Abstract: Provided is to achieve high call quality and improve wearability. A wireless earphone 1 includes a driver unit (50), a first microphone (80), a second microphone (90), and a housing (10) that accommodates the driver unit (50), the first microphone (80), and the second microphone (90). The housing (10) includes a first accommodating portion (13) that accommodates the first microphone (80), a second accommodating portion (14) that accommodates the second microphone (90), and a main body (11) that is connected to each of the first accommodating portion (13) and the second accommodating portion (14). The first accommodating portion (13) is projectingly provided from the main body (11). The second accommodating portion (14) is projectingly provided from the main body (11) in a direction different from a projecting direction of the first accommodating portion (13).

Abstract: The silyl phosphine compound of the present invention is represented by the formula (1) and has an arsenic content of not more than 1 ppm. The process for producing a silyl phosphine compound of the present invention is a process comprising mixing a basic compound, a silylating agent and phosphine to obtain a solution containing a silyl phosphine compound, removing a solvent from the solution to obtain a concentrated solution of a silyl phosphine compound, and distilling the concentrated solution, wherein an arsenic content in the phosphine is adjusted to not more than 1 ppm by volume in terms of arsine. The process for producing InP quantum dots of the present invention uses, as a phosphorus source, a silyl phosphine compound represented by the formula (1) and having an arsenic content of not more than 1 ppm by mass. (For definition of R, see the specification.

Abstract: The silyl phosphine compound of the present invention is represented by the formula (1) and has an arsenic content of not more than 1 ppm. The process for producing a silyl phosphine compound of the present invention is a process comprising mixing a basic compound, a silylating agent and phosphine to obtain a solution containing a silyl phosphine compound, removing a solvent from the solution to obtain a concentrated solution of a silyl phosphine compound, and distilling the concentrated solution, wherein an arsenic content in the phosphine is adjusted to not more than 1 ppm by volume in terms of arsine. The process for producing InP quantum dots of the present invention uses, as a phosphorus source, a silyl phosphine compound represented by the formula (1) and having an arsenic content of not more than 1 ppm by mass. (For definition of R, see the specification.

Abstract: The silyl phosphine compound is represented by the following general formula (1). A content of a compound represented by the following general formula (2) is not more than 0.3 mol %. In the general formula (1), each R is independently an alkyl group having not less than 1 and not more than 5 carbon atoms or an aryl group having not less than 6 and not more than 10 carbon atoms. In the general formula (2), R is the same as in the general formula (1).

Abstract: An earpiece whose inner cylinder is not crushed when the earpiece is inserted into an ear canal of a user is provided. An earpiece according to the present invention includes an inner cylinder 1 that includes one open end and the other open end and is attached to a sound conduit C of an earphone E, and an outer cylinder 2 connected to the one end of the inner cylinder and extending in an umbrella shape toward the other end of the inner cylinder so as to cover an outer surface 1b of the inner cylinder. The inner cylinder includes a fitting part 11 into which a tip of the sound conduit is fitted, and a sound guide part 12 configured to guide sound wave from the sound conduit to an ear canal.

Abstract: The silyl phosphine compound is represented by the following general formula (1). A content of a compound represented by the following general formula (2) is not more than 0.3 mol %. In the general formula (1), each R is independently an alkyl group having not less than 1 and not more than 5 carbon atoms or an aryl group having not less than 6 and not more than 10 carbon atoms. In the general formula (2), R is the same as in the general formula (1).

Abstract: The process for producing a silyl phosphine compound of the present invention comprises a first step of mixing a solvent having a relative dielectric constant of not more than 4, a basic compound, a silylating agent and phosphine to obtain a solution containing a silyl phosphine compound, a second step of removing the solvent from the solution containing a silyl phosphine compound to obtain a concentrated solution of a silyl phosphine compound, and a third step of distilling the concentrated solution of a silyl phosphine compound to obtain the silyl phosphine compound. The silyl phosphine compound of the present invention is a silyl phosphine compound represented by the following general formula (1), wherein a content of a compound represented by the following general formula (2) is not more than 0.5 mol %. (For explanatory notes of the formulas, see the specification.

Abstract: The silyl phosphine compound of the present invention is represented by the formula (1) and has an arsenic content of not more than 1 ppm. The process for producing a silyl phosphine compound of the present invention is a process comprising mixing a basic compound, a silylating agent and phosphine to obtain a solution containing a silyl phosphine compound, removing a solvent from the solution to obtain a concentrated solution of a silyl phosphine compound, and distilling the concentrated solution, wherein an arsenic content in the phosphine is adjusted to not more than 1 ppm by volume in terms of arsine. The process for producing InP quantum dots of the present invention uses, as a phosphorus source, a silyl phosphine compound represented by the formula (1) and having an arsenic content of not more than 1 ppm by mass. (For definition of R, see the specification.

Abstract: The process for producing a silyl phosphine compound of the present invention comprises a first step of mixing a solvent having a relative dielectric constant of not more than 4, a basic compound, a silylating agent and phosphine to obtain a solution containing a silyl phosphine compound, a second step of removing the solvent from the solution containing a silyl phosphine compound to obtain a concentrated solution of a silyl phosphine compound, and a third step of distilling the concentrated solution of a silyl phosphine compound to obtain the silyl phosphine compound. The silyl phosphine compound of the present invention is a silyl phosphine compound represented by the following general formula (1), wherein a content of a compound represented by the following general formula (2) is not more than 0.5 mol %. (For explanatory notes of the formulas, see the specification.