JPS6126580B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel thermal stabilizer that provides excellent thermal stability during molding and processing of chlorine-containing resins. More specifically, the present invention relates to a stabilizer for chlorine-containing resins containing a polyhydroxyester reaction product obtained by partially esterifying glycerin or polyglycerols with aromatic polybasic acids, aliphatic polybasic acids, or derivatives thereof. Chlorine-containing resins tend to become colored and deteriorate when irradiated with light or heated. Therefore, stabilizers are added to chlorine-containing resins to stabilize them against light or heat. Conventionally, such stabilizers are often lead salts or cadmium salts of higher saturated fatty acids such as lead stearate and cadmium stearate, or inorganic lead salts such as tribasic lead sulfate and dibasic lead phosphite. was used by. In addition, organotin compounds such as dibutyltin malate and dioctyltin malate have been widely used to maintain the transparency of chlorine-containing resins. However, these compounds containing lead, cadmium, or tin are harmful to the human body, and recently environmental and sanitary pollution caused by these heavy metals has become a problem. The use of stabilizers has been limited or regulated. Currently, stabilizers for chlorine-containing resins are shifting from the lead-based and cadmium-based stabilizers to zinc-based stabilizers such as calcium-zinc and barium-zinc, which are attracting attention as non-toxic compounds. However, these non-toxic stabilizers have significantly inferior stabilizing performance compared to the lead, cadmium and tin compounds mentioned above. Therefore, it is necessary to stabilize the chlorine-containing resin by adding a compound that is non-toxic to the human body and has an excellent ability to stabilize the chlorine-containing resin. Although various additives or additive aids have been proposed for this purpose, their effects have not yet been satisfactory. The present inventors combined at least one member selected from the group consisting of glycerin and polyglycerols into a group consisting of aromatic polybasic acids, aliphatic polybasic acids, and derivatives thereof such as esters, acid halides, and acid anhydrides. It has been discovered that a polyhydroxyester reaction product containing 10 to 40% hydroxyl groups partially esterified with at least one selected from It was completed. In addition, the said hydroxyl group content rate is shown by the following formula. Hydroxyl group content (%) Parts by weight of hydroxyl groups in polyhydroxy ester reaction product/Parts by weight of polyhydroxy ester reaction product x 100 The polyglycerin used in the present invention has the general formula () (where n is an integer of 0 or 1 or more) (for example, diglycerin where n = 0, triglycerin where n = 1, n =
2) such as tetraglycerin. The aromatic polybasic acids used in the present invention include di-, tri-, or higher-carbon polycarboxylic acids having 8 or more carbon atoms, such as phthalic acid, isophthalic acid, terephthalic acid, oxyphthalic acid, dioxyphthalic acid, hemitolitic acid, and trimellitic acid. , trimesic acid, pyromellitic acid, merophanic acid, mellitic acid and the like. Examples of aliphatic polybasic acids include dicarbonates having 4 or more carbon atoms,
tri- or higher polycarboxylic acids, such as maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, glutaconic acid, propane-1,
Examples include 2,3-tricarboxylic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, malic acid, tartaric acid, citric acid, and glyceric acid. Derivatives of these polybasic acids, such as esters, acid halides, and acid anhydrides, can also be used to partially esterify the polyols. In the present invention, when the reaction is carried out using, for example, 2 moles of diglycerin as the polyol component and 1 mole of adipic acid as the polybasic acid component, the resulting polyhydroxyester reaction product has the following structural formula: It is assumed that the compounds shown are the main ones. In the present invention, a reaction product having an arbitrary hydroxyl group content and ester value can be obtained by appropriately changing the molar ratio of glycerin or polyglycerols and aromatic and aliphatic polybasic acids or their derivatives. can. However, the thermal stabilization effect on chlorine-containing resins is not so great when all or most of the hydroxyl groups inherent in polyols are esterified, and conversely, when the degree of esterification of the hydroxyl groups is too low, polyols are Since the disadvantages of the polyols themselves will appear, the reaction product should have at least one ester bond per molecule of raw material polyol on average, and the reaction product should have 10 to 40% of hydroxyl groups. It is necessary to be present. Chlorine-containing resins that can be used with the stabilizer of the present invention include homopolymers such as vinyl chloride and vinylidene chloride, and copolymers and graft polymers of vinyl chloride. Among these copolymers, vinyl chloride and monomers copolymerizable with it, such as vinyl chloride-ethylene copolymer, vinyl chloride-vinyl acetate copolymer, and vinyl chloride-vinylidene chloride copolymer, are included. Includes copolymers with. Examples of the graft polymer include a graft copolymer obtained by graft-polymerizing vinyl chloride onto an ethylene-vinyl acetate copolymer.
Such chlorine-containing resins are not limited to being used alone, but may be used in combination of two or more types. The stabilizer of the present invention is particularly characterized in that it imparts good thermal stability to polyvinyl chloride resins which are generally widely used. Normally, when processing polyvinyl chloride resin,
Commonly known metal soap type stabilizers such as calcium-zinc type, barium-zinc type or magnesium-zinc type stabilizers or composite type liquid stabilizers are used.
The reaction product of the present invention has a strong function of further promoting the stabilizing effect of these stabilizers, and its use in combination with these stabilizers is the most preferred form of use. In addition to these zinc-based stabilizers, there is no problem in using lead-based, cadmium-based, tin-based stabilizers, etc. in combination, and the combination with tin-based stabilizers is particularly preferred as a low toxicity formulation. The amount of the stabilizer used in the present invention depends on the type and amount of the stabilizer, such as calcium-zinc, barium-zinc, or magnesium-zinc, but the amount of the stabilizer added is 100 parts by weight (parts by weight) of the chlorine-containing resin. ), the effect is higher than 0.1 part, and the higher the amount, the more heat coloring.
Although it takes longer to darken, it is actually enough to treat up to 10 areas. The heat resistance test was carried out by mixing the materials in accordance with the method actually used for processing chlorine-containing resins, kneading them with rolls, and creating a sheet.
A method is adopted in which the sheet is placed in a gear oven and its changes over time are observed. According to the test results, phenomena of blackening, opacity, and surface deterioration were observed early on in the case where the stabilizer of the present invention was not added, but in the case where the stabilizer of the present invention was added. ,
It was shown that the blackening time was significantly extended as the amount added was larger. Furthermore, it has been observed that the sheet surface to which the stabilizer of the present invention was added does not lose its gloss, the flexibility of the sheet is not impaired even if it becomes black, and mechanical deterioration is prevented. It was done. Regarding the stabilization mechanism of the polyhydroxyester reaction product of the present invention against chlorine-containing resins,
Although there are still many unclear points, high hydroxyl group content,
This is thought to be based on the good symmetry of the molecular structure and the good compatibility with resins due to the relatively high molecular weight. It is of course possible to use the stabilizer of the present invention in combination with other stabilizers against heat and light, and additives such as plasticizers, lubricants, and pigments. Next, the stabilizer of the present invention will be explained with reference to Examples. Example (1) Synthesis of stabilizer (polyhydroxy ester reaction product) 125 g (0.075 mol) of terephthalic acid was added to 25 g (0.15 mol) of diglycerin and heated to an internal temperature of 200 mol.
The dehydration reaction was carried out at ~250°C with stirring. The reaction time was 2 hours, and the amount of water removed was 25 g. The obtained diglycerin-terephthalic acid partial ester was a fairly viscous liquid at room temperature. The hydroxyl group content of this reaction product is 220%,
The ester value was 240 and the acid value was 0.4. This sample corresponds to sample No. 4 in Table 1 below. In the same manner, various polyhydroxy ester reaction products (Samples Nos. 1 to 9) were obtained using diglycerin and various polybasic acids as shown in Table 1.

【table】

[Table] (2) Chlorine-containing resin thermal stability test 100 parts of polyvinyl chloride resin, 3 parts of calcium-zinc liquid stabilizer, and 3 parts of epoxy soybean oil
A standard formulation (comparative example) consisting of 190 to 200 parts was added with 2 parts each of the various polyhydroxy ester reaction products shown in Table 1 above.
A sheet with a thickness of 1 mm was created by kneading it with a roll for 5 minutes at ℃, and the sheet was placed in a gear oven at 190 ℃, and the sheet was taken out at 10 minute intervals to observe coloration and changes over time. Example 1~
9). Additionally, the amount of sample No. 4 added to the standard formulation was varied to examine the effect of increasing the amount. (No.10
~12). The above results are shown in Table 2.

[Table] From Table 2, it can be seen that the products to which the stabilizer of the present invention was added had much better thermal stability than the comparative examples, and also had a remarkable weight-increasing effect.

Claims (1)

[Scope of Claims] 1. At least one selected from the group consisting of glycerins such as glycerin and polyglycerin, and at least one selected from the group consisting of aromatic polybasic acids, aliphatic polybasic acids, and derivatives thereof. Stabilizer for chlorine-containing resins containing a polyhydroxy ester reaction product containing 10-40% hydroxyl groups partially esterified with seeds. 2. The stabilizer according to claim 1, wherein the glycerin is diglycerin. 3 Aromatic polybasic acid is phthalic acid, isophthalic acid,
The stabilizer according to claim 1, which is terephthalic acid, trimellitic acid or pyromellitic acid. 4 Aliphatic polybasic acids include maleic acid, fumaric acid, succinic acid, adipic acid, sebacic acid, itaconic acid,
The stabilizer according to claim 1, which is tartaric acid, citric acid or malic acid. 5. The stabilizer according to claim 1, wherein the chlorine-containing resin is a vinyl chloride resin. 6. Claim 1 in which the stabilizer for chlorine-containing resin containing a polyhydroxyester reaction product with a hydroxyl group content of 10 to 40% also contains a zinc-based stabilizer such as calcium-zinc or barium-zinc. Stabilizers listed in section.