A method of producing a carbon fiber bundle is provided, involving performing a flame-proof treatment to a carbon-fiber-precursor acryl fiber bundle having a single-fiber fineness of 1.5 dtex or more and 5.0 dtex or less, and having a roundness of 0.7 or more and 0.9 or less in a cross-section shape perpendicular to a fiber axis of the single fiber to obtain a flame-proofed fiber bundle; and performing a carbonization treatment to the flame-proofed fiber bundle.

A prepreg includes; sizing agent-coated carbon fibers coated with a sizing agent; and a thermosetting resin composition impregnated into the sizing agent-coated carbon fibers. The sizing agent includes an aliphatic epoxy compound (A) and an aromatic compound (B) at least containing an aromatic epoxy compound (B1). The thermosetting resin composition includes a thermosetting resin (D) and a latent hardener (E), and optionally includes an additive (F) other than the thermosetting resin (D) and the latent hardener (E). The (a)/(b) ratio is within a predetermined range where (a) is the height of a component at a binding energy assigned to CHx, C—C, and C═C and (b) is the height of a component at a binding energy assigned to C—O in a C.sub.1s core spectrum of the surfaces of the sizing agent-coated carbon fibers analyzed by X-ray photoelectron spectroscopy.

A substantially flat-plate-shaped laminated base material has at least a layer-shaped body α and a layer-shaped body β are layered or disposed side by side, the layer-shaped body α having one or more cut prepregs A in which reinforcing fibers oriented in one direction are impregnated with a resin composition, the volume fraction of fiber is 45-65%, and at least a portion of the reinforcing fibers are segmented into a fiber length of 10-300 mm by a plurality of cuts, and the layer-shaped body β having one or more base materials B in which reinforcing fibers having a fiber length in the range of 10-300 mm are impregnated with a resin composition.

Provided are a surface-treated glass cloth capable of enhancing insulation reliability when used to prepare a prepreg, a prepreg and a printed wiring board using the surface-treated glass cloth. The surface-treated glass cloth includes a surface treatment layer on a surface, a glass constituting the glass cloth has a composition containing 52.0 to 60.0 mass % of SiO.sub.2, 15.0 to 26.0 mass % of B.sub.2O.sub.3, 9.0 to 18.0 mass % of Al.sub.2O.sub.3, 1.0 to 8.0 mass % of MgO, 1.0 to 10.0 mass % of CaO, 0 to 6.0 mass % of SrO, 0 to 6.0 mass % of TiO.sub.2, and 0.1 to 3.0 mass % in total of F.sub.2 and Cl.sub.2, based on the total amount of the glass, the glass cloth has a surface coverage of 75.0 to 100.0% and a thickness of 8 to 95 μm, and the surface treatment layer contains a silane coupling agent having a methacrylic group and contains no surfactant.

A glass cloth including warp yarns and weft yarns that are glass yarns each formed by bundling 30 to 44 glass filaments each having a circle-equivalent diameter of 3.0 to 4.4 μm, wherein the weaving density of the warp yarns and the weft yarns is 85 to 125 yarns/25 mm, at least either of the warp yarn and the weft yarn is a flat glass yarn formed of flat glass filaments, the weaving density thereof is less than 100 yarns/25 mm, the major axis DL of the flat glass filament is 3.3 to 6.0 μm, the minor axis DS is 2.0 to 3.9 μm, the number of twists T of each of the flat glass yarns is 0.70 twists/25 mm or less, and the number of the flat glass filaments F constituting each of the flat glass yarns, T, DL, and DS satisfy the following expression:

[00001]$89.0\le F\times \left(\mathrm{DL}\times \left(1-T^{1/2}\right)+\mathrm{DS}\times T^{1/2}\right)/\left(\mathrm{DL}/\mathrm{DS}\right)\le 129.0.$

Some embodiments of the present disclosure relate to an article comprising a reinforced glass mat. In some embodiments, the reinforced glass mat includes a glass mat and a reinforcement material. In some embodiments, the glass mat includes a web of glass fibers. In some embodiments, the reinforcement material is embedded into the web of glass fibers of the glass mat. In some embodiments, the reinforced glass mat includes a sufficient amount of the reinforcement material, so as to result in a nail shank shear resistance of 13 lbs to 17 lbs, when the article is tested according to ASTM 1761 at 140° F. Methods of making the article, specific embodiments of the reinforcement material in the form of a polymeric binder, and methods of forming a roofing shingle from the article are also disclosed.

Some embodiments of the present disclosure relate to an article comprising a reinforced glass mat. In some embodiments, the reinforced glass mat includes a glass mat and a reinforcement material. In some embodiments, the glass mat includes a web of glass fibers. In some embodiments, the reinforcement material is embedded into the web of glass fibers of the glass mat. In some embodiments, the reinforced glass mat includes a sufficient amount of the reinforcement material, so as to result in a nail shank shear resistance of 13 lbs to 17 lbs, when the article is tested according to ASTM 1761 at 140° F. Methods of making the article, specific embodiments of the reinforcement material in the form of a polymeric binder, and methods of forming a roofing shingle from the article are also disclosed.

Use of a sizing agent having a heat weight loss B-1 of 65% or more as determined by a specific measurement method, or a sizing agent containing a surfactant and a compound represented by formula (1):

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The disclosure relates to methods for producing poly(cyclohexadiene) homopolymers (PCHD). The PCHD is formed by polymerizing a 1,3-cyclohexadiene monomer in the presence of a catalyst, in a hydrocarbon solvent, and at a temperature of −100° C. to 120° C. The catalyst is selected from the group consisting of a Bronsted acid, a Lewis acid, and combinations thereof. PCHD produced under these conditions has good solubility in non-polar solvents, and a number average molecular weight of 300 to 5,000 Dalton; a weight average molecular weight of 5,000 to 15,000 Delton; and a polydispersity index of 3.0 to 8.0. The PCHD is useful for producing crosslinked materials having good physical properties. The crosslinked materials can be combined with a rubbery polymer to produce compositions valuable for further downstream uses.

Disclosed herein are copolymers formed by cationic polymerfization of one or more cyclic dienes and a comonomer selected from the group consisting of a monoterpene, a branched styrene, and combinations thereof, in the presence of a catalyst. Random copolymers having repeat units derived from a cyclic conjugated diene, such as 1,3-cyclohexadiene, and a comonomer such as a monoterpene, can be prepared as soluble products in hydrocarbon solvents. The copolymers can be crosslinked with various crosslinking agents to form materials having good oxidative stability and fire retardancy. The uncrosslinked and crosslinked copolymers have useful properties such as a low dissipation factor, low dielectric constants, and a good balance of thermomechanical and electrical properties that make them valuable in electronic applications.