摘要:
A tubular switch which is normally off, instantaneously turned on by external pressure, and has long detection distance. The tubular switch comprises a tubular hose member having insulating property and elasticity, and a plurality of flexible conductive members which are spirally fixed to the internal surface of the hose member so that the surfaces of the conductive members should be partially exposed to the internal space of the hose member at any section of the hose member. The tubular switch has durability, can be installed any place, and can have a long detection range, and, in addition, any faults are easily found, repaired and adjusted, it has a simple structure and flexibility, and it can be manufactured at a low cost.
摘要:
A process for producing a lactic acid-based copolyester by the ring-opening copolymerization and transesterification of a lactide (A) with an aromatic polyester (B) and/or an aliphatic polyester (C) in the presence of a ring-opening polymerization catalyst (D), and a packaging material comprising the lactic acid-based copolyester obtained by the process are disclosed. According to the present invention, a lactic acid-based degradable copolyester which has a sufficiently high molecular weight and satisfactory toughness and also has suitable rigidity, pliability, and transparency according to applications can be produced. Further, a general-purpose packaging material, e.g., a sheet or film, which comprises the lactic acid-based copolyester produced by the process and is excellent in formability, degradability, and transparency can also be produced.
摘要:
Disclosed is a process for producing a material having hydrophilic surface which comprises forming a hydrophobic photopolymerizable composition comprising a hydrophobic compound (a) having two or more polymerizable unsaturated double bonds per molecule and a photopolymerization initiator into a desired form and irradiating the resultant shape (b) with actinic rays while keeping the surface of the shape (b) in contact with a hydrophilic liquid (d) containing a hydrophilic compound (c) having one or more polymerizable unsaturated double bonds under such conditions that a photopolymerization reaction is prevented from occurring in the hydrophilic liquid (d) except at the interface between the liquid (d) and the shape (b), whereby the shape (b) is cured and, at the same time, the hydrophobic compound (a) is copolymerized with the hydrophilic compound (c) at the interface between the shape (b) and the hydrophilic liquid (d) to chemically bond molecules of the hydrophilic compound (c) to the surface of the hydrophobic shape (b). The process is advantageous in that the kind and density of hydrophilic groups can be easily controlled and the structure and properties inherent in the material formed from the photopolymerizable composition are not impaired.
摘要:
A lift for loading and unloading a truck. The truck has a loading chamber, a rear body portion and a chassis frame, and the lift has support posts mounted at an end and at each side of the truck at the rear body portion. A connecting member connecting the lower ends of each support post is provided. A drive moves the support posts in an upward and downward direction. A lift table has an opening formed in a portion corresponding to the chassis frame. The lift table is supported by the connecting member and is slidable on the connecting member in a longitudinal direction to the loading chamber thereby traversing the connecting member.
摘要:
A novel process for the preparation of a high molecular lactic copolymer polyester is provided, which includes allowing a lactide (A), a polyester terminated by hydroxyl group at both ends (B1), a polyvalent carboxylic acid having 3 or more functionalities and/or acid anhydride thereof (C) to undergo ring opening copolymerization in the presence of a ring opening polymerization catalyst (D). A novel process is also provided which includes allowing the lactide (A) and the polyester (B1) to undergo ring opening copolymerization in the presence of the catalyst (D) to prepare a polyester, and then reacting the polyester with the component (C). A novel process is further provided which includes reacting the polyester (B1) with the polyvalent carboxylic acid component (C) to obtain a polyester terminated by hydroxyl group at both ends having a weight-average molecular weight of from 10,000 to 300,000 (B2), and then allowing the polyester (B2) and the lactide (A) to undergo ring opening copolymerization in the presence of the catalyst (D). Another novel process is provided which includes allowing a dicarboxylic acid, a diol and the polyvalent carboxylic acid component (C) to undergo dehydration reaction and/or deglycolation reaction to obtain a polyester having a weight-average molecular weight of from 10,000 to 300,000 (B3), and then allowing the polyester (B3) and the lactide (A) to undergo ring opening copolymerization in the presence of the catalyst (D).
摘要:
The present invention provides a process for the preparation of a decomposable lactic copolymer polyester which exhibits a sufficiently high molecular weight, heat resistance and thermal stability and further exhibits a rigidity, flexibility and transparency depending on the purpose. The process for the preparation of a high molecular lactic copolymer polyester includes reacting a polyester terminated by hydroxyl group at both ends (B1) with a polyvalent isocyanate (E) having 2 or more functionalities to obtain a polyester (B4) having a weight-average molecular weight of from 10,000 to 300,000, and then allowing said polyester (B4) and lactide (A) to undergo ring opening copolymerization in the presence of a ring opening polymerization catalyst (D). A process is also provided which includes allowing a lactide (A) and a polyester terminated by hydroxyl group at both ends (B1) to undergo ring opening copolymerization in the presence of a ring opening polymerization catalyst (D) to prepare a polyester having a weight-average molecular weight of from 10,000 to 300,000, and then reacting said polyester with a polyvalent isocyanate having 3 or more functionalities.
摘要:
A process for continuously producing a linear lactide copolymer having a weight-average molecular weight of from 20,000 to 400,000 using a continuous reaction apparatus composed of three or more stirred flow reactors connected in series, which process comprises the steps of continuously feeding from 50 to 98 parts by weight of a lactide and from 2 to 50 parts by weight of a polymer having a hydroxyl group in a molten state or as dissolved in a solvent to the first reactor of said continuous reaction apparatus, and transferring the reaction mixture from said first reactor to the following reactors successively while maintaining the reaction pressure and the reaction temperature in every reactor in the range of from 1 to 5 atm. and of from 140.degree. to 210.degree. C., respectively, to conduct ring opening copolymerization. According to the process of the present invention, the production problems associated with conventional continuous production methods for lactide copolymers, i.e., high viscosity of the reaction system, thermal decomposition of the polymer produced, and coloration of the polymer produced can be eliminated, and a degradable lactide copolymer endowed with broader range properties than conventional lactide copolymers and therefore useful in wider fields can be obtained continuously and efficiently.