Mixed powder for paste wax and paste wax using the same

Abstract

The present invention provides: a mixed powder for paste brazing materials; a paste brazing material which is produced using this powder; and a method for producing a paste brazing material.　A paste brazing material according to the present invention is able to be produced by mixing 8.0 parts by mass to 22.0 parts by mass of an aqueous solution that contains an organic solvent or the like into 100 parts by mass of a mixed powder for paste brazing materials, wherein the mass ratio of a brazing filler material powder to a resin powder, which serves as a water-soluble thickening agent, is 99.88-97.90:0.12-2.10. It is preferable that the resin powder is composed of a cellulose-based material; and it is particularly preferable that the resin powder is composed of one or two materials selected from among methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and hydroxypropylmethyl cellulose.

Description

Technical Field

[0001] The present invention relates to a raw material powder for paste solder used for joining stainless steel or the like, and a paste solder manufactured using the same.

Background Art

[0002] Conventionally, when joining stainless steel, particularly when corrosion resistance is required, a solder material mainly composed of nickel, iron, or cobalt is applied and joined by furnace brazing. And, as the method of applying the solder material, methods such as placement brazing of an amorphous foil, dispenser coating, screen printing, and sprinkling printing using paste solder are adopted. In particular, in order to suppress the application amount of the solder material, a coating method using paste solder is adopted.

[0003] This paste solder is obtained by kneading a solder powder and a binder, and requires three processes: solder powder production, binder production, and paste production. For example, the paste solder shown in Patent Document 1 can be mentioned.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] For paste wax binders, both hydrophobic (oil-based) and water-based binders are used. However, water-based binders are preferable because they have a lower environmental impact and do not require special working environments or explosion-proof equipment. However, in the manufacturing process of water-based binders, when dissolving the water-based resin, which acts as a thickening agent, in an aqueous solution, clumps called "mamako" (clumps where only the outer surface of powder particles or aggregates is hydrated, forming a viscous gel layer that inhibits water penetration into the interior) are generated. This requires strong stirring, prolonged stirring, or a long dispersion period for the water-based binder to stabilize, thus limiting the rate of paste wax production. In addition, problems such as unstable viscosity due to the generation of mamako and the evaporation of water during manufacturing also occur. [Means for solving the problem]

[0006] The inventors have developed a new paste funnel that suppresses the occurrence of mamaco and eliminates the binder manufacturing process, as well as a mixed powder for use with the paste funnel.

[0007] Specifically, the paste wax mixed powder of the present invention comprises a waxing agent powder and a water-soluble thickening agent resin powder, characterized in that the mass ratio of the waxing agent powder to the resin powder is 99.88 to 97.90:0.12 to 2.10.

[0008] Furthermore, the resin powder used as a thickening agent is preferably cellulose-based, and is characterized by being one or two types selected from methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, etc.

[0009] The paste wax of the present invention can be obtained by mixing 8.0 to 26.6 parts by mass of water with 100 parts by mass of the paste wax mixed powder.

[0010] Furthermore, the paste wax of the present invention can also be obtained by kneading 100 parts by mass of the above-mentioned mixed powder for paste wax with 7.8 parts by mass or less in total of 1 to 3 organic solvents selected from acetone, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, ethylene glycol, and glycerin (hereinafter referred to as organic solvents) (except when the total amount of organic solvents is 0 parts by mass) and 2.0 to 20.0 parts by mass of water, in which case the total amount of water and organic solvents is 8.0 to 22.0 parts by mass.

[0011] Alternatively, the paste wax of the present invention can be obtained by kneading 100 parts by mass of the above-mentioned paste wax mixed powder with water and one or two of the water-soluble resins, polyvinyl alcohol, urethane resin, acrylic resin, and vinyl acetate, in a total of 1.0 part by mass or less (except when the total is 0 parts by mass), in which case the total amount of water and water-soluble resin is 8.0 to 22.0 parts by mass.

[0012] Furthermore, the paste wax of the present invention contains, per 100 parts by mass of the mixed powder for paste wax, a total of 7.8 parts by mass or less of 1 to 3 of the following organic solvents: acetone, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, ethylene glycol, and glycerin (except when the total amount of organic solvents is 0 parts by mass), and a total of 1.0 part by mass or less of one or two water-soluble resins selected from polyvinyl alcohol, urethane resin, acrylic resin, and vinyl acetate (except when the total amount is 0 parts by mass), with the remainder being water, and the total amount of water, organic solvents, and water-soluble resins being 8.0 to 22.0 parts by mass. Preferably, the remaining water is 2.0 to 20.0 parts by mass.

[0013] Furthermore, when manufacturing the paste wax of the present invention, it is preferable to use the polyvinyl alcohol, urethane resin, acrylic resin, and vinyl acetate in aqueous solution form, diluted with water, rather than using them in solid form. As such aqueous solutions, for example, a solution with a solid content of 50% by mass or less can be used, such as polyvinyl alcohol with a solid content of about 10% by mass, urethane resin with a solid content of about 30% by mass, or vinyl acetate with a solid content of about 40% by mass.

[0014] Furthermore, since the paste brazing material of the present invention is used for furnace brazing of stainless steel, the brazing powder is preferably a brazing material whose main component is nickel, iron, or cobalt.

[0015] Furthermore, the waxing powder contained in the paste wax mixed powder of the present invention is preferably an alloy powder produced by the atomization method, and its particle size is preferably 250 μm or less.

[0016] To suppress sedimentation of the waxing agent powder in the paste wax of the present invention, the particle size of the waxing agent powder is preferably 150 μm or less, and more preferably 63 μm or less.

[0017] Next, we will explain the reasons for limiting the components and blending ratios of the paste wax mixed powder and paste wax using the present invention.

[0018] The water-soluble thickener in the paste wax mixed powder of the present invention has the function of suppressing the sedimentation and separation of the wax material powder. However, if the amount is less than 0.12 parts by mass per 100 parts by mass of paste wax mixed powder, the thickening effect is weak and the wax material powder settles. If it exceeds 2.10 parts by mass, the viscosity of the paste wax increases, impairing the workability of application, and the amount of decomposition gas of the resin is increased during the brazing process, causing brazing defects. For this reason, the amount of water-soluble thickener added is limited to the range of 0.12 to 2.10 parts by mass.

[0019] The water-soluble thickener is preferably cellulose-based, as it suppresses the sedimentation and separation of the wax powder. However, any water-soluble powdered thickener other than cellulose-based can be used.

[0020] When preparing a paste wax using the mixed powder for paste wax of the present invention and adding only water, if the amount of water added per 100 parts by mass of the mixed powder for paste wax is less than 8.0 parts by mass, the viscosity of the paste wax is high, impairing its application properties. Conversely, if the amount exceeds 26.6 parts by mass, the viscosity of the paste wax becomes low, the wax powder is prone to settling, and the application properties are also impaired. Therefore, the amount of water in the paste wax is limited to the range of 8.0 to 26.6 parts by mass.

[0021] The addition of organic solvents allows for better adhesion to the stainless steel base material even if oil or grease adheres to it, as well as providing a preservative effect on the paste and allowing for adjustment of the drying speed (fast or slow). Since the thickener is water-soluble, water-soluble organic solvents can be selected, and 1 to 3 types can be included from acetone, methyl alcohol (methanol), ethyl alcohol (ethanol), n-propyl alcohol, isopropyl alcohol, ethylene glycol, and glycerin. When adding organic solvents to the paste, as mentioned above, the total amount of water and organic solvent is preferably in the range of 8.0 to 22.0 parts by mass per 100 parts by mass of the mixed powder for paste wax. In this case, if the amount of water added is less than 2.0 parts by mass, or if the total amount of organic solvent exceeds 7.8 parts by mass, the amount of water that reacts with the water-soluble thickener will be small, the viscosity of the paste wax will not be stable, the wax powder will be more likely to precipitate, and the application workability will be impaired. Therefore, the amount of water added was limited to the range of 2.0 to 20.0 parts by mass, and the total amount of organic solvent added was limited to 7.8 parts by mass or less.

[0022] Furthermore, the paste brazing material of the present invention can contain one or two kinds selected from water-soluble polyvinyl alcohol, urethane resin, acrylic resin, and vinyl acetate in order to suppress sedimentation separation of the brazing material powder and improve adhesion to the base stainless steel. However, when the addition amount to the paste exceeds 1.0 part by mass, the amount of decomposition gas generated increases in the brazing process, causing brazing defects. Therefore, the addition amount to the paste is limited to a range of 1.0 part by mass or less. When adding a water-soluble resin to the paste, the total amount of water and the water-soluble resin is preferably in the range of 8.0 to 22.0 parts by mass with respect to 100 parts by mass of the mixed powder for paste brazing. And in the case of the paste brazing material containing water, an organic solvent, and a water-soluble resin, similarly to the above, the total amount of water, the organic solvent, and the water-soluble resin is preferably in the range of 8.0 to 22.0 parts by mass.

Embodiments for Carrying out the Invention

[0023] The brazing material powder produced by the atomization method and adjusted to a predetermined particle size, for example, in addition to BNi-1 to BNi-13 and BCo-1 shown in "JIS Z 3265 Nickel Brazing" and "AWS A5.8 Specification for Filler Metals for Brazing and Braze Welding", and development materials shown in Patent No. 3354922, Patent No. 5269888, Patent No. 5783641, Patent No. 5858512, etc., and a water-soluble thickener are homogeneously mixed at a predetermined ratio using a V-type mixer or the like to obtain the mixed powder for the paste brazing material of the present invention. As the brazing material powder in the present invention, for example, the Ni-based heat-resistant brazing material described in Patent No. 3354922, which consists of 25 to 35% Cr, 4 to 8% P, 3 to 6% Si, a total of 9 to 11.5% of P + Si, and the balance being Ni and unavoidable impurities, is preferable.

[0024] Furthermore, a solution mixed with water, an organic solvent, etc. is added in a predetermined amount to the above-mentioned mixed powder for paste brazing, and kneaded using a kneader (mixer) or the like, whereby a paste brazing material using the mixed powder for paste brazing of the present invention can be obtained.

[0025] By adjusting the amount of the water-soluble thickener in the paste welding mixed powder and the amount of water or solution in the paste welding produced using the same, it is possible to obtain a viscosity of the paste welding suitable for the target coating method, and it can be used for dispenser coating, screen printing, metal mask, dipping, etc. In particular, by adjusting the viscosity of the paste welding to 100 to 1500 dPa·s, good coating workability can be obtained.

Example

[0026] The brazing paste was prepared by the above procedure so as to have the mixing ratio shown in Table 1. After kneading, it was put into a sealed container, stored at 25°C for 12 hours, and then the viscosity of the paste was confirmed using a viscometer VT-06 manufactured by Rion Co., Ltd. (using a No. 2 rotor, rotor rotation speed 62.5 rpm). Also, it was confirmed whether the brazing powder had settled in the sealed container.

[0027] Regarding the paste viscosity, considering the coating workability, a range of 100 to 1500 dPa·s was regarded as passing, and further, it was regarded as passing that there was no precipitation of the brazing powder 12 hours after the paste preparation.

[0028] Table 1 shows the mixing ratios, paste viscosities, and precipitation status of the brazing powder in the examples and comparative examples. The Ni-29Cr-6P-4Si-based alloy powder described in Japanese Patent No. 3354922 was used as the brazing powder.

[0029]

Table 1

[0030] Examples No. 1 to No. 11 had paste viscosities in the range of 100 to 1500 dPa·s, and no precipitation of wax powder was observed. On the other hand, Comparative Example No. 12 contained less than 0.12 parts by mass of thickener, Comparative Example No. 13 contained more than 2.10 parts by mass of thickener, Comparative Example No. 14 contained more than 7.8 parts by mass of organic solvent, and Comparative Example No. 15 contained more than 1.0 part by mass of vinyl acetate. In these cases, the paste viscosity deviated from the target range of 100 to 1500 dPa·s, or precipitation of wax powder was observed. Notably, no occurrence of plaque was observed in any of the examples and comparative examples of pastes prepared using the present invention.

[0031] Furthermore, the production procedure of the present invention was used to evaluate the suppression of mamaco occurrence and the number of days required for paste wax production. The results are shown in Table 2.

[0032] [Table 2]

[0033] Example No. A shows the manufacturing breakdown of Example No. 2 described in Table 1, and in addition to the manufacturing and preparation of the mixed powder for paste wax (Step I), the paste manufacturing process (Steps II and III) required one day.

[0034] In contrast, in Comparative Example No. B, which used the same components as Example No. 2 but added a thickener to the paste wax powder without mixing, the number of days required for the paste manufacturing process (total of steps II and III) was 1 day, similar to Example No. A. However, in step III of the paste manufacturing process, granules formed, rendering the paste wax unusable. Furthermore, in Comparative Examples No. C and No. D, which represent a typical paste wax manufacturing process, Comparative Example No. C, which involved prolonged stirring in binder manufacturing step II, required a total of 3 days for the paste manufacturing process (total of steps II and III), which was longer than the manufacturing time of the present invention. In addition, it was confirmed that the viscosity of the paste wax tended to increase as the moisture in the binder evaporated in step II, leading to unstable paste viscosity. Therefore, in Comparative Example No. D, which involved short-time stirring in binder manufacturing step II to suppress moisture evaporation, granules formed in binder manufacturing step II, and it took 5 days for them to disperse. The viscosity of the paste wax was equivalent to that of Example No. A, but the manufacturing process for the paste (total of steps II and III) took a long time, totaling 7 days.

[0035] In other words, the method for producing paste wax of the present invention is more effective than the current method for producing paste wax in terms of the occurrence of mold, the number of days required for production, and the viscosity stability of the paste wax. [Industrial applicability]

[0036] As described above, the mixed powder for paste wax according to the present invention and the paste wax using it have a viscosity suitable for paste wax application, do not cause sedimentation of wax material powder, and produce a paste wax with excellent application workability. Furthermore, it is expected to be a new paste production method that can simplify the binder manufacturing process in paste wax production.

Claims

1. It consists of wax powder and resin powder, which is a water-soluble thickener, and the mass ratio of the wax powder to the resin powder is 99.88 to 97.90:0.12 to 2.

10. The brazing powder is an alloy powder produced by an atomization method, with nickel, iron, or cobalt as the main component. The resin powder is one or two selected from methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose. A mixed powder for paste wax, characterized in that the particle size of the wax material powder is 250 μm or less.

2. It consists of a waxing agent powder and a water-soluble thickening agent resin powder, with a mass ratio of waxing agent powder to resin powder of 99.88 to 97.90:0.12 to 2.

10. The resin powder is one or two selected from methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose. A mixed powder for paste wax, characterized in that the particle size of the wax material powder is 250 μm or less.

3. A paste wax characterized in that, per 100 parts by mass of mixed powder for paste wax, it contains a total of 1.0 part by mass or less of one or two water-soluble resins selected from polyvinyl alcohol, urethane resin, acrylic resin, and vinyl acetate (except when the total is 0 parts by mass), the remainder being water, and the total amount of water and water-soluble resin being 8.0 to 22.0 parts by mass, The aforementioned paste wax mixed powder consists of a waxing agent powder and a water-soluble thickening agent resin powder, and the mass ratio of the waxing agent powder to the resin powder is 99.88 to 97.90:0.12 to 2.10, or The aforementioned paste wax mixed powder consists of a waxing agent powder and a water-soluble thickening agent resin powder, wherein the mass ratio of the waxing agent powder to the resin powder is 99.88 to 97.90:0.12 to 2.10, and the waxing agent powder is an alloy powder produced by atomization, with nickel, iron, or cobalt as the main component. The resin powder is one or two selected from methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose. The particle size of the aforementioned wax powder is 250 μm or less. Paste wax.

4. A paste wax characterized in that, per 100 parts by mass of mixed powder for paste wax, it contains a total of 7.8 parts by mass or less of one to three organic solvents selected from acetone, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, ethylene glycol, and glycerin (except when the total amount of organic solvents is 0 parts by mass), and a total of 1.0 part by mass or less of one or two water-soluble resins selected from polyvinyl alcohol, urethane resin, acrylic resin, and vinyl acetate (except when the total amount is 0 parts by mass), with the remainder being water, and the total amount of water, organic solvents, and water-soluble resins being 8.0 to 22.0 parts by mass, The aforementioned paste wax mixed powder consists of a waxing agent powder and a water-soluble thickening agent resin powder, and the mass ratio of the waxing agent powder to the resin powder is 99.88 to 97.90:0.12 to 2.10, or The aforementioned paste wax mixed powder consists of a waxing agent powder and a water-soluble thickening agent resin powder, wherein the mass ratio of the waxing agent powder to the resin powder is 99.88 to 97.90:0.12 to 2.10, and the waxing agent powder is an alloy powder produced by atomization, with nickel, iron, or cobalt as the main component. The resin powder is one or two selected from methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose. The particle size of the aforementioned wax powder is 250 μm or less. Paste wax.

5. A method for producing paste wax, characterized by including a step of mixing only 8.0 to 26.6 parts by mass of water with 100 parts by mass of mixed powder for paste wax, The aforementioned paste wax mixed powder consists of a waxing agent powder and a water-soluble thickening agent resin powder, and the mass ratio of the waxing agent powder to the resin powder is 99.88 to 97.90:0.12 to 2.10, or The aforementioned paste wax mixed powder consists of a waxing agent powder and a water-soluble thickening agent resin powder, wherein the mass ratio of the waxing agent powder to the resin powder is 99.88 to 97.90:0.12 to 2.10, and the waxing agent powder is an alloy powder produced by atomization, with nickel, iron, or cobalt as the main component. The resin powder is one or two selected from methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose. The particle size of the aforementioned wax powder is 250 μm or less. A method for manufacturing paste wax.

6. A method for producing paste wax, comprising the step of mixing 100 parts by mass of paste wax mixed powder with 7.8 parts by mass or less in total of 1 to 3 organic solvents selected from acetone, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, ethylene glycol, and glycerin (except when the total amount of organic solvents is 0 parts by mass) and 2.0 to 20.0 parts by mass of water, wherein the total amount of water and organic solvents is 8.0 to 22.0 parts by mass, The aforementioned paste wax mixed powder consists of a waxing agent powder and a water-soluble thickening agent resin powder, and the mass ratio of the waxing agent powder to the resin powder is 99.88 to 97.90:0.12 to 2.10, or The aforementioned paste wax mixed powder consists of a waxing agent powder and a water-soluble thickening agent resin powder, wherein the mass ratio of the waxing agent powder to the resin powder is 99.88 to 97.90:0.12 to 2.10, and the waxing agent powder is an alloy powder produced by atomization, with nickel, iron, or cobalt as the main component. The resin powder is one or two selected from methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose. The particle size of the aforementioned wax powder is 250 μm or less. A method for manufacturing paste wax.

7. A method for producing paste wax, comprising the step of mixing 100 parts by mass of paste wax mixed powder with a total of 1.0 part by mass or less (except when the total is 0 parts by mass) of one or two water-soluble resins selected from polyvinyl alcohol, urethane resin, acrylic resin, and vinyl acetate, and water only, wherein the total amount of water and water-soluble resin is 8.0 to 22.0 parts by mass, The aforementioned paste wax mixed powder consists of a waxing agent powder and a water-soluble thickening agent resin powder, and the mass ratio of the waxing agent powder to the resin powder is 99.88 to 97.90:0.12 to 2.10, or The aforementioned paste wax mixed powder consists of a waxing agent powder and a water-soluble thickening agent resin powder, wherein the mass ratio of the waxing agent powder to the resin powder is 99.88 to 97.90:0.12 to 2.10, and the waxing agent powder is an alloy powder produced by atomization, with nickel, iron, or cobalt as the main component. The resin powder is one or two selected from methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose. The particle size of the aforementioned wax powder is 250 μm or less. A method for manufacturing paste wax.

8. A method for producing paste wax, comprising the step of mixing 100 parts by mass of paste wax mixed powder with 7.8 parts by mass or less of one to three organic solvents selected from acetone, methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, ethylene glycol, and glycerin in total (except when the total amount of organic solvents is 0 parts by mass), 1.0 part by mass or less of one or two water-soluble resins selected from polyvinyl alcohol, urethane resin, acrylic resin, and vinyl acetate in total (except when the total amount is 0 parts by mass), and water only, wherein the total amount of water, organic solvents, and water-soluble resins is 8.0 to 22.0 parts by mass%, The aforementioned paste wax mixed powder consists of a waxing agent powder and a water-soluble thickening agent resin powder, and the mass ratio of the waxing agent powder to the resin powder is 99.88 to 97.90:0.12 to 2.10, or The aforementioned paste wax mixed powder consists of a waxing agent powder and a water-soluble thickening agent resin powder, wherein the mass ratio of the waxing agent powder to the resin powder is 99.88 to 97.90:0.12 to 2.10, and the waxing agent powder is an alloy powder produced by atomization, with nickel, iron, or cobalt as the main component. The resin powder is one or two selected from methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose. The particle size of the aforementioned wax powder is 250 μm or less. A method for manufacturing paste wax.

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