 DEG C / 8h) to prepare the thermal expansion microsphere with the core-shell structure. 2-cyano-2-propylbenzo dithio acid ester is preferably used as an RAFT reagent, so that the compactness of a shell layer of the obtained microsphere polymer is remarkably improved, the expansion rate is higher, the temperature resistance is better, and the application range of the thermal expansion microsphere is widened.

The utility model relates to the technical field of thermal expansion microsphere production, and particularly discloses equipment for producing small-particle-size thermal expansion microspheres, which comprises a water phase homogenizing kettle, an oil phase homogenizing kettle, a water-oil phase homogenizing kettle, a centrifugal pump, a primary static mixer, a secondary static mixer, a polymerization kettle, a bypass assembly and a backflow assembly, the water phase homogenizing kettle and the oil phase homogenizing kettle are respectively connected with the water-oil phase homogenizing kettle through pipelines, the water-oil phase homogenizing kettle is connected with the centrifugal pump through a pipeline, the first-stage static mixer is connected with the centrifugal pump through a pipeline, the second-stage static mixer is connected with the first-stage static mixer through a pipeline, and the second-stage static mixer is connected with the second-stage static mixer through a pipeline. The polymerization kettle is connected with the second-stage static mixer through a pipeline, the bypass assembly and the backflow assembly are both connected with the pipeline between the centrifugal pump and the first-stage static mixer, and through the arrangement, the thermal expansion microspheres with better particle size distribution, better expansion performance and lower residual monomer amount can be obtained.

The invention relates to the technical field of molding powder coatings, in particular to low-temperature curing type electrostatic spraying molding powder and a production process thereof. The coating comprises modified polyester resin, thermal expansion microspheres, modified amide wax, a latent curing agent, a conductive composite filler, a pigment filler and an auxiliary agent, through a dual leveling system constructed by thermal expansion microspheres and modified amide wax, the resin viscosity can be reduced through microsphere expansion stress in the initial low-temperature melting stage, meanwhile, amide wax directionally forms a lubricating layer through hydrogen bonds, the surface tension is dynamically adjusted, and the problem of insufficient leveling or excessive migration caused by a fixed proportion of a traditional auxiliary is solved; the flatness of the coating is improved, and surface defects are eliminated; through a'resin-wax-curing agent 'ternary covalent network, an interpenetrating cross-linked structure is formed in the low-temperature curing process, the cohesion strength and weather resistance of the coating are enhanced, and the adaptability and long-term protection capability of the coating to a base material are improved through the interface interpenetrating effect of the thermal expansion microspheres and a resin matrix.

Methods, kits fand photothermal compositions for removing nail coatings are described. The nail coatings include a thermally responsive material, such as thermally expandable microspheres, and a nail product to be removed (e.g. nail polish, gel, dip, nail art, and / or artificial nail. Optionally, a bottom coating, such as lipoic acid, is in contact with the nail surface. The method includes (ii) applying a removal stimulus to a removal layer containing a photothermal additive to induce heat generation and cause at least partial expansion, shape change, and / or phase change of the thermally responsive material or partial detachment of the nail product. Optionally the method includes applying the photothermal nail composition on top of a nail coating prior to step (ii).

The present invention relates to tannin-based heat-expandable microspheres, and also to a process for their preparation. The heat-expandable microspheres comprise a thermoplastic shell surrounding a hollow core, wherein the hollow core comprises a blowing agent, and the thermoplastic shell comprises tannin.

The invention provides an epoxy resin paint and a preparation method thereof, wherein the raw materials for preparing the epoxy resin paint include an epoxy resin component and a curing agent component, and the weight ratio of the epoxy resin component and the curing agent component is (3-5): 1; the raw materials for preparing the above-mentioned epoxy resin component include by weight: 100-110 parts of epoxy resin, 0-10 parts of diluent, 20-100 parts of heavy calcium, 5-15 parts of precipitated barium sulfate, 1-5 parts of expandable microspheres, 0-2 parts of titanium dioxide, 0.05-1 parts of dispersant, 0.05-1 parts of defoamer, 0.5-2 parts of anti-settling agent, and 0.05-1 parts of leveling agent; the raw materials for preparing the above-mentioned curing agent component include by weight: 100-110 parts of phenolic amine and 20-50 parts of polyaspartic acid ester. The epoxy resin paint of the present invention can be used for thermal spraying construction through the synergistic effect of each component, and has good heat insulation and thermal insulation effect.

The invention provides an electromagnetic shielding film material capable of quickly releasing adhesion as well as a preparation method and application thereof, and the electromagnetic shielding film material comprises the following components in percentage by mass: 8-30% of thermal adhesive resin, 60-80% of conductive particles and 5-20% of thermal expansion microspheres. The electromagnetic shielding film material solves the problems in the prior art that the electromagnetic shielding film material is difficult to effectively separate from a device, long in debonding time, easy to remain and easy to damage the device due to high bonding force of thermal bonding resin.

Intumescent composition comprising an acid donor (A), a carbon donor (B), a binder polymer (C) and a blowing agent (D). The acid donor (A) is selected from the group consisting of ammonium polyphosphate, ammonium dihydrogen phosphate, ethylenediamine phosphate, ammonium pentaborate, guanylurea phosphate, diguanidine phosphate and mixtures thereof. The carbon donor (B) is selected from the group consisting of glucose, arabinose and other monosaccharides, lactose, maltose and other disaccharides, starch, cellulose, dextrin and other polysaccharides, sorbitol, erythritol, pentaerythritol, dipentaerythritol, mannitol and other polyhydric alcohols and mixtures thereof. The blowing agent is provided in the form of microsphere particles comprising a thermoplastic polymer shell encapsulating a propellant, which microsphere particles are expandable microspheres.

The invention discloses a foamable polypropylene material as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials. Two kinds of expandable microspheres with different foaming property parameters are introduced into a polypropylene resin matrix, so that the dimensional stability of a product is improved; meanwhile, low-melting-point polypropylene resin and hyperbranched polyester are introduced into a polypropylene resin matrix for combined action, so that high dispersity and compatibility among the components are realized, sink marks on the surface of the product are avoided, the glossiness is low, the surface roughness is moderate, and the use requirements of decorative parts in an automobile are better met.

The invention relates to the technical field of polymer functional materials, in particular to heat-expandable microspheres with smooth surfaces and a preparation method thereof, comprising the following steps: S1: mixing unsaturated olefin monomers, a crosslinking agent, a modifier, an initiator and a foaming agent, stirring evenly to form a mixed oil phase; S2: mixing nano-lignin aqueous dispersion, an emulsifier and a water phase inhibitor evenly, stirring evenly to form a mixed water phase; S3: adding the mixed water phase obtained in step S2 to the mixed oil phase obtained in step S1, homogenizing and emulsifying at high speed to form an emulsion; S4: adding the emulsion obtained in step S3 to a reactor, sealing, pressurizing, stirring and heating to react, to obtain a heat-expandable microsphere suspension; and S5: adding an alkali washing solution to the heat-expandable microsphere suspension obtained in step S4 to dissolve the nano-lignin on the surface of the heat-expandable microspheres, filtering, alkali washing and drying in sequence to finally obtain heat-expandable microsphere powder with smooth surfaces.

The present invention relates to a foamable polymer composition containing a polymer selected from the group consisting of polyolefins (PO),polyolefin elastomers (POE), polyolefin block co-polymers (OBC), ethylene vinyl acetate copolymers (EVA), EVA / PO copolymers, EVA / OBC copolymers, polyvinylchloride (PVC), polymers of styrene, natural and synthetic rubbers, polyamides, polyimides, and combinations thereof, a functionalized particulate bicarbonate, and thermally expandable microspheres, to methods for manufacturing a foamed polymer using such foamable polymer composition, and the use of said foamed polymers.

A coating composition, a preparation method therefor and use thereof are provided. The coating composition includes at least 60% heat-expandable microspheres having a wall thickness of less than or equal to 5 μm, a water-based thermoplastic resin, a water-based thermosetting resin, and a hot-melt filling resin. Thin-shell spheres can be quickly softened and ruptured within a short time in the heat-expansion process, and with the volatilization of an organic solvent, the coating composition cross-links with a resin matrix in the coating to form a cross-linked network structure, thus strengthening the gap support of the coating, and enabling the coating to achieve stepped expansion. After expansion, some polymer materials wrap an airbag and harden to form a stable hollow structure. Therefore, the expanded coating can be used for the fixation of high temperature-resistant parts, and can maintain adhesive stability when placed in a high-temperature environment (140-180° C.) for a long time.

The invention relates to a composition comprising at least one thermoplastic polyamide, wherein the average carbon content of the repeating units of said at least one thermoplastic polyamide is greater than or equal to 7; from 0.1 to 6.0 % by weight of expandable microspheres, based on the total weight of the composition; and optionally at least one additional thermoplastic polymer; wherein the composition has a melt flow index lower than or equal to 150 g / 10 min. The invention also relates to a method for preparing such a composition, to an expanded composition obtainable from such a composition and to a method for producing said expanded composition.

An electronic device manufacturing method comprising: a step for preparing a structure (100) including an adhesive film (10) that is provided with a base material layer (A) and an adhesive resin layer (C), and a workpiece (20) that is temporarily fixed to the adhesive resin layer (C); and a step for processing the workpiece (20) temporarily fixed to the adhesive resin layer (C), wherein the adhesive resin layer (C) includes thermally expandable microspheres, and the sphericity R of the thermally expandable microspheres as calculated by a prescribed formula is 0.93 or more.

To provide alternative thermoplastic expandable microspheres whose thermoplastic polymeric shell is at least partially derived from a sustainable source, a method for preparing the microspheres, and use of the microspheres.SOLUTION: There are provided thermally expandable microspheres comprising a polymeric shell surrounding a hollow core, wherein the hollow core comprises a blowing agent, and the polymeric shell comprises isolated lignin. The isolated lignin preferably comprises Kraft lignin such as acetylated Kraft lignin. A method for preparing thermally expandable microspheres comprising a polymeric shell surrounding a hollow core comprises the steps of (i) preparing a mixture comprising the isolated lignin and the blowing agent in a solvent, and (ii) spray-drying the mixture obtained in step (i) to obtain thermally expandable microspheres.SELECTED DRAWING: Figure 1

The application discloses a preparation method of homogeneous poly-methacrylimide wave-absorbing foam, and belongs to the technical field of functional foam materials. Thermally expandable microspheres are used as carriers, and iron metal framework structures with 5-hydroxy isophthalic acid as monomers are loaded on the surfaces of the carriers to obtain dispersed thermally expandable microspheres, which can be uniformly dispersed in the wave-absorbing foam, realize uniform foaming, and have uniform foaming effect and insignificant layering phenomenon. Meanwhile, core-shell toughening composite powders generated by a molten salt method are used as fillers of the wave-absorbing foam, so that the impact resistance and performance stability of the wave-absorbing foam in the foaming process are effectively ensured. The strong covalence of Ti-B bonds in the shell of the core-shell toughening composite powders makes the core-shell toughening composite powders have high conductivity, can absorb electromagnetic wave energy through a dielectric loss mechanism, and the boron nitride of the core can assist in forming multiple scattering interfaces and prolonging the electromagnetic wave propagation path, so that the wave-absorbing performance of the absorbent is increased.

The present invention relates to an adhesive sheet. Provided is an adhesive sheet having an adhesive layer containing heat-expandable microspheres and having excellent pick-up properties when an adherend is peeled off. The adhesive sheet of the present invention has an adhesive layer containing heat-expandable microspheres, wherein the adhesive expansion property of the adhesive layer when heated to the foaming peak temperature of the heat-expandable microspheres (the thickness of the adhesive layer when heated to the foaming peak temperature of the heat-expandable microspheres / the thickness of the adhesive layer at 20°C) is 1.1 to 2. In one embodiment, the adhesive layer contains an active energy ray-curable adhesive.