JP3419975B2 - Monomer cast nylon molded from polyamide composition - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating monomer-cast nylon molded from a polyamide composition, particularly a composition obtained by uniformly dispersing and blending a wax in a polyamide resin. It is concerned. [0002] Polyamide, especially monomer-cast nylon, has a sliding property and is used as a sliding material in a lubricant-free state. Since lubricating properties become insufficient, it has been proposed to add a lubricant. Wax or the like is used as the lubricant. [0003] When wax is used as a lubricant, ε-caprolactam is anionically polymerized,
When the polyamide resin is obtained, the molten ε-caprolactam and the lubricant may be separated due to a difference in specific gravity or non-melting properties, and the dispersion of the lubricant may be uneven. When the dispersion of the lubricant becomes non-uniform, the degree of lubricity becomes partially non-uniform or a part having a different appearance is generated within a single product. Also, the degree of lubricity varies between products of the same type, or products having different appearances are generated. Furthermore, since the separation of the lubricant easily occurs, there is a disadvantage that the molding conditions are restricted. DISCLOSURE OF THE INVENTION The present inventors have solved the above-mentioned conventional problems and have as an object to obtain a monomer cast nylon molded from a polyamide composition obtained by uniformly dispersing and blending a lubricant. As a result, the present inventors have reached the present invention which achieves this object. That is, the gist of the present invention is as follows: 100 parts by weight of poly-ε-caprolactam, 1 to 12 parts by weight of a polyethylene wax, and 0.1 part of a modified polyethylene wax having a hydroxyl group or an epoxide group in a terminal and / or a side chain. Monomer cast molded from polyamide composition obtained by dispersing and blending at a ratio of ~ 5 parts by weight
Exist in nylon . DETAILED DESCRIPTION OF THE INVENTION The polyethylene wax (hereinafter abbreviated as PE wax) used in the present invention has a relatively low molecular weight such as a molecular weight of 800 to 12000, and usually has a melting point of 90 to 140. ° C., for example, as a by-product in the production of polyethylene by polymerizing ethylene, or by the decomposition or direct polymerization of ethylene. The modified polyethylene wax having a hydroxyl group or an epoxide group at a terminal and / or a side chain (hereinafter, the modified polyethylene wax is sometimes abbreviated as a modified PE wax) used in the present invention has a molecular weight of about 800 to 12000 and a melting point of about 800 to 12,000. Is usually 90-140 ° C. The production of these modified PE waxes having a polar group may be carried out according to a method conventionally known as a method for adding a polar group. For example, in order to add a hydroxyl group, the end of PE wax is once substituted with ethylene oxide, which is further changed to a hydroxyl group. The addition of the epoxide group
For example, by treatment with peracetic acid. The PE wax obtained by these methods having about 1 to 3 hydroxyl groups or epoxide groups at the terminal or side chain is used. In the present invention, the mixing ratio of PE wax is 1 to 100 parts by weight of poly-ε-caprolactam.
To 12 parts by weight, preferably 2 to 6 parts by weight. If this proportion is less than 1 part by weight, the lubricating effect is poor, while
Exceeds parts by weight, the monomers which are molded from the composition
The mechanical strength of cast nylon decreases, which is not preferable as an engineering plastic. In the present invention, the blending ratio of the modified PE wax having a hydroxyl group or an epoxide group at the terminal and / or the side chain is poly-ε-caprolactam 1
0.1 to 5 parts by weight, preferably 0.1 to 5 parts by weight, per 100 parts by weight.
3 to 3 parts by weight. When the proportion is less than 0.1 part by weight, the effect of dispersing the lubricant is poor, while when the proportion exceeds 5 parts by weight, the polymerization of ε-caprolactam is inhibited, and the monomer cast formed from the composition is cast. Niro
The mechanical strength of the emission is reduced. [0008] The modified PE wax compounded in the present invention has a hydroxyl group at the terminal and / or side chain.
Alternatively, a compound having an epoxide group in a side chain may be used alone or in combination of both, or in addition to these compounds, a modified PE wax having another polar group such as a carboxyl group may be added. The modified PE wax may have a polar group of a hydroxyl group or an epoxide group at one end (or side chain), and may have another polar group at the other end (or side chain). The composition used in the present invention can be produced by a conventionally known anionic polymerization method. That is, PE wax and the above-mentioned modified PE wax are added to anhydrous ε-caprolactam, and in the presence of an anionic polymerization catalyst and a polymerization promoter, the melting point of ε-caprolactam or more and the melting point of poly-ε-caprolactam or less (usually 130
To 180 ° C.) to anionically polymerize ε-caprolactam. The polymerization catalyst and the polymerization co-catalyst may be those usually used.Examples of the polymerization catalyst include alkali metals, alkaline earth metals or hydrides, hydroxides and oxides of these metals, and also as polymerization co-catalysts. Is used, for example, isocyanates, triazines, and substituted ureas in the range of usually 0.05 to 2 mol%. EXAMPLES Next, examples of the present invention and comparative examples for comparison therewith will be shown, but the present invention is not limited by the following examples. In the following Examples and Comparative Examples, a monomer cast molded by each composition was used.
For ILON , the limit PV value (unit: kg / cm ² · m
/ Min) and tensile strength (kg / cm ² ). The limit PV value indicates the evaluation of lubricity and wear resistance,
This value Toyo Baldwin Co. Suzuki type abrasion by friction tester, a monomer which is molded from a polyamide composition
Cast nylon and S-45C steel are subjected to surface pressure (P) 50 (k
g / cm ² ) and a friction speed (V) of 5 (m / cm ² ).
Min), and shows the maximum value of PV that does not cause abnormal wear for 3 minutes. The shape and dimensions of a mold for molding the monomer cast nylon are 50 mm in inner diameter and 120 mm in length.
It is a 0 mm iron cylinder with a bottom lid and is installed vertically. The tensile strength is a value obtained by performing the ASTM D-638 method at room temperature. Examples 1 to 11 and Comparative Examples 1 to 6 Anhydrous ε-caprolactam 50 was added to a stainless steel beaker.
Take parts by weight and adjust to 160 ° C. To this was added 0.5 parts by weight of a polymerization co-catalyst, tolylene diisocyanate, and a pre-melted PE wax (molecular weight 4000, melting point 132
° C) and 1-3 at the end of one molecule of PE wax or in the side chain.
Modified waxes into which individual hydroxyl groups or epoxide groups have been introduced are added in various parts by weight ratios described in Table 1 below, followed by uniform stirring. Anhydrous ε- is added to another stainless steel beaker.
Take 50 parts by weight of caprolactam, add 0.2 parts by weight of sodium hydride (63% oily) as a polymerization catalyst, and adjust to 150 ° C. This was mixed with the above-mentioned mixture containing PE wax and the like, and after homogenizing the system, the mixture was poured into a mold at 160 ° C. to obtain a cylindrical molded article of a poly ε-caprolactam composition in which a lubricant and the like were dispersed. Obtained. [0012] In the cylindrical molded article obtained as described above, the amount (parts by weight) of the PE wax blended in the production thereof and the modified wax include those having a hydroxyl group and those having an epoxide group. Separately, the respective compounding amount (parts by weight) and the limit PV value (unit: 50 mm from the upper part of the molded article) and lower part (the part 30 mm from the lower part of the molded article) of the obtained cylindrical molded article (unit: k
g / cm ² · m / min) and tensile strength (unit kg / cm ² )
Are shown in Table 1. In the table, Actual 1 is Example 1 and Ratio 1 is Comparative Example 1.
, And similarly displayed. [Table 1] Examples 12 to 14 and Comparative Examples 7 to 12 100 parts by weight of ε-caprolactam, previously adjusted to 160 ° C., were taken in a glass measuring cylinder having a capacity of 100 CC.
PE wax (molecular weight 4000, melting point 132 ° C.) which has been adjusted to 160 ° C. in advance and modified PE wax having 1-3 hydroxyl groups or epoxide groups introduced into one end and / or side chain of the molecular weight of PE wax are added thereto. The mixture was added in various parts by weight as described in Table 2 below, sealed, sealed, shaken for 20 seconds in order to mix completely completely, and then placed in an oven at 160 ° C.
Immediately after standing for minutes, the separated PE wax and modified P
Table 2 shows the separation amount (parts by weight) of both mixtures of E wax (referred to as total PE wax in Table 2 below). [Table 2] The mode of example in Table 2, both the invention
Pair used to mold nomer cast nylon
The amount of the total PE wax collected during the production of the product is compared with the total amount of the PE wax. at a ratio of outside invention are often separated of total PE wax, according to the mixing ratio, resulting monomer Cass
It is self-evident that the properties of the nylon are not uniform and unfavorable. Comparative Example 12 is shown for reference that separation does not occur even when a large amount of the modified PE wax is blended. Note that, in Table 2, Actual 12 represents Example 12 and Ratio 7 represents Comparative Example 7, and will be similarly indicated below. An embodiment of the present invention is as follows. (1) A modified PE wax produced by a monomer casting method, wherein 1 to 12 parts by weight of a PE wax is contained in 100 parts by weight of poly-ε-caprolactam and 1 to 12 parts by weight of a hydroxyl group or an epoxide group is present in a terminal and / or side chain Cast Niro molded from a polyamide composition obtained by dispersing and blending 0.1 to 5 parts by weight of
N. (2) PE wax to be blended has a molecular weight of 800 to 120.
A monomer key molded from a polyamide composition
Just nylon. (3) The PE wax to be blended is a monomer cast molded from a polyamide composition having a melting point of 90 to 140 ° C.
Nylon. (4) The modified PE wax to be blended has a molecular weight of 800-1.
2000 molded from a polyamide composition
-Cast nylon. (5) The modified PE wax to be blended has a melting point of 90 to 140.
The monomer cap molded from the polyamide composition at
STYLON. According to the present invention, it is difficult to disperse P by itself.
A polyamide composition in which the above blend is uniformly dispersed by blending E wax with a modified PE wax having a hydroxyl group or an epoxide group in a terminal and / or a side chain .
Thus, a molded monomer cast nylon is obtained.

Claims (1)

(57) Claims 1. 100 parts by weight of poly-ε-caprolactam, 1 to 12 parts by weight of a polyethylene wax and a modified polyethylene wax having a hydroxyl group or an epoxy group at a terminal and / or a side chain. Dispersed at a ratio of 0.1 to 5 parts by weight,
Monomer molded from blended polyamide composition
Cast nylon.