JPS6114168B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to new and useful acetylcellulose resin compositions. More specifically, the present invention relates to an acetyl cellulose resin composition plasticized with polycaprolactone polyol. If cellulose acetate is heated and melted as it is, it will decompose or become colored before it softens. Molding compositions therefore cannot be thermoplastically processed without the addition of plasticizers. For this purpose, suitable plasticizers must be mixed in before the thermoplastic processing. Various plasticizers are used for this purpose. Typical examples include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dimethoxyethyl phthalate, ethyl phthalyl ethyl glycolate, butylphthalyl butyl glycolate, diglycerin tetraacetate, O-toluenesulfonamide, P- Examples include toluenesulfonamide, triacetin, triphenyl phosphate, and tricresyl phosphate. That is, there are a limited number of plasticizers that are compatible with cellulose acetate, such as phthalic acid esters, glycolic acid derivatives, glycerin derivatives, and phosphoric acid esters, which have short alkyl groups. Molded products made from these resin compositions include sheets,
Films, pipes, rods, stamp materials, ornaments, eyeglass frames,
There is a wide variety of products such as car handles, tool handles, tableware handles, medical equipment, packaging materials, and toys. At the same time, these acetylcellulose resin compositions are now required to have a very wide range of performance, so the required performance as a plasticizer for acetylcellulose resin compositions is to have good plasticizing ability. , good retention, and high transparency. In other words, decorative items and eyeglass frames require low volatility, low migration, low extraction, and good hue.
When used in tools, oil resistance and impact resistance are required as important properties, and when used in food utensils, medical equipment, food packaging materials, toys, etc., toxicity, low migration, and antibacterial properties are required. Gender becomes an issue. When viewed from this perspective, the above-mentioned plasticizers that have been used conventionally have not always been able to satisfy these performances. As a result of various studies from this point of view, the present inventors have discovered that polycaprolactone polyol is a good plasticizer that satisfies the performance of acetyl cellulose resin compositions, and has arrived at the present invention. That is, the present invention is an acetyl cellulose resin composition containing a polycaprolactone polyol represented by the following general formula [1]. (l, m, n in the formula are positive integers, 1≦l+m
+n≦10, and R is the main chain of the polyhydric alcohol. ) The polycaprolactone polyol used in the present invention is synthesized by ring-opening reaction of ε-caprolactone using a polyhydric alcohol as an initiator, or by mixing and heating a polyhydric alcohol and oxycaproic acid to cause a dehydration esterification reaction. It is something that can be obtained. Polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, 1,
3-butylene glycol, 1,4-butylene glycol, 2-methyl-1,3-propylene glycol, 1,5-pentyl glycol, neopentyl glycol, 1,6-hexanediol, dipropylene glycol, 2,3,5 trimethylpentane Diol, trimethylol, propane, glycerin, trimethylolethane, pentaerythritol, dipentaneerythritol, sucrose, etc. can be used, and neopentyl glycol, trimethylolethane, trimethylolpropane, and glycerin are particularly preferred. As a catalyst for ring-opening polymerization of ε-caprolactone using a polyhydric alcohol as a starting point, organic titanium compounds, tin compounds, metal salts of acetylacetone, etc. are used. Examples of organic titanium compounds include tetrabutyl titanate, tetrapropyl titanate, tetraethyl titanate, etc.; examples of organic tin compounds include tin octylate, dibutyltin oxide, dibutyltin laurate, stannous chloride, stannous bromide,
It is preferable to use stannous iodide or the like. The amount of catalyst used is 0.05 to 5000 ppm, preferably 0.1 to 1000 ppm. The hydroxyl value of polycaprolactone polyol synthesized using the above polyhydric alcohol as an initiator is 35~
560 KOH-mg/g is preferred. More preferably, the polycaprolactone polyol synthesized using a dihydric alcohol as an initiator has a hydroxyl value of 37 to
370 KOH-mg/g, and the hydroxyl value of polycaprolactone polyol synthesized starting from trihydric alcohol is 150 to 560 KOH-mg/g. A specific example of the above-mentioned polycaprolactone polyol is one obtained by ring-opening reaction of ε-caprolactone using trimethylolpropane as an initiator.
Average molecular weight 310, hydroxyl value 543KOH-mg/g, melting point -40℃, average molecular weight 550, hydroxyl value 306
(KOH-mg/g) Melting point -43℃ Hazen hue 130
The following is a transparent liquid caprocton polyol. If the average molecular weight of the polycaprolactone polyol is less than about 250, the vapor pressure will be high and it will evaporate or thermally decompose during thermal processing, resulting in a lack of thermal stability as a plasticizer, and the polycaprolactone polyol will scatter over time. It lacks dimensional stability etc. On the other hand, as the molecular weight increases to about 1000 or more,
As crystallization progresses and the value approaches about 1300, the plasticizing ability of the plasticizer decreases significantly, and the transparency and mechanical properties of the acetyl cellulose resin composition decrease. In addition, various stabilizers are usually added to resin compositions to prevent thermal deterioration and thermal discoloration, but the acetyl cellulose resin composition of the present invention also contains weak organic acids, epoxy compounds, thioethers, amine derivatives, and phenols. General commercially available stabilizers such as derivatives, phosphite, thiophosphite, thiourea, imidazole, metal soap, etc. are added in the necessary amount to prevent thermal deterioration and thermal coloring, either alone or in a mixture of several types to produce a synergistic effect. I can't help it. In addition, other dyes and pigments, fillers, lubricants, antistatic agents, etc. may be added depending on the purpose. Generally, about 2 to 200 parts by weight of polycaprolactone polyol can be used per 100 parts by weight of the acetyl cellulose resin, preferably about 20 to 100 parts by weight per 100 parts by weight of the resin. The cellulose acetate resin used in the present invention is preferably a cellulose diacetate resin having a degree of acetylation of 52% or more. Next, the present invention will be explained in more detail based on Examples and Comparative Examples. The present invention is not limited to these Examples. Examples 1 to 6, Comparative Examples 1 to 3 Acetyl cellulose (degree of acetylation 54.4, degree of polymerization
The plasticizers shown in Tables 1 and 2 were added to 100 parts by weight of the powder of 170), stirred and mixed, and heated and kneaded using an extruder to prepare pellets. The pellets thus obtained were then molded into test pieces (dumbbells) using an injection molding machine, and various performance tests were conducted using the test pieces. The results are shown in Tables 1 and 2 below.

【table】

[Table] Tensile strength at break and tensile elongation at break were tested in accordance with ASTM D638, and degree of coloration was measured using a digital colorimetric color difference calculator manufactured by Suga Test Instruments Co., Ltd. As shown in Table 1, it can be seen that the acetylcellulose composition according to the present invention has good flexibility and a markedly improved degree of coloration.

Claims (1)

[Claims] 1. An acetyl cellulose resin composition containing a polycaprolactone polyol represented by the following general formula [1] (l, m, n in the formula are positive integers, 1≦l+m
+n≦10, and R is the main chain of the polyhydric alcohol. )