JPS60203648A - Manufacture of surface-modified expandable styrene resin beads - Google Patents

Abstract

PURPOSE:To obtain the titled styrene resin beads by coating, using silicone oil as a binder in the form of aqueous emulsion, surface modifier on expandable styrene resin beads to improve its coatability to enable the adhesive force of said modifier to be enhanced even with a small amount thereof. CONSTITUTION:The objective resin beads can be obtained by incorporating (A) expandable styrene resin beads containing volatile swelling agent with (B) 0.01- 2wt% of a surface modifier with a melting point 45-130 deg.C (e.g. an ester from 12-22C higher fatty acid and glycerin) and (C) an aqueous emulsion with a viscosity 4-5,000cps, prepared by dispersing (C1) 100pts.wt. of silicone oil (pref. methyl phenyl silicone oil), (C2) 5-50pts.wt. of a lipophilic cationic surfactant and (C3) 0-100pts.wt. of polyethylene glycol with a molecular weight 100-1,000 in (C4) 100-400pts.wt. of water in such an amount as to be 0.005-0.2wt% of the component (C1) based on the component (A).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing expandable styrene thread resin particles that causes less blocking during the production of pre-expanded particles and can reduce the total cooling time during molding of foamed objects.

Volatile expansion agent? The surface of the expandable styrenic resin particles contains stearamide, zinc stearate, hardened tallow oil, glycerin tripalmitate, beeswax,
A mixture of two or more types of glycerin mono-, di- or tristearate, glycerin tristearate, hydrogenated rapeseed oil, hydrogenated fish oil, etc. with a melting point of 45 to 1
A solid interfacial modifier (also called a cracking agent) is applied at room temperature of 0θ℃ to prevent particles from blocking each other during pre-foam molding, and the mold is filled with pre-foam resin particles. A technique for shortening the total cooling time during molding and cooling of a foam by heating it with steam and causing the pre-expanded particles to fuse together is known (% 1983-97060,
British Patent No. 53-109565, British Patent No. 1409285, British Patent No. 1392467, Japanese Patent Publication No. 57-53811,
(See Publications No. 58-56568, etc.).

As a method for coating the surface of the fully expandable styrenic resin particles with such a surface modifier, these prior art techniques have disclosed that a surface modifier and an i#
How to mechanically mix all the fat particles or surface modifier completely dissolved in a solvent such as alcohol, pentane, hexane, etc., and add the pattern fat particles to this solution? A complete method of mixing and then drying to remove all solvent is disclosed.

However, the former method, in which the surface modifier, which is solid at room temperature, is softened or melted by mechanical stirring force and adhered to the entire surface of the expandable styrenic resin particles, does not allow the surface modifier to be uniformly distributed throughout the surface modifier. Since it takes skill to do this, the latter method uses a dissolving solution or an emulsion in which the surface modifier is dispersed in water is applied to the surface of the expandable styrenic resin particles.
A method of drying is being implemented.

This method of using a solution or aqueous emulsion of the surface modifier has the advantage that the surface modifier can be uniformly applied to the entire surface of the expandable resin particles.

The above-mentioned surface modifier with a melting point of 45 to 130°C completely improves the cooling performance of the foamed super fat because the interfacial modifier causes minute cracks on the surface of the styrene thread resin particles. This is because the remaining volatile swelling agent will dissipate in a short time.

Immediately before pre-foaming, the surface modifier is applied by transporting expandable styrene resin particles from a hopper to a pre-foaming tank using a sonic scree feeder, and heating the particles at 90 to 120°C in the pre-foaming tank.
5~ of unfoamed resin particles heated with hot water or steam.
When obtaining 60 times more pre-expanded particles, a solution or aqueous emulsion of an interfacial modifier is supplied into a screw feeder or at the outlet of a hopper.

The thus obtained pre-foamed resin particles coated with the surface modifier are air-fed, passed through piping, stored in a storage chamber, and then subjected to foam molding.

The surface modifier of the styrene thread resin particles coated with an interface modifier with a melting point of 45 to 130°C does not have sufficient adhesion to the resin particles, so it is difficult to use a screw feeder when producing pre-foamed particle sounds. The surface modifier released from the inner wall of the casing and the surface of the screw becomes laminated over time, reducing the ability to supply resin particles and causing the pre-foaming sI.
The surface modifier that is released during the air transport of fat particles adheres to the inside of the piping over time, reducing the transport ability. Furthermore, the separated interface modifier scatters into the atmosphere, causing pollution.

In the mFi of the present invention, we have previously discovered that the problems caused by the low adhesion of such surface modifiers can be solved by using silicone oil with a binder function, and we have previously developed foams containing a volatile swelling agent. A method of coating the surface of polystyrene resin particles with an interfacial modifier having a melting point of 45 to 130°C and effective in preventing pronging between resin particles during pre-foaming and shortening cooling time during foam molding. In VC, a method for producing surface-modified expandable styrenic citrus resin particles using silicone oil as a binder for adhering the surface modifier to the surface of expandable styrene thread resin particles was provided (Showa (filed on March 28, 1959).

The surface-modified expandable styrene aged resin particles obtained by implementing the invention of this earlier application have a strong adhesion of the surface modifier to the resin particles, so that the above-mentioned problems can be solved (
・Of course, it has the following two advantages.

(1) The amount of the surface modifier that is solid at room temperature added is the minimum amount necessary to prevent blocking during pre-foaming and shorten the cooling time during foam molding.

(11) Since the surface modifier is treated uniformly, the anti-blocking properties of the resin particles during pre-foaming can be further improved, and the cooling time during foam molding can be further shortened. Further, the fusing properties of the foam particles of the obtained foam are improved, and the appearance is also improved.

In the invention of the earlier application, the present invention completely improves the coating properties of the surface modifier by using silicone oil in the form of an aqueous emulsion, and also makes the surface modifier more effective, i.e., silicone oil alone. This is intended to prevent primary blocking and improve the cooling cycle during foam molding with a smaller amount of surface modifier than that used in foam molding.

In other words, is the present invention a volatile swelling agent? The surface of the contained expandable styrene thread resin particles is fully coated with a surface modifier that has a melting point of 45 to 130°C and is effective in preventing blocking between resin particles during pre-foaming and shortening the cooling time during foam molding. A method for producing surface-modified expandable styrene thread resin particles, characterized in that an aqueous emulsion of silicone oil is used as a binder for adhering the surface modifier to the surface of the expandable styrene thread resin particles. This is what we provide.

However, before the surface modifier is removed, the expandable styrene thread pattern fat particles are homopolymers of styrene thread monomers such as styrene, methylstyrene, dimethylstyrene, and chlorostyrene, and mutual copolymers of these monomers. In the process of producing polymers or co-N polymers with these styrene monomers and other vinyl monomers such as butadiene, acrylonitrile, methyl methacrylate, isogrene, vinyl chloride, etc. by candlelight,
or after manufacture, volatile swelling agents such as propane, n-
Aliphatic hydrocarbons such as butane, isobutane, n-pentane, neopentane, hexane, etc., halogenated hydrocarbons such as methyl chloride, dichlorodifluoromethane, dichlorodifluoroethane, tetrachloroethylene, or petroleum ether, etc. are mixed into resin particles. 3 to 15% by weight, preferably 4
~81 Children can be impregnated and formed.

Examples of the surface modifier having a melting point of 45 to 130°C, preferably 55 to 95°C, include polyethylene wax, acid amides such as stearinamide, 12-hydroxydioleic acid amide, stearic acid amide, aluminum stearate, etc. Metal salts of saturated or unsaturated cylindrical carboxylic acids (so-called metal soaps), mixtures of partial or complete esters of higher fatty acids and polyhydric alcohols, such as glycerin monostearate, glycerin distearate rate, glycerin tristearate, glycerin tristearate, hydrogenated tallow oil, hydrogenated rapeseed oil,
Hydrogenated fish oil, beeswax, mixtures of sorbicun monostearate, nlupitan distearate, nlubitan tristearate, ethylene glycol distearate, glopylene glycol distearate, aliphatic alcohols such as cetyl alcohol and stearyl alcohol. Examples include higher fatty acids such as palmitic acid, stearic acid, and myristic acid;

These surface modifiers are 0.0
It is used in a proportion of 1 to 2% by weight, preferably 0.1 to 1% by weight.

Among the surface modifiers, (A) mono-, di- or hatriesters of glycerin and stearic acid, or mixtures of these esters, (B) metal soaps having a lubricating effect on the weight part of A surface modifier blended in an amount of 100 parts by weight is preferred.

Next, as the silicone oil as a binder, dimethylpolysiloxane, methyl heptadylpholysiloxane (
Examples include silicone oils having a viscosity at 25° C. of 3,000 centistokes or less, preferably 10 to 1,000 centistokes, such as methylphenyl silicone oil) and methylhydrodiene polysiloxane. Among these, methylphenylpolysiloxane having a phenyl group and no hydroxyl group is particularly preferred.

The amount of silicone oil used for the expandable styrenic resin particles is 0.005 to 0.2% by weight, preferably 0.01 to 0.08% by weight. If the amount of o, oos is less than t% by weight, the effect of improving adhesion is insufficient. 0.2% by weight
Exceeding this limit will prevent the foam particles from fusing together during foam molding, and will be economically disadvantageous.

In the present invention, silicone oil is used in the form of water Ilf-wl'feL in order to reduce the amount of surface modifier used and to improve coating properties.

This aqueous dispersion contains 100 parts by weight of silicone oil.
5 to 5 lipophilic cationic surfactants as dispersion stabilizers
0 parts by weight, preferably 10 to 30 parts by weight, 100 parts by weight of water
-400 parts by weight. In order to adjust the viscosity of this aqueous dispersion of silicone oil, a polyalkylene glycol such as polyethylene glycol or polypropylene glycol having a molecular weight of 100 to 1.000 is added as a viscosity modifier to 100 parts by weight of silicone oil in an amount of 20 to 100 parts by weight. By using the same amount, the aqueous dispersion can be made to have a low viscosity, and it can be easily applied to the expandable styrenic resin particles.

The lipophilic cationic surfactant is an ethylene oxide adduct of an alkylamine, especially jetanol 2.
Preferred are urylamine and jetanolstearylamine. When using an aqueous dispersion of silicone oil, the amount of surface modifiers that are solid at room temperature can be completely eliminated because the lipophilic cationic surfactant and polyalkylene glycol are used as antistatic agents and foamable styrene threads. This is because it functions as a surface modifier that causes all the cracks to occur on the surface of the resin particles.

The aqueous emulsion (dispersion) of B.
The mold viscosity is 4-s, ooo centipoise, preferably lO
Adjustment to ~2,000 centipoise facilitates coating.

The surface modifier is removed from the surface of the expandable styrene pattern fat particles by using the foamable styrene thread resin particles, the surface modifier having a melting point of 45 to 130°C, an aqueous dispersion of silicone oil, and the entire pre-foaming tank described above. Mix with a screw feeder or Henschel mixer.

In addition, when using a combination of gold maple soap and an ester of enteral fatty acid and polyhydric alcohol as a surface modifier, the surface of the foamable styrene thread resin particles is coated with gold maple soap in advance. side particles, the aqueous dispersion of the above ester and silicone oil, and t
They may also be prepared by mixing.

The thus obtained expandable styrene paulownia resin particles whose surfaces are coated with the same narrow-face modifier at room temperature are pre-foamed to a size of 5 to 60 times by a known method, and then steam is passed through them. The pre-expanded particles are filled into a mold cavity with slits and holes through which the resin does not pass, heated with steam, the particles are fused together, and then cooled to form desired materials such as cushioning materials, insulation boards, floating devices, etc. It is molded into a foam product in the shape of .

Hereinafter, the present invention will be explained in more detail with reference to Examples. In addition, parts and parts in the examples are based on weight unless otherwise specified in %.

Example of producing expandable polystyrene phase resin particles 100 parts of styrene, 0.3 parts of benzoyl peroxide, t-
A solution containing 0.1 part of butylperoxybenzony) and 2.0 parts of cyclohexane was dissolved in 100 parts of deionized solution containing 3 parts of tertiary calcium phosphate Q and 3 parts of sodium dodecylbenzenesulfonate. The mixture was dispersed in water and heated in an il earth pressure autoclave at 90° C. for 6 hours to carry out suspension polymerization. Then, after injecting 9 parts of butane into the dispersion, the temperature was raised to 115°C,
Suspension polymerization was completed by holding at the same temperature for 3 hours.

The dispersion was then cooled to 40°C, dehydrated and dried, and the obtained tree fat particles were further sieved into beads of 0.8 to 11 beads, and lead stearate was added to the surface of the beads to a thickness of 0.1 mm. Expandable polystyrene resin particles were obtained by coating as described above.

Examples 1 to 5 of H preparation of silicone oil aqueous emulsion 100 parts of methylphenylpolysiloxane "KF-54" (trade name) manufactured by Shin-Etsu Chemical was added to 300 parts of deionized water, and laurylamine was added while stirring with a homomixer. jetanol adduct (hereinafter abbreviated as AR) t-2 parts, 5 parts,
Aqueous emulsions of each silicone oil were prepared by adding 1 part, 20 parts, and 50 parts, respectively, and the viscosity and storage stability of the emulsions were examined.

The results are shown in Table 1.

Examples 6-10 Deionized water aoo parts, silico/oil (K)l'54)lo
o part and laurylamine with jetanol m9E20
After preparing the mixture into an emulsion using a homomixer, polyethylene glycol with a molecular weight of 300 (hereinafter referred to as PIC) was prepared.
Abbreviated as G) 10 parts, 20 parts, 50 parts and 1'00 parts were added to form an emulsion of silicone oil, and the viscosity reduction and stability of the emulsion were determined by IJ.

The results are shown in Table 2.

Example 1 To 100 parts of expandable polystyrene 411 fat particles obtained in the above example, hardened beef Fh (melting point: 59°C) (melting point: 59°C) (1,
4 parts and 0.22 m of the aqueous emulsion of silicone oil obtained in Example 9 above (0.0 of silicone oil & CL 1 resin particles)
5%) to obtain modified expandable handle particles, which were pre-foamed approximately 60 times with water vapor of 1.0 rim-〇 using a fully continuous pre-foam molding machine, resulting in a density force of A prefoam mass of approximately 16 mm was obtained.

During the above pre-foaming, the feed scale of the expandable polystyrene particles at which the expansion ratio was approximately 60 times in the pre-foaming machine (temperature 98° C.) was set at 6.5. In addition, a lO-pharyngeal mesh sieve 1 was placed at the extrusion outlet of the pre-foaming machine, and the total amount of coagulum (-blocking material) remaining on the sieve was measured and found to be 0%.

After the pre-foamed particles thus obtained were stored at room temperature for 24 hours to mature, they were molded using a polystyrene foam molding machine "D-5000F" (trade name) manufactured by Daisen Industries Ltd., which has a large number of steam permeable holes. The cavity of the mold was filled with pre-foamed resin particles, and heated with 0.7 kg/dG steam for 10 seconds to fuse the particles to each other. Thickness 50w
The minimum time t11+ required for cooling (flowing 25° C. water into the chamber of the mold) until the product does not deform even after it is taken out was determined to be 130 seconds. Further, the bulk density of the product was 18.

Divide the obtained envelope by the body dimension to calculate the rate of internal cross-sectional failure of the foam particles themselves, not at the interface between the foam particles. I ended up with 95
It's %. The appearance f:i of this foam was very excellent.

Comparative Example 1 The same procedure as in Example 1 was repeated except that 0.05 part of methylphenylborisilokine ν-KF-54' was used in place of the silicone mail aqueous emulsion 022-1'11XO (modified foamed with ~). Pre-expanded particles, pre-expanded particles, and foamed molded articles were obtained.

Example 2 In Example 1, V +
In addition to using the upper layer of 116, in the same manner as 1-1, modified expandable particles, pre-expanded particles, and foam molding 1 bottle 4: Incubation.

FIG. 1 shows the surface state of the expandable resin particles obtained in Example 1. Electron micrograph (2,000x) shown in Figure 2 shows comparative example 1.
Electron micrograph showing the surface condition of the expandable resin particles obtained in (2)
,000 times) busy.

4 Figure...1 of 1?11 Simple theory, I! J4 Figure 1 1-j 8-modified r inclusion Boris narene tree Jl? obtained according to Example 1 of the present invention. +It is a diagram showing the state of the surface of the particle, and the second
The figure is a diagram showing the surface state of modified expandable borisdyrene resin particles of Comparative Example 1. .

Patent applicant Yuka Birdishe Co., Ltd.
1゛Buyaka-Pl Kawa Hide Toshiyoshi Hirohito Patent Attorney Mo Nagao Masahisa No. 11'21 Figure 42 Procedural Amendment (Method) July 3, 1980 1, Indication of Case Patent Application No. 60141 of 1982 2,
Name of the invention: Method for producing surface-modified expandable styrenic resin particles 3, Relationship to the amended case Name of patent applicant: Yuka Bardatesier Co., Ltd. 4, Agent address: 2-5-2 Marunouchi, Chiyoda-ku, Tokyo 5. Date of amendment order: June 6, 1980 (the mortar sent was June 26, 1980) 6.
Section 7 of the Detailed Description of the Invention and Drawings of the Specification Subject to Amendment
Delete the description from line 7 to line 20.

(2) Lines 1 to 6 of the brief description of drawings in the specification
Delete the line description.

Claims (1)

[Claims] 1) The surface of the expandable styrenic resin particles containing a volatile expansion agent has a melting point of 45 to 130°C, which prevents the resin particles from blocking each other during pre-foaming and during foam molding. In the method of using an ice surface modifier that has the effect of shortening the cooling time, an aqueous emulsion of silicone oil and kumquat is used as a binder to be attached to the surface of the surface modifier (t@foaming styrenic resin particles). A method for producing surface-modified expandable styrene thread pattern fat particles. 2) The aqueous emulsion of silicone oil contains a) 100 parts by weight of silicone oil, b) 5 to 50 parts by weight of lipophilic cationic thread surfactant, and C) 0 to 100 parts by weight of polyethylene glycol having a molecular weight of 100 to 1.000. The method according to claim 1m, wherein the composition is dispersed in gold water and is an aqueous emulsion having a viscosity of 4 to 5,000 centipoise at 20°C. Claim 1 or 2, wherein the silicone oil is methylphenyl silicone oil.
Manufacturing method 14) according to claim 1 or 2, characterized in that the amount of silicone oil used is 0.005 to 0.2% by weight relative to the styrene thread resin particles. Production method. 5) The surface modifier having a melting point of 45 to 130°C is a seven-, di-, or triester of a fatty acid having 12 to 22 carbon atoms and glycerin, or a mixture of two or more of these. A manufacturing method according to claim 1 or 2.