JP3106751B2 - Method for producing resin modifier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a resin modifier comprising gelatin powder or glue powder. According to the present invention
The resulting gelatin powder and glue powder are blended or adhered to a synthetic resin or rubber composition and used as a modifier.

[0002]

2. Description of the Related Art Sheets, films, synthetic leathers, and the like formed from synthetic resin or rubber compositions are contaminated by electrification and become ugly, lack of moisture absorption / desorption properties, and feel like plastic. Gives a sense of incongruity and is less pleasant to feel than natural products. In order to improve the properties of such synthetic resins, Japanese Patent Application Laid-Open No. 53-121902,
JP-A-1-197600 discloses that a leather powder is mixed in a synthetic resin. However, leather powder is fibrous and difficult to finely pulverize, and has low fluidity, so that when it is mixed with a resin, it is difficult to produce a product having a smooth surface and a thin product. In addition, since the moisture absorption / release properties of the leather powder itself are low, the moisture absorption / release properties of the obtained molded product are small. In addition, when a large amount of fats and oils are molded by heating, the fats and oils bleed on the surface of the molded product to give a sticky feeling, cause contamination, and have low hygroscopicity.

Further, Japanese Patent Application Laid-Open No. 63-147635, 15
Nos. 2480 and 152485 disclose the use of gelatin for the same purpose. Gelatin has a low oil content, and is superior in moisture absorption / release properties, antistatic properties, and uniform dispersibility as compared with leather powder. However, gelatin has very high hydrophilicity and poor affinity with a resin. For this reason, when a large amount of gelatin is added to the synthetic resin, phase separation occurs, the surface becomes sticky, and the strength tends to decrease.

As described above, gelatin powder is preferable for modifying a synthetic resin, but has a problem of high hydrophilicity. In order to avoid such drawbacks and to impart air permeability, a method of blending gelatin into a synthetic resin and subjecting it to hot water treatment to elute unreacted gelatin (Japanese Patent Application Laid-Open No. 63-15248).
No. 2) has also been proposed. However, such a method complicates the process and raises the processing cost, and depending on the elution conditions, 90% or more of the added gelatin elutes, so that wastewater treatment is required.

In order to solve these problems, 100 μm
It has also been disclosed that an insolubilized gelatin fine powder of m or less is compounded in a synthetic resin (Japanese Patent Application Laid-Open No. 3-237165).
The insolubilized gelatin used here has a particle size of about 45 microns even at the smallest, and the insolubilization method is a conventionally known heating method or a solution insolubilization reaction.

As a method of insolubilizing gelatin, there is a method of treating a gelatin solution with a gelatin crosslinking agent such as formalin, glutaraldehyde, chromium alum, etc.
In this method, since gelatin itself is a polymer and the viscosity of the solution is high, if the degree of insolubilization is considerably increased, a strong gel is formed, and it may be difficult to perform the subsequent treatment.

Other methods include heating at a high temperature of 100 to 200 ° C. and irradiating infrared rays or ultraviolet rays. However, these methods may cause a problem because gelatin itself is denatured. Further, as a method for adjusting the hydrophilicity of gelatin, a chemical modification method using a reaction of a functional group such as an amino group, a casboxyl group, or a hydroxyl group of gelatin,
There are enzymatic methods, graft polymerization methods, etc., but these methods complicate the process, difficult to control the degree of modification, degree of grafting, etc., have problems with quality stability, and increase the manufacturing cost. Is difficult.

[0008] In addition, a method of kneading a rubber composition by adding glue to a rubber composition for the purpose of producing a rubber product having hygroscopicity and antistatic properties has also been known. In this method, glue was once dissolved in warm water, gelled by cooling, and then kneaded with rubber. However, since the glue itself is a polymer, such a method requires a lot of time and labor to obtain a concentrated solution having a high viscosity in a solution state. Further, when the rubber raw material and the glue are kneaded, there are also problems such as poor adhesion of the mixture to the kneading roller. Solve these issues,
As a method of improving the hygroscopicity of the obtained rubber product and reducing the chargeability, a method of lightly curing, pulverizing, and then kneading the powder swollen with water with a rubber compound.
(Japanese Patent Publication No. 48-23661) is also known, but the difference in particle size has not been studied, and the degree of curing is low.

[0009]

OBJECTS OF THE INVENTION It is an object of the present invention is excellent in moisture sorption, state after insolubilization does not occur a problem such as a stable aggregate, handling simple gelatin powder or glue powder Tona
That the resin modifier order to manufacture, in a simple and low cost, is to provide a superior method in quality stability.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies on the above-mentioned problems, and as a result, surprisingly, the average particle diameter was 5
A resin modifier comprising an insoluble gelatin powder or glue powder having a cross-linkability of 30 to 30 μm solves the above-mentioned problems, and the gelatin powder is treated with a cross-linking agent while the gelatin powder remains solid. Have been found to be able to be insolubilized, and the present invention has been completed. The invention is conflict with the crosslinking agent held in the flow body condition gelatin powder or glue solid powder, and performing insolubilization reaction (hereinafter, including glue powder
Simply referred to as gelatin powder) .

The average particle size of the gelatin powder used in the insolubilization reaction is 5 to 30 μm, preferably 5 to 25 μm, and more preferably 10 to 20 μm. In the present invention, "crosslinked and insolubilized" means that all or a part of the powder is crosslinked and thus insolubilized. This includes an uneven crosslinked state, such as when only the surface is crosslinked.
The cross-linking ratio of the gelatin powder may be arbitrarily selected depending on the purpose, but it is sufficient that the degree of insolubilization is 5% or more. More preferably, the degree of insolubility is 80% or more.

[0012] The degree of insolubility is determined by mixing 1 g of gelatin fine powder with 99 g.
Dispersed in mL of water, stirred at 70 ° C. for 10 minutes, and then separated into solid and liquid by centrifugation (10000 G × 20 minutes). The amount of nitrogen in the supernatant was determined by a semi-micro Kjeldahl method.
It is calculated by the following equation.

Degree of insolubility (%) = {(a−x) / a} × 100 a: Semi-micro Kjeldahl value of 1 g of a comparative sample X: Semi-micro Kjeldahl value of a supernatant The raw material gelatin used in the reaction of the present invention is Cowhide,
It may be obtained from any of pig skin, cow bone, etc., and may be gelatin treated with any of acid and alkali.

[0014] The gelatin powder used is preferably fine in consideration of the effect of fine pulverization, but may be finer than about 12 mesh. Such a gelatin powder is obtained by, for example, finely pulverizing a powder having a particle size of about 12 to 22 mesh pass using a fine victory mill, a jet pulverizer, or the like, and then sieving.

On the other hand, as the cross-linking agent, any of those conventionally known as gelatin cross-linking agents such as aldehydes such as formalin and glutaraldehyde, organic compounds having an epoxy group such as epoxide, and alums can be used. Good. These crosslinking agents are reacted in a flow material in gaseous, liquid, or mist, such as with respect to the gelatin powder.

For example, a low-boiling crosslinking agent such as formalin is used in gaseous form. In addition, the crosslinking agent that is liquid at room temperature is
The fine particle gelatin suspended in the air may be subjected to a contact reaction in the form of a mist, or the fine particle gelatin may be dispersed in a dispersion medium, and a cross-linking agent may be added thereto to cause a contact reaction,
After the reaction, the solvent may be evaporated.

The reaction conditions of the gelatin fine particles and the crosslinking agent vary depending on the particle size of the gelatin, the kind of the crosslinking agent and the reaction method, but it is preferable to carry out the reaction at a normal temperature to 150 ° C. for about 1 hour to 1 week. For example, when formalin is used as a cross-linking agent for gelatin, the treatment is performed at room temperature to 80 ° C. for 1 to 7 days in the above-mentioned atmosphere. Conventionally, a method of adjusting the hydrophilicity of gelatin using a gelatin crosslinking agent such as formalin or glutaraldehyde is known,
All are liquid phase reactions with a gelatin solution as described above. In the present invention, the gelatin powder is reacted with these cross-linking agents in a solid state, which is essentially different.

Next, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples.

[0019]

EXAMPLES Example 1 Gelatin Powder Obtained from Alkaline Treated Ossein
(12 mesh pass) was further pulverized with a jet mill pulverizer to obtain a fine gelatin powder having an average particle size of 15 μm. 50 g of each of the gelatin fine powders was thinly spread in five closed polyethylene containers (16 × 23 × 9 cm). Prepare four glass beakers (30 ml) containing 5 ml of formalin (37% concentration), put them together in the above-mentioned closed plastic container in a sealed state (25 ° C.) for 24 hours each. , 48 hours, 72 hours and 96 hours. The other one was a comparative sample.

After a lapse of a predetermined time, the gelatin fine powder was taken out, mixed well and sampled, and the degree of insolubilization was examined by the method described above. In addition, the insolubilized gelatin powder having a reaction time of 96 hours was treated in boiling water for 5 minutes and 10 minutes.
After stirring for minutes, the degree of insolubility (%) was measured using the same method. Table 1 shows the results.

[Table 1] ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Reaction time (hour) 24 48 72 96 ──────────────────────────────────── Insolubilized 70 ° C for 10 minutes 22 48 75 88 ° C Boiling 5 minutes in water---78 (%) 〃 10 minutes---55 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ━━━ The results show that the gas-solid reaction between the gelatin powder and formalin gas sufficiently promotes the insolubilization reaction. In addition, even after insolubilization, aggregation of the gelatin powders was not observed, and the handling was easy.

Example 2 The same gelatin powder (12 mesh pass) as in Example 1 was finely pulverized by a jet mill pulverizer, and the average particle size was 5, 15, 25, 35, and 100 μm.
Various types of gelatin fine powder were obtained. Each of these fine gelatin powders was allowed to stand in a formalin atmosphere at 40 ° C. for 96 hours in the same manner as in Example 1 to obtain gelatin having a degree of insolubilization of 96%.

Next, a modified synthetic rubber sheet was molded using the obtained fine gelatin powder as a modifier. For molding, while kneading 100 parts of synthetic rubber (SBR) with a kneading roller, 20 parts of each of the above gelatin modifiers, 50 parts of carbon black and 2 parts of sulfur, 8 parts of a softener, and 1 part of an antioxidant were added,
The kneading was carried out uniformly. The obtained rubber sheet was subjected to 10, 20, 3 in an atmosphere of a relative humidity of 90% (30 ° C.).
The hygroscopicity (g / m ² ) after holding for 0 and 60 minutes was measured. Table 2 shows the results.

[Table 2] Time (minutes) Gelatin grains Diameter ───────────────────── (μm) 10 20 30 60 ───────────────────── ─────────────── 5 1.42 1.61 1.82 2.31 15 1.39 1.58 1.80 2.30 25 1.36 1.56 1.79 2.30 35 1.13 1.49 1.70 2.28 100 0.80 1.05 1.40 2.15 ━━━━━━━━━━く As is clear from Table 2, the synthetic rubber sheet using the gelatin modifier of the present invention is particularly excellent. It shows hygroscopicity.

Example 3 Four kinds of gelatin powders having different insolubilization degrees produced in Example 1 (insolubility degree: 22,
48, 75, and 88%; average particle size of 15 μm) and a comparative sample (degree of insolubility: 0%) were used as modifiers to mold six types of modified synthetic resin films.

For molding, 50 parts of a urethane resin agent, 50 parts of dimethylformamide and 10 parts of a modifier are mixed with stirring.
The mixture was coated on release paper to a thickness of 50 μm. After drying, the coating film was peeled off from the release paper to obtain a film. The obtained film was cut, and samples Nos. 1 to 5 were kept in hot water at 80 ° C. for 1 hour, then dried at 50 ° C. and subjected to a moisture absorption test.

In the moisture absorption test, the film was held for 1, 6, 12, and 18 hours in an atmosphere having a relative humidity of 90% (30 ° C.), and then the weight of the film was measured. The moisture absorption (g / m ² ) of the film is shown below.

[Table 3] 試 料 Sample time No Degree of insolubility ( %) 1 6 12 18 ──────────────────────────────────── 10 0.91 2.93 3.18 3.52 2 22 2.02 3.25 3.44 3.80 3 48 2.31 3.38 3.61 3.93 4 75 2.40 3.50 3.86 4.18 5 88 2.72 3.72 3.99 4.42 6 No additive 0.22 0.28 0.29 0.31 ━━━━━━━━━━━━━━━━━━━━━よ り From the above results, the film using the comparative sample (No. 1) and the film (No. 6) containing no gelatin powder were the modifiers of the present invention. Is inferior to the film containing the compound. Further, the modifier of Sample No. 5 having a degree of insolubilization exceeding 80% shows a very excellent effect.

[0029]

According to the present invention, insolubilized gelatin can be produced simply and at low cost. The synthetic resin and the rubber molded product containing the insolubilized gelatin of the present invention are superior in hygroscopicity to the conventional one. When the particle size of the insolubilized gelatin is 5 to 25 μm, the moisture absorption rate is particularly high, and the moisture absorption is excellent.

Claims (2)

(57) [Claims] 1. A method for producing a resin modifier, wherein solid gelatin powder or glue powder is brought into contact with a crosslinking agent to carry out an insolubilization reaction. 2. The method according to claim 1, wherein the particle size of the powder is 5 to 30 μm, and the powder is brought into contact with a crosslinking agent in a fluid state.