CN100503698C - Expandable styrene resin particles, foamed hollow particle, and foamed article - Google Patents

Abstract

A process of producing expandable styrene resin particles, wherein in suspension polymerization of styrene monomers, the concentration of oxygen in a reaction vessel is kept low at least in a late stage of the polymerization, and the resulting styrene resin particles are impregnated with an expanding agent before or after completion of the polymerization. Preferably, at a polymerization rate of 60% or higher, the concentration of oxygen in the reaction vessel is kept at 7 volt % or lower. When additional styrene monomers are added during the polymerization, they are added and adsorbed to styrene resin particles in the course of polymerization while the concentration of oxygen is kept low. By this method, the particles whose internal portion has a low molecular weight and surface portion has a high molecular weight are obtained. A foamed article produced from the particles has high strength and a good appearance.

Description

Vinylbenzene resin expandable beads, foaming hollow bead and foaming and molding spare

Technical field

The present invention relates to vinylbenzene resin expandable beads and manufacture method thereof, further relate to polystyrene foaming hollow bead and foaming and molding spare.

Background technology

Polystyrene foaminess resin owing to have characteristics such as good heat insulating ability, economy and wholesomeness how as food product containers, wrapping material, cushioning material etc.These foaming and molding spares are by with vinylbenzene resin expandable beads steam heating, and pre-frothing is to desired bulk density, pass through maturing process then after, be filled in the form metal mould, the method that forms of foamable is made once more.This vinylbenzene resin expandable beads demonstrates good foaminess in pre-frothing stage and the foamable shaping stage in mould, in addition, and big drip molding intensity when also having obtained to make drip molding and good drip molding outward appearance.

In the past, in order to increase the intensity of foaming and molding spare, method that improves drip molding density and the method that the thickness of drip molding self is thickeied had been adopted.But any in these methods all is difficult to say so economical owing to the weight that increases drip molding, and considers also existing problems from the viewpoint of environment.In addition, the method that has also adopted the molecular weight to the vinylbenzene resin expandable beads that its polymer is quantized, and also adopted kind and addition that resin particle is carried out the employed softening agent of plasticising to carry out methods such as decrement adjustment.

On the other hand, as the method for the foaminess that improves the vinylbenzene resin expandable beads, to making the degraded method of molecular weight and make resin particle plastifying method, and the method etc. that changes the ratio of components of whipping agent is studied.

In general, for the method for the intensity that increases this foaming and molding spare and the method that improves its foaminess are mutual restriction, be difficult to take into account simultaneously.

As the method that addresses these problems, open the spy and to have proposed the surface portion of a kind of particle in flat 8-No. 295756 communiques and centre portions is a lower molecular weight, and the particle middle portion is the high-molecular weight resin particle.

But this particle can excessively promote thermal welding because the molecular weight of the surface portion of particle be the lower molecular weight identical with the particle centre portions when foamable is shaped, thereby existence makes the shortcoming of appearance deterioration of drip molding and so on.

In addition, open in flat 7-No. 188454 communiques, also disclose the high resin particle of molecular weight ratio particle overall molecule amount of top layer part the spy.

According to this communique record, when the excessive polymer of skin section quantized, then foam performance reduced, and diminished the outward appearance of drip molding, and consequently intensity reduces.This can think that owing to particle disclosed herein along with the polymer quantification of top layer part, centre portions also polymer quantizes.That is, in these resin particles, there is the top layer part shortcoming of polymer quantification fully.

In addition, have good surface appearance, when the polystyrene foaming hollow bead of filling carries out the foamable shaping, it is generally acknowledged that the space of eliminating fully between each hollow bead is necessary in to the form metal mould in order to make existing foaming and molding spare.But the space of eliminating fully between each hollow bead is difficult.Therefore, vinylbenzene foaminess resin particle self-characteristic is improved and the forming technique of the function that comprises forming mill etc. improved and reduce the space to greatest extent.

For example, in the improvement that vinylbenzene foaminess resin particle self characteristics is carried out, method that the kind that makes resin particle plastifying softening agent and addition are adjusted and the adjustment of having carried out making molecular weight lower molecular weightization etc. have been taked.But these methods are when the thermotolerance that makes resin particle reduces, because the foamable when being shaped, are melt into the surface of body, have the shortcoming that has increased the space.

In addition, in the improvement of the forming technique of the function that comprises forming mill etc., study the control method of the heating process of forming mill, adopted the method for more effectively utilizing steam.And, in the form metal mould, studied the method for similarly more effectively utilizing steam by increasing slit number etc.But these methods can list following shortcoming: the burden of additional investments such as machine rebuilding expense and metal die improvement expenses is big, if be difficult to accomplish whole once and to improve all these be difficult., still so-called owing a little can appear then.

Summary of the invention

The object of the present invention is to provide the intensity of moulded work drip molding big, the vinylbenzene resin expandable beads that foaminess is good, expanded beads foaming hollow bead and frothing mold product drip molding.

In addition, the present invention also aims to provide the outward appearance of moulded work drip molding good, the vinylbenzene resin expandable beads that foaminess is good, expanded beads foaming hollow bead and frothing mold product drip molding.

The feature of the manufacture method of vinylbenzene foaminess resin particle of the present invention is, in the suspension polymerization of styrenic monomers, at least in polymerization during the later stage, in the low oxygen concn, carries out polyreaction in keeping reactive tank.

By such method, can control the decline of molecular weight of the surface portion of vinylbenzene foaminess resin particle.

Method of the present invention also is applicable to the polyreaction of using nuclear.

In addition, in the polymerization later stage, if add styrenic monomers, then surface portion is quantized by polymer, thereby drip molding intensity increases.Also can not add styrenic monomers and carry out polymerization.

When adding styrenic monomers, add under the state of keeping low oxygen concn and carry out in the polymerization later stage.

For example, in an embodiment of method of the present invention, in the suspension polymerization of styrenic monomers, when the polymerization degree is 60% when above, keep oxygen concn in the reactive tank below 7 volume %, add styrenic monomers simultaneously, in polymerization process, the styrenic monomers of being added is adsorbed onto carries out polyreaction on the styrene resin particle, before polyreaction finishes or after the polyreaction end, and the dipping whipping agent.

By this method, can obtain following vinylbenzene resin expandable beads.

1. vinylbenzene resin expandable beads, carry out 5 five equilibriums from particle surface to the center, begin from the surface when middle mind-set is surperficial, to begin to the weight-average molecular weight height of the centre portions of 1/5 place formation from the center to the weight-average molecular weight ratio of 1/5 surface portion that forms;

Bimodal or acromion appears on the spectrogram of the gel permeation chromatography of its surface portion.

2. according to 1 above-mentioned vinylbenzene resin expandable beads, the weight-average molecular weight of its centre portions is 200,000～300,000 scope, the weight-average molecular weight of surface portion is 300,000～450,000 scope, the weight-average molecular weight of surface portion are more than 1.2 times of weight-average molecular weight of centre portions.

3. vinylbenzene resin expandable beads, mind-set surface forms weight-average molecular weight up to the resin part of 30～60 weight % 200 in resin particle, 000～300,000 scope, from the surface in be formed centrally weight-average molecular weight up to the resin of 60～30 weight % part 300,000～450,000 scope, and surface portion is a centre portions up to 1.2～2.2 times of the weight-average molecular weight of 30～60 weight % up to the size of the weight-average molecular weight of 60～30 weight %.

4. vinylbenzene resin expandable beads, carry out 5 five equilibriums from particle surface to the center, the slope that begins in the relational expression of log (R.MS radius) 1/5 surface portion that forms, that measured by the GPC/MALLS method and log (MW) from the surface is below 0.53.

From polymerization, in the polymerization degree reached polymerization process more than 60%, the oxygen concn of keeping in the reactive tank was below the 1 volume %, added styrenic monomers in the polymerization degree reaches polymerization process more than 60%.

By this method, can obtain following vinylbenzene resin expandable beads.

1. vinylbenzene resin expandable beads, carry out 5 five equilibriums from the resin particle surface to the center, the surface portion that will begin from the surface to form to 1/5 place further carries out 6 five equilibriums from the surface to the center again, begin to the part of 1/6～6/6 place formation from the surface of this moment, reducing to the surface does not appear in weight-average molecular weight.

2. vinylbenzene resin expandable beads, the ratio (B)/(A) * 100 (%) of the weight-average molecular weight (A) that the weight-average molecular weight (B) of the surface portion that begins from the surface of 6 five equilibriums to form to 1/6 place and resin particle are all is more than 130.

3. vinylbenzene resin expandable beads, carry out 5 five equilibriums from the resin particle surface to the center, bimodal or acromion appears in the spectrogram that begins the gel permeation chromatography of the surface portion that forms to 1/5 place from the surface, is more than 130 from the ratio (B)/(A) * 100 (%) of all weight-average molecular weight (A) of the weight-average molecular weight (B) and the resin particle of surface portion that surface portion is carried out to the center that the surface of 6 five equilibriums begins to form to 1/6 place from the surface further again.

4. vinylbenzene resin expandable beads, it is by carrying out suspension polymerization to styrene monomer, before polyreaction finishes or after the polyreaction end, the dipping easy volatile whipping agent and obtain, it is characterized in that, from resin particle surface beginning in the ratio (B)/(A) * 100 (%) that is formed centrally up to all weight-average molecular weight (A) of the weight-average molecular weight (B) of the resinous principle of 10wt% and resin particle be more than 130, in 200.

Description of drawings

Fig. 1 is the explanatory view that is used to illustrate with the measuring method of the molecular weight of the each several part of particle 5 timesharing such as grade.

Fig. 2 is used to illustrate particle by the explanatory view of the measuring method of the molecular weight of the each several part of further 6 timesharing such as grade such as the surface portion of 5 timesharing such as grade.

Fig. 3 is the explanatory view of measuring method of molecular weight that is used to illustrate the foamed cell of particle surface.

Fig. 4 is the change of molecular weight figure from center to face of expression embodiment 1 and comparative example 1.

Fig. 5 is the GPC spectrogram of embodiment 1,2 and comparative example 1.

Fig. 6 is the change of molecular weight figure from center to face of expression embodiment 10,13,14 and comparative example 1.

Fig. 7 is the GPC spectrogram of embodiment 13,15.

Embodiment

Vinylbenzene resin expandable beads of the present invention is obtained by the styrenic monomers polymerization.As styrenic monomers, can use vinylbenzene and with the styrene derivatives of vinylbenzene, with the mix monomer of the methyl acrylic ester of the esters of acrylic acid of methyl acrylate, ethyl propenoate, butyl acrylate etc., methyl methacrylate, Jia Jibingxisuanyizhi, butyl methacrylate etc. as the α-vinyl toluene of main component, chloro-styrene, Vinyl toluene etc.In addition, also can use the linking agent of Vinylstyrene, diallyl phthalate etc.

Make the preferred suspension polymerization of method of ethene resin expandable beads, also can adopt existing known method.In general, be that the styrene monomer that will dissolve catalyzer such as organo-peroxide is dispersed in the aqueous medium that contains dispersion agent, make its generation free radical and carry out polymerization.

As dispersion agent, both can use insoluble inorganic salt and tensio-active agent simultaneously, also can use existing known materials such as organic dispersing agent such as PVA.

The insoluble inorganic salt can use trimagnesium phosphate, tricalcium phosphate etc.Tensio-active agent can use sodium oleate, Sodium dodecylbenzene sulfonate, other any in general aniorfic surfactant that uses or the nonionic surface active agent when suspension polymerization.Organic dispersing agent can use polyvinyl alcohol, polyvinylpyrrolidone and methylcellulose gum etc.

Organo-peroxide can use the decomposition temperature that declined in 10 hours half at 50～100 ℃ existing known material.For example, lauroyl peroxide, benzoyl peroxide, tert butyl peroxy benzoate, tert-butyl hydroperoxide sec.-propyl carbonic ether etc.The consumption of organo-peroxide is preferably 0.001 weight %～0.5 weight % with respect to polymerizable monomer.Can use one or more organo-peroxide.

All molecular weight can perhaps be adjusted by this two aspect by adjusting catalyst concn or also using chain-transfer agent.

Chain-transfer agent can use now known spicy thioalcohol, lauryl mercaptan, α-methyl styrene dimer body etc.The addition of chain-transfer agent is preferably 20ppm～100ppm with respect to polymerizable monomer.

In manufacture method of the present invention, at least in polymerization during the later stage, reaction is carried out under the low oxygen concentration in keeping reactive tank, before polyreaction finishes or after polyreaction finishes, floods the easy volatile whipping agent.

Though this method polymerization begin or polymerization process in, also can be low oxygen concentration in the reactive tank, should be low oxygen concentration in the polymerization later stage at least.

In general, when carrying out polymerization under the state that aerobic exists in reactive tank, the formation amount of the low molecular weight product in the styrene resin particles can increase.Particularly in the polymerization later stage, because remaining a small amount of polymerizing catalyst and no longer produce free radical, easy formation low molecular weight product in the styrene resin particles upper layer, thus diminish the outward appearance of drip molding.

On the other hand, in manufacture method of the present invention, in the polymerization later stage, owing to keep the interior low oxygen concentration of reactive tank, thus can suppress the generation of low molecular weight product.Oxygen concn preferably remains below the 7 volume %, more preferably below the 5 volume %, is preferably especially below the 1 volume %.Oxygen concn can be regulated by replacing with inactive gass such as nitrogen.

In addition, the polymerization later stage is preferably the polymerization degree and reaches more than 60%, and more preferably the polymerization degree reaches more than 60%, the stage below 97%.

In first kind of manufacture method of the present invention, reach more than 60% in the polymerization degree, be preferably and reach more than 60% 97% when following, the oxygen concn in keeping reactive tank adds styrene monomer in below 7 volume %.

If oxygen concn surpasses 7 volume %, then in the process that the interpolation styrene monomer reacts, may form low molecular weight product at the upper layer of styrene resin particles.Heat when the generation meeting of the low molecular weight product of epidermis excessively promotes foaming and molding fuses, thereby when the intensity of drip molding is reduced, appearance is worsened.

In second kind of manufacture method of the present invention, begin to reach more than 60% from polymerization to the polymerization degree, be preferably and reach more than 60% 97% when following, the oxygen concn in keeping reactive tank adds styrene monomer in below 1 volume %.

At this moment, the oxygen concn in the reactive tank is by remaining on below the 1 volume % oxygen concn with the oxygen in the replacement(metathesis)reaction grooves such as nitrogen in advance when polymerization begins.Oxygen concn is low more good more.After this, when carrying out polymerization,, both can continue to keep with the interior oxygen of nitrogen replacement reactive tank for anti-block enters in the reactive tank, also can be in displacement stops back sealed reaction groove.

Carry out under the polymeric situation at the confined reaction groove, polymerization reactant from feed temperature when temperature of reaction rises, or when the reaction of polymerizing catalyst, because in the moisture and the oxygen that contains in the styrene monomer, the oxygen that produces when being rolled into oxygen in the solution and polyreaction etc. by stirring separate out, when making oxygen concn surpass 1 volume %, replace with nitrogen etc. once more.

Till the styrene monomer interpolation end of adding, the oxygen concn in the reactive tank is controlled at below the 1 volume %.Because oxygen concn will remain on below the 1 volume % in polymerization, can connect oxymeter and control.

If oxygen concn is lower than 1 volume %, then polymerization quantizes to carry out towards polymer, can obtain high-intensity drip molding.

Be lower than in the polymerization degree under 60% the situation, can promote the absorption of styrene resin particles to styrene monomer, like this, because the molecular weight polymer of centre portions quantizes, the welding of foaming power and drip molding then reduces possibly.In addition, surpass under 97% the situation in the polymerization degree, styrene resin particles reduces the absorption of styrene monomer, free base unit weight in the resin particle and polymerization catalyzed dosage reduce, like this, because the molecular weight lower molecular weightization of the surface portion of resin particle, then excessively promote thermal welding during foaming and molding and make the strength degradation of drip molding probably, appearance is worsened.Therefore, preferred degree of polymerization is carried out adding of styrene monomer more than 85% below 97%.

The addition of styrene monomer is that the olefine resin particle is 5 weight %～30 weight % with respect to the benzene second that finally obtains preferably.Preferred scope is 10 weight %～15 weight %.

When addition was less than 5 weight %, it is little that the polymer of the surface portion of styrene resin particles quantizes effect, the effect of the intensity that often can not fully be improved.On the contrary, when addition during greater than 30 weight %, because resin particle is softening, promoted the absorption of styrene monomer, the highest weightization part in the particles such as the molecular weight polymer quantification of centre portions moves to centre portions, thereby, often foaming power reduces, and drip molding then is difficult to welding.

The temperature of suspension polymerization is generally 80 ℃～95 ℃.The interpolation temperature of styrene monomer both can be former temperature, also can heat up.For the amount minimizing of styrene monomer remaining in the polystyrene foamex particle that will finally obtain, consider that from the manufacturing efficient of industry polymerization temperature is preferred more than 90 ℃, the interpolation temperature of styrene monomer is preferably carried out in intensification.

The third manufacture method of the present invention is that from polymerization, the oxygen concn in reactive tank reacts below remaining on 7 volume %, does not add styrene monomer in reaction process.

In manufacture method of the present invention, preferably the hydrogen ion concentration at aqueous dispersions is 8～10 times beginning polymerizations, reaches at 20%～50% o'clock in the polymerization degree, adds the insoluble inorganic salt at least one time.The preferably water dispersion liquid is an external phase.

If hydrogen ion concentration is outside above-mentioned scope, the size-grade distribution when then suspension polymerization finishes is just narrowless probably.Hydrogen ion concentration can be regulated by basic inorganic salt.

In addition, for the same reason, can be 20%～50% o'clock in the polymerization degree, add the insoluble inorganic salt.

The number of times of adding the insoluble inorganic salt for example, can be added 2～3 times more than being at least once.In addition, the insoluble inorganic salt can be added when polymerization begins further carrying out.

Though the easy volatile whipping agent can be pressed into when adding styrene monomer, general preferably after adding, styrene monomer carries out, preferably before polyreaction finishes or after the end, the easy volatile whipping agent is immersed in the styrene resin particles.

The easy volatile whipping agent is selected from the aliphatic hydrocarbons such as propane, Trimethylmethane, normal butane, iso-pentane, Skellysolve A, pentamethylene.In addition, as frothing aid, except aliphatic hydrocarbon, clicyclic hydrocarbons such as hexanaphthene and aromatic hydrocarbons and easy volatile whipping agent can be used simultaneously.

During polymerization, also can be as required, the additive that suitably uses solvent, softening agent, foamed cell nucleator, weighting agent, fire retardant, flame retardant, lubricant, tinting material etc. and when making the vinylbenzene resin expandable beads, use.

In addition, in manufacture method of the present invention, can adopt and utilize polystyrene foamex particle or regenerated phenylethene resin beads as the seeding polymerization method of examining.Also to carry out the low oxygen concn of aforesaid control in this method.

The vinylbenzene resin expandable beads by taking out in the polymerization system, after dehydrating, can be covered surface-coated dose after the dipping of whipping agent finishes as required again.The coating agent that such coating agent can select for use existing known foamed styrene resin beads to use.For example, Zinic stearas, glycerol stearate, glyceryl monostearate, Semen Ricini winterized stearin, amide compound, silicone, static inhibitor etc.

Usually, the weight-average molecular weight (molecular weight) of the polystyrene foamex particle of being made by suspension polymerization is by the amount decision of polymerizing catalyst, and the molecular weight of particle centre portions, middle portion and top layer part is certain substantially.

But,, then will obtain the high polystyrene foamex particle of molecular weight of molecular weight ratio centre portions of the surface portion of resin particle if according to first kind of manufacture method of the present invention.From the molecular weight gradient of center to face owing to be not to rise with certain ratio at leisure, so sharply increase near surface.

In the polystyrene foamex particle that obtains according to manufacture method of the present invention,, can keep the low-molecular-weight while to obtain high molecular at centre portions at surface portion because molecular weight sharply increases near surface.In general, if centre portions is a lower molecular weight, then can bring into play good foaminess, if surface portion is a high molecular, then the intensity of drip molding increases.Therefore, particle of the present invention can satisfy the requirement of foaminess and drip molding intensity simultaneously.For example, in the foaminess that keeps to a certain degree, can obtain quite high drip molding intensity.

Particularly, can obtain carrying out under the situation of 5 five equilibriums to the center from the resin particle surface, the weight-average molecular weight that begins the surface portion that forms to 1/5 place from the surface than from during the mind-set surface, begin the high polystyrene foamex particle of weight-average molecular weight of the centre portions that forms to 1/5 place from the center.

Here, surface portion and centre portions are illustrated with accompanying drawing.As shown in Figure 1,5 five equilibriums have been carried out from the surface of resin particle 10 to the center.Be positioned at outermost, promptly begin from the surface to be surface portion to the part 1 of 1/5 place formation.The weight-average molecular weight of surface portion is the weight-average molecular weight of this part 1.Be positioned at part 5 the most inboard, that promptly begin from the center to form and be centre portions to 1/5 place.The weight-average molecular weight of centre portions is the weight-average molecular weight of this part 5 being carried out the center of 5 five equilibriums.

And, bimodal or acromion appears on the spectrogram of the gel permeation chromatography of preferred surface part.Occur bimodal or acromion means that molecular weight has rapid variation.Acromion is formed by flex point.Among the present invention, the spectrogram of gel permeation chromatography uses two Hitachis to change into the chromatographic column of industry (strain) society system, and GL-R400M measures.In addition, though flex point can occur in the bottom, two ends of spectrogram usually, in the alleged acromion of the present invention, do not contain these (with reference to Fig. 5,7) yet.

In addition, the weight-average molecular weight of preferred center part of the present invention is 200,000～300, in 000 the scope, the weight-average molecular weight of surface portion is 300,000～450, in 000 the scope, simultaneously, the size of the weight-average molecular weight of surface portion is more than 1.2 times of weight-average molecular weight of centre portions.

The weight-average molecular weight of centre portions less than 200,000 situation under, drip molding intensity reduces possibly.In addition, because molecular weight less than 200,000, in manufacturing processed, must increase the usage quantity of catalyzer, thereby not preferred.

The weight-average molecular weight of centre portions greater than 300,000 situation under, foaminess reduces possibly.

In addition, preferably the weight-average molecular weight of centre portions is 200,000～250, and in 000 the scope, and the molecular weight of the part that forms from center to 3/5 place roughly is uniform.

When the molecular weight of surface portion less than 300,000 situation under, be difficult to obtain the very high drip molding of intensity.

When the molecular weight of surface portion greater than 450,000 situation under, foaming power reduces, and does not promote the appearance of the drip molding of heat fusing to worsen, and is difficult to welding.

In addition, the weight-average molecular weight of preferred surface portion is 350,000～450,000 scope.

The weight-average molecular weight of surface portion is preferably more than 1.5 times with the ratio (molecular weight ratio) of the weight-average molecular weight of centre portions, is generally below 2.2 times.

In addition, if manufacturing method according to the invention, then surface element branch takes place to be considered to the impossible grafting that does not have in the existing cinnamic radical polymerization, may generate the high-molecular weight apparatus derivatorius.

Like this, the apparatus derivatorius that surface portion has true as can be known following, for example, particle is carried out 5 five equilibriums from the surface to the center, when the surface portion that begins to form to 1/5 place from the surface is measured with the GPC/MALLS method, log (R.M.S radius) is below 0.53 with the slope of the relational expression of log (MW), is preferably below 0.52, more preferably below 0.50.Here, GPC means gel permeation chromatography, and MALLS (Multi Angle Laser Light Scattering) means the multiple angle laser light scattering analyzer, and R.M.S (Root Mean Square) radius means the rootmean-square radius, and MW means absolute molecular weight.

In addition, this slope is 0.55～0.60 in the polystyrene of the linear chain structure that is obtained by common radical polymerization (suspension system).

And, the weight-average molecular weight of this surface portion according to above-mentioned same reason preferably more than 350,000, below 450,000.

If adopt second kind of manufacture method of the invention described above, auto-polymerization began to the polymerization later stage, and by oxygen concn being remained on below the 1 volume %, last in polyreaction promptly, particularly in the part near the surface, can prevent the reduction of molecular weight.

Vinylbenzene resin expandable beads particularly of the present invention, 5 five equilibriums are carried out to the center in surface from resin particle, the surface portion that will begin from the surface to form to 1/5 place carries out 6 timesharing such as grade from the surface to the center more further, begin to the part of 1/6～6/6 place formation from the surface of this moment, weight-average molecular weight can not reduced towards the surface, more preferably rise towards the surface.

Here, to " beginning to the part of 1/6～6/6 place formation ", be illustrated with accompanying drawing from the surface.Shown in Fig. 2 (a), at first, 1/2 place of resin particle 10 is cut, then, carry out 5 five equilibriums from the surface to the center.In outermost, the part A that will begin from the surface to form to 1/5 place is carried out 6 five equilibriums again shown in Fig. 2 (b)." begin to the part of 1/6～6/6 place formation " to be meant, reach the each several part of this 6 five equilibrium from the surface from the surface.

At this moment, the weight-average molecular weight (B) of the surface portion that the present invention preferably begins from the surface of above-mentioned 6 five equilibriums to form to 1/6 place is bigger than the weight-average molecular weight (A) of resin particle integral body, the weight-average molecular weight (B) of the surface portion that particularly, begins from the surface of above-mentioned 6 five equilibriums to form to 1/6 place and the ratio (B)/(A) * 100 (%) of the weight-average molecular weight (A) of resin particle integral body are more preferably more than 130.And this ratio is generally below 200.

Among the present invention, usually, the surface portion that begins to form from the surface to 1/6 place roughly with from the beginning of resin particle surface in be formed centrally up to the resinous principle of 10wt% suitable.

Quantize by the relative polymer of molecular weight that makes surface portion, the intensity of drip molding can more increase.

Like this, the generation of the low molecular weight product of the surface portion of the resin particle that is obtained by first and second kinds of manufacture method is suppressed, in addition, because this surface portion has the high-molecular weight apparatus derivatorius, compare with the foaming and molding spare that utilizes the common polymerization manufacturing that does not suppress oxygen concn, the thermotolerance of particle surface part improves, and can obtain outward appearance or the good foaming and molding spare of physical strength.

In addition, if use the third manufacture method of the invention described above, even in the scope of the foamed cell size in polystyrene foaming hollow bead relatively under the situation of molecular weight, also can obtain the undiminished vinylbenzene resin expandable beads of molecular weight of surface portion.Its result has obtained the good foaming and molding spare of outward appearance.

In addition, the average particle diameter of vinylbenzene resin expandable beads of the present invention is generally 0.05～2.0mm.

Foaming hollow bead of the present invention is made the foaming of vinylbenzene resin expandable beads.In addition, foaming and molding spare of the present invention forms manufacturing by the hollow bead that should foam.

General, the vinylbenzene resin expandable beads is pre-expanded to the bulk density of regulation with heating such as steam, again through the curing process manufacturing hollow bead that foams.Then, the hollow bead that will foam is filled into foamable shaping once more in the form metal mould, makes foaming and molding spare.

Among the present invention, the foaminess of vinylbenzene resin expandable beads with obtained good balance by the intensity of its drip molding that makes.Drip molding of the present invention is applicable to food product containers, wrapping material, cushioning material etc.

According to the present invention, can provide the intensity of drip molding big, the vinylbenzene resin expandable beads that foaminess is good, foaming hollow bead and foaming and molding spare.

Embodiment

The evaluating characteristics of embodiment and comparative example is as follows.

(1) weight-average molecular weight (molecular weight)

The molecular weight of vinylbenzene resin expandable beads is measured particle foaming back.The vinylbenzene resin expandable beads volume multiple that foams in saturated steam is 80ml/g.

The measuring method of the molecular weight of the each several part during＜5 particles such as branch such as grade 〉

Get arbitrarily 2～3 of expanded particles, as shown in Figure 1 half of particle 1 equally spaced is divided into 5 five equilibriums,, form 1,2,3,4,5 parts from the outside with razor.To the part 1 (surface portion) of face side with the former state determining molecular weight; The most inboard part 5 (centre portions) is extracted the centre portions that this part is divided into 5 five equilibriums, determining molecular weight with the entry needle break-through.To part 3 (3/5 part) from the center with the identical centre portions of entry needle break-through extraction and part 5, determining molecular weight.

In addition, molecular weight is with gel permeation chromatography (GPC), uses following device and condition to measure.In addition, with regard to surface portion, obtained spectrogram (GPC spectrogram) with the GPC method.

Determinator: (strain) Hitachi makes society's system

Elutriant: THF, flow: 2ml/ branch

Analyzer: UV220nm

Chromatographic column: Hitachi changes into industry (strain) society system, 2 of GL-R400M

＜surface portion of particle 5 timesharing such as grade is carried out again the measuring method (embodiment 10-16, comparative example 1,4) of molecular weight of the each several part of 6 timesharing such as grade 〉

The molecular weight root that " begins to the part of 1/6～6/6 place formation from the surface " is measured by following.Shown in Fig. 2 (a), at first, expanded particle is cut at 1/2 place, then, begin to carry out 5 five equilibriums to the center from the surface.Further will be positioned at outermost, begin the part A that forms to 1/5 place from the surface, shown in Fig. 2 (b), be divided into 6 five equilibriums at microscopically, obtain a, b, c, d, e, f part.Measure part a respectively, b, c, d, e, the molecular weight of f.The molecular weight of part a is the molecular weight that begins from the surface to the part of 1/6 place formation, and part a, the mean value of the molecular weight of b are the molecular weight that begins from the surface to the part of 2/6 place formation, part a, b, the mean value of the molecular weight of c are the molecular weight that begins from the surface to the part of 3/6 place formation, part a, b, c, the mean value of the molecular weight of d are the molecular weight that begins from the surface to the part of 4/6 place formation, part a, b, c, d, the mean value of the molecular weight of e are the molecular weight that begins from the surface to the part of 5/6 place formation, part a, b, c, d, e, the mean value of the molecular weight of f are that the word table face begins to the molecular weight of the part of 6/6 place formation.

And molecular weight uses with same GPC method and measures.

The measuring method of the molecular weight of the foamed cell on the surface of＜particle (embodiment 17,18, comparative example 5) 〉

Prepare 5～6 foaming hollow bead (median sizes: 3.0mm), cut into two halves respectively.Subsequently, as shown in Figure 3, begin from the surface of the foaming hollow bead that cuts into two halves to confirming and be partitioned into layer segment X and layer segment Y at microscopically with the thickness of 1 foamed cell between center etc.Measure the molecular weight of surface layer part (layer segment X) and surface layer part (part that layer segment X and Y are merged).Surface layer part is the part of 1 foamed cell, and surface layer part is the part of 2 foamed cell.The molecular weight of surface layer part is to be tried to achieve by the mean value of the molecular weight of layer segment X and layer segment Y.

In the present embodiment, the surface layer part of so-called 1 foamed cell is represented the roughly size of 50～100 μ m, and the surface layer part of 2 foamed cell is represented the roughly size of 100～200 μ m.

And molecular weight is measured with same GPC method.

(2) foaminess

Foaminess is when the volatile component amount that vinylbenzene is washed the foaminess resin particle is 7.0 weight %, the bulk density (foam degrees) that foaming was measured in the time of 3 minutes in 100 ℃ of boiling water.

(3) flexural strength

Use HBP-700 foaming machine of the テ of Hitachi Network ノ プ ラ Application ト (strain) system to make the foaming of vinylbenzene resin expandable beads and make the foaming hollow bead.And VS-500 forming mill that uses セ Application industry (strain) to make is the drip molding that this foaming hollow bead of shaping obtains 550mm * 335mm * 150mm under the 0.08MPa at vapor pressure.

The flexural strength density of drip molding is that the foaming and molding spare of 60ml/g is measured according to JIS-A-9511 standard.

(4) with the GPC/MALLS method polymer architecture of particle surface part is analyzed

With surface portion shown in Figure 11 as the mensuration sample.Carry out under following device and condition with the GPC/MALLS method, obtain the slope of the relational expression of log (R.M.S radius) and log (MW) then.

Chromatographic column: Shodex, KF-807L, two

Column temperature: 40 ℃

Elutriant: THF

Flow velocity: 1.00ml/min

Injection rate: 100 μ m

Analyzer: Ri and Wyatt technology.DAWN DSP-F (optical maser wavelength: 632.8nm)

Multi-angle is adjusted (fit) method: the Berry method

(5) outward appearance (surface smoothness)

With roller black printing printing ink is coated on the surface portion of the drip molding of similarly making with (3) thinly, this surface portion is placed in the image processing apparatus.Owing to there is not coating and printing printing ink in the space of surface portion, the area of therefore obtaining the black part and the ratio of full coat cloth area are used as the figure of merit of outward appearance as surface smoothness.

(6) polymerization degree

The resin particle that the polymerization degree is got in synthesizing is measured under following device and condition.

Determinator: (strain) Hitachi makes made

Elutriant: acetonitrile/distilled water=70/30, flow: 1ml/min

Analyzer: UV 230nm

Chromatographic column: Inertsil ODS-2

＜only to keep oxygen concn in the polymerization later stage be 7% to add monomeric example when following 〉

Embodiment 1

In having 14 liters autoclave of stirrer, with 230 rev/min speed stir on one side and add 6000g pure water, 9g tricalcium phosphate, 0.3g Sodium dodecylbenzene sulfonate on one side.The hydrogen ion concentration of this moment is 8.0.

Then, add 5400g vinylbenzene while stirring, 22.0g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.

Behind reinforced the end, in the airtight polymerization tank.Be warming up to 90 ℃,, add tricalcium phosphate respectively into 3g heating up end after back 2 hours and 3 hours.The polymerization degree of this moment is respectively 40% and 46%.

Then, 2 hours big constantly adding once more under 90 ℃, have been incubated into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate.The polymerization degree of this moment is 95%.Speed with 200～300ml/min in polymerization tank was led to nitrogen replacement 10 minutes.Oxygen concn in the polymerization tank of this moment is 3.1 volume %.Then, the limit is warmed up to 100 ℃, and the limit dripped 600g vinylbenzene in 3 hours continuously.

Then, with the 90g hexanaphthene, after 1 hour 420g butane (Trimethylmethane/normal butane ratio=4/6) being pressed into, be incubated 4 hours more again in 1 hour.Then, cool to room temperature is taken out by autoclave.

After the slurries process washing of taking out, dehydration, dry each operation, under 14 mesh sieves, carry out sieve classification on 26 mesh sieves, further surface-coated 0.08% Zinic stearas, 0.05% Semen Ricini winterized stearin and 0.02% dimethyl siloxane obtain the vinylbenzene resin expandable beads.

Measure the molecular weight and the characteristic of resulting vinylbenzene resin expandable beads, it the results are shown in table 1.In addition, the change of molecular weight from middle mind-set surface is shown in Fig. 4.

In addition, surface portion is measured spectrogram (GPC spectrogram) with the GPC method.This spectrogram is shown in Fig. 5 (a).

Embodiment 2

In having 14 liters autoclave groove of stirrer, carry out nitrogen replacement after 30 minutes with the speed of 500～600ml/min, with 230 rev/min speed stir on one side and add 6000g pure water, 9g tricalcium phosphate, 0.3g Sodium dodecylbenzene sulfonate on one side.At this moment, hydrogen ion concentration is 8.0.

Then, add 5400g vinylbenzene while stirring, 23.6g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.

Behind reinforced the end, in the airtight polymerization tank.Open ventilation with pipe arrangement after, feed nitrogen with the speed of 200～300ml/min.Be warming up to 90 ℃,, add the 3g tricalcium phosphate respectively heating up end after back 1.5 hours and 2.5 hours.The polymerization degree of this moment is respectively 39% and 46%.

Then, the moment that has been incubated 2 hours under 90 ℃ is added once more into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate.Till this moment, still constantly feed nitrogen.The polymerization degree of this moment is 96%, and measuring oxygen concn is 0.1 volume %.After having measured oxygen concn, stop logical nitrogen, close ventilation with pipe arrangement after, the limit is warmed up to 100 ℃, dripped 600g vinylbenzene in 3 hours continuously on the limit.

After the dipping whipping agent, carry out 1 identical operations with embodiment.

Determining molecular weight and characteristic, it the results are shown in table 1.

In addition, to surface portion, measure spectrogram (GPC spectrogram) with the GPC method.This spectrogram is shown in Fig. 5 (b).

Comparative example 1

Measure the molecular weight and the characteristic of vinylbenzene resin expandable beads (trade(brand)name S-HCM-K, south, Hunan Plot water and wastewater industry (strain)), it the results are shown in table 1 and table 3.In addition, the molecular weight variation from middle mind-set surface is shown in Fig. 4.

In addition, to surface portion, measure spectrogram (GPC spectrogram) with the GPC method, this spectrogram is shown in Fig. 5 (c).

As shown in Figure 4, no matter be the particle of embodiment 1 or the particle of comparative example 1, mind-set surface therefrom, it is big that molecular weight all becomes.But with respect to the rising gradually of the particle of comparative example 1, the particle of embodiment 1 almost is not have big variation uniformly from the center to 3/5 place, and sharply raises at the near surface molecular weight.Hence one can see that, and the particle of embodiment 1 keeps low-molecular-weight state near the center, uprise at the near surface molecular weight.

In addition, as Fig. 5 (a), (b) and (c) shown in, the GPC spectrogram of the particle that sharply increases as the molecular weight of embodiment 1,2 has acromion.There is flex point at these acromion places.Acromion is to form owing to high molecular polymer ratio increases.On the other hand, on the particle GPC spectrogram that the molecular weight of comparative example 1 increases gradually, can see several bulges, not have flex point not form acromion.

Embodiment 3

In having 14 liters autoclave of stirrer, with 230 rev/min speed stir on one side and add 6000g pure water, 9g tricalcium phosphate, 0.3g Sodium dodecylbenzene sulfonate on one side.The hydrogen ion concentration of this moment is 8.0.

Then, add 5400g vinylbenzene while stirring, 20.4g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.

Behind reinforced the end, in the airtight polymerization tank.Be warming up to 90 ℃,, add tricalcium phosphate respectively into 3g heating up end after back 2 hours and 3 hours.The polymerization degree of this moment is respectively 35% and 44%.

Then, the moment that has been incubated 2 hours under 90 ℃ is added once more into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate.The polymerization degree of this moment is 91%, and after in the speed usefulness nitrogen replacement polymerization tank of 200～300ml/min 10 minutes, the oxygen concn of mensuration is 4.8 volume %.After this, the limit is warmed up to 100 ℃, and the limit dripped 600g vinylbenzene in 3 hours continuously.

After the dipping whipping agent, carry out 1 identical operations with embodiment.

Determining molecular weight and characteristic, it the results are shown in table 1.

Embodiment 4

In having 14 liters autoclave of stirrer, with 230 rev/min speed stir on one side and add 6000g pure water, 9g tricalcium phosphate, 0.3g Sodium dodecylbenzene sulfonate on one side.This moment, hydrogen ion concentration was 8.0.

Then, add 5700g vinylbenzene while stirring, 20.4g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.

Behind reinforced the end, in the airtight polymerization tank.Be warming up to 90 ℃,, add tricalcium phosphate respectively into 3g heating up end after back 2 hours and 3 hours.The polymerization degree of this moment is respectively 35% and 44%.

Then, the moment that has been incubated 2 hours under 90 ℃ is added once more into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate.The polymerization degree of this moment is 90%, and after in the speed usefulness nitrogen replacement polymerization tank of 200～300ml/min 10 minutes, the oxygen concn of mensuration is 4.5 volume %.After this, the limit is warmed up to 100 ℃, and the limit dripped 300g vinylbenzene in 1.5 hours continuously.

After the dipping whipping agent, carry out 1 identical operations with embodiment.

Determining molecular weight and characteristic, it the results are shown in table 1.

Embodiment 5

In having 14 liters autoclave of stirrer, with 230 rev/min speed stir on one side and add 6000g pure water, 9g tricalcium phosphate, 0.3g Sodium dodecylbenzene sulfonate on one side.This moment, hydrogen ion concentration was 8.0.

Then, add 5400g vinylbenzene while stirring, 20.0g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.

Behind reinforced the end, in the airtight polymerization tank.Be warming up to 90 ℃,, add tricalcium phosphate respectively into 3g heating up end after back 2 hours and 3 hours.The polymerization degree of this moment is respectively 34% and 43%.

Then, the moment that has been incubated 2 hours under 90 ℃ is added once more into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate.The polymerization degree of this moment is 90%, and after in the speed usefulness nitrogen replacement polymerization tank of 200～300ml/min 10 minutes, the oxygen concn of mensuration is 4.0 volume %.After this, the limit is warmed up to 100 ℃, and the limit dripped 600g vinylbenzene in 3 hours continuously.

After the dipping whipping agent, carry out 1 identical operations with embodiment.

Determining molecular weight and characteristic, it the results are shown in table 1.

Embodiment 6

In having 14 liters autoclave of stirrer, with 230 rev/min speed stir on one side and add 6000g pure water, 9g tricalcium phosphate, 0.3g Sodium dodecylbenzene sulfonate on one side.This moment, hydrogen ion concentration was 8.0.

Then, add 5400g vinylbenzene while stirring, 22.4g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.Behind reinforced the end, in the airtight polymerization tank.Be warming up to 90 ℃,, add tricalcium phosphate respectively into 3g heating up end after back 2 hours and 2.5 hours.The polymerization degree of this moment is respectively 38% and 43%.

Then, the moment that has been incubated 0.5 hour under 90 ℃ is added once more into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate.The polymerization degree of this moment is 61%, and after in the speed usefulness nitrogen replacement polymerization tank of 200～300ml/min 10 minutes, the oxygen concn of mensuration is 4.1 volume %.After this, the limit is warmed up to 100 ℃, and the limit dripped 600g vinylbenzene in 5 hours continuously.

After the dipping whipping agent, carry out 1 identical operations with embodiment.

Determining molecular weight and characteristic, it the results are shown in table 1.

Embodiment 7

In having 14 liters autoclave of stirrer, with 230 rev/min speed stir on one side and add 6000g pure water, 9g tricalcium phosphate, 0.3g Sodium dodecylbenzene sulfonate on one side.This moment, hydrogen ion concentration was 8.0.

Then, add 4200g vinylbenzene while stirring, 21.7g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.Behind reinforced the end, in the airtight polymerization tank.Be warming up to 90 ℃,, add tricalcium phosphate respectively into 3g heating up end after back 1.5 hours and 2 hours.The polymerization degree of this moment is respectively 35% and 40%.

Then, the moment that has been incubated 1.5 hours under 90 ℃ is added once more into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate.The polymerization degree of this moment is 96%, and after in the speed usefulness nitrogen replacement polymerization tank of 200～300ml/min 10 minutes, the oxygen concn of mensuration is 3.8 volume %.After this, the limit is warmed up to 100 ℃, and the limit dripped 1800g vinylbenzene in 6 hours continuously.

After the dipping whipping agent, carry out 1 identical operations with embodiment.

Determining molecular weight and characteristic, it the results are shown in table 1.

Embodiment 8

In having 14 liters autoclave of stirrer, with 230 rev/min speed stir on one side and add 6000g pure water, 9g tricalcium phosphate, 0.3g Sodium dodecylbenzene sulfonate on one side.This moment, hydrogen ion concentration was 8.0.

Then, add 5400g vinylbenzene while stirring, 22.4g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.Behind reinforced the end, in the airtight polymerization tank.Be warming up to 90 ℃,, add tricalcium phosphate respectively into 3g heating up end after back 2 hours and 2.5 hours.The polymerization degree of this moment is respectively 38% and 43%.

Then, the moment that has been incubated 0.5 hour under 90 ℃ is added once more into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate.The polymerization degree of this moment is 61%, and after in the speed usefulness nitrogen replacement polymerization tank of 200～300ml/min 10 minutes, the oxygen concn of mensuration is 6.5 volume %.After this, the limit is warmed up to 100 ℃, and the limit dripped 600g vinylbenzene in 5 hours continuously.

After the dipping whipping agent, carry out 1 identical operations with embodiment.

Determining molecular weight and characteristic, it the results are shown in table 1.

Embodiment 9

(constituting the manufacturing of nuclear by the regenerated phenylethene resin beads)

With foamed styrene is that resin molded part (changing into industry (strain) the system Ha イ drip molding that PVC-ズ SSB-HX obtains by Hitachi) shrinks with 220 ℃ hot blasts, obtaining apparent specific gravity is 0.8, size is 500mm * 400mm * 100mm, the constrictor of heavily about 16kg.This constrictor carries out coarse reduction with the pulverizer (ZA-560 type pulverizer, the ホ of Co., Ltd.-ラ イ trade(brand)name) of the filtering net that 10mm is installed.The maximum length that the meal that obtain this moment minces is about 10mm, and bulk density is 0.65.Then, Henschel mixer (Mitsui three pond chemical industry systems, FM10B) in, (woods changes into system to add the talcum powder that this meal of 2000g minces, the 20g median size is 10 μ m, little white #5000) and the two stearylamides of N-vinyl of 0.6g, and with the rotating speed of 2000rpm mixed 2 minutes.To mince with the meal of the two stearylamides linings of this talcum powder and N-vinyl with the forcing machine (sheet is pressed dark 1mm1mm for T pattern, the wide 300mm of sheet) of the 30mm that has outlet while use and draw guide card with the roughly the same speed of extruded velocity and melt extrude.And, before cooling curing, with roller at interval 1mm is set flatly extruding direction relatively, be the slit of 0.5mm deeply, behind the cooling curing, with the sheet of stapling machine cut-out into about 10～15cm.Then, it is broken the cut off machine of the sheet phenylethylene resin series of gained to be carried out fine powder with the pulverizer (VM-16 type pulverizer, the オ リ エ of Co., Ltd. Application ト trade(brand)name) of the filtering net that 2mm is installed.With fine powder mince screen sizing in the scope of 0.6～1.2mm as the regenerated styrene resin particles.

The weight-average molecular weight of this regenerated styrene resin particles is 16.9 ten thousand, and proportion is 0.91.

(manufacturing of reclaimed expandable styrene resin particles)

In 5 liters withstand voltage stirred vessel, add the 1900g deionized water, 1100g regenerated phenylethene resin beads (nuclear), 12.0g tricalcium phosphate, 0.09g Sodium dodecylbenzene sulfonate, warming while stirring to 75 ℃.

Then, in the monomer dispersion cup, add 400g deionized water and 1.3g polyvinyl alcohol and mix, the tert-butyl peroxide of 0.2g and the styrene monomer of 3.9g benzoyl peroxide (wet%) have been dissolved to wherein adding 200g again, use intimate mixing device (special machine chemical industry system) to stir 120 seconds, make styrene monomer be fine dispersed (mean diameter of monomer oil droplet is 10～100 μ m) with the rotating speed of 5800rpm.This styrene monomer dispersion liquid was added in the container in 30 minutes, be incubated 60 minutes then after, be warming up to 90 ℃.

Then, in 5 hours, add the 900g styrene monomer continuously with uniform velocity (3.0g/min).At this moment, in withstand voltage stirred vessel, feed nitrogen, make oxygen concn remain on 0.5～1 volume %.The styrene monomer containing ratio of this moment is 10% (polymerization degree 90%).

Then, after adding that 2.2g tricalcium phosphate and 0.05g Sodium dodecylbenzene sulfonate, be warming up to 115 ℃, be incubated 2 hours.Then, be cooled to 100 ℃, be pressed into the whipping agent butane (i/n=4/6, same under the weight ratio) of 180g at twice, keep 10 hours to carry out the dipping of whipping agent.

To be cooled after room temperature, take out the reclaimed expandable styrene resin particles of being flooded by whipping agent, dehydrate.

Then, with this resin particle mesh screen sizing that is 0.6mm～1.7mm, the resin particle that obtains is added the Zinic stearas of 0.1 weight %, the sclerosis Semen Ricini oil of 0.1 weight % carries out surface-coated, obtains reclaimed expandable styrene resin particle.

Determining molecular weight and characteristic, it the results are shown in table 1.

In the present embodiment, resulting reclaimed expandable styrene resin particle is pre-expanded to 50ml/g, after slaking in about 18 hours, use the based resin molded machine VS-300 of ダ イ セ Application industry system foamed styrene, in compacting pressure is to be shaped under the 0.08Mpa, obtains the drip molding of 550mm * 335 * 150mm.

Comparative example 2

In having 14 liters autoclave of stirrer, with 230 rev/min speed stir on one side and add 6000g pure water, 9g tricalcium phosphate, 0.3g Sodium dodecylbenzene sulfonate on one side.The hydrogen ion concentration of this moment is 8.0.

Then, add 6000g vinylbenzene while stirring, 20.8g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.

Behind reinforced the end, in the airtight polymerization tank.Be warming up to 90 ℃,, add tricalcium phosphate respectively into 3g heating up end after back 2 hours and 3 hours.The polymerization degree of this moment is respectively 38% and 44%.

Then, the moment that has been incubated 2.5 hours under 90 ℃ is added once more into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate.The polymerization degree of this moment is 95%, and oxygen concn is 18.7 volume %.In 1 hour, be warmed up to 100 ℃ then.

After the dipping whipping agent, carry out 1 identical operations with embodiment.

Determining molecular weight and characteristic, it the results are shown in table 1.

Comparative example 3

In having 14 liters autoclave of stirrer, with 230 rev/min speed stir on one side and add 6000g pure water, 9g tricalcium phosphate, 0.3g Sodium dodecylbenzene sulfonate on one side.The hydrogen ion concentration of this moment is 8.0.

Then, add 5700g vinylbenzene while stirring, 24.8g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.Behind reinforced the end, in the airtight polymerization tank.Be warming up to 90 ℃,, add tricalcium phosphate respectively into 3g heating up end after back 1 hour and 2 hours.The polymerization degree of this moment is respectively 39% and 48%.

Then, the moment that has been incubated 2 hours under 90 ℃ is added once more into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate.The polymerization degree of this moment is 98%, and oxygen concn is 19.0 volume %.The limit was warmed up to 100 ℃ of limits and dripped 300g vinylbenzene in 1.5 hour then.

After the dipping whipping agent, carry out 1 identical operations with embodiment.

Determining molecular weight and characteristic, it the results are shown in table 1.

＜auto-polymerization begins to reduce oxygen concn to the polymerization later stage, particularly in the polymerization later stage, keeps oxygen concn below 7 volume %, adds monomeric example in the polymerization later stage 〉

Embodiment 10

In having 14 liters autoclave of stirrer, with 230 rev/min speed stir on one side and add 6000g pure water, 9g tricalcium phosphate, 0.3g Sodium dodecylbenzene sulfonate on one side.The hydrogen ion concentration of this moment is 8.0.

Then, add 5400g vinylbenzene while stirring, 22.4g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.

Behind reinforced the end, in the airtight polymerization tank.Open ventilation and carry out nitrogen replacement with pipe arrangement.The oxygen concn of this moment is 12 volume %.Close after nitrogen replacement finishes after ventilation becomes air-tight state after with pipe arrangement, be warming up to 90 ℃, heat up finish back 2 hours and 3 hours after, add the 3g tricalcium phosphate respectively.The polymerization degree of this moment is respectively 40% and 49%.

Then, reaching at 95% o'clock in 2.5 hours polymerization degree of 90 ℃ of following insulations adds into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate.The oxygen concn of this moment is 3.1 volume %.After this, the limit is warmed up to 100 ℃ of limits with the dropping continuously in 3 hours of 600g vinylbenzene.

Then, with the 90g hexanaphthene, after 1 hour 420g butane (Trimethylmethane/normal butane ratio=4/6) being pressed into, be incubated 4 hours more again in 1 hour.Then, cool to room temperature is taken out by autoclave.

After the slurries process washing of taking out, dehydration, dry each operation, be classified as under 14 mesh sieves, on 26 mesh sieves, carry out surface-coatedly again with the dimethyl siloxane of 0.08% Zinic stearas, 0.05% Semen Ricini winterized stearin and 0.02%, obtain the vinylbenzene resin expandable beads.

Measure the molecular weight and the characteristic of resulting vinylbenzene resin expandable beads, it the results are shown in table 2.In addition, the molecular weight variation from middle mind-set surface is shown in Fig. 6.

Embodiment 11

In having 14 liters autoclave of stirrer, behind nitrogen replacement, with 230 rev/min speed stir on one side and add 6000g pure water, 9g tricalcium phosphate, 0.3g Sodium dodecylbenzene sulfonate on one side.The hydrogen ion concentration of this moment is 8.0.

Then, add 5400g vinylbenzene while stirring, 22.4g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.

Behind reinforced the end, in the airtight polymerization tank.Open ventilation and use pipe arrangement, carry out nitrogen replacement once more.The oxygen concn that measure with oxymeter this moment is 5.4 volume %.Close after nitrogen replacement finishes ventilation with pipe arrangement after, be warming up to 90 ℃, heat up finish back 2 hours and 3 hours after, add the 3g tricalcium phosphate respectively.This moment, the ground polymerization degree was respectively 40% and 49%.

Then, 90 ℃ of down insulations 2.5 hours, reach moment of 95% to add in the polymerization degree into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate.The oxygen concn of this moment is 4.8 volume %.After this, the limit is warmed up to 100 ℃, and the limit dripped 600g vinylbenzene in 3 hours continuously.

The addition of whipping agent and dipping time temperature, and after this comprise processing and surface treatment, carrying out similarly to Example 10 to resulting vinylbenzene foaminess resin particle.

Determining molecular weight and characteristic, it the results are shown in table 2.

Embodiment 12

In having 14 liters autoclave of stirrer, with 230 rev/min speed stir on one side and add 6000g pure water, 9g tricalcium phosphate, 0.3g Sodium dodecylbenzene sulfonate on one side.The hydrogen ion concentration of this moment is 8.0.

Then, add 5400g vinylbenzene while stirring, 22.4g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.

Behind reinforced the end, in the airtight polymerization tank.Open ventilation and use pipe arrangement, carry out nitrogen replacement.The oxygen concn of this moment is 11 volume %.After nitrogen replacement finishes, closing ventilation and use pipe arrangement, become air-tight state after, be warming up to 90 ℃, heating up end after back 2 hours and 3 hours, add the 3g tricalcium phosphate respectively.The polymerization degree of this moment is respectively 40% and 49%.

Then, 90 ℃ down insulation 2.5 hours reach moment of 95% in the polymerization degree and add into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate.The oxygen concn of this moment is 5 volume %.After this, the limit is warmed up to 100 ℃, and the limit dripped 600g vinylbenzene in 3 hours continuously.

The addition of whipping agent and dipping time temperature, and after this comprise processing and surface treatment, carrying out similarly to Example 10 to resulting vinylbenzene foaminess resin particle.

Determining molecular weight and characteristic, it the results are shown in table 2.

Table 2

＜auto-polymerization begins to keep oxygen concn below 1 volume % to the polymerization later stage, adds monomeric example in the polymerization later stage 〉

Embodiment 13

In having 14 liters autoclave of stirrer, behind nitrogen replacement, with 230 rev/min speed stir on one side and add 6000g pure water, 9g tricalcium phosphate, 0.3g Sodium dodecylbenzene sulfonate on one side.The hydrogen ion concentration of this moment is 8.0.

Then, add 5400g vinylbenzene while stirring, 22.4g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.

Behind reinforced the end, in the airtight polymerization tank, open ventilation and use pipe arrangement, carry out nitrogen replacement once more.The oxygen concn of this moment of measuring with oxymeter is 0.6 volume %.After being warming up to 90 ℃, carry out nitrogen replacement, make oxygen concn become 0.6 volume % once more.Heating up end after back 2 hours and 3 hours, add the 3g tricalcium phosphate respectively.The polymerization degree of this moment is respectively 40% and 49%.

Then, reaching at 95% o'clock in the polymerization degree in 2.5 hours 90 ℃ of following insulations adds into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate.The oxygen concn of this moment is 0.6 volume %.After this, the limit is warmed up to 100 ℃, and the limit dripped 600g vinylbenzene in 3 hours continuously.

The addition of whipping agent and dipping time temperature, and after this comprise processing and surface treatment, carrying out similarly to Example 10 to resulting vinylbenzene foaminess resin particle.

Measure the molecular weight and the characteristic of resulting vinylbenzene resin expandable beads, it the results are shown in table 3.In addition, therefrom the change of molecular weight on mind-set surface is shown in Fig. 6.

In addition, for surface portion, measure spectrogram (GPC spectrogram) with the GPC method.This spectrogram is shown in Fig. 7 (a).

Embodiment 14

In having 14 liters autoclave of stirrer, behind nitrogen replacement, with 230 rev/min speed stir on one side and add 6000g pure water, 9g tricalcium phosphate, 0.3g Sodium dodecylbenzene sulfonate on one side.The hydrogen ion concentration of this moment is 8.0.

Then, add 5400g vinylbenzene while stirring, 22.4g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.

Behind reinforced the end, in the airtight polymerization tank, open ventilation and use pipe arrangement, carry out nitrogen replacement once more.The oxygen concn of this moment of measuring with oxymeter is 0.9 volume %.After being warming up to 90 ℃, carry out nitrogen replacement, make oxygen concn become 0.9 volume % once more.Heating up end after back 2 hours and 3 hours, add the 3g tricalcium phosphate respectively.The polymerization degree of this moment is respectively 40% and 49%.

Then, 90 ℃ down insulation made polymkeric substance reach moment of 95% in 2.5 hours to add into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate.The oxygen concn of this moment is 1.0 volume %.After this, the limit is warmed up to 100 ℃, and the limit dripped 600g vinylbenzene in 3 hours continuously.

Then, with the 90g hexanaphthene, after 1 hour 420g butane (Trimethylmethane/normal butane ratio=4/6) being pressed into, be incubated 4 hours more again in 1 hour.Then, cool to room temperature is taken out by autoclave.

After the slurries process washing of taking out, dehydration, dry each operation, be classified as under 14 mesh sieves, on 26 mesh sieves, carry out surface-coatedly again with the dimethyl siloxane of 0.08% Zinic stearas, 0.05% Semen Ricini winterized stearin and 0.02%, obtain the vinylbenzene resin expandable beads.

The molecular weight of the vinylbenzene resin expandable beads of gained and the measurement result of characteristic are shown in table 3.In addition, the molecular weight variation from middle mind-set surface is shown in Fig. 6.

As shown in Figure 6, the particle among the embodiment 13,14 does not descend at the molecular weight of near surface, still, comparative example 1, the particle of embodiment 10 has but descended at the molecular weight of near surface.

Embodiment 15

In having 14 liters autoclave groove of stirrer, behind nitrogen replacement, add the 6000g pure water, the 9g tricalcium phosphate, the 0.3g Sodium dodecylbenzene sulfonate stirs with 230 rev/mins speed simultaneously.This moment, hydrogen ion concentration was 8.0.

Then, add 5100g vinylbenzene while stirring, 25.6g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.

Behind reinforced the end, in the airtight polymerization tank, open ventilation and use pipe arrangement, continue to make nitrogen to flow into the speed of 300ml/min.The oxygen concn of this moment is 0.1 volume %.After being warming up to 90 ℃, measuring oxygen concn once more and become below the 0.1 volume %,, add the 3g tricalcium phosphate respectively heating up end after back 1.5 hours and 2.0 hours.This moment, the ground polymerization degree was respectively 40% and 47%.

Then, 90 ℃ down insulation to arrive polymkeric substance in 2.0 hours be to add into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate in 95% o'clock.The oxygen concn of this moment is below the 0.1 volume %.After this, finish nitrogen replacement, after complete closed cell was interior, the limit was warmed up to 100 ℃, dripped 600g vinylbenzene in 5 hours continuously in the limit.

The processing of the vinylbenzene foaminess resin particle of gained and surface treatment are carried out according to the processing identical with embodiment 10 after the addition of whipping agent and the dipping time temperature.

Measure the molecular weight and the characteristic of resulting vinylbenzene resin expandable beads, it the results are shown in table 3.

In addition, for surface portion, measure spectrogram (GPC spectrogram) with the GPC method.This spectrogram is shown in Fig. 7 (b).

Shown in Fig. 7 (a) and (b) and Fig. 5 (c), bimodal and acromion appears in the particle that molecular weight sharply increases as embodiment 13,14 on the GPC spectrogram.On acromion, there is flex point.Acromion forms owing to high molecular polymer ratio.On the other hand,, can see several bulges on the GPC spectrogram of the particle that molecular weight increases gradually, not have flex point, not form acromion as comparative example 1.

Embodiment 16

In having 14 liters autoclave of stirrer, behind nitrogen replacement, continue with speed that 300ml/ divide groove in to feed nitrogen on one side, add the 6000g pure water while stirring, 9g tricalcium phosphate, 0.3g Sodium dodecylbenzene sulfonate with 230 rev/mins speed simultaneously.The hydrogen ion concentration of this moment is 8.0.

Then, add 5400g vinylbenzene while stirring, 22.4g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.

Behind reinforced the end, in the airtight polymerization tank, open the ventilation pipe arrangement, continue in groove, to feed nitrogen with the speed that 300ml/ divides.The oxygen concn of this moment is 0.7 volume %.After being warming up to 90 ℃, carry out nitrogen replacement once more, make oxygen concn become 0.7 volume %.Heating up end after back 2 hours and 3 hours, add the 3g tricalcium phosphate respectively.The polymerization degree of this moment is respectively 40% and 49%.

Then, 90 ℃ down insulation 2.5 hours reach moment of 95% in the polymerization degree and add into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate.The oxygen concn of this moment is below the 0.4 volume %.After this, finish nitrogen replacement, after complete closed cell was interior, the limit was warmed up to 100 ℃, and the limit dripped 600g vinylbenzene in 3 hours continuously.

The addition of whipping agent and dipping time temperature, and after this comprise processing and surface treatment, carrying out similarly to Example 10 to resulting vinylbenzene foaminess resin particle.

Measure the molecular weight and the characteristic of resulting vinylbenzene resin expandable beads, it the results are shown in table 3.

Comparative example 4

In having 14 liters autoclave of stirrer, add the 6000g pure water while stirring with 230 rev/mins speed, 9g tricalcium phosphate, 0.3g Sodium dodecylbenzene sulfonate.The hydrogen ion concentration of this moment is 8.0.

Then, add 6000g vinylbenzene while stirring, 20g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.

Behind reinforced the end, be warming up to 90 ℃, open ventilation and use pipe arrangement, carry out polymerization.Heating up end after back 2 hours and 3 hours, add the 3g tricalcium phosphate respectively.The polymerization degree of this moment is respectively 34% and 43%.

Then, 90 ℃ down insulation 3 hours reach moment of 95% in the polymerization degree and add into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate.The oxygen concn of this moment is 13.0 volume %.After this, in 1 hour, be warmed up to 100 ℃.

Later operation the carrying out similarly to Example 10 of dipping whipping agent.

Measure resulting molecular weight and characteristic, it the results are shown in table 3.

＜auto-polymerization begins to remain on below the 7 volume % to polymerization later stage oxygen concn, does not add monomeric example 〉

Embodiment 17

In having 14 liters autoclave of stirrer, with 230 rev/min speed stir on one side and add 6000g pure water, 9g tricalcium phosphate, 0.3g Sodium dodecylbenzene sulfonate on one side.The hydrogen ion concentration of this moment is 8.0.

Then, add 6000g vinylbenzene while stirring, 20.8g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.

Behind reinforced the end, in the airtight polymerization tank.Open ventilation with pipe arrangement after, feed nitrogen, when oxygen concn becomes the stage of 6.5 volume %, closing the ventilation pipe arrangement.Be warming up to 90 ℃,, add the 3g tricalcium phosphate respectively heating up end after back 2 hours and 3 hours.The polymerization degree of this moment is respectively 34% and 43%.

Then, 3 hours the moment of insulation is added once more into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate down at 90 ℃.The result who measures the oxygen concn in the polymerization tank at this moment is 5.8 volume %.After this, in 1 hour, be warmed up to 100 ℃.

Then, with the 90g hexanaphthene, after 1 hour 420g butane (Trimethylmethane/normal butane ratio=4/6) being pressed into, be incubated 4 hours more again in 1 hour.Then, cool to room temperature is taken out by autoclave.

After the slurries process washing of taking out, dehydration, dry each operation, be classified as under 14 mesh sieves, on 26 mesh sieves, carry out surface-coatedly again with the dimethyl siloxane of 0.08% Zinic stearas, 0.05% Semen Ricini winterized stearin and 0.02%, obtain vinylbenzene resin expandable beads (median size: 0.85mm).

Determining molecular weight and characteristic, it the results are shown in table 4.

Embodiment 18

Finish to play till the polymerization under 90 ℃ finishes except reinforced certainly, in polymerization tank, continue to feed nitrogen, oxygen concn in the controlled polymerization groove is beyond below the 0.1 volume %, and all the other carry out similarly to Example 1, obtain vinylbenzene resin expandable beads (median size: 0.85mm).

Determining molecular weight and characteristic, it the results are shown in table 4.

Comparative example 5

In having 14 liters autoclave of stirrer, with 230 rev/min speed stir on one side and add 6000g pure water, 9g tricalcium phosphate, 0.3g Sodium dodecylbenzene sulfonate on one side.The hydrogen ion concentration of this moment is 8.0.

Then, add 6000g vinylbenzene while stirring, 20.8g (wet75%) benzoyl peroxide, 2.4g tert-butyl hydroperoxide isobutyl carbonate propyl ester and 3g ethylene bisamide.

Behind reinforced the end, be warming up to 90 ℃, open ventilation and carry out polymerization with pipe arrangement.The interior oxygen concn of polymerization tank this moment is 20.7 volume %.Heating up end after back 2 hours and 3 hours, add the 3g tricalcium phosphate respectively.The polymerization degree of this moment is respectively 33% and 42%.

Then, the moment that has been incubated 3 hours under 90 ℃ is added once more into 6g tricalcium phosphate and 0.3g Sodium dodecylbenzene sulfonate.The result who measures the oxygen concn in the polymerization tank at this moment is 15.8 volume %.After this, in 1 hour, be warmed up to 100 ℃.The later operation of dipping whipping agent is carried out similarly to Example 1, obtains vinylbenzene resin expandable beads (median size: 0.85mm).

Determining molecular weight and characteristic, it the results are shown in table 4.

Table 4

Claims (12)

1. the manufacture method of a vinylbenzene resin expandable beads, it is characterized in that, in the suspension polymerization of styrenic monomers, in the polymerization degree is 60% when above, keeping the interior oxygen concn of reactive tank is to carry out polyreaction under the following condition of 7 volume %, before polyreaction finishes or after the polyreaction end, the dipping whipping agent.

2. the manufacture method of vinylbenzene resin expandable beads according to claim 1, it is characterized in that, keep above-mentioned oxygen concn be below the 7 volume % in, add styrenic monomers, the monomer of this interpolation is adsorbed by the styrene resin particle in polymerization process and carries out polyreaction.

3. the manufacture method of a vinylbenzene resin expandable beads, it is characterized in that: in the suspension polymerization of styrenic monomers, begin to reach 60% when above from polyreaction to the polymerization degree, keeping the interior oxygen concn of reactive tank is to carry out polyreaction under the following condition of 7 volume %, before polyreaction finishes or after the polyreaction end, the dipping whipping agent.

4. the manufacture method of vinylbenzene resin expandable beads according to claim 3, it is characterized in that: keep above-mentioned oxygen concn be below the 7 volume % in, add styrenic monomers, the monomer of this interpolation is adsorbed by the styrene resin particle in polymerization process, and carries out polyreaction.

5. the manufacture method of vinylbenzene resin expandable beads according to claim 3, it is characterized in that: in the suspension polymerization of styrenic monomers, begin to reach 60% when above from polymerization to the polymerization degree, keep the interior oxygen concn of reactive tank below 1 volume %, add styrenic monomers simultaneously, the monomer of this interpolation is adsorbed by the styrene resin particle in polymerization process and carries out polyreaction, before polyreaction finishes or after the polyreaction end, and the dipping whipping agent.

6. according to the manufacture method of the described vinylbenzene resin expandable beads of claim 2,4 or 5, it is characterized in that: the styrenic monomers amount of above-mentioned interpolation is the 5 weight %～30 weight % of above-mentioned vinylbenzene resin expandable beads.

7. according to the manufacture method of any described vinylbenzene resin expandable beads of claim 1～5, it is characterized in that: in the suspension polymerization of above-mentioned styrenic monomers, in the hydrogen ion concentration of aqueous dispersions is to begin polymerization at 8～10 o'clock, in the polymerization degree is 20%～50% o'clock, adds the insoluble inorganic salt at least one time.

8. the manufacture method of vinylbenzene resin expandable beads according to claim 6, it is characterized in that: in the suspension polymerization of above-mentioned styrenic monomers, in the hydrogen ion concentration of aqueous dispersions is to begin polymerization at 8～10 o'clock, in the polymerization degree is 20%～50% o'clock, adds the insoluble inorganic salt at least one time.

9. the manufacture method of vinylbenzene resin expandable beads according to claim 1 is characterized in that: use the nuclear that is made of the regenerated phenylethene resin particle, it is added styrenic monomers.

10. the vinylbenzene resin expandable beads that obtains by the manufacture method of any described vinylbenzene resin expandable beads of claim 1～9.

11. the polystyrene foaming hollow bead that the described vinylbenzene resin expandable beads foaming of claim 10 is made.

12. the polystyrene foaming and molding spare that makes by the described polystyrene of claim 11 foaming hollow bead.

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