JPH0565361A - Foamable composition, rigid foam prepared therefrom, and preparation of rigid foam - Google Patents

Abstract

PURPOSE:To prepare a rigid foam which has a high closed cell content, a high expansion ratio, and a low water absorption capacity and emits little odor. CONSTITUTION:A rigid foam is prepd. from a foamable compsn. contg. a vinyl chloride resin, a blowing agent consisting of N,N'- dinitrosopentamethylenetetramine, a blowing aid consisting of a metal oxide having an electronegativity of the metallic ion of 7-14, and an org. solvent as the main components.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foamable composition, a rigid foam comprising the same, and a method for producing the same. More specifically, it forms a cell having a large closed cell ratio, has a high expansion ratio, and has improved odor and non-water absorption, a hard foam, a method for producing the same, and a foaming property used for producing the foam. It relates to a composition.

[0002]

2. Description of the Related Art In recent years, N, N'-dinitrosopentamethylenetetramine (hereinafter referred to as DPT) has been widely used as an inexpensive and easily available foaming agent. However,
When DPT is used, the decomposition temperature of the DPT is high, and therefore, it has to be heated and pressed at a high temperature of, for example, 170 to 210 ° C, which deteriorates the vinyl chloride resin and reduces the closed cell ratio. There is a problem that a foam having a high expansion ratio cannot be obtained, the manufacturing cycle becomes long, and the productivity becomes poor.

Therefore, when a foam is produced, in order to lower the decomposition temperature of DPT and obtain a foam having a high expansion ratio at a low temperature, hydroxy compounds such as urea and ethylene glycol, salicylic acid and benzoic acid are used. A weak organic acid is used as a foaming aid.

However, when these compounds are used as a foaming aid, a malodor is emitted due to the decomposition residue of the foaming agent remaining in the obtained foam and the foaming aid, and is also obtained. Further, since the foam has a high water absorption property, there is a problem that the heat insulating performance gradually deteriorates when it is used in a field such as a heat insulating material for construction which is used for a long period of time.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances and has a large closed cell ratio and a high foaming ratio, and does not cause a bad odor. It is an object of the present invention to provide a foamable composition for obtaining a foam having a low water absorption property, a hard foam made of the same, and a method for producing the same.

[0006]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present inventors have proposed that DPT uses an organic weak acid.
Presumed from the fact that it decomposes at a temperature of 170 ° C or less, we could make use of the fact that the metal atoms present on the surface of a specific metal oxide have acidic points (so-called acidity), and we have conducted extensive studies. As a result, when a metal oxide containing a metal atom with an electronegativity of metal ion of 7 to 14 was used as a foaming aid, the DPT decomposed in the low temperature region of 130 to 170 ° C. and the DPT of It has been found that the deodorization of the decomposition residue improves the odor and non-water absorption of the obtained foam, and has completed the present invention.

That is, the present invention is a vinyl chloride resin,
A foaming composition comprising DPT as a foaming agent, a metal oxide having an electronegativity of metal ions of 7 to 14 as a foaming aid, and an organic solvent, and a hard foam obtained by foaming the foaming composition, and Mix the effervescent composition and about
The present invention relates to a method for producing a hard foam, which comprises pressurizing in a temperature range of 130 to 170 ° C., cooling to a foaming suitable temperature, and depressurizing to foam.

[0008]

[Functions and Examples] The foamable composition of the present invention comprises a vinyl chloride resin (hereinafter referred to as PVC), DPT as a foaming agent,
The main component of the foaming aid is a metal oxide having an electronegativity of metal ions of 7 to 14 and an organic solvent.

The mechanism by which the metal oxide contributes to the decomposition of DPT is not yet clear, but the metal atom present on the surface of the specific metal oxide is apt to become an acidic point, which is
It is presumed that it acts similar to so-called acid on DPT and causes a decomposition reaction.

In general, it is said that in a metal oxide, the higher the partial charge of the oxygen atom, the lower the electron density of the coexisting metal atom, and the stronger the characteristic as an acidic point. The partial charge of the oxygen atom has a correlation with the electronegativity of the ion of the metal atom forming the metal oxide, and thus can be generally expressed by the electronegativity of the metal ion.

In the present invention, focusing on the above-mentioned phenomenon, the strength and weakness of the acidic points on the surface of the metal oxide are arranged on the scale of the electronegativity of the metal ion, to develop a new concept that has never existed, and We have succeeded in identifying a metal oxide suitable as a foaming aid.

The present invention is the first time that a metal oxide whose metal ion has a specific electronegativity is used as a foaming aid for the DPT.

The PVC is compatible with PVC, including vinyl chloride homopolymers and copolymers containing 50% by weight or more, preferably 70% by weight or more, more preferably 80% by weight or more of vinyl chloride. Blending resins such as chlorinated vinyl chloride resin, chlorinated polyethylene, ethylene-
It also includes a mixture with at least one kind such as a vinyl acetate copolymer, in which the proportion of the blending resin in the mixture is 50% by weight or less, preferably 30% by weight or less, more preferably 20% by weight or less. It is a concept. Among the above copolymers, a vinyl chloride-vinyl acetate copolymer is particularly preferable. If the vinyl acetate content of the vinyl chloride-vinyl acetate copolymer is too high, the viscosity of the foamable composition tends to decrease, so the foaming suitability temperature decreases, and The foam tends to be difficult to obtain, and when it is too small, the solubility in a solvent tends to be low, so that it is 3 to 20% by weight, preferably 3 to 15% by weight, and further Preferably 3-8% by weight
Is desirable.

The degree of polymerization of the PVC is usually 1500 to 50.
It is preferably 00, especially 2000 to 4000. When the degree of polymerization is smaller than the above range, the foaming
It tends to be unable to withstand the gas pressure of DPT, and as a result, the closed cell ratio tends to decrease and a high expansion ratio may not be obtained.
Unless a large amount is used, it tends to be difficult to obtain a foam having a high expansion ratio.

A typical example of PVC used in the present invention is a vinyl chloride homopolymer. The type and production method of such PVC is not particularly limited in the present invention, but suspension-polymerized vinyl chloride resin is inexpensive, and paste vinyl chloride resin is easily soluble in a solvent. Is preferred. Here, the suspension-polymerized vinyl chloride resin refers to a porous vinyl chloride resin having a particle size of 100 to 300 μm, which is an aggregate of primary particles having a particle size of about 1 μm, and is produced by a so-called suspension polymerization method. is there. The primary particles are so-called domain particles having a particle size of about 0.1 μm, and the domain particles further have a size of 0.01 μm.
It consists of so-called microdomain particles of about m 2.

Here, the paste vinyl chloride resin is a pearl-like fine powder having a particle size of several μm or less, which is produced by a so-called emulsion polymerization method or micro suspension polymerization method. The powder is composed of a large number of fine particles having a smaller diameter.

In the present invention, DPT is used as the foaming agent. DPT is inexpensive, and conventionally, there has been desired a technique for obtaining a foam having a high expansion ratio by using DPT alone and in a large amount. However, due to the drawbacks as described above, a sufficiently satisfactory technique has not been established. As described above, the present invention overcomes the above-mentioned problems of the prior art, and makes it possible to obtain a foam having an extremely good quality.

A mixture of DPT and another foaming agent may be used as long as the object of the present invention is not impaired.

Specific examples of the other foaming agents include azodicarbonamide, diazocarbonamide, azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), diazoaminobenzene and p. -Toluenesulfonyl hydrazide, 1-phenyl-5-mercapto-1H-
Examples include tetrazole.

The DPT and other foaming agents all generate nitrogen gas by thermal decomposition. The foaming agent that generates such nitrogen gas is such that the nitrogen gas generated immediately after foaming. Since it does not easily permeate and escape from the cell membrane containing the solvent, it has an advantage that the expansion ratio hardly decreases due to shrinkage immediately after foaming.

The amount of DPT used varies depending on the desired expansion ratio, the type of solvent and the amount thereof, but is usually PVC.
It is 5 to 100 parts, preferably 10 to 70 parts, and more preferably 10 to 50 parts, relative to 100 parts (parts by weight, the same applies hereinafter). If the amount of DPT used is less than the above range, the desired expansion ratio may not be obtained, and if it exceeds the above range, the cell membrane is likely to be broken during foaming. A foam having a high expansion ratio tends to be difficult to obtain.

In the present invention, a metal oxide having a metal ion electronegativity of 7 to 14 is used as a foaming aid. The electronegativity is preferably 8 to 12, and more preferably 8 to 11. is there. When the electronegativity of the metal ion of such a metal oxide is smaller than the above range and when it exceeds the above range, the decomposition of DPT is not promoted, so that a foam having a high expansion ratio is obtained. However, the water absorption tends to be relatively large. Preferred examples of such metal oxides include aluminum oxide, lead oxide, titanium oxide, and yttrium oxide. Among these, aluminum oxide that can be obtained at low cost is preferable, and among them, Activated alumina with high surface activity, especially 2% by weight of water
The following activated aluminas are even more preferred. The metal oxide may be a single compound or a compound containing two or more metal atoms.
For example, it can be used as a composite of alumina silicate, zinc borate and the like. The water content of the metal oxide is 2% by weight or less, preferably 1 from the viewpoint of foaming efficiency.
It is desirable that the content is not more than weight%.

The particle size of the metal oxide is preferably small in order to increase the probability of contact with DPT, but particularly preferably the average particle size is less than 100 μm.

The amount of the metal oxide used is preferably adjusted appropriately according to the intended use of the foam as the final product, but is usually 0.2 to 5 times by weight the amount of DPT added, It is preferably 0.5 to 2 times by weight. When the amount of such metal oxide used is less than 0.2 times by weight the amount of DPT used, the decomposition of DPT is not sufficiently promoted, undecomposed DPT remains, and a good expansion ratio is obtained. If it exceeds 5 times by weight, most of the DPT will be decomposed, making the addition meaningless.

Examples of the organic solvent include aromatic solvents, ketone solvents, ether solvents, etc. These may be used alone or in admixture of two or more. Specific examples of the organic solvent include, for example, toluene, xylene,
Examples thereof include aromatic solvents such as monochlorobenzene, ketone solvents such as acetone, methyl ethyl ketone and cyclohexanone, and ether solvents such as tetrahydrofuran and dioxane.

Among the above organic solvents, an organic solvent having a dipole moment of 1.0 or more is particularly preferable in order to make the gas composition generated by the decomposition of DPT large in nitrogen gas. Examples of the organic solvent having a dipole moment of 1.0 or more include methyl ethyl ketone, monochlorobenzene and phenol. Among these,
Monochlorobenzene, phenol, etc., which do not react with the by-product of DPT, are preferable when non-coloring property is required.
The generated gas composition and the amount of decomposition heat generation change greatly depending on the temperature and pressure when the DPT decomposes.For organic solvents with a dipole moment of 1.0 or more, especially the generated gas composition contains a lot of nitrogen gas. It is supposed to control.

The amount of the organic solvent used is appropriately adjusted according to the average degree of polymerization of PVC, the amount of fibrous inorganic material and granular inorganic material used, and is usually 20 to 2000 parts, preferably 200 to 2000 parts, relative to PVC. It is desirable that it is 1000 copies. When the amount of such an organic solvent used is less than 20 parts with respect to 100 parts of PVC, it tends to be difficult to obtain a high-magnification foam, and when it exceeds 2000 parts, the foaming suitable temperature is It becomes difficult to produce on a commercial scale in, and it tends to be difficult to obtain a good foam.

In the present invention, in order to immobilize hexamethylenetetramine produced by the decomposition of DPT and a lower amine which is a decomposition product thereof and to impart a further low water absorption property, the foam composition of the present invention contains novolac. It is preferred to add a type phenolic resin. When the novolac type phenol resin is added, the water absorption amount can be reduced to a fraction of that in the case where the novolac type phenol resin is not added.

The novolac type phenolic resin preferably has a melting point of 60 ° C. or higher, preferably 65 ° C. or higher, more preferably 75 ° C. or higher.

The amount of the novolac type phenolic resin used is preferably adjusted appropriately according to the intended use of the obtained hard foam, but usually 0 to 50 parts per 100 parts of PVC,
Especially 0 to 20 copies are desirable. When the amount used exceeds 50 parts, the immobilization of the novolac type phenolic resin tends to proceed to the crosslinking reaction between the novolac type phenolic resins, which hinders the elongation of the cell membrane during foaming, resulting in a high closed cell ratio. Tend to be difficult to maintain. In order to sufficiently bring out the effect of adding the novolac type phenolic resin, that is, non-water absorption, the amount of the novolac type phenolic resin used is 0.5 parts or more, preferably 5 parts or more. .

If necessary, the foamable composition may contain a fibrous inorganic material and a granular inorganic material as a filler, a stabilizer and the like.

The above-mentioned fibrous inorganic substance is easily floated in the air and has a diameter of 0.03 to 0.08, which is very difficult to handle in order to improve industrial productivity and safety.
Asbestos, glass fiber, ceramic fiber, alumina fiber, carbon fiber, quartz fiber, boron fiber, various metal fibers having a diameter of 1 μm or more, not including asbestos of about 0.1 μm,
Various types of whiskers may be used, and these fibers may be used alone or in combination of two or more. Among these, rock wool is particularly preferable from the viewpoints of ease of foam molding, various physical properties of the obtained hard foam, and cost.

Further, the longer the fiber length of the fibrous inorganic substance, the greater the effect of filling the hard foam obtained,
On the other hand, the shorter the length, the better the filling efficiency.
m to 50 mm, preferably 20 μm to 20 mm, more preferably
30 μm to 10 mm is desirable.

The amount of the fibrous inorganic material used is appropriately adjusted according to the combustion characteristics of the obtained hard foam, but usually PV
It is 2 to 300 parts, preferably 10 to 100 parts, relative to 100 parts of C. If the amount of the fibrous inorganic material used is less than 2 parts, cracks or shrinkage tend to occur, and it tends to be difficult to impart good combustion characteristics. If it exceeds 300 parts, In addition, the inorganic fibers tend not to be contained in the foam cell membrane, and it tends to be difficult to obtain a foam having a high expansion ratio. When rock wool is used, the amount used is appropriately adjusted according to the application of the final product, a rigid foam, but is usually 300 per 100 parts of PVC.
Parts or less, preferably 10 to 100 parts. The amount of rock wool is
If it exceeds 300 parts, the inorganic fibers tend not to be contained in the foam cell membrane, and it tends to be difficult to obtain a foam having a high expansion ratio.

The granular inorganic material has an average particle size of 0.
About 0.1 to 300 μm is preferable, and the type is not particularly limited, but talc, calcium carbonate, etc. from the viewpoints of price and availability, and aluminum hydroxide etc. from the viewpoint of improving combustion characteristics. Is preferred,
In addition to these, hollow bodies such as Shirasu balloon,
It is also possible to use a porous material such as zeolite or activated carbon.

The amount of the above-mentioned granular inorganic material is appropriately adjusted according to the ease of foaming and the intended use of the hard foam which is the final product. Normally, the total amount of the above-mentioned fibrous inorganic material and granular inorganic material is 100 parts of PVC. 3,000 parts or less, preferably 10 to
It is adjusted to 1000 parts, more preferably 50 to 1000 parts.

The fibrous inorganic material and the granular inorganic material can be used alone or in combination.

As the above-mentioned stabilizer, any stabilizer can be used as long as it has the ability to prevent decomposition and deterioration of PVC. Specific examples of such stabilizers include, for example, dibasic lead stearate, dibasic lead phosphite, tribasic lead sulfate and zinc stearate, calcium stearate, magnesium stearate, dibutyltin stearate, dibutyltin laurate, Examples thereof include dibutyltin distearate and dibutyltin dilaurate, and these stabilizers may be used alone or in admixture of two or more. The amount of the stabilizer is usually 1 to 100 parts of PVC.
20 copies, especially 1-10 copies. When the compounding amount of the stabilizer is less than 1 part, the effect of adding the stabilizer may be lacking, and when it exceeds 20 parts, the effect of using more than that from the viewpoint of the stabilizing effect may not be obtained. The improvement is small and the cost is disadvantageous.

Further, in the present invention, for example, various antioxidants, ultraviolet absorbers, titanium oxide,
Pigments such as ultramarine; antistatic agents such as tertiary amines and alkyl sulfonates, nucleating agents such as talc, and the like, which are usually used as additives for plastics, may be appropriately adjusted and used as necessary. Of course.

Next, an example of the method for producing the rigid foam of the present invention will be described.

First, a predetermined amount of raw materials are put into a kneader such as a double-arm kneader. Knead at a temperature above the temperature at which the solvent is compatible with PVC and below the boiling point of the solvent until each raw material is uniformly dispersed, lower the temperature of the mixture once if necessary, and add a foaming agent to make it uniform. Knead until dispersed.

Next, the foamable composition thus prepared is filled in a sealable mold made of, for example, an aluminum alloy, and the mold is set in, for example, a hydraulically driven multi-stage hot press machine. The foamable composition is heated under pressure.

The pressurization and heating conditions differ depending on the constituents of the foamable composition, but since it is necessary to substantially complete the decomposition of the decomposable foaming agent DPT, the heating temperature is about 130 ° C. or higher. It is preferable that

As described above, since DPT has a large decomposition calorific value, at a conventional pressing temperature (for example, about 175 ° C.), PVC will be thermally decomposed, and the thermal decomposition of PVC will occur. As a result, the cell membrane is liable to break during foaming, making it difficult to obtain a foam having a high expansion ratio. At the same time, when the pressure inside the mold during pressing reaches a high pressure of about 200 kg / cm ² , the amount of polar gases other than nitrogen gas such as ammonia gas and water vapor increases, and therefore the gas that permeates the cell membrane. Even if the amount becomes large and the closed cell ratio becomes high, it shrinks and the expansion ratio decreases. Therefore, the heating temperature is preferably about 170 ° C. or less in consideration of the amount of heat generated by decomposition, and the internal pressure of the mold is preferably adjusted to about 200 kg / cm ² or less. The pressure inside the mold at the time of pressing is usually 100 kg / cm ² or more, preferably 140 kg / cm ² or more in consideration of foamability.

Next, when the temperature reaches about 130 ° C., 1 to
It is preferable to maintain the state for about 30 minutes to make the temperature in the press uniform. After that, the pressure heating plate temperature of the pressing machine is lowered to a foaming suitable temperature by using a cooling medium such as water while the die is being pressurized. The foaming suitability temperature varies depending on the composition of the foamable composition, the shape of the mold and its size, etc., but is usually lower than the pressure heating temperature, and the foaming gas does not escape when the cell membrane is broken during foaming. The temperature that gives the viscoelasticity of the PVC phase, such as 20
It is about 100 ℃. When the content of the mold reaches the foaming suitable temperature, the mold is opened, and the content of the mold is released under atmospheric pressure to decompress the final foam.

Since the used solvent remains in the hard foam immediately after foaming, the residual solvent is volatilized and removed by leaving it at a suitable temperature according to the solvent for a suitable time. The removal of the organic solvent from the hard foam can be promoted by cutting with a cutter or the like to increase the surface area.

If the foam is directly contacted with steam before the residual solvent is volatilized and removed, the surface of the foam is covered with water, and the non-water-soluble solvent is heated in a state in which the volatilization is slowed. The foam can be further foamed. Therefore, in this case, there is an economic advantage such that the amount of the foaming agent added can be reduced.

The expansion ratio of the obtained hard foam may be any as long as it can be produced, but if it exceeds 200 times, it will not be a normal foam. Even if a good rigid foam is obtained, the physical properties such as strength will be insufficient, so it is preferably 200 times or less. When used as a heat insulating material for construction, the expansion ratio is preferably 20 times or more in order to maintain physical properties such as thermal conductivity and reasonable economy.

The above is one example of the method for producing a rigid foam of the present invention, in which an organic solvent is used in a foamable composition containing DPT as a foaming agent, and when the foam is produced, a temperature of 130 to 170 ° C. is used. If the basic operation of pressurizing in a temperature range and depressurizing at a temperature suitable for foaming is satisfied, the organic solvent mixing method, temperature increase / decrease, pressurizing method, etc. can be done by any other method. Good.

The water absorption of the hard foam is preferably 1.0 g / 100 cm ² or less, and more preferably 0.7 g / 100 cm ² or less in order to maintain the heat insulating performance for a long period of time.

Furthermore, the closed cell ratio of the rigid foam is 80%.
The above is preferable, and 90% or more is desirable from the viewpoint of maintaining the heat insulating property for a long time.

The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

Examples 1 to 18 The raw materials shown in Table 1 were weighed in proportions shown in Tables 2 and 3 so that the total amount would be 5000 g.

Raw materials other than metal oxides, which are foaming aids, are put into a double-arm kneader having an effective capacity of 3 liters, hot water is passed through the jacket of the kneader to adjust the kneading temperature to 80 to 100 ° C. The mixture was kneaded for 50 minutes to obtain a mixture.

Next, pass warm water through the kneader jacket,
The temperature of the mixture in the kneader was lowered to about 80 ° C. or lower, metal oxide was added, and the mixture was kneaded for 10 minutes to obtain a foamable composition.

Cavity dimensions of the foamable composition after kneading 1
Fill a 60mm x 160mm x 22mm aluminum alloy mold, cover the mold with an aluminum plate, and set it on a hydraulically driven hot press machine from room temperature (about 20 ° C) to about 145 ° C.
The temperature was raised in 10 minutes.

The tightening pressure of the hot press machine was about 150 kg per 1 cm ^{2 of} die area in each example.

Next, after holding the mold at 145 ° C. for 10 minutes, hot water was passed through a cooling plate of a hot press machine to lower the mold temperature to a temperature suitable for foaming (25 to 60 ° C.) in about 20 minutes.

After that, when the tightening pressure of the hot press machine was released, the mold contents instantly completed foaming.

Each of the obtained hard foams had a beautiful appearance and the uniformity of bubbles on the cut surface was good.

The hard foam was placed in a hot air circulation oven,
It was left at 75 ° C for about 2 days to volatilize and remove the organic solvent.

Next, the apparent density, foaming ratio, water absorption, closed cell ratio and foam odor of the hard foam were measured according to the following methods. The results are shown in Tables 2-3.

(A) Apparent density A cube of 200 mm square was cut out from a hard foam, and the volume and weight were measured and calculated.

(B) Foaming ratio The apparent density of PVC in the hard foam was calculated by the formula: [in hard foam] from the amount of inorganic substances and the blending amount of foaming agent and stabilizer (parts) per 100 parts of PVC in Tables 2-3. Apparent density of PVC] = [Apparent density of rigid foam (kg / m ³ )] × 100 / (100+ [Amount of inorganic substances (parts by weight)]
+ Amount of foaming agent (parts by weight) + amount of stabilizer (parts by weight) + amount of novolac type phenolic resin (parts by weight)] (kg / m ³ ).

The expansion ratio was calculated from the formula: [expansion ratio] = [1.4 × 10 ³ / apparent density of PVC in rigid foam] (times), with the specific gravity of PVC being 1.4 × 10 ³ .

(C) Water absorption amount Measured according to JIS A-9511 "Polystyrene foam heat insulating material".

(D) Closed cell ratio Measured using an air-comparison hydrometer manufactured by Toshiba Beckman Co., Ltd. based on ASTM-D2856.

(E) Odor of foam The foam was put in an oven to sufficiently volatilize the organic solvent, and then the foam was cut at an arbitrary position, and the odor of the cut was evaluated with a pad. The evaluation criteria are as follows.

(Evaluation Criteria) A: No odor is felt. B: A slight odor is felt. C: Some odor is felt. D: The odor is clearly felt.

Comparative Examples 1 to 3 The raw materials shown in Table 1 were weighed in proportions shown in Tables 2 to 3 so that the total amount would be 5000 g. Next, Example 1 was performed except that the temperature at the time of pressurizing with a hot press machine was adjusted as shown in Tables 2 and 3.
A hard foam was obtained in the same manner as described above, and the physical properties of the hard foam were measured. The results are shown in Tables 2-3.

[0071]

[Table 1]

[0072]

[Table 2]

[0073]

[Table 3]

As is clear from the results shown in Tables 2 and 3, when the foamable composition of the present invention is used, the hard foam having a small water absorption rate, a large closed cell ratio without bad odor, and a high expansion ratio. You can see that you can get it.

[0075]

Industrial Applicability According to the production examples of the present invention, it is possible to industrially advantageously and easily obtain a hard foam having a large closed cell ratio, a high expansion ratio, an excellent low water absorption and almost no odor. The hard foam thus obtained can be suitably used as various building materials having heat insulating properties.

Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location // C08L 27:06

Claims (28)

[Claims] 1. A vinyl chloride resin, N, N 'as a foaming agent
A foamable composition containing dinitrosopentamethylenetetramine, a metal oxide having a metal ion electronegativity of 7 to 14 as a foaming aid, and an organic solvent as main components. 2. The foamable composition according to claim 1, wherein the vinyl chloride resin is a suspension-polymerized vinyl chloride resin and / or a paste vinyl chloride resin. 3. The foamable composition according to claim 1, wherein the metal oxide is aluminum oxide. 4. The foamable composition according to claim 1, wherein the organic solvent is one kind or two or more kinds selected from an aromatic solvent, a ketone solvent and an ether solvent. 5. The foamable composition according to claim 1, which contains 20 to 2000 parts by weight of an organic solvent with respect to 100 parts by weight of a vinyl chloride resin. 6. The foamable composition according to claim 1, which comprises a novolac type phenolic resin. 7. The foamable composition according to claim 1, which contains 0 to 300 parts by weight of rock wool based on 100 parts by weight of the vinyl chloride resin. 8. The foamable composition according to claim 1, which contains 0 to 3000 parts by weight of an inorganic filler with respect to 100 parts by weight of a vinyl chloride resin. 9. The foamable composition according to claim 1, which contains 1 to 20 parts by weight of a stabilizer with respect to 100 parts by weight of the vinyl chloride resin. 10. A vinyl chloride resin, N as a foaming agent,
A hard foam formed by foaming a foamable composition mainly composed of N'-dinitrosopentamethylenetetramine, a metal oxide having a metal ion electronegativity of 7 to 14 as a foaming aid, and an organic solvent. 11. The rigid foam according to claim 10, wherein the vinyl chloride resin is a suspension-polymerized vinyl chloride resin and / or a paste vinyl chloride resin. 12. The rigid foam according to claim 10, wherein the metal oxide is aluminum oxide. 13. The rigid foam according to claim 10, wherein the organic solvent is one kind or two or more kinds selected from an aromatic solvent, a ketone solvent and an ether solvent. 14. A vinyl chloride resin 100 as the foamable composition.
The rigid foam according to claim 10, which contains 20 to 2000 parts by weight of an organic solvent with respect to parts by weight. 15. The rigid foam according to claim 10, which comprises a novolac type phenolic resin. 16. The hard foam according to claim 10, wherein 0 to 300 parts by weight of rock wool is contained with respect to 100 parts by weight of the vinyl chloride resin. 17. The rigid foam according to claim 10, which contains 0 to 3000 parts by weight of an inorganic filler with respect to 100 parts by weight of a vinyl chloride resin. 18. The rigid foam according to claim 10, which contains 1 to 20 parts by weight of a stabilizer based on 100 parts by weight of the vinyl chloride resin. 19. The expansion ratio is 20 to 200 times.
The rigid foam according to 0. 20. A vinyl chloride resin, N as a foaming agent,
A mixture of N'-dinitrosopentamethylenetetramine, a metal oxide having a metal ion electronegativity of 7 to 14 as a foaming aid, and a foamable composition containing an organic solvent as a main component is mixed,
A method for producing a hard foam, comprising pressurizing in a temperature range of 130 to 170 ° C., cooling to a foaming suitable temperature, and depressurizing to foam. 21. The method for producing a rigid foam according to claim 20, wherein the vinyl chloride resin is a suspension-polymerized vinyl chloride resin and / or a paste vinyl chloride resin. 22. The method for producing a rigid foam according to claim 20, wherein the metal oxide is aluminum oxide. 23. The method for producing a rigid foam according to claim 20, wherein the organic solvent is one kind or two or more kinds selected from an aromatic solvent, a ketone solvent and an ether solvent. 24. The foamable composition is a vinyl chloride resin 100.
21. The method for producing a rigid foam according to claim 20, which comprises 20 to 2000 parts by weight of an organic solvent with respect to parts by weight. 25. The method for producing a rigid foam according to claim 20, wherein the foamable composition contains a novolac type phenolic resin. 26. The foamable composition is a vinyl chloride resin 100.
The method for producing a rigid foam according to claim 20, wherein 0 to 300 parts by weight of rock wool is contained with respect to parts by weight. 27. The vinyl chloride resin 100 as the foamable composition.
The method for producing a rigid foam according to claim 20, wherein the inorganic filler is contained in an amount of 0 to 3000 parts by weight based on parts by weight. 28. The foamable composition is a vinyl chloride resin 100.
21. The method for producing a rigid foam according to claim 20, which contains 1 to 20 parts by weight of a stabilizer with respect to parts by weight.