CN100595002C - Special additive for powder coating used in lost form casting - Google Patents

Abstract

The invention discloses a special powder coating additive for pulverous expendable pattern casting, and the powder additive comprises the following components: suspending agent (15-25 wt%), rheological agent (20-25 wt%), adhesive (35-55 wt%), organosilicon defoamer (4-10 wt%) and preservative agent in balancing amount. When the special additive is prepared, various pulverous materials are weighedby the required proportion, interposed into the powder stirrer in sequence to stir for 20 to 40 minutes at a low speed and then discharged and packed. When the powder coating is prepared by adopting the additive, the powder coating additive is weighed and prepared in the ratio of refractory material and additive of 100 to (6-10). After the low-speed stirred vessel is turned on, the powder coatingweighed is interposed into the stirrer in batches, the stirring time is 10 to 20 minutes, and then the powder coating is discharged and packed. The additive is utilized after the powder coating manufactured is prepared into the slurry in a certain water-to-powder ratio; therefore, the special coating has the advantages of good suspension property, high intensity, uniform coating, good thixotropy,good leveling property, glabrous surface, no bubbles, no cracks and the like. Moreover, the user can adopts the dip-coating method, the hang-coating method and the brush-coating method, the viscositychange of coating materials can be decided upon the demands of the user, and different viscosities can realize different coating thicknesses.

Description

Special-purpose additive for powder paint for lost foam casting

Technical field

The invention belongs to metal material processing and metallurgical class technical field, what relate to is a kind of Powdered lost foam cast steel, cast iron special-purpose additive for powder paint, this additive mixed mutually with refractory material in proportion promptly get the mould that disappears with cast steel, cast iron powdery paints, do not need to add other auxiliary material, when preparing lost foam casting cast steel, cast iron, have the characteristics that equipment is simple, operation is short with coating.

Background technology

The lost foam casting coating technology is one of critical process that influences the technology success.Because the lost foam casting technology is to introduce external advanced foundry engieering, supporting coating price costliness.Therefore China most lost foam casting manufacturer adopts the water base gluey coating of self-control to deal with production at present, the coarse even generation casting flaw of the cast(ing) surface that obtains.The lost foam paint of supplying on the China market is most of for water base gluey coating, is powder type coating preparation on a small quantity.Water base gluey coating is packed with metal bucket or Plastic Drum, has increased cost for the user, and very inconvenience of transportation.Part powdery paints on the market can solve transportation and packaging Problems, but is mixed with behind the gluey coating second-rate.It is personal that China part lost foam casting producer gets used to oneself disposing coating, but owing to the configuring technical content that lacks special coating technology, especially powder type coating preparation is higher, the assurance that often on coating quality, can not get.

Cast steel, cast iron lost foam paint require the brushing performance to satisfy several essential condition: coating is wanted uniformity, and once is coated with and hangs thickness and reach more than 0.3, and secondary is coated with to be hung thickness and reach more than the 0.8mm; Non-foam will be arranged in good thixotropy, stirring and the use coating or lather collapse is very fast, do not ftracture behind the dry paint layer.Also to satisfy conditions such as good hot permeability, elevated temperature strength are arranged simultaneously.Gong Ying marketed coating is difficult to satisfy simultaneously these requirements in the market.

Summary of the invention

The object of the present invention is to provide a kind of special-purpose additive for powder paint for lost foam casting, that this specialist additive has is pollution-free, packed and transported is simple and convenient, deposit for a long time, not putrid and deteriorated advantage,

Special-purpose additive for powder paint for lost foam casting provided by the invention, its component and mass percent are:

Suspending agent 15～25%, rheological agent 20～25%, binding agent 35～55%, silicone defoaming agent 4～10%, remainder are anticorrisive agent;

Above-mentioned suspending agent is at least a in lithium bentonite, sodium bentonite, the palygorskite soil;

Above-mentioned rheological agent is at least a in sodium carboxymethylcellulose, hydroxyethylcellulose, mineral thixotropic agent, the lignocellulosic;

Above-mentioned binding agent is at least a in dextrine powder, a starch, white glue with vinyl, the pva powder;

Foregoing preservatives is Sodium Benzoate, potassium sorbate, isothiazolinone at least one of the preservatives.

Easy to use, advantages such as processing performance good, operating characteristics is excellent, transportation facility that Powdered lost foam casting specialist additive has.The user only need purchase refractory material, does not need other auxiliary agent auxiliary, has the preparation characteristics of " a ticket system ", labor and material saving.Preparation only need take by weighing refractory aggregate and additive during powdery paints in proportion, puts into low-speed mixer and stirs and get final product.Powdery paints that obtains and water mixing, the colloidal coating that obtains are placed after several hours and are used, and have that suspension is good, intensity is high, coating is even, advantages such as good leveling property, any surface finish, still, flawless.The user can dip-coating, hang and be coated with, brush, and dope viscosity changes on the user to be needed decide, and different viscosity can obtain different coating layer thicknesses.Intensity height, coating do not have cavity, crack defect behind the dry paint layer.

The specific embodiment

Additive provided by the invention is pulverulence, and this additive is mixed in proportion mutually with the refractory aggregate that is applicable to lost foam cast steel, ironcasting, adopts slow spin blade mixer to stir, and can obtain powder dispellable mould casting cast steel, iron casting coating.The powdery paints water is stirred the back use, the powder liquid mass ratio that stirs material is 1: 1.1～1.4.Stirring means is as follows: take by weighing a certain amount of powdery paints, take by weighing an amount of water in the recommendation ratio of last table again and put into stirred vessel.After opening stirred vessel, divide to add the powdery paints that takes by weighing in batches.The first high-speed stirred of user with good conditionsi 20～40 minutes stirred under low-speed conditions 1～3 hour again, disappeared until whirlpool.Coating after stirring is preferably placed a period of time and is used (main effect is slaking, uses better after 3～5 hours, even uses after one day).This coating has good rheological characteristic, thixotropy.

After the aqueous coating dilution, adopt dip coating.Foam is touched sample immerse in the coating, slightly stir foam and touch sample, take out after 5～10 seconds, control out unnecessary coating, dry then.General foam is touched sample and is wanted dip-coating 2 times or 3 times.Once be coated with and hang the back coating layer thickness greater than 0.4mm, coating layer thickness reached more than the 1.0mm after secondary was coated with and hangs.

Below by will describing the present invention more in detail by following examples, and following examples only are illustrative, and the present invention is not subjected to the restriction of these embodiment.

Embodiment 1

Getting the spiral mixer that suspending agent 15kg (mass ratio of suspending agent is 15% for lithium bentonite 10kg, thunder holder stone 5kg) puts into the 100kg capacity stirred 5 minutes; Take by weighing rheological agent 20kg (sodium carboxymethylcellulose 15kg, hydroxyethylcellulose 5kg, the mass ratio of rheological agent are 20%); (mass ratio is 4% to take by weighing silicone defoaming agent 4kg then, 3003 silicone defoaming agents that Shanghai Saibo Chemical Co., Ltd. produces), binding agent 55kg (a starch 50kg, white glue with vinyl 5kg, the mass ratio of binding agent is 55%), liquid defoamer (polyether antifoam agent), adopt the 6kg Sodium Benzoate as anticorrisive agent (mass ratio is 6%), add and continue to stir discharging in 40 minutes in the mixer.

Embodiment 2-6

Utilize the method for embodiment 1, the proportioning described in each component according to the form below is processed processing, prepare required powder type coating preparation.(" % " in the following table all refers to mass percent, and the mineral thixotropic agent is selected the OBTN thixotroping lubricant of Wuhan Kai Pu trade Co., Ltd for use)

Example	Suspending agent	Binding agent	Rheological agent	Defoamer	Anticorrisive agent
						2	25% sodium bentonite 15kg, palygorskite soil 10kg	35%, 35kg (pva powder 30kg, white glue with vinyl 5kg)	25%, 25kg (hydroxyethylcellulose 15kg, mineral thixotropic agent 10kg)	10%, the 10kg silicone defoaming agent	OIT 5%, 5kg
3	20%, the 20kg lithium bentonite	40%, 40kg (a starch 30kg, pva powder 10kg)	23%, 23kg (hydroxyethylcellulose 13kg, mineral thixotropic agent 10kg)	%, the 8kg silicone defoaming agent	9%, 9kg (potassium sorbate 5kg, OIT 4kg)
						4	25%, 25kg (sodium bentonite 15kg, thunder holder stone 10kg)	45%, 45kg (a starch 30kg, white glue with vinyl 15kg)	20%, 20kg (sodium carboxymethylcellulose 15kg, lignocellulosic 5kg)	5%, the 5kg silicone defoaming agent	5%, the 5kg Sodium Benzoate
5	20%, 20kg (sodium bentonite 15kg, thunder holder stone 5kg)	45%, 45kg (dextrine powder 30kg, white glue with vinyl 15kg)	20%, 20kg mineral thixotropic agent	7%, the 7kg silicone defoaming agent	8%, the 8kg OIT
						6	15%, 15kg (thunder holder stone)	50%, 50kg (a starch 30kg, dextrine powder 20kg)	25%, 25kg (sodium carboxymethylcellulose 20kg, lignocellulosic 5kg)	5%, the 5kg silicone defoaming agent	5%, the 5kg Sodium Benzoate

The above is preferred embodiment of the present invention, but the present invention should not be confined to the disclosed content of this embodiment.So everyly do not break away from the equivalence of finishing under the spirit disclosed in this invention or revise, all fall into the scope of protection of the invention.

Claims (1)

1, a kind of special-purpose additive for powder paint for lost foam casting, its component and mass percent are:

Suspending agent 15～25%, rheological agent 20～25%, binding agent 35～55%, silicone defoaming agent 4～10%, remainder are anticorrisive agent;

Above-mentioned suspending agent is at least a in lithium bentonite, sodium bentonite, the palygorskite soil;

Above-mentioned rheological agent is at least a in sodium carboxymethylcellulose, hydroxyethylcellulose, mineral thixotropic agent, the lignocellulosic;

Above-mentioned binding agent is at least a in dextrine powder, a starch, white glue with vinyl, the pva powder;

Foregoing preservatives is Sodium Benzoate, potassium sorbate, isothiazolinone at least one of the preservatives.