The powdered polymer composition for the manufacture of abrasive tools


B24D3/30 - for close-grained structure

 

(57) Abstract:

The inventive powdered polymer composition for manufacturing an abrasive tool comprises, by weight.h.: phenol-formaldehyde Novolac oligomer 100, hexamethylenetetramine 6 - 12, epoxydodecane resin is the condensation product of epichlorohydrin and on-crazyforbargains resin 10 - 100. Based binder made grinding wheels, has a discontinuous speed 123,0 - 132 m/C, grinding coefficient of 2.0 - 2.4 cm2/cm2. 3 table.

The invention relates to composite materials based on phenol-formaldehyde polymers, in which the curing agent is used hexamethylenetetramine (GMHA), and in particular can be used for abrasive tools made both the cold and hot pressing.

A known mass of abrasive tools hot pressing, containing abrasive (54-62.), powdered organic binder (19-30 about. ), mineral filler (6-17 about.) and humidifier (about 2-10.), consisting of a solution of epoxy resin in the furfural concentration 25-75% [1]

A disadvantage of the known solutions is that it is used only for hot squeezes on manufacturability abrasive mass because there is an additional operation preparation of a solution of epoxy resin in the furfural. In addition, the liquid epoxy resin is very time consuming due to their high adhesive ability when in contact with different objects (working capacity, hands working etc).

The closest in technical essence and the achieved effect is a binder for the manufacture of abrasive tools containing Novolac phenol-formaldehyde oligomer and curing agent is hexamethylenetetramine, on 100 wt.h. oligomer add 6-10 wt.h. hexamethylenetetramine. The powder components are mixed in the abrasive mixer and then used as a powdered binder for the manufacture of abrasive tools. Curing of the binder occurs during the subsequent thermal treatment of the products at a temperature of 160-200aboutWith, resulting in a three-dimensional structure of bakelite, which determines the mechanical strength and the heat resistance of the ligament [2]

A disadvantage of the known powder binder (TFP) for the manufacture of abrasive tools is its low strength and heat resistance, when heated tool (circle) in the work the here to get free (0-5% ERP) polymer composition with a high content of binder (up to 40 vol.) cold pressing. Used powdered binder for cold pressing in the heat treatment process provides about 3% of volatile gases, which together with other volatile (e.g. from wetting grinding grain) does not allow to make the instrument more compact structure (pores less than 20 vol.), with increased binder content (up to about 40. ) because it results in heat "sciam", delamination, which dramatically reduces the strength and performance properties of the instrument.

The task of the invention is directed regulatory structure, hardness, strength and performance properties of the instrument, in particular, increased strength and heat resistance, according to his purpose, and reduced emission of volatile gases.

The problem is solved by creating a powder composition comprising a Novolac phenol-formaldehyde oligomer (phenol-formaldehyde resin TFE), and it has been the product of the condensation of epichlorohydrin with articlesinformation Novolac resin type (epoxydodecane mixture EDF) in the following ratio, wt.h. TFP 100 IT HAS BEEN 6-12 ENNS 10-100

All components of the polymer compositions are in a powdered state, therefore, the introduction of the ENS in the abrasive mass does not increase Legalna resin (TFE), It has been and epoxydodecane resin (EDF) are in stoichiometric ratios, providing the most complete passage of the curing reaction (intermolecular crosslinking). The formation of stable chemical bonds in the polymer composition increases strength, heat resistance, etc. outside of these ratios remain unreacted source components, the degree of "matching" smaller, so the mechanical properties and heat resistance is also reduced.

It should be noted that the amount of volatile gases in the recipe is reduced by 2-3 times compared to known due to the fact that during a chemical reaction curing phenol-formaldehyde resin hexamethylenetetramine (it has been) allocated water, ammonia, phenol, formaldehyde.

When participating in the curing reaction epoxydodecane resin is not released ammonia, water and other volatile as between the nitrogen atoms included in the structure it has been, and carbon chemical bond occurs, thereby inhibiting ammonia and formaldehyde, which are products of decomposition of hexamethylenetetramine. Since the curing resin composition is not by the mechanism of polycondensation, the allocation of water as is and with a high content of ligaments as cold and hot pressing, and stitched Enns phenol-formaldehyde resin with it has been to offer high durability, good adhesion, high temperature resistance. Specific example:

Prepare samples of the binder with the maximum, minimum and optimum content of the components (table.3), from which are made the tablet and the molding material for circles HH.

Tablets are made with a diameter of 15 mm, height 7 mm and bakaliaros at 160aboutC. half of the tablets again heated to 300aboutWith a shutter speed of 30 min.

The original samples and samples after heating to 300about(Thermal loading) crush on a bench with a force of 1,000 kg in Parallel manufactured and tested samples for impregnation (example 7, table.1).

The results of the tests are presented in table.2.

Cutting circles HH made of a binder according to examples 1-7 of table.1 according to the following formulation, by weight.h.

Grinding material brand IN 100 Liquid bakelit brand BJ-3 8,2 Binder powder 14 Cryolite 6

Making circles (mixing the molding material, extrusion, heat treatment) produced by the conventional technology.

Made circles have the strength and ekspluatatsionnye of the binder, according to the invention have high strength properties, heat resistance and performance circles.

The POWDERED POLYMER COMPOSITION FOR MANUFACTURING an ABRASIVE TOOL comprising phenol-formaldehyde Novolac oligomer and hexamethylenetetramine, characterized in that it further comprises epoxydodecane resin is the condensation product of epichlorhydrin and on-crazyforbargains resin in the following ratio, wt.h.:

Phenol-formaldehyde Novolac oligomer - 100

Hexamine - 6 - 12

Specified epoxydodecane resin 10 - 100

 

Same patents:

FIELD: chemistry.

SUBSTANCE: invention concerns process of heatproof binder production for permeation of glass-cloth filler used in production of chimney vent shafts, offtake collector pipes for hot aggressive gas etc. The process involves stirring of basic resin - epoxy novolac heated to 80-100°C beforehand - in acetic-alcohol-toluene solvent for up to 12 hours. For at least 3 hours at 30-50°C phenol formaldehyde novolac with particle size of 2-3 cm is added to the obtained solution and stirred. Further promoting 2,4,6-tris/dimethylamino/methyl/phenol or diethylaminomethylethoxysilane is introduced and stirred continuously for at least 20 minutes. Obtained binder of given density is filtered.

EFFECT: obtaining a binder with excellent thermophysical properties and good technological cost-effective processing parametres.

3 cl, 2 tbl, ex, dwg

FIELD: electricity.

SUBSTANCE: invention is attributed to the field of electric engineering specifically to epoxide thin filling compounds used for electric insulating and reinforcing by means of embedding of high-voltage power supply units, transformers, electric circuitry, uncased and cased electric couplers, for sealing and protecting elements of radio-electronic devices against moisture and mechanical impacts. Composition for filling compound with moderate initial viscosity contains 30-36 wt-p. of epoxide diane resin, 12-20 wt-p. of threeglycid polyoxypropylene triol ether, 10-12 wt-p. of monoglycid n-butanol ether, 18-22 mass-p. of low-polymeric polyamid resin and 7-10 wt-p. of aliphatic amine.

EFFECT: creation of electric insulating filling compound composition keeping resiliency not less than for an hour, having high specific volume, high value of surface electric resistance and increased elasticity.

1 tbl

FIELD: production processes.

SUBSTANCE: blemished surface is covered with polyester resins Derakane 8084 as primer coat, after drying surface is covered with at least two layers of powder-bonded glass-fiber mat and three layers of surface film as reinforcing layer, these layers are resinated by Derakane 411-350, rolled, after drying protecting cover as wax top coat based on isophthalic polyester is applied.

EFFECT: improvement of coating service life.

3 cl, 1 dwg

FIELD: chemistry.

SUBSTANCE: composition contains a homogeneous mixture consisting of at least one bromine-functionalised epoxy resin, at least one epoxy curing agent and at least one pigment, filler and/or coating additive. Content of bromine in the bromine-functionalised epoxy resin is equal to 5-60%. The composition also contains alkanol amine and at least one zinc borate compound. Alkanol amine is selected from a group consisting of diethanol amine and tris(hydroxymethyl)aminomethane. The method of preparing the composition involves mixing components, heating to melting point of the mixture, extrusion of the molten mixture, cooling, crushing and grinding to powder. The composition provides a coating with high glass transition temperature and acceptable flexibility when depositing the coating onto a metallic or plastic base, in particular metallic and plastic pipes.

EFFECT: coatings can have high adhesion in hot and humid conditions and optimum short-term and long-term protection from cathodic disbonding at high temperature and humidity.

14 cl, 3 tbl, 7 ex

FIELD: chemistry.

SUBSTANCE: binder for preparing prepregs is a product of reacting polyamide acid and an epoxy-novolac oligomer with the following ratio of components in wt %: polyamide acid 1-20, epoxy-novolac oligomer - the rest. The invention also discloses a method of preparing the said binder and a prepreg from the said binder.

EFFECT: invention enables to obtain a product with homogeneous phase distribution of the polyimide component.

10 cl, 5 dwg, 2 tbl, 6 ex

FIELD: chemistry.

SUBSTANCE: invention relates to preparation of epoxy binder for construction polymer composite materials based on carbon fibre filler, which can be used in aviation, space, machine- and shipbuilding industries, as well as other industries. The binder contains the following (pts.wt): epoxy-novolak resin 24-35, nitrogen-containing epoxy resin 27-32, hardener - 4,4'-diaminodiphenylsulphone 30-32, diglycidyl ether of diethyleneglycol 5-10 and a product of condensing glycol with dimethyterephthalate 2-5. The prepreg contains the following (in wt %): said epoxy binder 30-50 and fibrous filler - carbon bundles, tapes, fabric 50-70.

EFFECT: invention enables to obtain composite material and article with good strength properties, high crack resistance and impact viscosity.

4 cl, 4 tbl, 5 ex

FIELD: chemistry.

SUBSTANCE: binder contains the following (pts.wt): epoxy-novolak resin with epoxy equivalent weight of 169-181, containing 2.5-3.6 glycidyl groups per mol of the epoxy resin - 100, hardener - anhydride of methyl-endo-cis-5-norbornene dicarboxylic acid - 80-95, curing accelerator - 0.1-2.0, and target additives - 0.5-2.0. The binder has acceptable application life for producing fibre-glass.

EFFECT: high shearing strength along the fibre and splitting strength along the fibre.

2 cl, 2 tbl, 3 ex

FIELD: electricity.

SUBSTANCE: method for production of a multiple application impregnating composition for manufacture of mica-paper capacitors is as follows: the impregnating composition base is represented by diphenylolpropane dicyanate which is heated, one introduces a catalyst, performs a polymerisation stage with a reversible polymerisation stage performed by way of heating diphenylolpropane dicyanate up to a temperature of 955C, the catalyst is represented by diphenylolpropane in an amount of 1.5-2%, before repeated usage of the worked-out impregnating composition one performs introduction of no less than 50% of freshly prepared impregnating composition. One also proposes a method for mica-paper capacitors manufacture. One produces the multiple application impregnating composition, manufactures mica-paper capacitors using such composition; thus one enables the catalyst application simplification and efficient expenditure of expensive dicyanate used for capacitors impregnation.

EFFECT: method ensures the required value of the impregnating composition viscosity by way of the composition polymerisation process adjustment under prolonged temperature exposures and the required electrical parameters of mica-paper capacitors impregnated with the multiple application composition.

2 cl, 3 tbl, 2 dwg, 5 ex

FIELD: chemistry.

SUBSTANCE: invention relates to novel benzoxazine siloxanes of general formula , where R1 denotes trimethylsilyl, dimethylsilylpropyl-8-methoxy-N-R2-1,3-benzoxazine, pentamethylsiloxypropyl- N-1,3-benzoxazine; R2 denotes alkyl C1-C4, hydroxyethyl, phenyl; X denotes oxygen, methylene, isopropyl, hexafluoropropyl; m=0-8, n=0-32; at certain conditions, values of X, R1 and number links in benzoxazine siloxanes. Heat-curable compositions for heat-resistant adhesives, filling compounds and coatings are obtained from the benzoxazine siloxanes and epoxy resins. The composition contains (pts.wt) one or seven benzoxazine siloxane compounds in amount of 10-50; epoxy-diane or epoxy-phenol-formaldehyde resin in amount of 100-50; a curing agent - isomethyl tetrahydrophthalic anhydride in amount of 0-83; filler - boron or aluminium nitrides in amount of 0-15.

EFFECT: coatings and adhesives obtained based on the invention withstand high thermal action.

2 cl, 3 tbl, 18 ex

FIELD: chemistry.

SUBSTANCE: invention relates to polymer compositions intended for making porous high-elasticity abrasive and diamond tools for machining articles from steel and nonferrous metals. Proposed composition comprises epoxy-novolac block copolymer resin, butadiene-nitrile resin, gas forming agent, hardener, stearin, cryolite, silicon carbide or electrocorundum. Said epoxy-novolac block copolymer resin includes the product of copolymerisation of epoxy diane resin and phenol-formaldehyde resin with the products of alcoholysis of secondary PETF while gas-forming agent represents izoisobutyronitrile while tri-ethanolamine makes the hardener, at the following ratio of components in wt %: product of copolymerisation of epoxy diane resin and phenol-formaldehyde resin with the products of alcoholysis of secondary PETF - 100, butadiene-nitrile resin - 30-100, izoisobutyronitrile - 3-10, tri-ethanolamine - 0.3-0.7, stearin - 1-3, cryolite - 25-65, silicon carbide or electrocorundum - 300-700.

EFFECT: homogeneous structure, density and elasticity of abrasive tool, better working qualities.

2 tbl, 1 ex

Up!