Abstract: The inner circumferential surface of through holes in a metal plate is chamfered or put to anchor fabrication and a thermoplastic resin is injection molding to the inner circumferential surface of the through hole thereby forming a resin portion over the entire surface of the through hole and the resin portion is removed by grinding while leaving the peripheral portion of the resin portion thereby forming a polished work holding hole. Thus, when a resin portion is formed to the inner circumference of the holding hole in a polished work holder comprising a metal plate, the production is high and the cost is reduced, and the resin portion is not detached from the bonding portion with no use of the adhesive.

Abstract: The inner circumferential surface of through holes in a metal plate is chamfered or put to anchor fabrication and a thermoplastic resin is injection molding to the inner circumferential surface of the through hole thereby forming a resin portion over the entire surface of the through hole and the resin portion is removed by grinding while leaving the peripheral portion of the resin portion thereby forming a polished work holding hole. Thus, when a resin portion is formed to the inner circumference of the holding hole in a polished work holder comprising a metal plate, the production is high and the cost is reduced, and the resin portion is not detached from the bonding portion with no use of the adhesive.

Abstract: A high-ortho phenolic novolac resin having excellent curability, heat stability and flowability can be produced safely at low cost by a process which comprises reacting a phenol and an aldehyde at a temperature of more than 100.degree. C. with (A) a catalyst effective for the addition reaction selected from the salts of divalent metals in combination with (B) a catalyst effective for the condensation reaction, or comprises reacting a phenol and an aldehyde under reflux in the presence of the catalyst (A), adding an acid to adjust the pH to 1-5, removing water under reduced pressure and then subjecting the product to reaction at a temperature of more than 100.degree. C. This process enables the addition reaction and the condensation reaction to proceed with a good balance, can solve problems arising in the prior process such as gelation, low yield and the like, and can produce a high-ortho type phenolic novolac resin safely at low cost. Accordingly, this process is quite advantageous in industry.

Abstract: Disclosed herein is a novel high-ortho phenolic novolac resin having excellent quick-curing property and thermal stability for use as phenolic resin molding material and perfectly free of divalent metal salt which is detrimental to the electrical properties of the molding material. This resin can be obtained by condensing a phenol and an aldehyde in an aldehyde/phenol molar ratio ranging from 0.6 to 1.0 and at a reaction temperature of more than 100.degree. C. at which the selectivity for condensation at the para-position is lowered (that is, the probability of the condensation at the ortho-position increases), with a weakly acidic catalyst having a specified dissociation constant (pKa value). The high-ortho phenolic novolac resin (having the specific molecular weight and ortho/para linkage ratio) obtained from said reaction is very useful for industrial applications as a phenolic injection molding material or epoxy/phenolic low-pressure encapsulation molding material with excellent electrical properties.