KR20130045573A - Cellulose ester based composites for eyeglass frame - Google Patents

Abstract

PURPOSE: A cellulose ester-based composite is provided to improve the heat flow of cellulose acetate, thereby conducting injection molding. CONSTITUTION: A cellulose ester-based composite comprises a cellulose ester and a polyalkylene glycol as a base material. The comprised amount of the cellulose ester is 50-90 weight% and the amount of the polyalkylene glycol is 10-50 weight% based on total the weight of the base material. The composite additionally comprises one or more additives selected from a filler, an oxidation preventing agent, dye, and a pigment. The comprised amount of the additive is 1-5 parts by weight based on 100.0 parts by weight. [Reference numerals] (AA,FF) Example 1; (BB,GG) Example 2; (CC,HH) Comparative example 1; (DD,II) Comparative example 2; (EE) Elution evaluation for a water soluble solvent plasticizer; (JJ) Elution evaluation for a fat soluble solvent plasticizer

Description

Cellulose ester-based composites for eyeglass frames {Cellulose ester based composites for eyeglass frame}

The present invention relates to a cellulose ester-based composite material for eyeglass frames, and more particularly, to an environment-friendly cellulose ester-based composite material capable of injection molding without the use of environmentally harmful plasticizers and having high gloss.

Cellulose Acetate (hereinafter referred to as 'CA') is a material that distinguishes itself from general-purpose eyeglass frame material, and expresses beautiful color and pattern after pigment incorporation compared to other synthetic polymer eyeglass frames, and has a separate coating even when scratch occurs Gloss can be restored by polishing without a process, and has been spotlighted as a high value-added spectacle frame material due to its excellent form stability. In addition, the market share is showing a steady growth in recent years, the interest and demand for CA eyeglass frames are increasing in Korea.

However, CA alone does not have enough thermoplastic, and if melted by heating as it is, there is a problem of causing decomposition or coloring before softening. The molding method of CA generally used is a solution extraction method using a solvent, and this method has a disadvantage in that environmental recovery is large and productivity is low due to difficult recovery of the solvent. In order to overcome this disadvantage, a melt processing method for forming by heat by reducing the Tg by using a plasticizer has been developed and has been used until now for the molding of CA eyeglass frames and various films.

Plasticizers used for melt processing include various types of phthalic acid, trimellitic acid, phosphite, epoxy series, etc., depending on the chemical structure, and about 80% of the plasticizers used are phthalate-based plasticizers. However, as phthalate plasticizers were identified as environmental hormones that are harmful to humans and the environment in the 1980s, their use is being restricted worldwide, including the EU. Research and CA melting technology is in progress.

According to the traditional manufacturing method for CA eyeglass frames, CA eyeglass frames are produced by injecting phthalate-based plasticizers to melt-melt, then producing pellets and then producing a plate to go through numerous subsequent processes such as cutting and polishing of eyeglass frame types. . However, in the melt extrusion process in which phthalate plasticizer is introduced, the problem of plasticizer fuming due to the high temperature extrusion conditions negatively affects the working environment, and is also caused by the formation of a large number of bubbles in the plasticizing resin due to the plasticizer fuming problem. Injection molding is not possible due to the problem of deterioration of the quality of the product.

Republic of Korea Patent Publication No. 10-20011-00515575 "Eco-friendly plastic composite materials and eco-friendly automotive interior materials" in the triacetin and epoxidized soybean oil as a plasticizer to introduce lignin as a compatibilizer and to increase the thermal fluidity to make a composite material with CA and polypropylene Was introduced. Although the patent has an advantage of producing an environmentally friendly composite material using an eco-friendly plasticizer, the melting characteristics of CA and polypropylene are limited, so triacetin and epoxidized soybean oil are introduced, and triacetin, a monomolecular plasticizer, is also introduced. There is still a problem of plasticizer volatilization due to use.

According to an aspect of the present invention, a cellulose ester and polyalkylene glycol are included as a main agent, the cellulose ester is 50 to 90% by weight, and the polyalkylene glycol is 10 to 50% by weight based on the total weight of the main material. Provided is a cellulose ester-based composite material for an eyeglass frame.

According to another aspect of the present invention, cellulose acetate and polyethylene glycol as a main body, the cellulose acetate 50 to 90% by weight, the polyethylene glycol contains 10 to 50% by weight relative to the total weight of the main body, the polyethylene Provided is a cellulose ester-based composite material for eyeglass frames having a mass average molecular weight of glycol of 200 to 4000.

According to another aspect of the invention, there is provided a spectacle frame comprising the composite material.

1 is a photograph of a CA plate produced according to the Examples and Comparative Examples. (A) Example 1, (b) Example 2, (c) Comparative Example 1, and (d) Comparative Example 2.
2 is a plasticizer elution test results of the CA plate prepared according to the Examples and Comparative Examples.
Figure 3 is a photograph of Example 1 and Comparative Example 1 melt extrusion carried out under the extrusion conditions of Table 1.

The cellulose ester-based composite material for eyeglass frames according to an embodiment of the present invention includes cellulose ester and polyalkylene glycol as main components. Wherein the cellulose ester contains 50 to 90% by weight and the polyalkylene glycol contains 10 to 50% by weight relative to the total weight of the base.

In addition, the cellulose ester-based composite material for the spectacle frame may further include one or more additives selected from fillers, antioxidants, dyes, and pigments based on the above components. The additive may be used 1 to 5 parts by weight based on 100 parts by weight of the main body of the cellulose ester-based composite material for eyeglass frames of the present invention.

The cellulose ester, which is one of the main components of the present invention, is not particularly limited as long as it has a processability and mechanical properties suitable for the manufacture of eyeglass frames. And cellulose decanoate, and the like, and these can be used alone or in combination. Among these, cellulose acetate (CA) can be used preferably.

In the present specification, the cellulose ester as the main ingredient includes cellulose fatty acid mixed ester as well as the cellulose fatty acid single esters listed above. That is, the cellulose esters include cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate propionate butyrate, cellulose acetate hexanoate, cellulose acetate octanoate, cellulose acetate decanoate, and the like. Cypionate can be preferably used.

Polyalkylene glycol, one of the main components of the present invention, is used as a plasticizer for melt processing, and specifically, a polyethylene glycol, polypropylene glycol and polybutylene glycol having a mass average molecular weight of 200 to 2000, preferably 200 to 1000. These etc. can be mentioned, These can be used individually or in combination. Among these, polyethyleneglycol can be used preferably.

The cellulose ester-based composite material for eyeglass frames according to an embodiment of the present invention includes cellulose acetate (CA) and polyethylene glycol (PEG) as main components. Here, the cellulose acetate 50 to 90% by weight, the polyethylene glycol contains 10 to 50% by weight relative to the total weight of the base material, the mass average molecular weight of the polyethylene glycol is 200 to 2000.

The CA, which is one of the main components of the present invention, uses a CA having an average substitution degree of 1.6 to 2.7, and PEG in consideration of compatibility and extrudability with polyethylene glycol (PEG) according to the change of the average substitution degree of the used CA. The usage of can be determined relatively. Average substitution degree refers to the number which the acyl group chemically couple | bonded among the three hydroxyl groups which exist per glucose unit of cellulose, and the maximum value of average substitution degree is 3.0. In the case of CA having low substitution value, it is desirable to increase the amount of low molecular weight PEG and PEG due to insufficient thermal fluidity.In the case of CA having high substitution value, high molecular weight PEG is used or PEG is used. It is desirable that this be reduced.

The CA is preferably used 50 to 90% by weight, more preferably 60 to 80% by weight of the total weight of the base material. At this time, if the amount of CA is less than the above range may be a weak mechanical properties, if used in excess of the above range because the compatibility and thermal fluidity with PEG may be reduced, there may be a problem during melt extrusion, use within the above range Good to do.

The PEG, which is one of the main components of the present invention, preferably uses 10 to 50% by weight, more preferably 20 to 40% by weight, based on the molecular weight of the PEG and its compatibility with CA. It can be determined relatively in consideration.

The cellulose ester composite material for eyeglass frames of the present invention can improve the thermal fluidity of CA by using PEG without the use of environmentally harmful plasticizers, which are conventionally used, and thus, injection molding is possible and the manufactured eyeglass frames have high glossiness. .

In the case of the specimen melt-extruded cellulose ester composite material for eyeglass frames of the present invention may have a high gloss of 90 or more surface gloss at a value of 65 ° for medium to high gloss. In addition, the specimen made of the cellulose ester composite material for the spectacle frame of the present invention is very small that the plasticizer is eluted with respect to the fat-soluble solvent. For example, when a specimen made of CA (70% by weight) and PEG (30% by weight) is immersed in gasoline at 25 ° C. for 72 hours, the total weight change due to PEG elution may be 5% by weight or less.

According to one embodiment of the present invention, an eyeglass frame including a cellulose ester-based composite material is provided. The cellulose ester-based composite material used for the spectacle frame includes cellulose ester and polyalkylene glycol. The cellulose ester-based composite material may be injection molded at a processing temperature of 160 to 230 ° C., or extruded to manufacture pellets, and then eco-friendly eyeglass frames may be manufactured through injection molding and a mold process.

The cellulose ester-based composite material of the present invention not only has excellent mechanical strength, but is also an environmentally friendly composite material, and the spectacle frame made of the composite material of the present invention is very excellent in gloss and may replace the existing spectacle frame material. It is expected.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the spirit of the present invention is not limited to the following Examples.

[Example]

1. Examples 1 and 2

CA (Eastman, mass average molecular weight 50,000) / PEG (Aldrich) composite material was prepared under the conditions shown in Table 1. CA and PEG were added to the extruder with the composition shown in Table 1 below and melt extruded at the screw chamber temperature of Table 1 to prepare CA composite pellets. The CA composite material prepared by the above method was manufactured in the dumbbell-shaped plate under the conditions of Table 1 using a melt molding machine for measuring various physical properties.

2. Comparative Examples 1 and 2

Two kinds of pellets for CA spectacle frames containing 30% by weight of diethylphthalate, a phthalate-based plasticizer, were obtained, and a dumbbell-shaped plate was formed under the molding conditions of Table 1 using an extrusion molding machine to measure various physical properties thereof. Prepared.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Composition CA Degree of substitution 2.5 2.5 Lotba CA
Pellets (USA) Mazukelly
CA pellet
(Italy) Mass average molecular weight 50,000 50,000 Content [wt%] 75 70 PEG Mass average molecular weight 400 400 Content [wt%] 25 30 Processing condition Extrusion conditions Chamber temperature [℃] 210 210 200 200 Machining time [min.] 5 5 5 5 Screw speed [rpm] 60 60 60 60 Molding conditions Molding temperature [℃] 210 210 200 200 Molding time [min.] 5 5 5 5

3. Test Example 1

Physical properties of the CA plate produced in the above Examples and Comparative Examples were measured using the following method. Tensile tests were carried out using a universal testing machine according to ASTM D 638, and measured the values of tensile strength, elongation and modulus of elasticity at room temperature and the results are shown in Table 2.

4. Test Example 2

The glossiness of the CA plate produced in Examples and Comparative Examples was measured using the following method. In order to make the surface state of the CA plate the same, the surface was polished using a polishing machine, and the abrasive used was a 0.25 탆 diamond abrasive and a 0.05 탆 alumina abrasive. The polishing rate was fixed at 600 rpm and the polishing time was performed for 1 minute. The surface glossiness of the surface of the polished film was measured by using a gloss meter, and the average value was obtained after five measurements of 65 ° value for medium to high gloss, and the results are shown in Table 2.

Mechanical properties Glossiness Tensile Strength (kgf / mm ² ) Elongation (%) Modulus of elasticity (kgf / mm ² ) Example 1 6.0 3.8 105.4 93.3 Example 2 5.6 3.9 94.3 94.4 Comparative Example 1 5.3 6.6 85.4 81.2 Comparative Example 2 5.4 6.7 87.9 82.3

5. Test Example 3

Plasticizer elution was measured to confirm the stability of the CA plate prepared in Examples and Comparative Examples. Distilled water, a water-soluble solvent, and gasoline, a water-soluble solvent, were used as the test solvent, and the film was vacuum-dried at 30 ° C. for 24 hours, cut into 2 cm and 5 cm lengths, and then immersed in 100 ml of solvent. After 24 hours, 48 hours, and 72 hours at 25 ° C., vacuum drying was again performed at 30 ° C. for 24 hours, and the weight loss rate of the film before and after dipping was measured to calculate migration as a percentage of weight change.

6. Evaluation

1 is a photograph of a CA plate produced in Examples and Comparative Examples. (A) Example 1, (b) Example 2, (c) Comparative Example 1 and (d) Comparative Example 2 are shown, respectively.

Looking at the experimental results of Table 2, in the case of Example 1 and Example 2 of the CA / PEG composite material in the present invention, excellent tensile strength when compared with Comparative Example 1 and Comparative Example 2, which is a CA resin for general eyeglass frames As it was confirmed, the elongation was also low, and thus the shape stability of the spectacle frame was also excellent.

In particular, it was confirmed that the glossiness corresponding to the physical properties important as the use of the spectacle frame also showed higher values than Examples 1 and 2.

2 is a plasticizer elution test results of the CA plate prepared according to the Examples and Comparative Examples. 2, in the case of Example 1 and Example 2, which is a CA / PEG composite material in the present invention, compared to Comparative Examples 1 and 2, which is a CA resin for general eyeglass frames, excellent stability in a fat-soluble solvent It was confirmed that the same level was seen in the water-soluble solvent.

Figure 3 is a photograph of Example 1 and Comparative Example 1 melt extrusion carried out under the extrusion conditions of Table 1. Referring to FIG. 3, as shown in the extrusion picture of FIG. 3, in the case of Comparative Example 1, which is a CA resin for general spectacle frames, it is extruded into an opaque foamed melt due to the fuming phenomenon of a phthalate-based plasticizer, whereas a CA / PEG composite In the case of Example 1, which is a raw material, a transparent melt without foaming is extruded.

As described above, in the present invention, by introducing PEG known as a biocompatible polymer without the use of phthalate-based plasticizers defined as environmental hormones, the smoke phenomenon is significantly reduced, and injection molding is possible as well as the existing mold processing method. Compared to the spectacle frame properties, composite materials for the spectacle frame possessing glossiness and mechanical properties equal to or higher than those of the spectacle frame may be manufactured.

Claims (7)

Mainly comprising cellulose ester and polyalkylene glycol,
A cellulose ester-based composite material for eyeglass frames containing 50 to 90% by weight of the cellulose ester, and 10 to 50% by weight of the polyalkylene glycol, based on the total weight of the main material. The method according to claim 1,
Cellulose ester-based composite material for eyeglass frames further comprising at least one additive selected from fillers, antioxidants, dyes and pigments. The method according to claim 1,
The additive is a cellulose ester-based composite material for eyeglass frames 1 to 5 parts by weight based on 100 parts by weight of the main material. The method according to claim 1,
The mass average molecular weight of the polyalkylene glycol is 200 to 2000 cellulose ester-based composite material for eyeglass frames. Mainly comprising cellulose acetate and polyethylene glycol,
50 to 90% by weight of the cellulose acetate, 10 to 50% by weight of the polyethylene glycol, based on the total weight of the main body,
Mass average molecular weight of the polyethylene glycol is 200 to 2000 cellulose ester-based composite material for eyeglass frames. The method according to claim 1,
Cellulose ester-based composite material for eyeglass frames including 1 to 5 parts by weight based on 100 parts by weight of the main material further comprising at least one additive selected from fillers, antioxidants, dyes and pigments. A spectacle frame comprising the composite material of any one of claims 1 to 6.

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