Search

EP-3412703-B1 - AROMATIC POLYSULFONE, PREPREG, AND METHOD FOR PRODUCING PREPREG

EP3412703B1EP 3412703 B1EP3412703 B1EP 3412703B1EP-3412703-B1

Inventors

  • OHTOMO, SHINJI
  • MATSUBARA, MASANOBU

Dates

Publication Date
20260506
Application Date
20170202

Claims (7)

  1. An aromatic polysulfone which is a thermoplastic aromatic polysulfone obtainable by polymerizing a dihalogeno compound (A) represented by a formula (A) and a dihydric phenol (B) represented by a formula (B), wherein a value of a ratio (Mw/Mn) between a number average molecular weight (Mn) and a weight average molecular weight (Mw) is at least 1.80 and less than 1.90, and the number average molecular weight (Mn) is at least 6,000 and less than 14,000, [wherein in the formulas (A) and (B), each of X and X' independently represents a halogen atom; each of R 1 , R 2 , R 3 and R 4 independently represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms; each of n 1 , n 2 , n 3 and n 4 independently represents an integer of 0 to 4; and when n 1 , n 2 , n 3 or n 4 is an integer of 2 to 4, a plurality of R 1 , R 2 , R 3 or R 4 groups may be the same or different from each other], wherein the dihalogeno compound (A) and the dihydric phenol (B) are dissolved in an organic polar solvent as a first stage; the dihalogeno compound (A) and the dihydric phenol (B) are polycondensed, as a second stage, by adding an alkali metal salt of carbonic acid to the solution obtained in the first stage; and as a third stage, from the reaction mixture obtained in the second stage, the unreacted alkali metal salt of carbonic acid, an alkali halide produced as a by-product and the organic polar solvent are removed to obtain an aromatic polysulfone; the amount used of the dihalogeno compound (A) in the polymerization is from 93 to 100 mol% with respect to the amount (number of moles) used of the dihydric phenol (B); the amount used of the alkali metal salt of carbonic acid is, as the alkali metal, from 95 to 105 mol%, with respect to the number of moles of the hydroxy group of the dihydric phenol (B); the polycondensation temperature in the second stage is from 300 to 400°C; and the polycondensation time in the second stage is 2 to 30 hours, wherein Mn and Mw/Mn are determined as set out in the specification.
  2. The aromatic polysulfone according to Claim 1, wherein in the formula (A), X and X' are chlorine atoms.
  3. The aromatic polysulfone according to Claim 1 or 2, wherein in said formula (A) or said formula (B), n 1 , n 2 , n 3 and n 4 are 0.
  4. The aromatic polysulfone according to any one of Claims 1 to 3, wherein a reduced viscosity of the aromatic polysulfone is from 0.22 to 0.28 dL/g, wherein the reduced viscosity is determined as set out in the specification.
  5. The aromatic polysulfone according to any one of Claims 1 to 4, wherein a glass transition temperature of the aromatic polysulfone is 215°C or higher and 235°C or lower, wherein the glass transition temperature is determined as set out in the specification.
  6. A prepreg formed from the aromatic polysulfone according to any one of Claims 1 to 5, a liquid epoxy resin, a curing agent and a reinforcing fiber.
  7. A method for producing a prepreg, comprising a step of impregnating a reinforcing fiber with a mixture obtained by mixing the aromatic polysulfone according to any one of Claims 1 to 5, a liquid epoxy resin and a curing agent.

Description

[Technical Field] The present invention relates to an aromatic polysulfone, a prepreg and a method for producing a prepreg. Priority is claimed on Japanese Patent Application No. 2016-021123, filed February 5, 2016, and Japanese Patent Application No. 2016-180849, filed September 15, 2016. [Background Art] Aromatic polysulfones have been used as various coating materials since they are not only excellent in heat resistance, chemical resistance, creep resistance and the like, but also exhibit favorable adhesion to materials such as metals, glass and ceramics. As an example of such a utilization method, a method of forming a coating film of a fluororesin on the surface of a substrate by applying an aromatic polysulfone solution containing a fluororesin to a metal substrate, followed by a heat treatment has been known. In order for the aromatic polysulfones to exhibit heat resistance suitable for such use, it is important that the molecular weight and the molecular weight distribution thereof are within appropriate ranges, and for example, an aromatic polysulfone having a number average molecular weight (Mn) of 11,000 to 25,000 and a polydispersity (Mw/Mn) of 3.0 or less has been known (see Patent Document 1). Patent Documents 2 to 5 relate to polyethersulfone (PES) having hydroxyphenyl end groups and disclose PES obtained from 4,4'-dihydroxydiphenyl sulfone and 4,4'-dichlorodiphenyl sulfone in the examples. [Citation List] [Patent Document] [Patent Document 1] Japanese Unexamined Patent Application, First Publication No. 2002-172675[Patent Document 2] EP 2 189 487 A1[Patent Document 3] JP 2010 077185 A[Patent Document 4] US 5 212 278 A[Patent Document 5] WO 2016/148133 A1 [Summary of Invention] [Technical Problem] Since the aromatic polysulfones have high glass transition temperatures (Tg), they are used as materials excellent in heat resistance in a number of fields including the field of electronic materials. However, it is desired to further improve the heat resistance of these aromatic polysulfones, and there is still room for improvement in order to exhibit high glass transition temperatures (Tg). When manufacturing an electronic device, components of the electronic device are sometimes exposed to high temperatures, as in the reflow process, for example. In order to suppress the deformation of components, the exhibition of high glass transition temperatures (Tg) is required. Further, in addition to the electronic devices, similar problems may arise for members exposed to high temperature conditions. The present invention has been made in view of such circumstances, with an object of providing a novel aromatic polysulfone capable of exhibiting a high glass transition temperature (Tg), a prepreg using the aromatic polysulfone, and a method for producing the prepreg. [Solution to Problem] In order to solve the above problems, a first aspect of the present invention provides an aromatic polysulfone which is a thermoplastic aromatic polysulfone obtained by polymerizing a dihalogeno compound (A) represented by a formula (A) and a dihydric phenol (B) represented by a formula (B), wherein a value of a ratio (Mw/Mn) between the number average molecular weight (Mn) and the weight average molecular weight (Mw) is at least 1.80 and less than 1.90, and the number average molecular weight (Mn) is at least 6,000 and less than 14,000. [In the formulas (A) and (B), each of X and X' independently represents a halogen atom;each of R1, R2, R3 and R4 independently represents an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms; each of n1, n2, n3 and n4 independently represents an integer of 0 to 4; and when n1, n2, n3 or n4 is an integer of 2 to 4, a plurality of R1, R2, R3 or R4 groups may be the same or different from each other.] A second aspect of the present invention is a prepreg using the aromatic polysulfone of the first aspect of the present invention, a liquid epoxy resin, a curing agent and a reinforcing fiber. A third aspect of the present invention is a method for producing a prepreg, including a step of impregnating a mixture obtained by mixing the aromatic polysulfone of the first aspect of the present invention, a liquid epoxy resin and a curing agent with a reinforcing fiber. That is, the present invention is as defined in the appended claims. [1] An aromatic polysulfone which is a thermoplastic aromatic polysulfone obtainable by polymerizing a dihalogeno compound (A) represented by a formula (A) and a dihydric phenol (B) represented by a formula (B), wherein a value of a ratio (Mw/Mn) between a number average molecular weight (Mn) and a weight average molecular weight (Mw) is at least 1.80 and less than 1.90, and the number average molecular weight (Mn) is at least 6,000 and less than 14,000, [wherein in the formulas (A) and (B), each of X and X' independently represents a halogen atom;each of R1, R2, R3 and R4 independently represents an alkyl group having 1 to 4 carbo