JPH09328567A - Crosslinked vinyl chloride resin foam plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a crosslinked vinyl chloride resin foam plate which does not undergo deformation by softening and shrinkage when laminated with an FRP plate by crosslinking and foaming a vinyl chloride resin. SOLUTION: One hundred pts.wt. vinyl chloride resin having a degree of polymerization of 1,000-4,000 is mixed with 1-100 pts.wt. carboxylic acid anhydride, 0.1-10 pts.wt. blowing agent, tolylene diisocyanate in an amount to give a weight ratio of 0.10 or above and 20-80 pts.wt. isocyanate compound represented by the formula (wherein x is 0.5-1.5 on the average) to obtain an expandable composition. This composition is packed into a mold and heated for 10-50min to 100-200 deg.C to crosslink and expand it. The obtained primary foam is then heated to 80-130 deg.C by contact with hot water or steam to obtain the secondary foam being a crosslinked vinyl chloride resin foam plate having a density of 20-60kg/m<2> and a% area retention of 80% or above (when measured after immersion in a styrene monomer at 50 deg.C for 1hr).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a crosslinked vinyl chloride resin foam plate. More specifically, ships,
The present invention relates to a crosslinked vinyl chloride resin foam plate that can be suitably used as a core material of an FRP laminated plate used for structural panels such as pools.

[0002]

2. Description of the Related Art Conventionally, a laminated body panel in which a rigid polyurethane foam is used as a core material and FRP plates are laminated on both surfaces thereof is used as a structural panel for ships, pools and the like.

However, the rigid polyurethane foam used as the core material in the laminate panel is FR
Since the adhesiveness to the P plate is poor, peeling easily occurs between the two, and bending strength and compression strength are low.

Therefore, in recent years, FR has been used as a structural panel.
As a core material having excellent adhesiveness to a P plate, a non-crosslinked vinyl chloride resin foam has been proposed.

Although the structural panel has excellent adhesiveness between the FRP plate and the non-crosslinked vinyl chloride resin foam, the non-crosslinked vinyl chloride resin foam is softly deformed and contracts. There is a drawback that.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and it does not soften and deform or shrink even when laminated with an FRP plate. It is an object to provide a resin foam plate.

[0007]

According to the present invention, a vinyl chloride resin is crosslinked and foamed to have a density of 20 to 60 kg / m.
^And a crosslinked vinyl chloride resin foam plate having an area retention of 80% or more after being immersed in a styrene monomer at 50 ° C. for 1 hour.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The crosslinked vinyl chloride resin foam plate of the present invention is obtained by crosslinking and foaming a vinyl chloride resin as described above, and has a density of 20 to 60 kg / m.
³ has, but 1 hour soaked area retention of then allowed to the 50 ° C. styrene monomer is more than 80%.

According to the research conducted by the present inventor, the cause of softening deformation and shrinkage of the non-crosslinked vinyl chloride resin foam during the production of the structural panel comprising the FRP plate and the non-crosslinked vinyl chloride resin foam is caused by the FRP. It was found to be in the styrene monomer used as the raw material monomer for the plate.

Therefore, the present inventor has conducted extensive studies in view of such a fact, and as a foam plate, not a conventional non-crosslinked vinyl chloride resin foam plate but a crosslinked vinyl chloride resin foam plate is used. Moreover, the crosslinked vinyl chloride resin foam plate has a density of 20 to 60.
When the area retention of the crosslinked vinyl chloride resin foam plate having a weight ratio of kg / m ³ after being immersed in styrene monomer at 50 ° C. for 1 hour is 80% or more, FRP
It has been found that softening deformation and shrinkage do not occur even when a laminate with a plate is used.

The present invention has been completed based on such findings.

The crosslinked vinyl chloride resin foam plate of the present invention includes, for example, vinyl chloride resin, carboxylic acid anhydride, foaming agent, tolylene diisocyanate and general formula (I):

[0013]

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It can be obtained by foaming a foamable composition containing an isocyanate compound consisting of a polyisocyanate represented by the formula (wherein n is 0.5 to 1.5 on average).

The vinyl chloride resin includes, for example, vinyl chloride homopolymers, vinyl chloride-vinyl acetate copolymers and other copolymers, and vinyl chloride homopolymers and copolymers as well as vinyl chloride. It is a concept including a mixture of a resin exhibiting compatibility with and in a poor amount. Resins usually referred to as blend resins such as chlorinated vinyl chloride resins, chlorinated polyethylenes, and ethylene-vinyl acetate copolymers are preferred as resins that can be mixed with the vinyl chloride homopolymers and copolymers. The polymerization degree of the vinyl chloride resin is usually preferably from 1,000 to 4,000, more preferably from 1,500 to 3,000. Further, among the vinyl chloride-based resins, the paste vinyl chloride-based resin can be a foamable composition having so-called sol-like fluidity, and is suitable because it may be industrially convenient to handle. It can be used. Here, the paste vinyl chloride resin is a substantially spherical fine powder having a particle diameter of several μm or less, which is produced by a so-called emulsion polymerization method or microsuspension polymerization method, and the fine powder is further It is composed of a large number of small particles.

The blending amount of the vinyl chloride resin should be 20% by weight or more, especially 30% by weight or more with respect to the foamable composition in order to prevent the cell membrane of the foam from breaking during foaming. Is preferable, and in order to prevent the density of the foam from becoming too high and the value as a lightweight structural material from being lost, 9 is added to the foamable composition.
It is preferably 0% by weight or less, especially preferably 60% by weight or less.

As a typical example of the carboxylic acid anhydride,
For example, monobasic carboxylic anhydrides such as propionic anhydride, isobutyric anhydride, and benzoic anhydride; dibasic carboxylic anhydrides such as phthalic anhydride and maleic anhydride; and the like, alone or in combination of two or more. These are used in combination.

The blending amount of the monobasic carboxylic acid anhydride varies depending on whether the monobasic carboxylic acid anhydride and the dibasic carboxylic acid anhydride are used in combination, and cannot be unconditionally determined. .

When the monobasic carboxylic acid anhydride is used alone without using the monobasic carboxylic acid anhydride and the dibasic carboxylic acid anhydride together, the monobasic carboxylic acid anhydride is used. For example, in order to sufficiently shorten the time required for secondary foaming, it is desirable that the blending amount be 1 part by weight or more, preferably 5 parts by weight or more, based on 100 parts by weight of the vinyl chloride resin. In order to eliminate the risk of the cell membrane breaking due to excessive speed, it is desirable that the amount be 100 parts by weight or less, preferably 80 parts by weight or less, and more preferably 70 parts by weight or less with respect to 100 parts by weight of the vinyl chloride resin. .

When the monobasic carboxylic acid anhydride and the dibasic carboxylic acid anhydride are used in combination, the blending amount of the monobasic carboxylic acid anhydride is, for example, a sufficient time required for secondary foaming. In order to reduce the amount to 0.5 parts by weight, it is desirable that the amount is 0.5 parts by weight or more, preferably 1 part by weight or more, and more preferably 5 parts by weight or more, relative to 100 parts by weight of the vinyl chloride resin. Vinyl chloride resin 1 to eliminate the risk of the cell membrane breaking
It is desirably 70 parts by weight or less, preferably 60 parts by weight or less, more preferably 50 parts by weight or less based on 00 parts by weight.

When the monobasic carboxylic acid anhydride and the dibasic carboxylic acid anhydride are used in combination, the compounding amount of the dibasic carboxylic acid anhydride is 100 parts by weight of the monobasic carboxylic acid anhydride. It is preferably 50 parts by weight or more, especially 100 parts by weight or more. In addition, if the compounding amount of the dibasic carboxylic anhydride is too large, the cost increases, so that the monobasic carboxylic anhydride 100
The amount is preferably 1,000 parts by weight or less with respect to parts by weight, and in order to sufficiently exhibit the effect of shortening the time required for secondary foaming, the amount is preferably 500 parts by weight or less.

The foaming composition contains a foaming agent. Such a foaming agent is roughly classified into a decomposable foaming agent and an evaporative foaming agent, and any of the foaming agents may be used in the present invention. preferable.

Examples of the decomposition type foaming agent include azobisisobutyronitrile, azodicarbonamide, diazoaminobenzene, N, N'-dinitrosopentamethylenetetramine, p-toluenesulfonylhydrazide and the like. The blowing agents may be used alone or in combination of two or more.

Examples of the evaporating foaming agents include propane, butane, and soft freon such as Freon-123.
A mixture of more than one species is used. Note that among these, it is preferable to use propane, butane, or the like, which has a small effect on the ozone layer.

The blending amount of the foaming agent cannot be unconditionally determined because it depends on the blending amounts of the isocyanate compound and the carboxylic acid anhydride, the desired foaming ratio and the type of the foaming agent. The amount of the foaming agent is usually 0.1 parts by weight or more, preferably 0.3 parts by weight or more, relative to 100 parts by weight of the vinyl chloride resin in order to impart a desired expansion ratio to the foam. More preferably, the content is preferably 0.5 parts by weight or more, and in order to prevent the foamable composition from leaking from the molding die during multi-stage pressing and the cell membrane from breaking during foaming, 10 parts by weight or less, preferably 7 parts by weight based on 100 parts by weight of the vinyl resin.
It is desirable that the amount is not more than 6 parts by weight, more preferably not more than 6 parts by weight.

The foaming agent may be used in combination with a foaming aid such as urea, if necessary.

When the foamable composition is heated in the molding die, the isocyanate compound dissolves the vinyl chloride resin and unravels it to a molecular size order, so that the isocyanate compound and the vinyl chloride resin are entangled with each other. Become. As a result, when the isocyanate compound, the carboxylic acid anhydride, and water react during the secondary foaming, the vinyl chloride resin is physically incorporated into the crosslinked chain,
In the obtained foam, the polymer chain of the vinyl chloride resin and the crosslinked polymer chain formed by the reaction of the isocyanate compound, the carboxylic acid anhydride and water are intertwined with each other, and a part of the crosslinked polymer chain is chlorinated. It has excellent solvent resistance, heat resistance, mechanical strength, etc. by being graft-bonded to the polymer chain of vinyl resin.

In the foamable composition, as the isocyanate compound, tolylene diisocyanate and the general formula (I):

[0029]

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A polyisocyanate represented by the formula (wherein n is 0.5 to 1.5 on average) is used.

Since the polyisocyanate represented by the general formula (I) is used in combination with the tolylene diisocyanate in the foamable composition, excellent styrene monomer resistance is imparted to the crosslinked vinyl chloride resin foam plate. Granted.

The value of the weight ratio of tolylene diisocyanate and polyisocyanate represented by the general formula (I) (tolylene diisocyanate / polyisocyanate represented by the general formula (I)) is such that cracks occur during secondary foaming. In order to reduce the strain, 0.10 or more, preferably 0.
It is preferably 15 or more, more preferably 0.20 or more, and in order to improve styrene monomer resistance, it is 3.0 or less, preferably 2.8 or less, more preferably 2.6 or less. desirable.

The amount of the above-mentioned isocyanate compound is 20 parts by weight or more, preferably 25 parts by weight, based on 100 parts by weight of the vinyl chloride resin in order to improve the moldability by improving the fluidity of the foamable composition. It is desirable that the amount of the vinyl chloride resin is 100 parts by weight or more, and more preferably 30 parts by weight or more. In order to prevent the obtained crosslinked vinyl chloride resin foam plate from breaking, a vinyl chloride resin 100 is used.
It is desirable that the amount is 80 parts by weight or less, preferably 75 parts by weight or less, and more preferably 70 parts by weight or less with respect to parts by weight.

The isocyanate compound generates carbon dioxide gas at the same time as the crosslinking reaction proceeds, and the carbon dioxide gas can be used as a foaming agent.

Further, if necessary, for example, a stabilizer, an inorganic filler (filler), a pigment and the like may be appropriately added to the foamable composition as long as the object of the present invention is not impaired.

The stabilizer is not particularly limited as long as it has the ability to prevent decomposition and deterioration of the vinyl chloride resin. Specific examples of such stabilizers include, for example, dibasic lead stearate, dibasic lead phosphite, tribasic lead sulfate and zinc stearate, calcium stearate,
Examples thereof include lead phosphite, and these stabilizers are used alone or in combination of two or more.

Examples of the inorganic filler include talc, calcium carbonate, shirasu balloon and the like.

The above-mentioned pigment is used for coloring the obtained foamed material to a desired color, and in addition to white pigments which can also serve as an inorganic filler such as calcium carbonate, for example, titanium white. , Benzidine orange, benzidine yellow, and watching red.

It is preferable that the foamable composition is sufficiently kneaded with a kneader such as a double-arm kneader before being filled in a molding die to form a sol having a uniform composition. In addition, the temperature at the time of kneading is not particularly limited, and usually may be room temperature.

Next, the prepared foamable composition is filled in a molding die made of, for example, an aluminum alloy, and the molding die is set in, for example, a hydraulically driven multi-stage hot press machine and the molding die is set. The mold is closed, clamped, and heated.

The heating temperature varies depending on the constituents of the foamable composition, but is a suitable temperature depending on the type and blending amount of the foaming agent in the foamable composition, for example, 100 to 200 ° C.
Preferably 140-190 ° C, more preferably 150
It is desirable that the temperature be 180 ° C.

When the foamable composition is heated to the above-mentioned heating temperature, the foamable composition usually contains 50 to 350 kg / c.
m ² · G, preferably 100 to 300 kg / cm ² ·
About G, more preferably 150 to 250 kg / cm ²
・ It has a pressure of about G.

When the heating temperature reaches the above temperature range, it is usually 10 to 10, though it depends on the shape of the molding die.
It is preferable to maintain that state for about 50 minutes.

Next, while the molding die is still being pressurized, the temperature of the heating plate under pressure of the pressing machine is cooled to room temperature or a temperature in the vicinity thereof using a cooling medium such as water, and the molding die is opened. By doing so, a primary foam is obtained.

The carboxylic acid anhydride in the foamable composition does not directly react with the isocyanate compound, but becomes a carboxylic acid in the presence of water, and the generated carboxylic acid reacts with the isocyanate compound.

Therefore, the obtained primary foam is brought into contact with hot water or high-temperature steam to advance the reaction, and at the same time, secondary foaming is carried out by the carbon dioxide gas produced. In this case, the temperature of the hot water or high-temperature steam is set to 80 to 130 ° C. in order to allow the reaction and the secondary foaming to proceed sufficiently.
Degree, preferably 85-110 ° C, more preferably 9
Desirably, the temperature is 0 to 100 ° C. If the temperature is 80
When the temperature is lower than ° C, the foam does not expand to a predetermined size, or even when expanded, it takes a long time for secondary foaming. When the temperature exceeds 130 ° C, the cell membrane tends to be broken. Note that the temperature is desirably 100 ° C. or lower in order to prevent an increase in equipment cost due to the need for special heating equipment.

Thus, the crosslinked vinyl chloride resin foam plate of the present invention is obtained.

The thickness of the crosslinked vinyl chloride resin foam plate cannot be unconditionally determined because it depends on the application and the like. When the application is, for example, a core material for structural panels such as ships and pools, the thickness of the crosslinked vinyl chloride resin foam plate provides mechanical strength and heat insulation required for structural panels. For 1m
m or more, preferably 3 mm or more, more preferably 5 m
It is preferably m or more, and from the viewpoint of weight reduction and cost, it is preferably 150 mm or less, preferably 120 mm or less, and more preferably 100 mm or less.

The shape of the crosslinked vinyl chloride resin foam plate is not particularly limited, but is usually a flat plate shape or a semi-cylindrical shape.

The density of the crosslinked vinyl chloride resin foam plate is usually adjusted appropriately by the amount of foaming agent, foaming conditions and the like. The density of the crosslinked vinyl chloride resin foam plate is 20 kg / m ³ or more, preferably 25 k from the viewpoint of mechanical strength of the crosslinked vinyl chloride resin foam plate.
g / m ³ or more, more preferably 30 kg / m ³ or more, and 60 kg / m ³ from the viewpoint of heat insulation and weight reduction.
The following is preferably 55 kg / m ³ or less, more preferably 50 kg / m ³ or less.

The area retention of the crosslinked vinyl chloride resin foam plate of the present invention is determined by adjusting the composition of the foamable composition used for the crosslinked vinyl chloride resin foam plate as described above. Particularly, by using an isocyanate compound composed of tolylene diisocyanate and the polyisocyanate represented by the general formula (I) in the foamable composition, it can be adjusted to 80% or more.

The area retention rate referred to in the present specification is the average value of the dimensions before and after the dipping of the center of each of the vertical and horizontal sides of a foam plate having a length of 100 mm × a width of 100 mm × a thickness of 10 mm and 50 ° C. After measuring the average value of the dimensions after immersion in the styrene monomer for 1 hour, the formula: [Area retention rate (%)] = [Average value of the area before immersion (mm ² )]
÷ [Average value of area after immersion (mm ² )] × 100

The crosslinked vinyl chloride resin foam plate of the present invention has a density of 20 to 60 kg / m ³ and a temperature of 50 ° C.
The area retention after immersing in the styrene monomer for 1 hour is 80% or more, so even if the FRP plates are laminated, they exhibit the excellent property of not softening and deforming or shrinking. .

[0054]

EXAMPLES Next, the crosslinked vinyl chloride resin foam plate of the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 5 and Comparative Examples 1 to 2 Raw materials were prepared so as to have the compositions shown in Table 1, and the total amount was 1 k.
g, and kneaded with a double-arm kneader having an effective volume of 1 liter at room temperature for 45 minutes to obtain a foamable composition.

The foamable composition thus obtained has an inner size of 155 mm.
It was filled in an aluminum alloy molding die of x155 mm x 20 mm, set in a pressing machine, and the molding die was sealed and clamped. Steam is passed through the hot plate of the press, the temperature of the mold is raised to 175 ° C., and the pressure is 210 kg / cm ^2.
After holding for 35 minutes at G, the press hot plate was cooled down to 30 ° C. or less by passing industrial water, the clamping pressure of the press was released, and the forming mold was opened to obtain a primary foam. The size of the obtained primary foam is 180 mm × 180 mm × 23
mm. Thereafter, the primary foam was secondary foamed in hot water at 95 ° C.

Next, the obtained secondary foam was put in industrial water at about 30 ° C., left to cool for 30 minutes, then taken out, and the attached water was air-dried to obtain a crosslinked vinyl chloride resin foam plate. . When the expansion ratio of the obtained crosslinked vinyl chloride resin foam plate (secondary foam) was examined, it was 3
It was 0 to 40 times.

Next, a cross-linked vinyl chloride resin foam plate (2
The secondary foam) was finished to a size of 100 mm × 100 mm × 10 mm, and the density and area retention of the crosslinked vinyl chloride resin foam plate (secondary foam) were examined. The results are also shown in Table 1.

The abbreviations in the table mean the following.

PSH-650A: Paste vinyl chloride resin (Kanefuchi Chemical Industry Co., Ltd., average degree of polymerization: 2400) TDI: Tolylene diisocyanate ISCN: Polyisocyanate (in the general formula (I), n is 1 on average) .2) PP: propionic anhydride PA: phthalic anhydride ACA: azodicarbonamide SL: dibasic lead stearate Next, as the physical properties of the crosslinked vinyl chloride resin foam plate obtained, The deformation state of the laminate was examined based on the following method.

(Deformation status of laminate with FRP plate) After placing glass fiber mats (area weight: 450 g / m ² ) on both surfaces of the crosslinked vinyl chloride resin foam plate, gel coat (containing 45% by weight of styrene monomer was not contained). Saturated polyester) was applied at an application amount of 900 g / m ² and aged at room temperature for 24 hours to prepare a laminate with an FRP plate.

Next, the obtained laminated body was left in an atmosphere of 70 ° C. for 3 hours to conduct a deformation acceleration test of the laminated body, and then the deformed state of the laminated body was visually observed. Table 1 shows the observation results.

[0063]

[Table 1]

From the results shown in Table 1, the crosslinked vinyl chloride resin foam plates obtained in Examples 1 to 5 were softened and deformed even when laminated with the FRP plate. It can be seen that there is no contraction.

[0065]

EFFECTS OF THE INVENTION The crosslinked vinyl chloride resin foam plate of the present invention does not soften, deform or shrink even when laminated with an FRP plate. Therefore, it is a structural panel for ships, pools and the like. It can be preferably used as a core material of the FRP laminated plate used in.

Claims (2)

[Claims] 1. A vinyl chloride resin is cross-linked and foamed, has a density of 20 to 60 kg / m ^3, and has an area retention of 80 after being immersed in a styrene monomer at 50 ° C. for 1 hour.
% Crosslinked vinyl chloride resin foam plate. 2. A vinyl chloride resin, a carboxylic acid anhydride,
Blowing agents, and tolylene diisocyanates and the general formula (I): The crosslinked vinyl chloride resin according to claim 1, which is obtained by foaming a foamable composition containing an isocyanate compound consisting of a polyisocyanate represented by the formula (wherein n is 0.5 to 1.5 on average). Foam plate.