JPH0120178B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to polystyrene resin particles having self-extinguishing properties. Conventionally, polystyrene resin foams generally have excellent heat insulation, light weight, and processability, so
It is widely used as a building material, including wall materials, roofing material, tatami core material, and tatami base material. Therefore, these building materials are required to have self-extinguishing properties.
To this end, the following two methods have conventionally been adopted. The first method is tetrapromopisphenol A
Polystyrene resin expandable particles containing flame retardants such as 2.3 dimethyl and 2.3 diphenylbutane, flame retardant aids such as 2.3 dimethyl and 2.3 diphenylbutane, and expanding agents such as butane and pentane are pre-foamed with steam, and after ripening, they are filled into a mold. This is a method in which the resin particles are heated and expanded, the expanded and molten resin particles are fused together, and then cooled.
The second method is to manufacture a foam by a conventional method and apply a flame retardant paint to the surface of the foam. However, the first method has the disadvantage that the expanding agent remains after molding and the foam burns. Therefore, in order to make the foam exhibit self-extinguishing performance, it is necessary to dissipate the remaining swelling agent.
Generally, the drawback is that the product must be kept in stock for long periods of time due to the slow escape rate of the blowing agent. In addition, the second method requires the purchase of new coating equipment and the securing of a place to install the equipment, and is therefore economically difficult to implement. Therefore, we focused on the first method, and there is a known method proposed in Japanese Patent Application Laid-Open No. 109565/1983 as a method to improve the drawbacks of the first method. In this method, crack generators such as paraffin oil are In particular, it is desirable to add it just before pre-foaming, which requires an addition device, and there is a time constraint in that the time up to pre-foaming or foam molding must be controlled at a constant level. The present invention has been made with attention to such conventional problems, and its purpose is to treat the surface and/or the vicinity of the surface of polystyrene resin expandable particles with triglyceride during the resin particle manufacturing process. An object of the present invention is to provide polystyrene-based resin particles having self-extinguishing properties, which are treated with an ester that is a mixture of polystyrene and diglyceride and/or monoglyceride. That is, the self-extinguishing polystyrene resin particles according to the present invention contain a crack generator, that is, triglyceride, on the surface and/or near the surface of the polystyrene resin expandable particles containing a flame retardant and a volatile foaming agent. The present invention is characterized in that it is a mixture of di-glyceride and/or mono-glyceride, and is formed by containing at least 0.05 parts by weight of a processing agent containing triglyceride in a proportion of 20 to 90% by weight per particle. Here, the polystyrene resin expandable particles before being coated with the cracking generator are polymers such as styrene, methylstyrene, dimethylstyrene, chlorostyrene, and copolymers of these and butadiene. During or after the production of copolymers with acrylonitrile, isoprene, vinyl chloride, isobutylene, methyl methacrylate, etc. in suspension systems in the presence of flame retardants, volatile blowing agents such as propane , butane, isobutane, pentane, neopentane, hexane, or other aliphatic hydrocarbons, methyl chloride, tetrachloroethylene, or other halogenated hydrocarbons, or petroleum ether, etc., are impregnated into the particles in an amount of 2 to 15% by weight based on the resin. It was formed. Flame retardants include tris-dipromopropyl phosphate, chlorparaffin, tetrapromopisphenol A, hexapromocyclododecane, tetrapromobutane, tetrapromophthalic anhydride, tetrapromobisphenol A diglycidyl ether, perchloro Halogen-containing alicyclic or aromatic hydrocarbon compounds such as pentacyclodecane or derivatives thereof, and halogen-containing organic compounds such as 3.5.3'.5'-tetrapromo-4,4' dihydroxydiphenylsulfone are generally used. These are used in an amount of 0.1 to 20% by weight, preferably 0.5 to 2.0% by weight, based on the weight of the combustible material in the resin particles. If necessary, add flame retardant aids from 0.01 to 5% by weight.
It is preferably blended in a proportion of 0.1 to 1.0% by weight. Examples of flame retardant aids include organic peroxides such as methyl-t-butyl peroxide, di-t-butyl peroxide, dicumyl peroxide, ferrocene or 2,3-dimethyl-2,3-diphenylbutane, Alternatively, metal chelate compounds such as nickel salicyl aldehyde can be used. The fatty acids in the above fatty acid and glycerin esters range from C ₈ to about C ₃₀ , more preferably from C ₁₂ to about C 30.
Specifically up to C ₂₂ , lauric acid, tridecylic acid,
myristic acid, pentadecyl acid, palmitic acid,
It is an ester of glycerin and one or more fatty acids such as marcaric acid and stearic acid. Tri-esters and di-esters of fatty acids and glycerin
The optimum mixing ratio of tri-esters in the mixture with esters and/or mono-esters is between 20 and 90% by weight, preferably between 30 and 75% by weight. The reason why the mixing ratio is limited to 20 to 90% by weight is that if the mixing ratio is outside this range, an adverse effect will occur in any of the steps leading to obtaining the foamed molded product. That is, the tri-ester is 90
If it is more than 20% by weight, the generation of agglomerated particles during pre-foaming will be significant, and the amount of charge of the particles will increase, making it impossible to maintain production safety, and if it is less than 20% by weight, the molded product will exhibit self-extinguishing properties. This is because the effect of shortening time and molding cycle is poor. However, suitable mixing ratios of mixtures of glycerol esters of fatty acids can be obtained by mixing pure triglycerides with mono- or di-glycerides or mixtures of mono-, di- and tri-glycerides. can be obtained easily. That is, as triglycerides, hydrogenated oils of natural animal fats and vegetable oils, such as hydrogenated beef tallow, hydrogenated soybean oil, hydrogenated coconut oil,
There are hardened palm oils, etc., and glycerin esters of fatty acids (usually composed of mono-esters and di-esters) obtained by the reaction of glycerin and fatty acids.
A fatty acid that can be obtained by mixing appropriate amounts of distilled and purified glycerides obtained from glycerin esters of such fatty acids by appropriate distillation operations. The blending ratio of the ester of and glycerin to the styrenic resin expandable particles is 0.05 to 1.0 per 100 parts by weight of the styrene resin.
Parts by weight are suitable, and more preferably 0.1 parts by weight or more. The reason why 0.05% is set as the lower limit is that below 0.05%, the time until self-extinguishing occurs after foam molding cannot be shortened. In addition, the method of making the ester of fatty acid and glycerin exist on the surface and/or near the surface of the expandable styrenic resin expandable particles involves adding the foamed resin to the foamed resin in a continuous or batch mixer that is usually used industrially. A method in which the ester of a fatty acid and glycerin is stirred or mixed with the ester of the fatty acid and glycerin, a method in which the ester of the fatty acid and the glycerin is made into an emulsion and attached to the surface of the resin expandable particle, or simply the resin expandable particle and the There is a method of stirring and mixing the ester, or a method of dissolving the ester in a volatile solvent, adding the foamable resin particles thereto, stirring and mixing, and then volatilizing the solvent to coat the particle surface. However, the method is not particularly limited to these methods. These methods can be carried out in the process of manufacturing resin particles, and
Unlike the coating with crack generators such as paraffin oil and metal salts of unsaturated fatty acids in the well-known Japanese Patent Application Laid-Open No. 53-109565, there is no restriction that it must be added before pre-foaming, especially just before pre-foaming, and there is no addition device. Not necessary. Next, Examples and Comparative Examples of the present invention will be shown, in which (1) the surface and/or the vicinity of the surface of the polystyrene resin expandable particles is not coated immediately before pre-foaming, and the resin particles are manufactured. Even if coating treatment is sometimes performed, it is possible to leave the product for a sufficient period of time without being constrained by the requirement that the time from coating treatment to pre-foaming should be short or accurate. (2) Almost no condensation occurs during pre-foaming, and the charging potential of the pre-foamed particles is low; (3) the degree of fusion of the resin particle molded body does not decrease; (4) the molded body It will be revealed that the time required for self-extinguishing properties to develop after obtaining a product can be significantly shortened. In addition, all % in Examples and Comparative Examples means weight %. Further, the flame-retardant polystyrene resin expandable particles, which are the raw materials used in the Examples and Comparative Examples, were manufactured by the following method. That is, a mixture having the composition shown below was stirred in a pressure-resistant stirring reaction vessel and heated at 70°C for 10 hours, then at 85°C for 2 hours, and further at 90°C for 5 hours to polymerize the styrene monomer. Styrene monomer 100 parts by weight Water 100 parts by weight Polyvinyl alcohol (suspending agent) 0.3 parts by weight Benzotic peroxide (polymerization initiator)
0.3 parts by weight n-pentane (expansion agent) 4.0 parts by weight butane (expansion agent) 3.0 parts by weight hexapromocyclododecane (flame retardant)
1.0 parts by weight 2,3-dimethyl-2,3 diphenylbutane (flame retardant aid) 0.2 parts by weight After cooling the obtained globules, they were separated from the aqueous phase, washed with water,
Dry. The swelling agent was contained in the particles in an amount of 6.2% by weight. These small spheres were divided into particles having a particle size of 1.0 to 2.5 mm and used as a raw material in the following Examples and Comparative Examples. [Example 1] 100 kg of raw material was put into a batch type ribbon mixer,
Stearic acid triglyceride/stearic acid monoglyceride finely powdered to 200 μ or less = 70/30
100g of the mixture was added and stirred and mixed for 10 minutes. 1
After a day, the obtained expandable styrene resin particle composition was pre-foamed using a continuous foaming machine to an apparent density of 25 g/min, and the time required for foaming was measured. The amount of coagulum in the pre-expanded beads was measured using a wire mesh with an opening of 10 mm, and the ratio to the foamed beads was determined. After preliminary foaming, the amount of charge on the beads immediately after being air-transported to a storage silo was measured using a current collector type electric meter. Also, the state of adhesion of the pre-expanded grains to the silo at that time was observed. After the pre-expanded grains are aged in a storage silo at room temperature for 24 hours, they are molded into products with dimensions of 400mm x 400mm using a fully automatic molding machine.
A partially sealed mold measuring mm x 50 mm was filled with compressed air. Immediately after that, heat mold with 0.8Kg/cm ² G steam, change the cooling time after heat molding, take out the product, measure the molded product dimensions, and find that it is almost the same as the mold within ±3% of the mold size. The cooling time was determined as the appropriate cooling time. The molded product was fractured by bending force, and the ratio (%) of the number of broken foam particles to the total number of foam particles on the fracture surface was determined as the degree of fusion. On the other hand, the obtained foam product was stored in a drying room at 50°C, and a combustion test was conducted in accordance with JISA-9511, and the number of storage days until it passed the test, the so-called number of days for self-extinguishing properties to appear, was measured. . The above results are shown in Table 1. [Example 2] Expandable styrene resin particles whose surface was coated in the same manner as in Example 1 were pre-foamed in the same manner after 3 days.
Aging, molding and combustion tests were conducted. The results are shown in Table 1. [Comparative Example 1] 0.1% paraffin oil having a viscosity of 60 centistokes and a specific gravity of ^0.86 as measured at 15° C. was added to the raw materials, and the mixture was stirred and mixed for 10 minutes using a batch ribbon mixer. 1
After a day, the same operation as in Example 1 was performed. The results are shown in Table 1. [Comparative Example 2] The raw material whose surface was coated in the same manner as in Comparative Example 1 was pre-foamed immediately after the surface coating, and the same operation as in Example 1 was carried out. The results are shown in Table 1. [Example 3] Tri-glyceride/di-glyceride/mono-glyceride of stearic acid glycerin ester =
The same operation as in Example 1 was carried out except that the mixing ratio of 55/20/25 was changed to 100 g. The results are shown in Table 1. [Comparative Example 3] The same operation as in Example 1 was carried out except that the glyceryl stearate ester was not added. The results are shown in Table 1. From the above results, it can be seen that the mixed coating agent of tri-glyceride/di-glyceride/mono-glyceride produces the above-mentioned effects when it is coated during the manufacturing process of styrenic resin particles without being coated immediately before pre-foaming. . [Comparative Example 4] The same operation as in Example 1 was carried out except that the glycerin ester of stearic acid was changed to one in which only 100 g of stearic acid triglyceride was added.
The results are shown in Table 1. From this result, it is clear that although the presence of triglyceride shortens the time for the foam product to develop self-extinguishing properties, triglyceride alone causes significant coagulation of pre-foamed particles and deterioration of charging properties. [Comparative Example 5] Tri-glyceride/di-glyceride/mono-glyceride = glycerin ester of stearic acid
The same operation as in Example 1 was carried out except that the mixture was changed to 100 g with a mixing ratio of 10/40/50. The results are shown in Table 1. [Comparative Example 6] The same operation as in Example 1 was carried out except that 10 g of glycerin ester of stearic acid was added. The results are shown in Table 1. The results of Comparative Examples 5 and 6 show that when the mixing ratio of triglyceride is small and the amount of glyceryl stearate added is small, the effect of shortening the time to develop self-extinguishing property and the effect of shortening the cooling cycle are small. it is obvious. [Example 4] The amount of glycerin ester of stearic acid added
The same operation as in Example 1 was carried out except that the weight was changed to 500 g. The results are shown in Table 1. As is clear from the above, the self-extinguishing polystyrene resin particles of the present invention contain fatty acids and/or fatty acids on the surface and/or near the surface of the polystyrene resin expandable particles containing a flame retardant and a volatile blowing agent. Since the ester of fatty acid and glycerin is present, which is a mixture of glycerin triester and monoester and/or diester, and the blending ratio of triester is 20 to 90% by weight, the following effects are exhibited. (1) There is no restriction that the leaving time from coating polystyrene resin expandable particles containing a flame retardant and volatile foaming agent to pre-foaming must be kept short or accurately controlled. (2) Therefore, since the coating agent can be applied to the expandable resin particles during the production of the resin particles, addition work and addition equipment during pre-foaming are unnecessary. (3) There is little delay in pre-foaming time and less generation of agglomerated particles during pre-foaming, and it is easy to fill molds and transfer through pipes during the molding process. (4) The pre-expanded particles have a low charge potential and there are no safety issues. (5) A strong foam molded product with a high degree of fusion in the mold can be obtained. In addition, the cooling time for foam molding within the mold is greatly reduced, making it very economical. (6) The time required for self-extinguishing properties to develop after obtaining the product can be significantly shortened, and the product inventory period can be shortened, making it extremely economical. 【table】

Claims (1)

[Claims] 1 Triglyceride, diglyceride and/or on the surface and/or near the surface of polystyrene resin expandable particles containing a flame retardant and a volatile blowing agent.
Or self-extinguishing polystyrene-based resin particles, which are a mixture with monoglycerides and contain at least 0.05 parts by weight of a processing agent containing triglycerides in an amount of 20 to 90% by weight per particle.