摘要:
An aramid paper suitable for use in electronic applications which has a density of 0.20-0.65 g/cm3 and a grammage of 30-280 g/m2, which paper comprises 10-40 wt. % of aramid shortcut with a linear density of 2.6 dtex or lower and a length of 0.5-25 mm and 10-90 wt. % of aramid fibrid, wherein the aramid shortcut comprises at least 70 wt. % para-aramid shortcut and the aramid fibrid including at least 70 wt. % para-aramid fibrid. It has been found that the use of a paper with the above properties in electronic applications ensures a low CTE in combination with good homogeneity and a good dimensional stability resulting from good resin adhesion and penetration. Use of the aramid paper in a composite sheet including at least one layer of aramid paper and a resin, or in a substrate board for electronic applications.
摘要:
Provided is a method of producing a structure for producing a casting, including: a process (I) of obtaining a slurry composition containing an organic fiber, an inorganic fiber, a thermosetting resin, and water; a process (II) of obtaining a fiber laminate by subjecting the slurry composition to papermaking; and a process (III) of dehydrating the fiber laminate and thereafter drying the resultant, in which the process (I) includes a process (I-1) of beating a mixture containing the organic fiber and water, a process (I-2) of mixing the mixture obtained in the process (I-1) and water, and a process (I-3) of mixing the mixture obtained in the process (I-2) and the inorganic fiber, the thermosetting resin is mixed in at least any of the process (I-1), the process (I-2), and the process (I-3), and an average fiber length of the inorganic fiber in the structure for producing a casting is 1 mm or longer and 5 mm or shorter.
摘要:
Provided are a pitch-formation suppressor and the like which can be widely applied independently of the substance that causes a pitch and of the situation to generate a pitch in a paper manufacturing process, and which can effectively suppress and prevent the troubles due to the pitch, such as foreign spots and defects in a paper, breakage of a paper, and lowering of workability. This pitch-formation suppressor comprises an alkaline solution in which a phenol resin and/or a modified phenol resin is dissolved, or an acid solution in which a phenol resin and/or a modified phenol resin is dissolved.
摘要:
A wet paper friction material, mainly used for a slip lock-up of an automatic transmission, obtained by impregnating a paper material with a thermosetting resin, thermosetting, and molding under pressure, to attain compatibility between a good frictional characteristic and good fatigue strength under compression, wherein the paper material, in addition to a cellulose pulp and a filler, contains 30 to 80 wt % of aramid pulp with its drainability being adjusted to 250 to 440 ml in a total amount of pulp, and further contains, as a friction modifier, diatomaceous earth cylindrically formed so as to be net-like in the cylinder part and having its mean length 4 to 6 .mu.m.
摘要:
There is disclosed a resin-coated overlay for bonding to solid substrates, and which imparts improved waterproofing and chemical resistance to the resulting resin-coated overlaid solid substrate. Depending upon the desired end use of resin-coated overlaid solid substrate, the resin-coating may be modified to impart desirable surface features and/or characteristics. For example, additives such as waxes, oils, silicones, fluorocarbons and fatty acid compounds may be used to promote the release of concrete from forms made of solid substrates overlaid with the resin-coated overlays of the present invention. Moreover, resin-coated overlaid solid substrates may be produced having a surface which is suitable for painting and which accepts application of various tape products. Other modifications are disclosed which can be used to gain desirable cure speed, cost, and chemical/mechanical properties in the resin-coating. In addition to variations on the resin-coated overlay, related methods are also disclosed for the production of resin-coated overlays and resin-coated overlaid solid substrates.
摘要:
Disclosed is a method for the production of paper and an adjuvant composition comprising the following ingredients: 30 to 80% by weight of phenolic resin or modified phenolic resin; 10 to 50% by weight of melamine resin; and 5 to 35% by weight of at least one naphthalene sulphonate salt. The ingredients are under granulated form or dissolved in an aqueous solution. The method comprises the step of admixing the adjuvant composition with a solution of one or several polyethylene oxide having a molecular weight varying from 1.times.10.sup.6 to 13.times.10.sup.6 and with an aqueous mixture comprising lignocellulosic particles and an aqueous medium to significantly improve the retention of particles such as fines and fibers, on a wire screen and the drainage of the aqueous medium.
摘要:
According to the invention, a process of making paper comprises forming a cellulosic suspension, adding retention aid to the suspension, draining the suspension through a screen to form a sheet, and drying the sheet and in this process we add to the suspension a retention system comprising polyethylene oxide and a greater amount (dry weight) of a phenolsulphone-formaldehyde resin (PSR resin) consisting essentially of recurring units of the formula--CH.sub.2 --X--wherein (a) 10 to 100% of the groups X are di(hydroxyphenyl) sulphone groups, (b) 0 to 90% of the groups X are selected from hydroxy phenyl sulphonic acid groups (i.e., groups which contain at least one hydroxy-substituted phenyl ring and at least one sulphonic group) and naphthalene sulphonic acid groups and (c) 0 to 10% of the groups X are other aromatic groups.
摘要:
Wood and other cellulose-based products are preserved with a water-based treating solution containing a phenolic resin prepolymer such as phenol formaldehyde resin prepolymer, a resorcinol formaldehyde resin prepolymer and water. The treatment is carried out by exposing the wood or other cellulose-based product, while submerged in the treating solution, to one or more cycles of reduced pressure (i.e. vacuum) and elevated pressure.
摘要:
A process for producing an inorganic fiber-based prepreg sheet, which comprises preparing a slurry containing 35-80% by weight of a phenolic resin powder of 0.01-100 .mu.m in average particle diameter, 65-20% by weight of an inorganic fiber (the amounts are based on the total amount of the two) and a nonionic high-molecular fixing agent, making the slurry into a sheet in the same manner as in the paper making, and allowing the sheet to contain a silane coupling agent; and a process for producing an insulating laminate, which comprises laminating a prepreg sheet produced by the above process. According to the present invention, there can be produced an inorganic fiber-based prepreg sheet which has high insulating, which is superior in heat resistance, moisture resistance, dimensional stability in thickness direction and through hole ability and which gives rise to no whiting even when made into a laminate; and there can also be produced, from a laminate obtained by laminating the above inorganic fiber-based prepreg sheet, a laminate sheet for printed substrates of high-density wiring and mounting.