JPS6381148A - Stabilizer for chlorine-containing polymer - Google Patents

Abstract

PURPOSE:To provide the titled stabilizer composed of lead silicate glass powder containing specific amounts of lead component and silica component and having specific particle size, reactivity with nitric acid, etc., easily dispersible in a chlorine-containing polymer and capable of giving a stabilized polymer having excellent thermal stability and whiteness and free from foaming tendency. CONSTITUTION:The objective stabilizer is composed of lead silicate glass powder having the following characteristics. The weight ratio of lead component to the silica component is 70:30-90:10 in terms of PbO:SiO2. The particle diameter is <=70mum. The nitric acid reactivity defined by the formula (X0 is gram-number of lead oxide in 5g of the lead silicate glass; X1 is gram-number of lead oxide dissolved by stirring 5g of the lead silicate glass in 50ml of 0.35N nitric acid for 20min) is >=30%, especially >=40%. The Hunter whiteness is >=80%. The powder exhibits X-ray diffraction pattern shown in the table.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a lead silicate glass stabilizer for chlorine-containing polymers, and more specifically, it has excellent dispersibility in chlorine-containing polymers, The present invention relates to a lead silicate glass heat stabilizer which has a small initial tendency to prematurely color the polymer, has excellent thermal stability, and completely eliminates the foaming tendency of the blended resin composition.

(Prior Art) It has been known for a long time that lead silicate has a thermal stabilizing effect on vinyl chloride resin and the like.

Fusing lead silicate (lead silicate glass), which is produced by reacting lead monoxide and silicic acid at high temperatures, has little reactivity, so it is said to be of no use as a stabilizer such as KM hibinyl. (Special Publication No. 32-757 No. 1)
For this reason, method 1 of producing lead silicate as a stabilizer by a wet method, for example, a method of reacting a water-soluble lead salt such as lead acetate or lead nitrate with sodium silicate or silicate sol (see the left column of the page). Kosho 28-5668, 30-1872, 31-68
Japanese Patent Publication No. 32-757) and - a method in which lead oxide and silicate gel are reacted in water in the presence of a catalyst such as acetic acid if necessary.

(Problems to be Solved by the Invention) However, silicic acid jaws produced by the wet method necessarily contain adsorbed water and hydrated water, and are mixed with a chlorine-containing polymer and subjected to aging such as extrusion. When the resin molded product is mixed with the resin, or when a resin molded product containing the resin is exposed to high temperature, the resin foams.

If thermal stability could be imparted to lead silicate glass by some means, the aforementioned foaming problem could be solved, and it is expected that it would also have excellent dispersibility in chlorine-containing polymers. Ru.

(Means for Solving the Problems) The present inventors have incorporated a lead oxide component in a highly reactive state into the lead silicate glass phase.

It has been found that unexpectedly excellent thermal stability against chlorine-containing polymers can be obtained for a fused silicate glass. In addition, since this heat stabilizer is a glassy material formed by a melting method, it does not contain any decomposed or volatile components, nor does it have the ability to absorb moisture, etc., completely eliminating the tendency to foam, and producing a white color. It was found that it has excellent properties and dispersibility in resin.

According to the present invention, the lead component and the silicon component are each replaced with PbO
and expressed as SiO2, PbO:5iO2=7
0: 30-9 Q: 10 especially 75: 25-8
It consists of lead silicate glass powder contained in a gL ratio of 8:12, the lead silicate glass powder has a particle size of 10 pm or less, where XQ is the lead contained in 5 g of silicate glass. is the number of grams of oxide, and X! is 0.3g of lead silicate glass
Silicone having a nitric acid reaction* (Rn) defined as the number of grams of lead oxide dissolved when stirred for 20 minutes in 50 ril of 5N nitric acid of 30% or more and a Hunter whiteness of 80% or more. A stabilizer for chlorine-containing polymers is provided, which is characterized in that it is an acid lead glass powder.

(Function) Although the lead silicate glass used in the present invention is obtained by melting and reacting lead oxide and silicon dioxide, it has a nitric acid reaction rate (Rn) of 30% or more, particularly 40% or more.
It is a remarkable feature that it has .

In this specification, nitric acid reaction rate has the following meaning. That is, in a certain system containing a lead oxide component and a silicon dioxide component, if all the lead oxide components exist in a free form, the nitric acid reaction rate (Rn) shows a value of 100%, 0.3
5N nitric acid is acidic enough not to solubilize the lead oxide component bound in the form of lead silicate glass, and thus in the above system, if all of the lead oxide component is present in the form of lead silicate, the nitric acid reaction The lead silicate glass used in the present invention exhibits a nitric acid reaction rate of 30% or more.Actually, the lead silicate glass used in the present invention exhibits a nitric acid reaction rate of 30% or more of the lead oxide component in the lead silicate glass composition. This means that lead oxide exists in a state close to that of lead oxide or free lead oxide.

Considering the formation stages of lead silicate glass in terms of time, the lead oxide component melts, silicon dioxide is dispersed in this molten continuous phase, silicon dioxide and molten lead oxide react on the surface of silicon dioxide particles, It is thought that lead silicate glass gradually forms in the glass phase, and eventually the glass phase becomes homogeneous throughout.

The lead silicate glass used in the present invention is obtained at an intermediate stage of the above-mentioned lead silicate glass reaction process, and has a composition in which lead silicate and lead oxide are mixed in the glass phase. It should be obvious.

The lead silicate glass powder used in the present invention has a nitric acid reaction rate (R
By setting n) to 30% or more, especially 40% or more,
Excellent thermal stabilizing effect on chlorine-containing polymers is obtained. Table A below shows the nitric acid reaction rate (Rn
) was used, and the following composition (based on weight - the same applies hereafter): 100 parts vinyl chloride resin, 50 parts plasticizer, 5 parts lead silicate glass, 0.3 parts stearic acid, and the heat stabilization time ( Molded product sample at 210℃
Place the sample in a gear oven until it turns black (rIB).
and hydrogen chloride scavenging ability (the time taken for the Congo red test paper to change color due to the generated hydrogen chloride when a molded product sample is placed in an oil bath at 210° C.).

According to the results in Table A above, among lead silicate glass powders, those with a nitric acid reaction rate (Rn) of 30% or more have unexpectedly excellent thermal stability against vinyl chloride resin without discoloring the resin. It can be seen that it has an effect.

Although the lead silicate glass used in the present invention contains free lead oxide, it has a low degree of coloring and has an excellent Hunter whiteness of 80% or more, particularly 90% or more. Thus, this lead silicate glass has a low tendency to stain chlorine-containing polymers, and what is commonly called an inorganic stabilizer is a chlorine-containing polymer from the beginning of its formulation.
#Has a tendency to color the polymer slightly yellow to slightly red. This initial coloration is thought to be due to the interaction between the chlorine-containing polymer and the inorganic stabilizer during melt-kneading. Compared to other lead-based stabilizers such as basic lead silicate, it has the advantage of significantly less initial coloring tendency.

In the lead silicate glass used in the present invention, PbO:Si0
It is also important that 2 is in a quantitative ratio of 70:30 to 90:10. That is, if PbO is less than the above range, a satisfactory thermal stabilizing effect cannot be obtained, and if it is more than the above range, it becomes difficult to vitrify as a homogeneous phase.

This silicate glass should be a fine powder with a particle size of less than 1107z, especially less than 7 pm, in terms of thermal stabilization and dispersibility in the resin. Although this lead silicate glass varies depending on its chemical composition, it generally has a ratio of 6 to 30 glue t/1.
00g oil absorption (JISK-SiO1-19) and 1.7
and a bulk specific gravity of 2.3 g/cc to 2.3 g/cc.
It is relatively dense, has low oil absorption, and has good dispersion in resins, and is easy to blend.

(Description of structure) The lead silicate used in the present invention is produced by melting and reacting lead oxide such as -lead oxide or lead sesquioxide with silicon dioxide so that the lead nitrate reaction rate (Rn) is within the above range. can get. The temperature and time for melting and reacting the lead oxide component and the silicon dioxide component vary considerably depending on the type of raw materials and the blending ratio of both components, and cannot be generally specified.However, in general, In other words, 600 to 1000 degrees Celsius.

Particularly from a temperature range of 700 to 950°C and a treatment time of from 10 minutes to 60 minutes, especially from 15 to 45 minutes.
Conditions may be selected such that the nitric acid reaction rate (Rn) described above is in the range of 30 or more E. The obtained molten reaction product is cooled by pouring it into water, etc., and granulated. This granulated material is pulverized dry or wet, and if necessary, classified to obtain a lead silicate glass stabilizer having a predetermined particle size.

There are several crystallographic types of lead silicate glass stabilizers used in the present invention. The first type is
This amorphous type, which is amorphous in terms of ray diffraction and whose X-ray diffraction image is shown in FIG. 1, is obtained by dry grinding a cooled molten reaction product.

The second type is essentially the following X-ray diffraction image I■Lσ
Upper Chubin IuL3 engineering 3.22 5 03.03
1 0 02.98
1 0 02.82
8 02.10 3
It has an xi diffraction image consistent with 01.85 3 0. The X-ray diffraction image is shown in FIG. 2, and this X-ray diffraction image is recognized to be unique to lead sesquioxide. The second type is obtained by wet milling of the cooled molten reactants. The reason why lead sesquioxide crystals are formed during wet milling is still unknown, but it is thought to be because free lead oxide components in the glass phase are oxidized and recrystallized during wet milling. Surprisingly, this type of material has excellent whiteness with a Hunter whiteness of 80% or more, despite having lead sesquioxide crystals. In the third type, the lead silicate glass powder is substantially below the X-ray diffraction image.
1 0 02.88
It has an X-ray diffraction image consistent with 90. The X-ray diffraction image is shown in FIG. 3, and this X-ray diffraction image is recognized to be unique to lead pyrosilicate (Pb3Si20+). The third type is the first type mentioned above.
, and the second type is the crystallization temperature of lead silicate,
Generally, it is obtained by heat treatment at a temperature of 500 to 650°C. This type is a slightly yellow colored powder.

The lead silicate glass used in the present invention is not limited to the three types mentioned above, for example, other crystals such as PbSiO2 Pb2SiOa, mixed crystals of two or more of these types,
Or these two! ! Naturally, the above-mentioned solid solutions are included.

The lead silicate stabilizer of the present invention has extremely small specific surface area and oil absorption, so even when used alone, it can be easily incorporated into chlorine-containing polymer resin and has excellent uniform dispersibility in the resin. However, if desired, the surface can be coated with various fatty acids, fatty acid soaps, fatty acid metal soaps, resin acid metal soaps, various waxes, and various resins.

Coating amount is 0.1 to 10 per lead silicate glass
A range of 00% is appropriate. Further, this coating layer can contain various organic stabilizers as stabilizing aids. Polyhydric alcohols, polyhydric phenols, β
- diketones are preferred.

Suitable examples thereof are mono- and dipentaerythritols, other polypentaerythritols, mancottol, sorbitol, glucose, fructose, trimethylolpropane, polyethylene glycol, polypropylene-
Polyoxyethylene block polymer, bisphenol A
, sterically hindered phenols, acetoacetate, acetylacetone, methylbenzoyl ketone, etc.

Further, examples of the chlorine-containing polymer used in the present invention include polyvinyl chloride, polyvinylidene chloride, k1
1z polyethylene, chlorinated polypropylene, 11! rubber, vinyl chloride-vinyl acetate copolymer, vinyl chloride; leuethylene copolymer, vinyl chloride-propylene copolymer,
Vinyl chloride-styrene copolymer, vinyl chloride-isobutylene copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-styrene-maleic anhydride ternary copolymer, vinyl chloride-styrene-acrylonitrile copolymer, Vinyl chloride-butadiene copolymer, vinyl chloride-isoprene copolymer, vinyl chloride-chlorinated propylene copolymer, vinyl chloride-vinylidene chloride-vinyl acetate terpolymer, vinyl chloride-acrylic acid ester copolymer, Polymers such as vinyl chloride-maleic acid ester copolymer, vinyl chloride-methacrylic acid ester copolymer, vinyl chloride-acrylonitrile copolymer, internally plasticized polyvinyl chloride, and these chlorine-containing polymers and polyethylene, polypropylene α-olefin bead aggregates with , polypterate, and poly-3-methylbutene can be used for polyolefins such as ethylene-vinyl acetate copolymers, ethylene-propylene copolymers, and their copolymers, polystyrene, acrylic resins, styrene, and others. copolymers with monomers (e.g. maleic anhydride, butadiene, acrylonitrile, etc.), acrylonitrile-butadiene-styrene copolymers, acrylic ester-butadiene-styrene copolymers, methacrylic ester-butadiene-styrene copolymers Examples include blended products with combinations.

The chlorine-containing polymer composition of the present invention may also contain various additives known per se, such as plasticizers, antioxidants, light stabilizers,
Nucleating agents, fillers, nonmetallic stabilizers, anhydrous anhydride, epoxy stabilizers, organic chelators, pigments, antistatic agents, basic inorganic acid salts, antifogging agents, plate-out inhibitors, surface treatment agents, lubricants,
Flame retardants, fluorescent agents, fungicides, bactericides, photodegradants, processing aids, mold release agents, and the like can be added.

(Operations and Effects of the Invention) According to the present invention, the dispersibility of the chlorine-containing polymer is improved, the initial coloring tendency of the polymer is small, the thermal stability is excellent, and the foaming tendency of the blended resin composition is completely eliminated. A lead silicate glass heat stabilizer is provided.

The invention is illustrated in the following examples.

Example 1 In this example, a stabilizer for chlorine-containing polymers having a ratio of PbO:SiO2 of 85:15 will be described.

The lead oxide (pbo) raw material is JIS K-1 with the following analysis values.
456, No. 1 approved product Glue Surge was used.

Furthermore, as the silicon dioxide (Si02) raw material, silica sand powder for crystal glass having the following analytical values and particle size was used.

Particle size The above raw materials were dry mixed so that the weight ratio of PbO:SiO2 was 85:15, melted at 850° C. using an alumina crucible, and the melt was quenched in water to obtain a force-left product. This cullet is taken into a pot mill, added with pure water, wet-pulverized, and then dehydrated.

It was dried to obtain a sample powder (A).

Further, the cullet was dried, taken into a bot mill, and dry-pulverized to obtain a sample powder (B).

Further, the sample powder (A) was calcined at 550°C and the sample powder (A) was calcined at 550°C.
C) was obtained. Separately, the above melt was slowly cooled in a furnace to obtain a glassy material, and this glassy material was wet-pulverized to obtain a sample powder (D).
A sample powder (E) was obtained by dry grinding.

Using these sample powders (A) to (E), the following formulation was roll-kneaded and then pressed to create a polyvinyl chloride sheet with a thickness of 1 mm. This sheet was tested for initial colorability, gear oven heat resistance at 210°C, and hydrogen chloride scavenging ability by the Congo Red method at 210°C.

Table 1 shows the powder properties of the blended sample powder and the test results of the polyvinyl chloride sheet.

Example 2 In this example, stabilizers for chlorine-containing polymers in which the PbO:SiO2 weight ratio is varied will be described.

A sample powder having a PbO:S 1o2ffI m ratio shown in Table 2 was obtained in the same manner as the sample powder (A) of Example 1.

Next, a polyvinyl chloride sheet was prepared using the same formulation as in the example, and the same test was conducted.

The respective results are shown in Table 2.

From Table 2 above, it can be seen that the PbO:5iOz weight ratio is 70:
If the PbO content is less than 30, thermal stability will be insufficient.

Furthermore, it is understood that when the PbO:5iOz ratio is about 90:10, although it has a hydrogen chloride trapping effect and a heat stabilizing effect, the discoloration of polyvinyl chloride is severe and the substance becomes unsuitable as a stabilizer.

[Brief explanation of the drawing]

FIG. 1 is an X-ray diffraction diagram of a dry-ground lead silicate glass stabilizer. FIG. 2 is an X-ray diffraction diagram of a wet-milled lead silicate glass stabilizer, and FIG. 3 is an X-ray diffraction diagram of a heat-treated lead silicate glass stabilizer. Patent Applicant Mizusawa Chemical Industry Co., Ltd. PS CPS Procedural Amendment (Sealed) November 4, 1985 Commissioner of the Patent Office Kuro 1) Akio Yu 1, Indication of the Case 1986 Patent Application No. 223867 2, Title of the Invention Stabilizer for chlorine-containing polymers 3, relationship with the case of the person making the amendment Patent applicant address: 4-5 Nihonbashi Muromachi, Chuo-ku, Tokyo Name: Mizusawa Chemical Industry Co., Ltd. 4, Agent: 105-5, No date of amendment order 6. Subject of correction (1) Figure 1 will be corrected as shown in the attached sheet. that's all

Claims (1)

[Claims] (1) The lead component and the silicon component are PbO and Si, respectively.
It consists of lead silicate glass powder expressed as O_2 and contained in a weight ratio of PbO:SiO_2 = 70:30 to 90:10, the lead silicate glass powder has a particle size of 10 μm or less, and has the following formula Rn = ( X_1/X_0)×100 In the formula, X_0 is the number of grams of lead oxide contained in 5 g of lead silicate glass, and X_1 is the number of grams of lead oxide contained in 5 g of lead silicate glass.
Lead silicate glass powder having a nitric acid reaction rate (Rn) defined as 30% or more and a Hunter whiteness of 80% or more. A stabilizer for chlorine-containing polymers. (2) The stabilizer according to claim 1, wherein the lead silicate glass powder is amorphous in terms of X-ray diffraction. (3) The lead silicate glass powder substantially has the following X-ray diffraction image\plane spacing (Å)\\relative intensity ratio (%)\ 3.22 50 3.03 100 2.96 100 2.82 60 2 .10 30 1.85 30 The stabilizer according to claim 1, which has an X-ray diffraction pattern corresponding to .10 30 1.85 30 . (4) The lead silicate glass powder substantially matches the following X-ray diffraction image\plane spacing (Å)\\relative intensity ratio (%)\3.25 60 2.90 100 2.86 90 The stabilizer according to claim 1, which has a diffraction image.