JP2971010B2 - PVC resin foam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high expansion ratio sol-foamed vinyl chloride resin foam containing a large amount of a plasticizer suitable as a base material such as a joint material, a seal material, or an adhesive tape.

[0002]

2. Description of the Related Art When a vinyl chloride resin foam is used for a base material such as a joint material, a seal material, or an adhesive tape, a large amount of a plasticizer is generally added together with a foaming agent. A vinyl chloride resin foam in the form of a paste sol is applied to a base material such as release paper by various means, and is heated and foamed. A so-called sol foamed vinyl chloride resin foam is preferably used. I have.

However, in the case of the paste sol of a vinyl chloride resin containing a large amount of the above-mentioned plasticizer, hitherto,
The paste sol has poor rheological (<< rheological >> deformation and flow) characteristics, and has a problem that it is extremely difficult to apply the paste sol uniformly to the substrate.

That is, since a paste sol containing a large amount of a plasticizer has a low viscosity at a low shear rate (for example, after the paste sol is applied to the base material), the paste sol easily flows after application and is smooth. It is extremely difficult to obtain a proper surface.

In order to solve such a problem, attempts have been made to add a thickener (for example, an oil-absorbing thickener). However, even in this attempt, the rheological properties of the paste sol were still not good.

That is, when various thickeners such as an oil-absorbing thickener are added, the viscosity at a low shear rate increases,
Since the viscosity at a high shear rate (for example, during kneading during paste sol preparation or during paste sol application) also increases, not only the paste sol itself cannot be prepared uniformly, but also a smooth and uniform coating. Becomes extremely difficult. in addition,
When these thickeners are used, when performing high foaming, side effects such as roughening of foam cells are also caused.

Accordingly, the present invention provides a sol-foamed vinyl chloride containing a large amount of a plasticizer and having a high expansion ratio, which can be suitably used in the fields of joint materials and seal materials without causing the above problems. An object of the present invention is to provide a resin foam.

[0008]

As a result of repeated studies to achieve the above object, the present inventor has found that (1) a paste in which a specific amount of a urea resin solution having a specific concentration is mixed with an emulsion polymerized vinyl chloride resin. In the sol, the rheological properties are higher than those of the conventional emulsion-polymerized vinyl chloride resin paste sol, not only when the paste sol itself is prepared, but also when the paste sol is applied, after the application, and at a high expansion ratio. Sometimes, it is extremely good, and (2) At this time, by using a specific plasticizer, the rheological properties can be improved satisfactorily. It can prevent bleeding of the agent and ensure the necessary flexibility and strength as a base material such as joint material, seal material, or adhesive tape. Door to be able to, was found.

The present invention has been made on the basis of such findings, and the invention relates to an emulsion-polymerized vinyl chloride resin 100.
A gist of the present invention is a vinyl chloride-based resin foam characterized in that 0.1 to 10 parts by weight of a urea-based resin solution having a urea-based resin concentration of 10 to 90% by weight is contained in parts by weight.

At this time, (1) 100 to 100 parts by weight of the emulsion-polymerized vinyl chloride resin contains 70 to 150 parts by weight of a phthalate ester plasticizer and / or trimellitic acid plasticizer; The expansion ratio of the resin foam is preferably 4 to 15 times.

The vinyl chloride resin in the foam of the present invention is a vinyl chloride resin polymerized by emulsion polymerization. Specifically, a vinyl chloride homopolymer resin, vinyl chloride and other monomers, for example, It is a copolymer resin with vinyl acetate, acrylonitrile, ethylene, and vinylidene chloride, and these can be used alone or in combination of two or more.

The urea-based resin of the urea-based resin solution to be added to the above emulsion-polymerized vinyl chloride-based resin includes:
Urea and aldehyde (Ardehyde)
Is a condensation polymer obtained by a condensation reaction with urea, and there are no particular restrictions on the blending ratio of urea and aldehyde and the condensation reaction conditions. Further, those obtained by etherifying the methylol group in urea with various alcohols to obtain an alcohol-modified urea-based resin, and those obtained by co-condensing with melamine during a condensation reaction to obtain a melamine-modified urea-based resin can also be used. . These urea-based resins (including the modified urea-based resins as described above, hereinafter the same when referred to as urea-based resins) can be used alone or in combination of two or more.

The degree of polymerization and the degree of crosslinking of these urea resins are not particularly limited, but if the degree of polymerization or the degree of crosslinking is too high,
The solubility in the solvent decreases, and the solvent does not sufficiently dissolve in the solvent as described below, and a uniform mixture with the emulsion-polymerized vinyl chloride resin cannot be obtained.

The solvent used for the above urea resin solution may be any of a variety of solvents, from those having a strong polarity (preferably used in the case of alcohol-modified urea resins having a methylol group etherified) to those having no polarity. Examples thereof include alcohols, aromatic hydrocarbon compounds, heterocyclic hydrocarbon compounds, and aliphatic hydrocarbon compounds, and these can be used alone or in combination of two or more.

The concentration of the urea-based resin solution is preferably such that the urea-based resin content in the solution is in the range of 10 to 90% by weight. If the concentration is less than 10% by weight, the amount of the solvent is too large, and there is an adverse effect such as abnormal foaming during foaming.
If the content is higher than the percentage by weight, the urea-based resin may precipitate, causing poor dispersion in the paste sol, making it impossible to improve the rheological properties of the paste sol.

The urea resin solution having the above concentration is used in an amount of 0.1 to 100 parts by weight of the emulsion polymerized vinyl chloride resin.
It is added so as to have a ratio of 10 parts by weight. If the amount is less than 0.1 parts by weight, the amount of the urea-based resin in the entire paste sol is too small, and the rheological properties required for obtaining a good product foam cannot be sufficiently improved, If it exceeds 10 parts by weight, on the contrary, the amount of the urea-based resin is too large, and it is difficult to perform good foaming.

The emulsion-polymerized vinyl chloride-based resin to which the above-mentioned urea-based resin is added is mixed with a plasticizer to form a paste sol. Plasticizers such as di-2-ethylhexyl phthalate (DOP), di-i-phthalate
-Nonyl (DINP), di-i-decyl phthalate (DI
DP), di-butyl phthalate (DBP), butylbenzyl phthalate (BBP), di-undecyl phthalate (DU)
P) and the like; general phthalate plasticizers such as trioctyl trimellitate (TOTM); dioctyl adipate (DOA); dioctyl sebacate (DO)
S), fatty acid ester-based plasticizers represented by dioctyl azelate (DOZ) and the like; tricresyl phosphate (T
A polymer plasticizer such as a phosphate plasticizer represented by CP); an epoxy plasticizer; a polyester plasticizer represented by polypropylene adipate; and chlorinated paraffin. These can be used alone or in combination of two or more. The compounding amount should just be an amount which can make a normal vinyl chloride resin paste foam a sol.

Particularly, in the present invention, the use of a phthalate ester plasticizer and / or a trimellitic acid plasticizer is more effective in exhibiting the thickening (rheological change) effect of the urea resin. Is preferred.

The amount of the phthalate ester plasticizer and / or trimellitic acid plasticizer is from 70 to 150 parts by weight per 100 parts by weight of the emulsion-polymerized vinyl chloride resin.
It is preferable to use parts by weight. When the amount is less than 70 parts by weight, not only the effect of effectively performing the rheological change effect is not exhibited, but also flexibility suitable for a base material such as a joint material, a sealing material, or an adhesive tape cannot be obtained.
If the amount exceeds 150 parts by weight, the strength of the obtained foam is too low, and it is difficult to use these as a substrate.

As the foaming agent to be mixed with the above-mentioned paste sol, a usual foaming agent used for a usual vinyl chloride resin, for example, azodicarbonamide (ADC)
A), oxybisbenzenesulfone hydrazide (OB
SH), cyazoaminoazobenzene, azobisisobutyronitrile (AIBN) and the like, and these can be used alone or in combination of two or more.

The above-mentioned paste sol may further contain, if necessary, additives such as stabilizers, fillers, pigments and the like used in ordinary vinyl chloride resins, together with the above-mentioned plasticizers and foaming agents. Can be blended in the amount when blended with the vinyl chloride resin.

The emulsion polymerized vinyl chloride resin paste sol containing the above urea resin solution, plasticizer, foaming agent and other components is thoroughly kneaded and stirred to disperse them uniformly. It is prepared into the inventive foam. That is, a paste sol in which a urea-based resin solution or the like is uniformly dispersed, for example, on a release paper, a stainless steel belt, or another appropriate substrate, a doctor knife coater, a comma doctor coater, a roll coater, an appropriate method such as a casting method. Then, it is applied with an appropriate thickness, heated and foamed to obtain a foam of the present invention.

The expansion ratio at this time is determined by the amount of the foaming agent,
Alternatively, it can be appropriately adjusted by appropriately adjusting foaming conditions such as a heating temperature. However, when the foam of the present invention is used as a base material such as a joint material, a sealing material, or an adhesive tape, 4 to 15 It is appropriate to double. Fifteen
If it exceeds twice, it becomes difficult to control the foam cell,
Cellular roughness and cell breakage occur, and when the ratio is less than 4 times, the flexibility is lowered, and the above-mentioned base material becomes unsuitable.

The above conditions for preparing the paste sol, that is, the temperature, stirring speed,
Alternatively, the ambient temperature, paste sol temperature, coating thickness, doctor knife coater, comma doctor coater, roll coater, and other clearances at the time of application, and other conditions are the conditions for preparing ordinary vinyl chloride resin foam. Is the same as

When the foam of the present invention is used as a base material such as a joint material, a sealing material, or an adhesive tape, an adhesive is applied to one surface. An adhesive used for sticking the resin foam can be used.

The foam of the present invention to which the pressure-sensitive adhesive has been applied may be a long one having an appropriate width, similarly to a general joint material, a sealing material, a pressure-sensitive adhesive tape, etc., with the intervention of ordinary release paper. , Stored and sold in a state wound on a core such as a paper tube,
The user cuts this into an appropriate length and uses it.

[0027]

In the foam of the present invention, the rheological properties are improved by the action of the urea resin blended in the emulsion polymerized vinyl chloride resin. Specifically, at the time of high shear rate during paste sol preparation and application, the viscosity is sufficiently low, so that the kneading operation becomes easy, and the urea-based resin solution, plasticizer, foaming agent, and other components are uniform. , A paste sol in a mixed state can be prepared and applied smoothly and uniformly. At a low shear rate after the paste sol is applied, the viscosity increases, leveling of the paste sol is suppressed, and a smooth and uniform applied surface can be maintained.

In addition, foaming properties are improved during heating and foaming, and even when the expansion ratio is increased, there is no adverse effect such as roughening of foam cells.

For this reason, the foam of the present invention is suitable as a base material such as a joint material, a sealing material, or an adhesive tape.
A sol-foamed vinyl chloride resin foam having a high foaming ratio can be easily prepared in a good state.

[0030]

【Example】

Examples 1 to 16 and Comparative Examples 1 and 2 (Preparation of Paste Sol) Paste sols having the formulations shown in Tables 1 to 3 were prepared.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

[Table 3]

In Tables 1 to 3, * 1 indicates an emulsion-polymerized polyvinyl chloride resin. In Examples 1 to 16 and Comparative Examples 1 and 2, an emulsion-polymerized polyvinyl chloride having an average polymerization degree of 1300 was used.

The plasticizer of * 2 was used in Examples 1 to 4 and Example 9.
-12 and Comparative Examples 1-2 use DOP, Examples 5-8 use TOTM, and Examples 13-16
An equal mixture of OP and TOTM was used. The foaming agent of * 3 was obtained in Examples 1 to 4, Examples 9 to 12, and Comparative Examples 1 to
In Example 2, ADCA was used. In Examples 5 to 8, OBSH was used. In Examples 13 to 16, AIBN was used. *
As the stabilizer of No. 4, a BaZn-based stabilizer was used in each of Examples 1 to 16 and Comparative Examples 1 and 2. * 5 filler is
In Examples 1 to 16 and Comparative Examples 1 and 2, CaCO ₃ was used. As the pigment of * 6, carbon black was used in Examples 1 to 16 and Comparative Examples 1 and 2.

* 7 URS indicates a urea-based resin solution,
In Examples 1-4, Examples 13-16 and Comparative Examples 1-2, a toluene solution of a polyurea resin was used.
In Example 8, an N-methylpyrrolidone solution of an alcohol-modified polyurea resin was used, and in Examples 9 to 12, an N-methylpyrrolidone solution of a melamine-modified polyurea resin was used. The concentration of each of these polyurea resins was determined in Examples 1 and 2,
5 to 6 and 9 to 10% by weight, Examples 3 to 4,
7 to 8, 11 to 90, 90% by weight, Examples 13 to 16
In this case, the content was 50% by weight.

* 8 thickener is Aerosil (<< Aero
sil >> A product name of Nippon Aerosil Co., Ltd. A fine particle size high purity anhydrous silica) thickener was used.

(Preparation of foam) A paste sol having the composition shown in Tables 1 to 3 was applied to release paper by a doctor knife method so as to have a thickness of 0.2 mm.
The mixture was heated for 1 minute to cause sol foaming, thereby preparing foamed sheets (18 types) having a thickness of 2.0 mm.

(Evaluation of Foam) The thickness variation of the foamed sheets (18 types) prepared as described above was measured, and the dispersion σ was calculated. Table 4-
It is shown in Table 6. The state of the foam cells was visually observed. The results are shown in Tables 4 to 8, with の も の for uniform shapes and sizes, を for round, slightly closed cells, and × for vertically long open cells with non-uniform shapes and sizes. Show.

(Evaluation of rheological properties) With respect to the paste sols (18 types) having the compositions shown in Tables 1 to 3, a high shear rate (1000 / sec) and a low high shear rate (10 / s) were used.
The viscosity (cps) at ec) was measured using a Seaverse viscometer (at high shear rates) and a Brookfield viscometer (at low shear rates). Table 4 to Table 8 show the results.
Are shown together.

[0041]

[Table 4]

[0042]

[Table 5]

[0043]

[Table 6]

[0044]

[Table 7]

[0045]

[Table 8]

As is clear from Tables 4 to 8, the foams of the present invention in all of Examples 1 to 16 have better rheological properties than the conventional foams of Comparative Examples 1 and 2. You can see that.

That is, in Comparative Example 1 in which neither a thickener nor a urea resin was blended, the viscosity at a high shear rate was low, so that good kneading was possible, a uniform paste sol was prepared, and a smooth and uniform paste sol was obtained. Can be applied to
The viscosity at a low shear rate is too low, so the leveling property after coating on release paper is poor, making it impossible to maintain a smooth and uniform coated surface. In the case of Comparative Example 2 in which the aerosil thickener was added, the viscosity at a low shear rate was high, and thus the leveling property after application on release paper was good, and a smooth and uniform application surface was maintained. However, the viscosity at high shear rates is too high and the preparation and application of the paste sol is poor.

On the other hand, in Examples 1 to 16, the viscosity at a high shear rate was not as high as that of Comparative Example 1, but was considerably lower than that of Comparative Example 2, and the preparation and application of the paste sol were good. In addition, the viscosity at a low shear rate has increased to near Comparative Example 2, and a good coated surface can be maintained.

As a result, in the foam of Comparative Example 1, the foam cells are uniform in both shape and size, but the dispersion of thickness σ is large, and in the foam of Comparative Example 1, the dispersion of thickness σ is large. Is small, but the foam cells are not uniform in shape and size. In contrast, Examples 1 to 16
In the foam, the thickness dispersion σ is smaller than that in Comparative Example 2, and the shape and size of the foam cell are both uniform.

Therefore, according to the foam of the present invention, compared with the conventional foams of Comparative Examples 1 and 2, the joint material,
It can be seen that the material can be used extremely excellently as a sealing material and a base material for an adhesive tape.

[0051]

As described in detail above, according to the present invention,
The rheological properties in the paste sol state are good, so the preparation of the paste sol itself and the work of applying the paste sol are good, and the coated surface after coating is also good, with a uniform thickness and a uniform shape and shape.
A foam having foam cells of a size can be obtained.
Further, this foam is excellent as a base material such as a joint material, a sealing material, and an adhesive tape.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C08J 9/00-9/42

Claims (3)

(57) [Claims] 1. An emulsion-polymerized vinyl chloride resin 10.
A vinyl chloride-based resin foam, characterized in that 0.1 part by weight of a urea-based resin solution having a urea-based resin concentration of 10 to 90% by weight is contained in 0 part by weight. 2. An emulsion-polymerized vinyl chloride resin 10.
The vinyl chloride resin foam according to claim 1, wherein the phthalate ester plasticizer and / or the trimellitic acid plasticizer are contained in an amount of 70 to 150 parts by weight in 0 part by weight. 3. A foaming ratio of a vinyl chloride resin foam is as follows:
The vinyl chloride resin foam according to claim 1, wherein the ratio is 4 to 15 times.