JPS58101126A - Expandable vinyl chloride resin composition for gasket of refrigerator - Google Patents

Abstract

PURPOSE:The titled composition for reducing power consumption, preventing reduction in performance caused by the rough of appearance, obtained by blending vinyl chloride polymer with specific amounts of polymethyl methacrylate, calcium carbonate, plasticizer, blowing agent, stabilizer and lubricant. CONSTITUTION:100pts.wt. vinyl chloride polymer is blended with 5-15pts.wt. polymethyl methacrylate, 10-30pts.wt. calcium carbonate, 60-80pts.wt. plasticizer (e.g., polyester of adipic acid, etc.), 0.5-1.5pts.wt. blowing agent (e.g. azodicarbonamide, etc.), 1-3pts.wt. stabilizer (e.g., calcium silicate, etc.) and 2- 4pts.wt. lubricant (e.g., plyethylene wax), to give the desired expandable vinyl chloride resin composition for gasket of refrigerator.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a foamed vinyl chloride resin composition for refrigerator gaskets.

Conventionally, refrigerator gaskets have been made of soft vinyl chloride resin. This soft PVC resin has a high thermal conductivity, so there is a large amount of heat leaking into the refrigerator from outside the refrigerator, and it is also affected by the cold air inside the refrigerator, causing the temperature of the part that comes into contact with the outside air to drop, and in high humidity environments. In this case, condensation was observed on the gasket surface. Heater capacity is required to prevent this condensation, which increases power consumption. Therefore, as previously filed in Utility Model Application No. 56-108°1, the present inventors revealed that it would be effective to make the refrigerator gasket a foam material in order to reduce this power consumption. . However, compared to non-foamed materials, foamed materials have the disadvantage that foaming causes roughness in appearance and lowers performance.

Until now, vinyl chloride resin foams have been studied sparingly, but
The reality is that a foamed vinyl chloride resin composition with performance that can be used for refrigerator gaskets has not yet been provided.

An object of the present invention is to provide a foamed vinyl chloride resin composition that eliminates the drawbacks of the prior art described above, has a beautiful surface, and satisfies the required performance as a refrigerator gasket. In other words, the present invention provides a gas foot surface K that is in contact with the outside air under a high humidity environment.
Although the foam does not cause condensation and does not increase power consumption, it prevents the appearance from becoming rough and reducing performance as with conventional foam. The present invention provides a foamed vinyl chloride resin composition for use in polyvinyl chloride.

In order to achieve the above object, the present inventors.

As a result of extensive research into vinyl chloride resin compositions through numerous experiments and detailed tests, we found that vinyl chloride polymers, polymethyl methacrylate (hereinafter abbreviated as PHMA), calcium carbonate, plasticizers, blowing agents, It has been found that it is sufficient to add appropriate amounts of stabilizers and lubricants -IIIJ/C.

That is, 1. The characteristic feature of the foamed vinyl chloride resin composition for cold door gaskets of the present invention is that 1.
00 parts by weight, PHMA 5-15 parts by weight.

Consists of 10-50 parts by weight of calcium carbonate, 60-80 parts by weight of a warming agent, ~1.5 parts by weight of a blowing agent O, S, 1-5 parts by weight of a stabilizer, and 2-4 parts by weight of a lubricant. be. The gasket obtained using such a composition of the present invention has a beautiful appearance, low thermal conductivity, and has the required tensile strength (80υ or more), elongation (200% or more),
Transferability to PS, heat loss (150℃, 1% or less after 15 minutes), flexibility, compressive strength (more than 5oooo times)
It satisfies the following.

As described above, the present invention provides vinyl chloride polymer K
This can only be achieved by simultaneously adding appropriate amounts of PHMA, calcium carbonate, plasticizer, blowing agent, stabilizer, and lubricant.

Next, the reason for limiting the blending amount of the materials used in the present invention will be described.

For 100 parts by weight of vinyl chloride polymer, Hl.

The reason why the amount is 5 to 15 parts by weight is that if more than 15 parts by weight is added, flexibility deteriorates, and if it is less than 5 parts by weight, the appearance becomes dull. The reason why calcium carbonate was set at 10 to 50 parts by weight for 100 parts by weight of vinyl chloride polymer was that adding more than 50 parts by weight would result in poor flexibility and elongation, while adding less than 10 parts by weight would result in poor tensile strength. Because it gets worse.

60 parts of plasticizer per 100 parts by weight of vinyl chloride polymer
~80 parts by weight is because if it is 80 parts by weight or more, ABS
This is because, if the amount is less than 60 parts by weight, the flexibility will deteriorate. The reason why the blowing agent is 0.5 to 1.5 parts by weight per 100 parts by weight of vinyl chloride is that if it exceeds 1.5 parts by weight, the appearance will deteriorate;
This is because foaming hardly occurs when the amount is less than 0.5 parts by weight. The reason why the amount of stabilizer is 1 to 5 parts by weight per 100 parts by weight of the vinyl chloride polymer is that even if 5 parts by weight or more is added, the effect of increasing the amount is not observed. This is to cause deterioration. Vinyl chloride polymer 10
The reason why the lubricant is 2 to 4 parts by weight compared to 0 parts by weight is 4 parts by weight.
This is because if more than 2 parts by weight is added, the gelation during resin crosstalk will be impaired, and if it is less than 2 parts by weight, the external properties will be poor.

Preferred vinyl chloride polymers used in the present invention include polymers having an average degree of polymerization of 800 to 1,500, such as those under the trade name Kane Ace (manufactured by Kanefuchi Kagakujima). Preferred HN in the present invention has a molecular weight of about 60,000 to 1
It is worth 50,000. Preferred plasticizers for the present invention include adipic acid polyester or a mixture of adipic acid polyester and epoxidized soybean oil. Preferred blowing agents for the present invention include azodicarbonamide, or a mixture of azodicarbonamide and zinc. Preferred stabilizers in the present invention include calcium, t or calcium-zinc silicate. Preferred lubricants in the present invention include polyethylene straw/X and montan acid wax.

Preferable gasket molding conditions for the composition of the present invention are as follows.

Depending on the foaming temperature of the composition, the cylinder temperature range CI,
Cm, Cs, C41t Set to lower IEO range 11.

Cs: 140-150°C.

Cs: 160-180°C.

Cs: 120-150°C.

C4: 120-130°C.

For each cylinder temperature, the die temperature is D: 120~1
30 degrees Celsius.

EXAMPLES The present invention will be specifically explained below using examples, and the effects of the present invention will be demonstrated using comparative examples.

For each of Examples 1 to 14, a finely powdered degraded vinyl polymer (a polymer with an average degree of polymerization of 800 to 1,500) was added to Product name "Kane Ace" manufactured by Fuchi Kagaku ■, powdered pH)
dA (molecular weight 60,000 to 150,000), calcium carbonate, and one of adipic acid polyester or a mixture of adipic acid polyester and epoxidized soybean oil as a plasticizer, and gas generation when thermally decomposed. The amount is 270n
atlt (measured at normal temperature and pressure) 1 decomposition temperature is 160
7Zodicarbonamide with a gas generation amount of 240 m4/f (measured at normal temperature and normal pressure) and a hot metal of I lead with a decomposition temperature of 150°C to 160°C as a blowing agent, Add one of calcium or calcium-zinc as a stabilizer, add one of polyethylene wax or heptathanic acid wax as a lubricant, and thoroughly tri-blend these to make them uniform. Or, after tri-blending, pelletize and extrude the next material into a gasket).

Among the properties of the obtained gasket, tensile strength, elongation, loss on heating, and compressive strength were measured, and migration properties, flexibility, appearance, and thermal deterioration were visually evaluated.

The results are summarized in Table 1. Table 1 also lists the judgment of whether or not it can be used as a gasket based on the above performance, and the thermal conductivity of these gaskets is o,
11F/*℃, and the thermal conductivity of conventional gaskets is 0.
It was relatively small compared to the 20 f/11&C.

Comparative Examples 1 to 14 For each of Comparative Examples 1 to 14, which are not based on the present invention, the same method as in the above example was applied to 4 of the blending ratio of parts by weight of each compounding material shown in Table 2. A gasket was manufactured using the same method, and its performance was measured and judged using the same method, and the results are listed in Table 2.9.

From the table in Figure 2, it can be seen that the amount of pMhIA, plasticizer, calcium carbonate, foaming agent, stabilizer, and lubricant, which are components of the composition of the present invention, is 1 from the amount of the present invention. In the case of non-containing ingredients, such as H-glue, stabilizers, and lubricants, the tensile strength, elongation, migration properties, loss on heating, flexibility, compressive strength, appearance, and thermal deterioration are However, it had at least one performance defect and was determined to be unusable as a refrigerator gasket.

As can be seen from the above description, the foamed vinyl chloride resin composition of the present invention, which is molded into a refrigerator gasket (K), satisfies the performance requirements of refrigerator gaskets and can be used to form foamed gaskets with low thermal conductivity. It can be molded and has a remarkable effect of reducing power consumption.

Claims (1)

[Claims] 1. 100 imaginary parts of vinyl chloride polymer and polymethyklf
5 to 15 parts by weight of i19V-t and 1G of calcium tanoate.
50 parts by weight, and 60 to 80 parts by weight of plasticizer. 0.5 to 1.5 parts by weight of a blowing agent and 1 to S parts by weight of a stabilizer. A foamed vinyl chloride resin composition for a refrigerator gasket, comprising 2 to 4 parts by weight of a lubricant. 2. The plasticizer is adipic acid polyester or a mixture of adipic acid polyester and epoxidized soybean oil, and the blowing agent is azodicarbonate or azodicarbonate and zinc hot metal; The stabilizer is silicic acid or calcium-zinc. 112. The foamed vinyl chloride resin composition for a refrigerator gas foot according to claim 111, wherein the lubricant is polyethylene wax or montan acid wax.