JPH03114525A - Liquid dispersant for use in mold release lubrication - Google Patents

Abstract

PURPOSE:To obtain a liq. dispersant for use in mold release lubrication excellent in dispersion stability, redispersibility, adhesiveness and mold release characteristics by mixing together powdered boron nitride having a specific surface area, dispersant, colloidal silica and water, each contained in an amt. of a specific wt.%. CONSTITUTION:The subject liq. dispersant is prepared by mixing together 0.5-30wt.% of powdered boron nitride having a specific surface area of at least 30m<2>/g, 0.005-10wt.% of the dispersant consisting of anionic surfactant such as fatty acid alkylate and alkyl sulfate, cationic surfactant such as amine halogen acid salt and quaternary ammonium salt, nonionic surfactant such as polyethylene glycol and alkyl ether and amphoteric surfactants in various amine solutions (A high-molecular surfactant of anionic polycarboxylic acid type is preferable), 0.1-20wt.% of colloidal silica (active as binder for boron nitride and having a particle diameter of less than 30m) and water for the balance. By such composition, there is obtained a liq. dispersant for use in mold release lubrication excellent in dispersion stability, redispersibility, adhesiveness and mold releasing characteristics.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides a dispersion for mold release lubricant, particularly a solid mold release lubricant, which is made by decomposing nitrided boron into water, has a stable dispersion, and is recyclable. This invention relates to a dispersion liquid for mold release lubrication that has excellent dispersibility and adhesion, and also has good environmental pollution prevention properties.

(Prior art) Conventionally, mold release lubricant dispersions have been prepared by dispersing powders of talc, graphite, molybdenum disulfide, boron nitride, etc. in water, oil, or solvent, and then spraying or applying a solution to the object to be coated. Among these, dispersions using boron nitride powder are used in a wide range of fields because of their excellent mold release lubricity at high temperatures.

(Problem B to be solved by the invention) However, the release lubricant dispersion obtained by dispersing boron nitride in water does not have a suitable binder, so the dispersion of boron nitride in water is unstable. However, this type of dispersion has the disadvantage that its redispersibility is generally unsatisfactory, and it is also inferior in quick-drying properties compared to solvent-based dispersions using chlorinated or fluorinated solvents. As a dispersion for mold release lubrication, a dispersion in which boron nitride is dispersed in an organic solvent is commonly used. There has been a growing demand for this, and this measure has become a problem.

(Means for Solving the Problems) The present invention relates to a dispersion liquid for mold release lubrication that can solve such problems.
/g or more boron nitride powder 0.5-30% by weight
, dispersant 0.005-10% by weight, colloidal silica 0
．． It is characterized by consisting of 1 to 20% by weight of water.

That is, as a result of various studies in order to develop an aqueous mold release lubricant dispersion with good dispersion stability, the present inventors determined that the boron nitride powder used herein had a specific surface area of +om2/g or more. When a dispersant and colloidal silica are added to the dispersion liquid, which is dispersed in water, there is no need to worry about environmental pollution because no organic solvent is used, and since the dispersant and colloidal silica are added, this dispersion liquid has high dispersion stability. We discovered that it exhibits high properties, high redispersibility, and high adhesion.
The present invention was completed by conducting research on the types and amounts of each component used here.

This will be explained in further detail below.

(Function) The present invention relates to a dispersion for mold release lubrication, which is made by dispersing a composition consisting of boron nitride, a dispersant, and colloidal silica in water.

The boron nitride used as the main agent in the dispersion for mold release lubrication of the present invention may be of any known type, but it may be used in combination with any surfactant as long as it has a specific surface area of less than 30 m''g. However, if the specific surface area is 30 m2/g or more, if a surfactant is used in combination, this dispersion will show a high degree of dispersion stability and redispersibility, resulting in high adhesion. Since the specific surface area becomes 30
m2/g or more is required.

However, if this amount is less than 0.5%, the coating film coated with the dispersion using this will be uniform, but in order to obtain sufficient mold release, it is necessary to It is necessary to take a long time to apply the coating, and in the case of paint coating, it is necessary to repeat the coating several times, which is disadvantageous, and if the amount is more than 30%, the dispersibility of the dispersion using this will deteriorate. , even if a surfactant is used in combination, the disadvantage is that the dispersion becomes paste-like;
．． It needs to be in the range of 5 to 30%, but the preferred range is 3 to 15%.

Next, the dispersant added to the above-mentioned boron nitride in the mold release lubricant dispersion of the present invention may be a known surfactant, and therefore it may be an anionic surfactant such as a fatty acid alkyl salt or an alkyl sulfate. Cationic surfactants such as surfactants, amine halogenates, and quaternary ammonium salts;
Nonionic surfactants such as polyethylene glycol alkyl ether or amphoteric surfactants such as various amine solutions may be used, but in order to achieve the purpose of the present invention, anionic polycarboxylic acid type high Preferably, it is a molecular surfactant. The amount added is 0.005% by weight relative to the 0.5 to 30% by weight of the boron nitride powder described above.
If it is less than 0.005 to 10% by weight, high dispersion stability cannot be obtained even with boron nitride, which has a large specific surface area, and no further effect can be obtained even if it is added in an amount greater than 10% by weight.
The preferred range is from 0.05 to
It is assumed to be 1.5% by weight.

In addition, the colloidal silica added to the boron nitride in the mold release lubricant dispersion of the present invention acts as a binder for the boron nitride, and the dispersion to which this is added acts as a binder for the boron nitride. Since it has a silanol group, it has excellent adhesion to the object to be coated, and this colloidal silica has a silanol group.
Since the silanol groups undergo a condensation-dehydration reaction at ~150°C to form a three-dimensional network structure of siloxane bonds, a dispersion containing this silanol group forms a strong film on the surface of the object to be coated. In addition, this colloidal silica has a particle size of 30 m.
If it is more than μ, the dispersion stability of the dispersion to which it is added will deteriorate, and the film properties will also deteriorate, so it is necessary to have a particle size of less than 30 mμ, and the amount added is also as described above. If the amount of nitriding is less than 0.1% by weight based on 0.5 to 30% by weight of boron, it is too small and a sufficient binder effect cannot be obtained, and if it is more than 20% by weight, the film obtained by applying this dispersion will deteriorate. Since partial peeling occurs after drying, the amount needs to be in the range of 0.1 to 20% by weight, and the preferred range is 0.3 to 10% by weight.

The dispersion liquid for mold release lubrication of the present invention is obtained by mixing predetermined amounts of the above-mentioned boron nitride, dispersant, and colloidal silica, and adding water in an amount to make the total 100% by weight and mixing and dispersing the mixture. However, in this case, the boron nitride powder has a specific surface f! 30 m2/g or more, to which a dispersant and colloidal silica with a particle size of less than 30 mμ are added, so it has excellent dispersion stability, redispersibility, and adhesion, and is easy to apply to the object to be coated. The coating film has good film-forming properties and exhibits excellent mold release properties, making it highly useful as a dispersion for mold release lubrication, and since it is an aqueous dispersion, it does not pollute the environment. It is considered to have the practical effect that there is no risk of

(Example) Next, Examples and Comparative Examples of the present invention will be given, and the sedimentation properties, redispersibility properties, and adhesion properties of the dispersion liquid in the examples are as shown in the following test results.

(Sedimentation) Pour the dispersion into a 100-rall graduated cylinder to exactly 10
One week after collecting 0111JZ and leaving it for a week, the numerical value at the top of the cloudy area was read.

(Redispersibility) Accurately add 100 tons of dispersion liquid to a 100nl graduated cylinder.
rlL was collected, and after one week of standing, a graduated cylinder was sealed with a rubber stopper and shaken several times (about 3 seconds) to check for the presence of precipitate, and if there was any precipitate, it was judged as defective.

(Adhesion) An adhesion test of the cellulose tape was conducted according to the method specified in JIS K 54006-1s.

Examples 1 to 6, Comparative Examples 1 to 4 Specific surface area is 80 m2/g, 35 m2/g or 25 m
2/g of nitriding is 5% by weight of boron powder, the amount of surfactant as a dispersant shown in Table 1, and Boyz 530 [Kao ■
product name], silica hydrosil in the amount shown in Table 1 with the average particle diameter shown in Table 1, and the total amount is 100% by weight
Mix and disperse the following amounts of water in a ball mill to obtain dispersion 10
Seeds were prepared and the settling and redispersing properties of these dispersions were examined, and the results shown in Table 1 were obtained.

Next, these dispersions were molded into a mold (StlS) using an air gun with an air pressure of 2 J/cm2 and a nozzle diameter of 0.5 m+n.
304> for 5 seconds, and then dried at 150° C. for 45 minutes in a ventilation dryer. When the adhesion of this film was examined, the results shown in Table 1 were obtained.

That is, in Examples 1 to 6, boron nitride with a specific surface area of 3 om2/g or more was 0.5 to 30% by weight, the amount of dispersant added was 0.005 to 10% by weight, and colloidal silica The average particle size is less than 30 μm and the amount added is 0.1 to 2
Since the concentration was 0% by weight, the dispersion stability, redispersibility, and adhesion were also good. However, in the comparative examples, boron nitride had a specific surface area of 25 m2/g (Comparative Example 1) or dispersion The amount of additive added is as small as 0.003% by weight (Comparative Example 2)
Therefore, these have poor dispersion stability and redispersibility, and furthermore, the colloidal silica content is low at 0.05% by weight (Comparative Example 3), and the particle size is large at 50 μm or more (Comparative Example 4). It was confirmed that all of these had poor adhesive properties.

(Effects of the Invention) The present invention relates to a dispersion for mold release lubrication, which, as mentioned above, has a specific surface area of 30 m2/g or more, contains 0.5 to 30% by weight of boron nitride, and 0.005% by weight of a dispersant. ~10% by weight
, 0.1 to 20% by weight of colloidal silica, and the balance water.This dispersion contains boron nitride with a specific surface area of 30 m2/g or more, and an appropriate amount of interfacial dispersant as a dispersant. Since it contains an activator and colloidal silica, it has excellent dispersion stability and redispersibility, and it also has good adhesion when applied to the object to be coated, so it is especially suitable as a lubricating mold release liquid. Considered useful.

Claims (1)

[Claims] 1. 0.5 to 30% by weight of boron nitride powder having a specific surface area of 30 m^2/g or more, and 0.005 to 10% by weight of a dispersant.
, 0.1 to 20% by weight of colloidal silica, and the remainder water. 2. The dispersion liquid for mold release lubrication according to claim 1, wherein the dispersant is a polycarboxylic acid type polymeric surfactant. 3. The dispersion for mold release lubrication according to claim 1, wherein the colloidal silica has an average particle diameter of 30 mμ or less.