JPS6049655B2 - Antifogging treatment method for cellulose acetate propionate plastic molded articles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for antifogging treatment of cellulose acetate propionate plastic moldings.

Recently, plastic molded products have been used in many fields such as general sunglasses, ski goggles, industrial dustproof glasses, and motorcycle windshield glasses, but conventional plastic molded products are sensitive to ambient temperature and humidity. It easily became cloudy as it changed, making it extremely inconvenient to use.

For this reason, there are 74-n-m-n-L゛↓'', /1-7-- in Plastier's first glance, but among them, for example,
As described in US Pat. No. 3,700,487, a method of making the surface of a molded article hydrophilic by saponification treatment to produce an antifogging effect is well known, and is widely used because the effect is semi-permanent with a simple treatment. For example, in the case of cellulose diacetate plastic molded products, the temperature is 30°C to 60°C.
A cellulose acetate plastic molded product having antifogging properties can be easily obtained by immersing the molded product in a sodium hydroxide or potassium hydroxide aqueous solution having a concentration of 112N to 1N at a temperature of 1 to 6 times. However, cellulose diacetate plastic has poor water resistance and dimensional stability, and has drawbacks such as deformation of molded products when left in a hot and humid environment for a long time. Therefore, there has been a desire for a plastic molded product that has anti-fog properties, excellent water resistance and dimensional stability. The present inventor attempted to mold and saponify cellulose acetate propionate plastics, which have far superior water resistance and dimensional stability than cellulose acetate plastics, but the conventional saponification treatment performed on cellulose diacetate plastic moldings It has become clear that the treatment method cannot impart any antifogging properties.

For this reason, the present inventors conducted extensive research on methods for imparting antifogging effects to cellulose acetate propionate molded articles, and as a result, they arrived at the present invention. That is, in the present invention, (a) sodium hydroxide or (and) potassium hydroxide 8 to 1000 y of water
0 to 140q1 (b) methanol or (and) ethanol 200 to 500CC1 and (c) lower fatty acid ester of glycerin or (and) phosphoric acid plasticity 10cc or more of solution (4) added and dissolved at 40°C to There is a method for antifogging treatment of cellulose acetate propionate plastic molded articles, which is maintained at 70 DEG C. and is immersed in this solution (4) for 4 to 3 hours.

Specific examples of lower fatty acid esters of glycerin used in the present invention include monoacetin, diacetin, and triacetin.

Further, specific examples of phosphoric acid-based plasticizers include trimethyl phosphate, triethyl phosphate, and tripropyl phosphate. As mentioned above, the present inventors have conducted many studies in order to impart antifogging properties to cellulose acetate propionate plastic molded products, but the above (a), (b), and (c) of the present invention It was not possible to obtain a cellulose acetate propionate plastic molded product having good antifogging properties using an aqueous solution other than those containing the three components.

That is, an aqueous solution of sodium hydroxide and potassium hydroxide alone will hardly provide antifogging properties no matter how high the concentration, and when methanol and ethanol are added alone or in combination, lower fatty acid esters of glycerin and phosphoric acid Even if a plasticizer is not added alone or in combination,
Almost no antifogging properties were imparted.

Also, in the reverse case, almost no antifogging property was imparted. In other words, the solution (4) of the present invention can impart desirable antifogging properties to cellulose acetate propionate molded articles. Cellulose acetate propionate, which is the main component of the cellulose acetate propionate plastic treated in the present invention, is a substance obtained by esterifying some or all of the hydroxyl groups of cellulose with acetic acid and propionic acid, and is treated in the present invention. In the case where the polymerization degree is 100 or more, the acetylation degree is particularly preferably 6 to 10%,
It has properties of a propionylation degree of 54 to 57%.

The proportion of plasticity added to such cellulose acetate propionate plastic is usually 5 to 50 parts by weight per 10 parts of cellulose acetate propionate. Such plasticizers include phthalic acid esters such as dimethyl phthalate, diethyl phthalate, dimethoxyethyl phthalate, and dimethoxyhexyl phthalate;
Phosphate esters such as triphenyl phosphate and tricresyl phosphate, glycerin derivatives such as triacetin and tributyrin, glycolic acid derivatives such as methyl phthalylethyl glycolate, ethyl phthalylethyl glycol, and butylphthalyl butyl glycolate, P-toluene Sulfonic acid derivatives such as sulfonamide, toluenesulfone-N-ethylamide, other adipic acid derivatives, azelaic acid derivatives, diglycerin, polyglycerin, pentaerythritol, dipentaerythritol, trimethylolpropane, trimethylolethane, ditriethylolethane, Polyhydric alcohol lower fatty acid esters such as ditrimethylolpropane, sorbitol, mannitol, and tris(2-hydroxyethyl) isocyanurate, 1, 2,
3-butanericarboxylic acid triester, bisphenol A
Plasticizers commonly used in cellulose acetate propionate plastics, such as type epoxy resins, can be used.

Furthermore, various dyes and pigments, fillers, stabilizers, etc. may be added to the cellulose acetate propionate plastic depending on the purpose.

Next, the molded product from cellulose acetate propionate plastic may be obtained by any known technique, but it is usually produced by the following method.

(1) Casting method (2) Wet method or block method (3) Dry method, i.e., a method for obtaining a molded product using a thermoforming machine such as an injection molding machine or an extruder Cellulose acetate propionate obtained by this method The desired molded product can be obtained by further processing the plastic molded product, such as cutting, cutting, bending, and adhesion, as necessary.

As the potassium hydroxide, sodium hydroxide, methanol, etamer, lower fatty acid ester of glycerin, phosphoric acid plasticizer, etc. used to make the treatment solution of the present invention, ordinary commercially available products may be used. It is preferable to use

In the treatment solution of the present invention, sodium hydroxide and potassium hydroxide are used as component (a), either alone or in combination, and the amount added is from 80q to 140 q to 1000 Da of water.
A range of y is preferred.

If the amount added is less than 80y, satisfactory antifogging properties cannot be imparted to the cellulose acetate propionate plastic molded product. Moreover, if the amount added is 140 V or more, adverse effects such as whitening and rough skin will occur on the surface of the cellulose acetate propionate plastic molded product, which is undesirable from the viewpoint of the intended use. Furthermore, as component (b), methanol and ethanol are used alone or in combination, but the amount added is 10% water.
The range of 200cc to 500cc is preferable for an aqueous solution in which component (a) is dissolved at a ratio of 80q to 140y per 00q.

When the amount added is less than 200 cc, it is difficult to impart satisfactory antifogging properties to cellulose acetate propionate plastic molded products. Furthermore, if the amount added is less than 500 cc, it is not preferable because it causes negative effects such as whitening and rough skin on the surface of the cellulose acetate propionate plastic molded product. In addition, lower fatty acid ester of glycerin and phosphoric acid plasticizer are used alone or in combination as component (c),
The amount of addition is 1 to 80y of component (a) per 1000g of water.
For an aqueous solution dissolved at a rate of 40q, from 10cc to 4
A range of 0 cc is preferred. If the amount added is less than 10 cc, it is difficult to impart satisfactory antifogging properties to the cellulose acetate propionate plastic molded product. Further, if the amount added is 40 cc or more, it is not preferable because it tends to cause adverse effects such as whitening and rough skin on the surface of the cellulose acetate propionate plastic molded product. According to the present invention, 200 to 500 cc of methanol or ethanol, alone or in combination, is added to an aqueous solution prepared by dissolving sodium hydroxide or potassium hydroxide alone or in combination at a ratio of 80 to 140 y to 1,000 y of water. Antifogging properties are imparted by immersing a cellulose acetate propionate plastic molded product in a solution (4) obtained by adding 10 cc or more of fatty acid ester or phosphoric acid plasticizer alone or in combination, but the immersion temperature and time condition range is 40°C to 70'C and 4
A period of 3 hours is preferable.

If the temperature is below 40°C, it is difficult to impart satisfactory antifogging properties to the cellulose acetate propionate plastic molded product. On the other hand, if the temperature is 70'C or higher, the cellulose acetate propionate plastic molded product is likely to be deformed, which is not preferable. If the immersion time is less than 4 times, it is difficult to impart satisfactory antifogging properties to the cellulose acetate propionate plastic molded product. or,
If the immersion time is 3 hours or more, the cellulose acetate propionate plastic molded product will swell, whiten, and be easily deformed, which is not preferable. Substances such as solvents, surfactants, buffers, and detergents are further added to the solution used for the antifogging treatment of cellulose acetate propionate plastic moldings according to the present invention to the extent that they do not impede the effects of the present invention. I can do it.

Cellulose acetate propionate plastic moldings treated by the method of the present invention can be used no matter how the ambient temperature and humidity change under normal living conditions (e.g. outdoors during rainy or snowy weather, (or when indoors, when going in and out of the bath, etc.), there is no fogging at all.

In addition, unlike cellulose diacetate plastic molded products, it has no inferiority in water resistance or dimensional stability, so it can be used outdoors and in hot and humid environments. Cellulose acetate propionate plastic molded products that are almost completely anti-fog treated in this way are used in ski goggles, industrial dustproof glasses, sunglasses, underwater glasses, windshield glasses for motorcycles, various glass substitutes for passenger cars, mirrors for molten metal, and windows. It can be used for many purposes such as glass substitutes and products.

Preferred embodiments of the present invention will be described below. Example 1
-5 and Comparative Examples 1-6 Cellulose acetate propionate plastic sheet (dimensions 40w1.IrrL
×70m. NoMXl. 3mI no m1 Product name Ceridor C
P-M1 (manufactured by Bayer AG) was subjected to antifogging treatment by the method shown in Table 1 and Table 2.

Claims (1)

[Claims] 1 For 1000 g of water, (a) sodium hydroxide or (and) potassium hydroxide 8
0 to 140 g, (b) methanol or (and) ethanol 200 to 500 cc, and (c) a solution obtained by adding and dissolving 10 cc or more of lower fatty acid ester of glycerin or (and) phosphoric acid plasticizer (A ) from 40℃ to 70℃
1. A method for antifogging treatment of cellulose acetate propionate plastic molded articles, which comprises immersing the cellulose acetate propionate plastic molded articles in this solution (A) for 45 minutes for 3 hours while maintaining the temperature at .degree.