JPH09291211A - Mixed polyamide chip, its production and polyamide moldings - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a kind of mixed polyamide chips which is composed of a mixture of two or more kinds of polyamide chips of different titanium oxide contents with specific chemical compounds, and able to retain improved homogeneity and always a constant composition and produce products of stable quality. SOLUTION: This kind of mixed polyamide chips comprises two or more kinds of polyamide chips that contain or does not contain different quantities of titanium oxide, and are mixed with a polyoxyalkylene compound (e.g. tetraoxyethylene nonyl phenylene ether) shown by a formula of R-A-O-(R'-O)n -H or R-O-(R'-O)n -H (R is a 1-16C alkyl; A is phenylene; R' is a 2-4C alkylene; (n) is 1-12). Preferably the polyoxyalkylene compound has kinematic viscosity of 5000cSt or less at 30 deg.C. Sufficient effects are obtained when the difference of titanium oxide contents is 0.03wt.% or more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved mixed polyamide chip obtained by mixing two or more kinds of titanium oxide-containing or non-containing titanium oxide polyamide chips. More specifically, the present invention relates to an improvement in mixing of two or more kinds of titanium oxide-containing or non-containing polyamide chips, which are difficult to uniformly mix because the titanium oxide contents are different from each other and therefore the electrostatic voltages due to friction are different.

[0002]

2. Description of the Related Art Generally, polyamide resins are excellent in abrasion resistance, impact resistance, chemical resistance, moldability and mechanical strength, and are used in a wide range of fields such as fibers and resins for industrial and clothing, and films. Has been done. Depending on the application, the luster of polyamide is unnecessary, so titanium oxide, a white pigment, is added as a matting agent. Since this titanium oxide needs to be uniformly dispersed in the polyamide, it is generally added when the polyamide is polymerized.

By the way, since the amount of titanium oxide added varies greatly depending on its use, it is necessary to produce many types of polyamides having different titanium oxide contents. However, it is inefficient and unsuitable for industrial production to obtain each of these various types of polyamides by polymerization. Therefore, a method is generally used in which a master chip having a large amount of titanium oxide is prepared in advance, and the master chip is added and mixed at the time of drying the polyamide chip to obtain a polyamide resin having a desired titanium oxide content. Is used for.

However, when polyamide chips having different titanium oxide contents are mixed and dried by a rotary vacuum dryer,
When taking out the mixed chips, there is a problem that the ratio of the master chips is reduced at the end of taking out the mixed chips, resulting in defective product uniformity. Although various additions of various additives have been proposed for improving the performance of polyamide chips, the disclosure discloses the finding that uniform mixing of two or more types of chips having different titanium oxide contents is improved. There is no.

[0005]

SUMMARY OF THE INVENTION Therefore, the present invention provides a polyamide mixed chip capable of improving the mixing uniformity of two or more kinds of polyamide chips having different titanium oxide contents and always having a constant composition. It is an object of the present invention to provide a polyamide mixed chip capable of producing polyamide molded products such as polyamide fibers, resin molded products, films and the like having stable quality without any trouble in the subsequent yarn making process and molding process.

[0006]

In order to achieve this object, the mixed polyamide chip of the present invention comprises two or more kinds of titanium oxide-containing or non-containing titanium oxide having different titanium oxide contents, and the polyamide chip. 1 to 700 ppm relative to the total weight of the polyoxyalkylene compound represented by the following general formula (I) or (II).

R-A-O- (R'-O) n-H .. (I) R-O- (R'-O) n-H .. (II) [where R is a carbon number 1 To 16 alkyl groups, A is a phenylene group, R'is a C2-4 alkylene group, and n is 1
Indicates an integer of -12. ]

Further, the method for producing a mixed polyamide chip of the present invention is such that when two or more kinds of titanium oxide-containing or non-containing polyamide chips having mutually different titanium oxide contents are mixed, 1 ~ 700
It is characterized by adding ppm of the polyoxyalkylene compound represented by the general formula (I) or (II).

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The polyamide that can be used in the present invention may be any known polyamide such as nylon 6 or nylon 66. Specifically, ε-
Caprolactam, 6-aminocaproic acid, ω-enanthlactam, 7-aminoheptanoic acid, α-pyrrolidone, α
-Polymers or copolymers obtained from piperidone etc., hexamethylenediamine, nonamethylenediamine,
Diamines such as dodecamethylenediamine and metaxylenediamine, and terephthalic acid, isophthalic acid, adipic acid,
Examples thereof include polymers or copolymers obtained by polycondensing dicarboxylic acids such as sebacic acid.

The polyamide chips having different titanium oxide contents used in the present invention may be those in which titanium oxide is added by any method, for example, they may be added by melt kneading after polymerization, or may be added at the time of polymerization. Good. Also,
There are no restrictions on the size or shape of the chip.

The polyamide chips used in the present invention may have any content of titanium oxide, one of which may be titanium oxide-free, that is, 0% by weight. The non-uniformity of mixing is caused by the relative difference in titanium oxide content of the polyamide chips to be mixed, and is remarkable when the difference in content is 0.03% by weight or more. The electrification voltage generated by friction when rotating and mixing the chips depends on the titanium oxide content of the chips, and the master chip with high titanium oxide content is strongly positive compared to the chip without titanium oxide or low content. Get charged. Therefore,
This strongly positively charged chip is likely to adhere to the wall surface of the dryer or the chip hopper, and the composition tends to be non-uniform when the chip is mixed or taken out. However, by adding an appropriate amount of the above-mentioned specific polyoxyalkylene compound, the electrification voltage of the mixed chip is lowered, chip separation is suppressed, and mixing uniformity is improved.

The polyoxyalkylene compound used in the present invention may be a compound represented by the above-mentioned general formula (I) or (II), specifically, tetraoxyethylene nonylphenylene ether, pentaoxyethylene dodecyl ether. And the like.

The viscosity of this polyoxyalkylene compound preferably has a kinematic viscosity of not more than 5000 cst at 30 ° C. Even if the viscosity is high, the uniform mixing property of the chips is improved, but it is not preferable because it takes a long time for mixing to easily generate polymer powder.

The addition rate of the polyoxyalkylene compound is 1
-700 ppm, preferably 10-100 ppm. When the addition rate is less than 1 ppm, the effect of uniform mixing of chips cannot be obtained, and when it exceeds 700 ppm, the mixing property of chips is improved, but the heat resistance of polyamide moldings obtained by using the added polyoxyalkylene compound. Is less suitable for practical use.

Any method may be used as a method of adding and mixing the polyoxyalkylene compound to the polyamide chips at the time of mixing, and the mixing may be carried out by using an ordinary blender or the rotary dryer. .

The mixed polyamide chips obtained by mixing by the above method are melt-molded by a method such as ordinary melt spinning, melt extrusion, melt injection molding or the like to produce polyamito molded articles such as polyamide fiber and polyamide film. It

[0017]

The present invention will be described in more detail with reference to the following examples.

[Evaluation method] (a) Charge voltage of mixed chips: 500 g of mixed polyamide chips were placed in a stainless steel container of 5 liters and left and right 3
After shaking for 0 second, the potential at a distance of 10 cm from the chip was measured by a current collector-type potential measuring device (KS-525 manufactured by Kasuga Denki).

(B) Color tone: The spun filament yarn is knitted in a tubular shape (knitting using 29 needles in 1 inch, 50
13 cm with 0 g load, 10.5 c without load
m) and the yellowness (Y) by S & M color computer (Suga Test Machine model SM-4).
I) and brightness (L) were measured by the reflection method. The heat treatment was performed with a hot air dryer at 150 ° C. for 1 hour, and the subsequent YI was treated with YI.

(C) Titanium oxide content: After wet-decomposing the mixed chip with sulfuric acid and perchloric acid, the absorbance at a wavelength of 410 nm was measured and calculated.

EXAMPLE 1 Titanium oxide-free nylon 6 chip A (diameter 2.0 mm, length 3.5 mm) having a relative viscosity of 2.75 (measured with a 1% solution of 98% by weight sulfuric acid at 25 ° C.) , Moisture content 0.020% by weight) 2231 kg, relative viscosity 2.60, nylon 6 chip B containing titanium oxide 2.05% by weight (shape and moisture content are the same as chip A) 1
64 kg, tetraoxyethylene nonyl phenyl ether (trade name "Nonipore" 40, Sanyo Kasei Co., Ltd.
2.5 g (1 pp for the total amount of nylon 6 tips)
m) was added, and the mixture was mixed for 1 hour at a rotation speed of 5 revolutions / minute using a rotary dryer at room temperature and atmospheric pressure.

Thereafter, the obtained mixed chips were taken out from the dryer at a constant speed for about 30 minutes. The titanium oxide content at that time was measured at the start and the end of taking out.
As shown in Table 2, the titanium oxide contents were almost the same at the beginning and the end of the take-out, and a substantially constant composition could be maintained from the beginning to the end of taking-out.

[Example 2] The type and amount of the polyaxyalkylene compound was changed to pentaoxyethylene alkyl ether (trade name "Nonipore" SS50, Sanyo Kasei Co., Ltd.).
Made) 22g (10pp for the total amount of nylon 6 tips)
Chips were mixed and taken out in the same manner as in Example 1 except that m) was changed. At that time, the titanium oxide contents at the beginning and the end of taking-out were almost the same as shown in Table 2, and a substantially constant composition could be maintained from the beginning to the end of taking-out.

[Example 3] Nylon 6 chip C containing 0.02% by weight of titanium oxide having a relative viscosity of 2.75 (measured with a 1% solution of 98% by weight sulfuric acid at 25 ° C) (shape and moisture content are as described above). 2231 kg (the same as the chip A) and 140 kg of the nylon 6 chip B used in Example 1, 45 g (nylon 6) of pentaoxyethylene alkyl ether (trade name “Nonipore” SS50, Sanyo Kasei Co., Ltd.)
20 ppm) was added to the total amount of chips, and chips were mixed and taken out in the same manner as in Example 1. At that time, the titanium oxide contents at the beginning and the end of taking-out were almost the same as shown in Table 2, and a substantially constant composition could be maintained from the beginning to the end of taking-out.

Example 4 Chips were mixed and taken out under the same method and conditions as in Example 2 except that the addition rate of the polyoxyalkylene compound was changed to 100 ppm. At that time, the titanium oxide contents at the beginning and the end of taking-out were almost the same as shown in Table 2, and a substantially constant composition could be maintained from the beginning to the end of taking-out.

[Example 5] Chips were mixed and taken out under the same method and conditions as in Example 3 except that the addition rate of the polyoxyalkylene compound was changed to 700 ppm. At that time, the titanium oxide contents at the beginning and the end of the taking-out were almost the same as shown in Table 2, and a substantially constant composition could be maintained from the beginning to the end of taking-out.

Comparative Example 1 Chips were mixed and taken out under the same method and conditions as in Example 1 except that no polyoxyalkylene compound was added. The content rate of titanium oxide in the mixed chips taken out at that time was much lower at the end than at the start, and the content rate decreased with time as the chips were taken out.

Comparative Example 2 Chips were mixed and taken out under the same method and conditions as in Example 1 except that the addition rate of the polyoxyalkylene compound was changed to 1000 ppm. At that time, the titanium oxide content at the start and the end of the extraction is shown in Table 2.
It was almost the same as shown in.

[0029]

[Table 1]

[0030]

[Table 2]

The mixed chips obtained in Examples 1 to 5 and Comparative Examples 1 and 2 were fed from a spinning hopper to a melt spinning machine,
Melt-spun and stretched in the usual manner to produce 70 denier 24 filament nylon 6 filament yarn. The obtained filament yarn was formed into a tubular knitted fabric by a usual method, and the color tone was measured. Further, the color tone after the heat treatment was measured.

Table 3 shows the results. In the cases of Examples 1 to 5 and Comparative Example 1, the color tone was good within the range where there was no problem. However, when added in excess of 700 ppm (Comparative Example 2), the heat resistance of the polymer was poor, and after heat treatment (150 ° C.).
The color tone of (× 1 hour) deteriorated. Further, in the case of Comparative Example 1, there was a large variation in the titanium oxide concentration in the mixed tip, so there was a large variation in the yellowness (YI) of the knitted fabric.

[0033]

[Table 3]

[0034]

EFFECTS OF THE INVENTION According to the present invention, mixed chips composed of two or more kinds of titanium oxide-containing or non-containing titanium oxide polyamide chips having mutually different titanium oxide contents can be always supplied with a stable composition. It is possible to obtain a stable polyamide product. Therefore, a polyamide composition having a constant titanium oxide content can be stably produced by the master chip method.

As a result, molded products such as polyamide fibers and films having stable quality can be easily manufactured industrially.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08L 71:02)

Claims (7)

[Claims] 1. Polyamide chips containing or not containing two or more kinds of titanium oxide having different titanium oxide contents, and 1 to the total weight of the polyamide chips.
A mixed polyamide chip, which is obtained by mixing 700 ppm of a polyoxyalkylene compound represented by the following general formula (I) or (II). R-A-O- (R'-O) n-H .. (I) R-O- (R'-O) n-H .. (II) [wherein R has 1 to 16 carbon atoms. An alkyl group, A is a phenylene group, R'is an alkylene group having 2 to 4 carbon atoms, and n is 1
Indicates an integer of -12. ] 2. The titanium oxide content of two or more types of titanium chips containing or not containing titanium oxide different from each other in titanium oxide content is different from each other by 0.03% by weight or more. Mixed polyamide chips. 3. The content of the polyoxyalkylene compound is 10 to 10 relative to the total weight of the polyamide chips.
It is 0 ppm, The mixed polyamide chip of Claim 1 or 2 characterized by the above-mentioned. 4. When mixing two or more kinds of titanium chips containing or not containing titanium oxide having different titanium oxide contents, the following general formula (1 to 700 ppm based on the total weight of the polyamide chips: I) or (I
A method for producing a mixed polyamide chip, which comprises adding the polyoxyalkylene compound represented by I). R-A-O- (R'-O) n-H .. (I) R-O- (R'-O) n-H .. (II) [wherein R has 1 to 16 carbon atoms. An alkyl group, A is a phenylene group, R'is an alkylene group having 2 to 4 carbon atoms, and n is 1
Indicates an integer of -12. ] 5. The mixing of the polyoxyalkylene compound and the polyamide chips containing or not containing two or more kinds of titanium oxide having different titanium oxide contents from each other is performed in a rotary dryer. A method for producing the mixed polyamide chip described. 6. The titanium oxide content of two or more types of titanium oxide-containing or non-containing polyamide chips having mutually different titanium oxide contents differ from each other by 0.03% by weight or more. 5. The method for producing a mixed polyamide chip as described in 5. 7. A polyamide molded product obtained by melt-shaping the mixed polyamide chip according to claim 1, 2, or 3.