JPS6258365B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a vinyl chloride resin composition. More specifically, the present invention relates to a vinyl chloride resin composition suitable for use in gaskets in which plasticizer transfer is small, particularly to acrylic coatings, etc., resulting in very little contamination of the coating. [Prior art] Soft vinyl chloride resin compositions have been widely used as gaskets, but when a general-purpose plasticizer such as DOP is used as a plasticizer, the plasticizer in the composition migrates. There were many cases of contamination and deterioration of the materials with which it came into contact. In order to improve this problem, it has been considered to increase the molecular weight of the plasticizer, and in fact, adipate polyester plasticizers with an average molecular weight of 1000 or more have come to be widely used. However, this does not necessarily satisfy everyone.
For example, as electric refrigerators, which were conventionally only white, become colored, a very small amount of plasticizer migration may occur on the contact surface between the steel plate painted with acrylic paint and the gasket. Of course, even if this degree of contamination occurs, it will not damage the coating under normal use conditions and is considered to be of no practical problem, but it may impair the aesthetics and other commercial value, and improvements are desired. Generally, as the molecular weight of a polyester plasticizer increases, the amount of migration tends to decrease, but an increase in the molecular weight leads to an increase in the viscosity of the plasticizer.
The actual situation is that the workability of mixing with the vinyl chloride resin is significantly reduced, which is undesirable, and the expected effects are not obtained. Furthermore, polymer blends of rubber-based polymers and vinyl chloride resins are difficult to obtain sufficient flexibility required for gaskets and are not practical. In addition, polyester with an average molecular weight of 1,000 or more consisting of an aliphatic dibasic acid, a diol, and a monohydric alcohol or a monobasic acid is used for polyvinyl chloride, and the diol component contains 2-ethyl-2-n-butyl-1.3.
- Vinyl chloride resin compositions containing 50% or more of propanediol (abbreviated as DMH) as a plasticizer have less migration of the plasticizer, especially migration to acrylic paints and very little contamination, but are soft at low temperatures. Sexuality is impaired. [Problems to be Solved by the Invention] The present invention provides vinyl chloride that has little plasticizer migration, does not impair low-temperature flexibility, and has low viscosity of the plasticizer, so it has good workability when mixed with vinyl chloride resin. An object of the present invention is to provide a resin composition. [Means for solving the problem] The present invention provides that, for 100 parts by weight of polyvinyl chloride,
A polyester plasticizer with an average molecular weight of 1,000 to 5,000 is prepared by using 2-ethyl-2-alkyl-1,3-propanediol as a diol mixed with 10 to 50% by weight of a trimellitic acid ester plasticizer.
This is a polyvinyl chloride resin composition containing 150 parts by weight. If the content of the trimellitic acid ester plasticizer used in the present invention is too low, sufficient low-temperature flexibility will not be obtained, and if the content is too high, the oil resistance, which is the original characteristic of polyester plasticizers, will be reduced.
Examples of the trimellitic acid ester plasticizers include tri(2-ethylhexyl) trimellitate, trioctyl trimellitate, triisooctyl trimellitate, tri(1-methylheptyl) trimellitate, tri(n-heptyl) trimellitate, and trimellitate. Tri(n-nonyl), triisodecyl trimellistate, trimellitic acid and n-
Mention may be made of triesters with a mixture of heptyl alcohol and n-nonyl alcohol, and triesters with a mixture of trimellitic acid and a primary alcohol having 6 to 10 carbon atoms. As the diol used in the present invention, 2-ethyl-
A polyester plasticizer using 2-alkyl-1,3-propanediol is disclosed in Japanese Patent Application Laid-open No. 1986-
It can be produced by the method described in No. 199049, and is obtained by heat-reacting an aliphatic dicarboxylic acid, an aliphatic diol, and an aliphatic alcohol in the presence of a catalyst such as tetraisopropyltitanate. As the aliphatic dicarboxylic acid to be used, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, etc. can be used alone or in a mixture of two or more thereof. Aliphatic diols include 2-ethyl, 2-alkyl 1.3
One or more mixtures of propanediol and the diol and other diols such as propylene glycol, butanediol, pentanediol,
Mixtures with hexanediol and the like can be used. The alkyl group of the 2-ethyl-2-alkyl 1,3 propanediol preferably has 2 to 4 carbon atoms, more preferably an ethyl group or n-
It is a butyl group. As the aliphatic alcohol, common aliphatic alcohols such as hexanol, heptanol, n-octanol, 2-ethylhexanol, stearyl alcohol, and cetyl alcohol can be used. Especially carbon number is 6~
Higher aliphatic alcohols of about 16% are preferred. When the molecular weight of the polyester plasticizer used in the present invention is less than 1000, non-migrating properties are required. On the other hand, if the molecular weight exceeds 5,000, the viscosity increases, which lowers the workability of mixing with polyvinyl chloride and lowers the low-temperature flexibility, which is undesirable. The polyvinyl chloride used in the present invention includes:
Commercially available homopolymers, copolymers or graft copolymers can be used. It is possible to use stabilizers, lubricants, fillers, pigments and other additives commonly used in soft vinyl chloride resin compositions, but metal soaps are recommended as stabilizers, and lead stabilizers and tin stabilizers are not recommended. Some polyester plasticizers are incompatible, so care must be taken when using them. Mixing and kneading methods for producing the composition of the present invention can be performed by known methods. [Example] The present invention will be explained below with reference to Examples and Comparative Examples.
Examples 1 and 2, Comparative Examples 1 to 4 Polyvinyl chloride resin (Nipolitto (trademark)
homopolymer with a degree of polymerization of 1300), 70 parts by weight of various plasticizers shown in Table 1, 3 parts by weight of epoxidized soybean oil as a stabilizer, 2 parts by weight of a Ba-Zn liquid stabilizer, and 1 part by weight of an organic phosphorite. Parts by weight were mixed in a Hensel mixer and kneaded for 7 minutes with an 8-inch roll at a roll temperature of 160°C. the obtained sheet
The sheet was press-molded in a press molding machine at 170° C. under a press pressure of 150 kg/cm ² for 3 minutes and cooling for 3 minutes, and predetermined test pieces were prepared from the obtained press sheets and subjected to various tests. These results are shown in Table 1. Plasticizer A used in these Examples and Comparative Examples
D represents the following: A: Commercially available polyester plasticizer with a weight average molecular weight of 1930 synthesized using adipic acid and 1,3-butanediol. B: Commercially available polyester plasticizer with a weight average molecular weight of 1730 synthesized using adipic acid and an equimolar mixture of 1,3-butanediol and 1,4-butanediol. C: Adipic acid and 2-ethyl-2-n-butyl-1.3 by the method disclosed in JP-A-60-199049.
- A polyester plasticizer with a weight average molecular weight of 1900 synthesized using propanediol. D: Adipic acid and 2-ethyl-2-n-butyl-1.
A polyester plasticizer with a weight average molecular weight of 2300 synthesized using an equimolar mixture of 3-propanediol and 2-ethylhexanol. The entire plasticizer used in Example 1 was Plasticizer C.
and trimellitic acid tri(2-ethylhexyl) ester (TOTM) in a ratio of 7:3, and the entire plasticizer used in Example 2 was plasticizer D.
and TOTM in a ratio of 7:3. The tensile strength and elongation were measured according to JIS K6723, the hardness test was measured according to JIS K6301 (spring type A type hardness tester), and the low temperature flexibility was measured according to the flexibility temperature test JIS K6745. In the migration test, a pre-weighed 50 x 50 x 1 mm sample was placed in close contact with two 60 x 60 x 0.5 mm acrylic painted plates, a 1 kg weight was placed on top of the sample, and a 1 kg weight was placed on top of the sample. 70℃ humidity
Leave it in a constant temperature and humidity chamber at 80% for 240 hours. Thereafter, the sample piece is taken out of the tank, the weight of the sample piece is measured, and the weight change rate is taken as the transfer rate. The above results are shown in Table 1. As can be seen from this table, the viscosity of the plasticizer according to the present invention is lower than that of the comparative example, and the performance of the vinyl chloride resin composition is excellent in non-migration properties, and does not impair low-temperature flexibility. 【table】

Claims (1)

[Scope of Claims] 1. 2-ethyl-2-alkyl-1.3 as a diol prepared by mixing 10 to 50% by weight of a trimellitic acid ester based binder to 100 parts by weight of polyvinyl chloride.
−Average molecular weight 1000 using propanediol
A polyvinyl chloride resin composition containing 20 to 150 parts by weight of a polyester plasticizer of ~5000. 2. The composition according to claim 1, wherein the alkyl in the 2-ethyl-2-alkyl-1,3-propanediol is an alkyl having 2 to 4 carbon atoms. 3 2-ethyl-2-alkyl-1,3-propanediol is 2,2-diethyl-1,3-propanediol and 2-ethyl-2-n-butyl-
The composition according to claim 2, which is at least one type of 1,3-propanediol.