Provided are a pentasil-type zeolite that is less likely to adsorb water compared to conventional zeolites and has excellent strength when used as a molded body, and a method for producing the pentasil-type zeolite.

A pentasil-type zeolite having a water adsorption amount of 4.0 g/100 g-zeolite or less under the conditions of 25° C. and a relative humidity of 90% and having a major axis diameter of primary particles of from 0.2 μm to 4.0 μm, and a method for producing the pentasil-type zeolite.

Provided are a pentasil-type zeolite that is less likely to adsorb water compared to conventional zeolites and has excellent strength when used as a molded body, and a method for producing the pentasil-type zeolite.

A pentasil-type zeolite having a water adsorption amount of 4.0 g/100 g-zeolite or less under the conditions of 25° C. and a relative humidity of 90% and having a major axis diameter of primary particles of from 0.2 μm to 4.0 μm, and a method for producing the pentasil-type zeolite.

The present invention relates to a process for the production of 2,2,4,6,6-pentamethyl-1,2,5,6-tetrahydro-pyrimidine comprising (i) providing a reactor containing a catalyst comprising a zeolitic material, wherein the zeolitic material comprises YO.sub.2 and optionally comprises X.sub.2O.sub.3 in its framework structure, wherein Y is a tetravalent element and X is a trivalent element; (ii) preparing a reaction mixture comprising acetone and ammonia; (iii) contacting the catalyst in the reactor with the reaction mixture prepared in (ii) for obtaining a reaction product comprising 2,2,4,6,6-pentamethyl-1,2,5,6-tetrahydro-pyrimidine; wherein the temperature programmed desorption of ammonia (NH.sub.3-TPD) profile of the zeolitic material comprised in the catalyst provided in (i) optionally displays one or more bands associated with medium acid sites, said one or more bands having maxima in the temperature range of from 250 to 500° C., wherein the integration of said one or more bands affords a total value of 0.5 mmol/g or less, and wherein the mixture prepared in (ii) and contacted with the catalyst in (iii) contains less than 10 wt.-% of water based on 100 wt.-% of the reaction mixture.

Provided are a pentasil-type zeolite that is less likely to adsorb water compared to conventional zeolites and has excellent strength when used as a molded body, and a method for producing the pentasil-type zeolite. A pentasil-type zeolite having a water adsorption amount of 4.0 g/100 g-zeolite or less under the conditions of 25° C. and a relative humidity of 90% and having a major axis diameter of primary particles of from 0.2 μm to 4.0 μm, and a method for producing the pentasil-type zeolite.

Provided are a pentasil-type zeolite that is less likely to adsorb water compared to conventional zeolites and has excellent strength when used as a molded body, and a method for producing the pentasil-type zeolite. A pentasil-type zeolite having a water adsorption amount of 4.0 g/100 g-zeolite or less under the conditions of 25° C. and a relative humidity of 90% and having a major axis diameter of primary particles of from 0.2 μm to 4.0 μm, and a method for producing the pentasil-type zeolite.

A family of crystalline aluminosilicate zeolites has been synthesized that is a layered pentasil zeolite. These zeolites are represented by the empirical formula:

M.sub.m.sup.n+R.sub.r.sup.p+Al.sub.1-xE.sub.xSi.sub.yO.sub.z

where M is an alkali, alkaline earth, or rare earth metal such as sodium or strontium, R can be a mixture of organoammonium cations and E is a framework element such as gallium, iron, boron, or indium. These zeolites are characterized by unique x-ray diffraction patterns and compositions and have catalytic properties for carrying out various hydrocarbon conversion processes.

The present invention relates to a process for preparing zeolite crystals having a multimodal particle size distribution, and the sizes of which are between 0.02 μm and 20 μm, said process comprising a first introduction of one or more seeding agents into the tubular reactor or upstream of the tubular reactor, and at least one second introduction of one or more, identical or different, seeding agents into the tubular reactor.

The present disclosure provides a sound absorbing material. The sound absorbing material comprises MFI-structural-type zeolite. The MFI-structural-type zeolite comprises a framework, and the framework comprises SiO.sub.2 and AlO.sub.3, and the mass ratio of Si to Al in the framework is less than 200 and not less than 50. The present disclosure also provides a speaker box applying the sound absorbing material. The sound absorbing material provided by the present disclosure and the speaker box using the sound absorbing material can further improve the performance of the speaker box, reduce the failure of zeolite and improve the performance stability of the speaker box.

A filler for resinous composition is contained and used in resinous composition constituting electronic packaging material for electronic device, and includes: a filler ingredient including a crystalline siliceous material with a crystal structure made of at least one member selected from the group consisting of type FAU, type FER, type LTA, type MFI and type CHA, and/or type MWW, wherein: the filler ingredient is free of any activity when evaluated by an “NH3-TPD” method; and includes the crystalline siliceous material in an amount falling in a range allowing the filler ingredient to exhibit a negative thermal expansion coefficient. The filler ingredient may further be free of a surface in which silver, copper, zinc, mercury, tin, lead, bismuth, cadmium, chromium, cobalt and nickel are exposed.

A filler for resinous composition is contained and used in resinous composition constituting electronic packaging material for electronic device, and includes: a filler ingredient including a crystalline siliceous material with a crystal structure made of at least one member selected from the group consisting of type FAU, type FER, type LTA, type MFI and type CHA, and/or type MWW, wherein: the filler ingredient is free of any activity when evaluated by an “NH3-TPD” method; and includes the crystalline siliceous material in an amount falling in a range allowing the filler ingredient to exhibit a negative thermal expansion coefficient. The filler ingredient may further be free of a surface in which silver, copper, zinc, mercury, tin, lead, bismuth, cadmium, chromium, cobalt and nickel are exposed.