JPH08217911A - Resin stabilizer based on basic zinc phosphite complex salt - Google Patents

Abstract

PURPOSE: To obtain a resin stabilizer which has an excellent effect of stabilizing a synthetic resin (e.g. vinyl chloride) against thermal deterioration during processing and a long-term change due to light and heat in service, is non-toxic unlike a heavy metal (e.g. lead) and is usable also in a transparent resin. CONSTITUTION: This stabilizer is based on a basic zinc phosphite complex salt and containing at least one metal selected from the group consisting of calcium, magnesium strontium and aluminum in an amount to give a molar ratio to the zinc of 0.1-3.0. It is desirable that this stabilizer further contains at least either cerium or silver in an amount of 1.0-20.0wt.%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly safe resin stabilizer used for synthetic resins such as vinyl chloride resin in place of toxic lead phosphite and the like. It is well known that the quality of synthetic resins such as vinyl chloride resin deteriorates due to heat changes during processing, changes with time due to light and heat during use, effects of microorganisms, and the like. To prevent such deterioration, toxic heavy metal compounds such as lead stearate, barium laurate, lead silicate, and dibutyltin laurate have been used. Among them, especially dibasic lead phosphite,
It has been widely used as a stabilizer that imparts excellent heat resistance, light resistance, and weather resistance to a hard vinyl chloride resin. However, since heavy metals such as lead are toxic, the emergence of highly safe resin stabilizers that replace these heavy metal-containing resin stabilizers has been desired. The present invention relates to a highly safe resin stabilizer for meeting such requirements.

[0002]

2. Description of the Related Art Up to now, many proposals have been made as alternatives to heavy metal-containing resin stabilizers. For example, JP-A-6-504978 discloses that basic calcium aluminum hydroxyphosphite is suitable as a stabilizer for halogen-containing polymers, particularly vinyl chloride resins. On the other hand, many inventions have been disclosed regarding zinc phosphite compounds. For example, Japanese Patent Publication Sho 5
6-9951 discloses that a basic zinc phosphite composition is useful as an inhibitor for tannin-induced stains in a coating composition for surface treatment of wood, and is disclosed in JP-A-58-194725. Disclose that a zinc hydroxyphosphite complex is excellent as a rust preventive pigment, and JP-A-59-204664 discloses that basic potassium zinc phosphite is excellent as a rust preventive pigment. It is disclosed. The applicant of the present invention also discloses in Japanese Unexamined Patent Publication No.
No. 8 discloses that a pigment containing zinc calcium phosphite as a main component has excellent rust preventive properties. Further, many inventions have been disclosed regarding aluminum phosphite compounds. For example, Japanese Unexamined Patent Publication (Kokai) No. 57-95814 discloses that an aluminum phosphite composition is excellent as an anticorrosive pigment. It has been disclosed that the aluminum phosphate crystal is a pigment excellent not only in rust prevention but also in coating properties. Also, many inventions have been disclosed regarding an ultraviolet absorber using cerium. For example, JP-A-3-70776 discloses that a resin composition containing cerium-containing zirconia particles has excellent light resistance, and JP-A-5-25458 discloses an ultraviolet absorber. , Hydroxyapatite is excellent, and cerium-substituted hydroxyapatite is also suitable. The present applicant also filed Japanese Patent Application No. 6-6
In 1978, an ultraviolet absorber containing a cerium-supported zinc phosphate double salt as a main component was disclosed.

[0003]

Conventionally, in synthetic resins such as vinyl chloride resin, stearin is used in order to prevent heat deterioration during processing, deterioration with time due to light and heat during use, and deterioration of quality due to the action of microorganisms. Lead acid, barium laurate,
Lead silicate, dibutyltin laurate and the like have been used as additives. However, although these impart excellent heat resistance, light resistance, and weather resistance, since heavy metals such as lead are toxic, safety to health has been a problem. For such a problem, a resin stabilizer containing no toxic heavy metal has been investigated, but a resin stabilizer having sufficient characteristics has not always been obtained. For example, basic calcium aluminum hydroxyphosphite disclosed in JP-A-6-504978 is an excellent stabilizer for halogen-containing polymers such as vinyl chloride resin, but has no transparency. It was difficult to use for applications requiring transparency. In addition, JP-A-3-707
The resin composition containing the cerium-containing zirconia particles disclosed in Japanese Patent Publication No. 76 has excellent light resistance, but has no transparency and is difficult to be used for applications requiring transparency. Although hydroxyapatite such as cerium-substituted hydroxyapatite disclosed in JP-A-5-25458 is suitable as an ultraviolet absorber,
There was no transparency, and it was difficult to use it for applications requiring transparency. The problem to be solved by the present invention is to develop a resin stabilizer that is not toxic like heavy metals such as lead, has an excellent resin stabilizing effect, and has other properties such as transparency. Especially.

[0004]

In order to solve the above-mentioned problems, the present inventors comprise calcium, magnesium, strontium and aluminum in a molar ratio of 0.1 to 3.0 with respect to zinc. A basic zinc phosphite double salt resin stabilizer (hereinafter referred to as "first invention") containing a basic zinc phosphite double salt containing one or more metals in the group as a main component, and zinc, The total amount is 1. to the basic zinc phosphite double salt containing at least one metal selected from the group consisting of calcium, magnesium, strontium and aluminum in a molar ratio of 0.1 or more and 3.0 or less. 0% by weight or more,
A basic zinc phosphite double salt-based resin stabilizer (hereinafter referred to as "a stabilizer" containing, as a main component, one or both of cerium and silver supported in a weight ratio of 20.0% by weight or less. Second invention "), and 0.3% by weight or more, 1
Inorganic fine particles such as harmless metal stearate, titanium oxide, hydrotalcite, and silica are added at a weight ratio of 0.0% by weight or less using a highly kneading device and treated. A basic zinc phosphite double salt-based resin stabilizer according to claim 1 or claim 2 (hereinafter referred to as "third invention") is provided.

In the production of the basic zinc phosphite double salt which is the main component of the resin stabilizer according to the first invention, zinc phosphite is produced in advance by reacting phosphorous acid with zinc or a zinc compound. From the above, a compound such as calcium, magnesium, strontium, or aluminum may be added to produce a phosphorous acid double salt, or phosphorous acid may be mixed with zinc,
Addition of oxides, hydroxides, carbonates, etc. of calcium, magnesium, strontium, aluminum etc. to produce zinc phosphite and phosphite of other metals simultaneously with the production of phosphite double salt. May be. The molar ratio of other metal to zinc in this phosphorous acid double salt is 0.1 or more, 3.
It must be 0 or less. If this molar ratio is less than 0.1 or more than 3.0, a sufficient amount of double salt is not formed and a sufficient resin stabilizing effect cannot be obtained. Either a wet reaction or a dry reaction can be used for the production of this phosphorous acid double salt, but the wet reaction is preferred. As the wet reactor, a kneader, an emulsifier, a media mill, etc. are used, but if a ball mill, a bead mill, a vibration mill or the like having a mechanochemical effect is used, the reaction can be performed more effectively, and the average particle size can be increased. It is easy to obtain fine particles having a diameter of 5 μm or less.

In the resin stabilizer according to the second aspect of the present invention, after the basic zinc phosphite double salt is produced by the above-mentioned method, either one or both of cerium and silver may be supported. In the above method, cerium may be produced after the zinc phosphite is produced, simultaneously with the production of the phosphite of another metal, or with the production of the zinc phosphite and the phosphite of the other metal. Alternatively, silver may be supported. The cerium and silver are supported by adding a water-soluble salt such as nitrate of these metals and reacting them. It is necessary that the total amount of cerium and silver carried is 1.0% by weight or more and 20.0% by weight or less. 1.0% by weight
If it is less than the above range, the effect of absorbing ultraviolet rays cannot be obtained, and if it exceeds 20.0% by weight, coloring may occur.

The resin stabilizer according to the third invention is the basic zinc phosphite double salt which is the main component of the resin stabilizer according to the first invention, or the basic zinc phosphite complex salt according to the second invention. 0.3% by weight or more and 10.0% by weight or more of a salt supporting 1.0% by weight or more and 20.0% by weight or less of a total amount of cerium and / or silver. Basic phosphorus-containing phosphorus characterized by being treated by adding inorganic fine particles such as harmless metal stearate, titanium oxide, hydrotalcite, and silica in the following weight ratios using a highly miscible device. Zinc acid double salt resin stabilizer. Examples of the harmless metal stearate include stearates of calcium, magnesium, strontium, aluminum, zinc and the like. The blending ratio of these inorganic fine particles is required to be 0.3% by weight or more and 10.0% by weight or less, and if less than 0.3% by weight, the dispersing effect of the resin stabilizer is not recognized, Further, if it exceeds 10.0% by weight, the effect as a resin stabilizer may be deteriorated. The addition treatment method of these inorganic fine particles may be either a wet method or a dry method, but when a wet ball mill or the like is used with a reactor having a high kneading property, it is necessary to keep the mixing within 1 hour. Is stable. Also, in dry mixing,
If a mixer with good mixing properties such as a Henschel mixer or a media mill having a grinding effect is used, surface treatment can be performed and a synergistic effect of the stabilizer can be expected.

[0008]

The basic zinc zinc phosphite double salt resin stabilizer according to the present invention not only has health safety, but also has an excellent stabilizing effect on resins such as vinyl chloride resin by any action. It is not known in detail whether the effect will be exhibited, but it is thought that the following actions are involved for the time being. First,
Since the zinc phosphite double salt is basic, the chlorine ion released from the vinyl chloride resin or the like is captured by the free base. Furthermore, since zinc forms a double salt with calcium, magnesium, strontium, aluminum, etc., which have different ionization potentials, these metals are activated and chlorine ions released from vinyl chloride resin, etc. are easily captured. To be done. Also, due to the strong reducing property of phosphorous acid,
Oxidative decomposition of the resin due to oxygen in the air or dissolved oxygen is prevented, and at the same time, generation of chlorine gas due to oxidation of chlorine ions is prevented. Further, since cerium and silver having an ultraviolet absorbing effect are supported, deterioration of the resin due to ultraviolet rays is prevented, and at the same time, coloring due to oxidation of silver and cerium is prevented due to the strong reducing property of phosphorous acid. In addition, since harmless metal stearate, titanium oxide, hydrotalcite, and inorganic fine particles such as silica are added and treated using a highly miscible device, basic zinc phosphite double salt and Since the material carrying cerium or silver thereon is finely dispersed, the resin stabilizing effect is further enhanced.

[0009]

【Example】

1. Preparation of basic zinc phosphite double salt and preparation of comparative sample [Example 1] 50% phosphorous acid (H ₃ P) heated to 70 ° C.
500 g of the O ₃ ) solution was placed in a 2 l beaker, and while stirring, 1100 g of a 25 wt% slurry consisting of 124 g of zinc oxide (ZnO) and 151 g of calcium hydroxide (Ca (OH) ₂ ) was gradually added and reacted. It was After cooling the reaction slurry, it was transferred to an alumina 2 l ball mill and kneaded for 16 hours to terminate the reaction. The pH of the slurry at that time was 6.7. The slurry was filtered, and the obtained filter cake was dried at 200 ° C. for 10 hours to obtain powder (hereinafter referred to as “powder 1”). The analysis result of the powder 1 is zinc 22.5%, calcium 18.4%, phosphorus 2
1.2%, theoretical composition Zn _1.5 Ca ₂ (HPO
₃ ) ₃ (OH), and the molar ratio of calcium to zinc was 1.33.

Example 2 500 g of a 50% phosphorous acid solution heated to 50 ° C. was transferred to a Futaba kneader, 62 g of aluminum hydroxide (Al (OH) ₃ ) was added and reacted, and then 250 g of zinc oxide was added. While kneading, it was gradually added and reacted to obtain a powder. Transferred water 1000g cerium nitrate this powder 2l bead mill _(Ce (NO _{3) 3} 6H
₂ O) (62 g) was added, and the mixture was further kneaded at 30 ° C. for 3 hours to terminate the reaction. The pH of the slurry at that time is 6.4.
Met. The slurry was filtered, the obtained filter cake was dried at 200 ° C. for 10 hours, and then transferred to an alumina vibration mill to obtain hydrotalcite (Mg _4.5 Al).
₂ (OH) ₁₃ CO ₃ 3.5H ₂ O Kyowa Chemical Industry Co., Ltd.
24 g of Alkamizer (manufactured by Alkamizer) was added and kneaded for 30 minutes to obtain a powder (hereinafter referred to as "powder 2"). The analysis result of the powder before adding the hydrotalcite was zinc 38.1%,
Aluminum 4.0%, cerium 5.1%, phosphorus 18.
5% and its theoretical composition Zn ₃ Al _0.78 (HP
O ₃ ) ₃ (OH) _1.3 , the ratio of aluminum to zinc is 0.26, the amount of cerium supported is 5.1% by weight and the amount of hydrotalcite is 4.
It was 6% by weight.

Example 3 28 g of magnesium oxide (MgO) and strontium carbonate (SrCO ₃ ) were stirred into 800 g of a 30% zinc phosphite (Zn (H ₂ PO ₃ ) ₂ ) solution heated to 70 ° C. After adding 310 g and making it react and hold | maintaining at 70 degreeC for 2 hours, it cooled to 30 degreeC and 2l.
The mixture was transferred to an alumina ball mill, 46 g of cerium nitrate and 4 g of silver nitrate (AgNO ₃ ) were added, and the mixture was kneaded for 15 hours to complete the reaction. The pH of this slurry was 7.8. The slurry was filtered, and the obtained filter cake was dried at 200 ° C. for 10 hours to obtain powder (hereinafter referred to as “powder 3”). The analysis result of the powder 3 is zinc 13.4%,
Strontium 36.5%, magnesium 3.3%, phosphorus 13.0%, cerium 2.9%, silver 0.5%, theoretical composition Zn _1.5 Sr ₃ Mg (HPO ₃ ) ₃ (O
H) ₅ and the total molar ratio of strontium and magnesium to zinc was 2.7 and the total amount of cerium and silver supported was 3.4% by weight.

Example 4 1230 g of a 20% phosphorous acid solution heated to 40 ° C. was put in a Dispermill, and 58 g of aluminum hydroxide, 37 g of calcium hydroxide and 245 g of zinc oxide were added and kneaded while mixing 2 Reacted for hours.
After cooling it to 30 ° C., 300 ml of water, 164 g of cerium nitrate and 12 g of titanium oxide (specific surface area 40 m ² / g manufactured by Ishihara Sangyo Co., Ltd.) were added, and the mixture was further kneaded for 30 minutes to terminate the reaction. It was The pH of the slurry at that time is 7.
It was 5. This slurry was filtered, and the obtained filter cake was dried at 200 ° C. for 10 hours to obtain powder (hereinafter referred to as “powder 4”). The analysis result of powder 4 is zinc 3
5.0%, calcium 3.4%, aluminum 3.4
%, Phosphorus 5.7%, cerium 9.5%, titanium 1.
3% and its theoretical composition Zn ₃ Ca _0.5 Al
_0.74 (HPO ₃ ) ₃ (OH) _3.85 , the total molar ratio of calcium and aluminum to zinc is 0.4, and the amount of cerium supported is 9.5% by weight.
And the amount of titanium oxide was 2.1% by weight.

Example 5 1350 g of 20% aluminum dihydrogen phosphite (Al (H ₃ PO ₃ ) ₃ ) at 30 ° C. was placed in an attritor and strontium hydroxide (Sr (O
H) ₂ ) 122 g and zinc oxide 224 g were added and kneaded for 2 hours, then cooled to 30 ° C., and further cerium nitrate 98 g
Then, 10 g of silver nitrate and 20 g of titanium oxide (manufactured by Teika Co., Ltd., average particle size: 0.2 μm) were added and kneaded for 30 minutes to complete the reaction. The pH of the slurry at that time was 7.5. Furthermore, after adding 10 g of calcium stearate and kneading for 10 minutes, the slurry was filtered, and the obtained filter cake was dried at 180 ° C. for 10 hours to obtain a powder (hereinafter referred to as “powder 5”). The analysis result of the slurry before adding calcium stearate was as follows: zinc 30.1%, strontium 13.3%, aluminum 4.2%, phosphorus 14.2
%, Cerium 5.1%, silver 0.9%, titanium 1.9
% And the theoretical composition Zn ₃ SrAl (HPO ₃ ).
₃ (OH) ₅ , the total molar ratio of strontium and aluminum to zinc is 0.66, the total amount of cerium and silver supported is 6.0% by weight, and the total amount of titanium oxide and calcium stearate is Was 4.6% by weight.

[Comparative Sample] As a comparative sample, hydrotalcite fine particles (Mg _4.5 Al ₂ (OH) ₁₃ CO ₃
3.5 H ₂ O Kyowa Chemical Industry Co., Ltd., Ltd.) and "powder 6", the titanium oxide fine particles (TiO ₂ Co. Tayca) and "powder 7 ', zinc phosphate crystallites _(Zn 3 ( PO ₄ )
₂ 2H ₂ O Taihei Chemical Industrial Co., Ltd., Ltd.) and "powder 8"
Dibasic lead phosphite microcrystal (2PbO ・ PbHPO ₃ 1
/ 2H ₂ O Sakai Chemical Co., Ltd. was designated as "Powder 9".

2. Thermal stability test Powder 1 obtained in Examples 1 to 5 and comparative sample
Each of Nos. 9 to 9 was plasticized by using the twin roll kneader with the composition shown in Table 1 at 180 ° C. for different kneading times, and then molded into a sheet having a thickness of 1 mm. This 3
A sample was cut into a size of 0 mm × 50 mm.

[Table 1]

Table 2 shows the relationship between discoloration and the time of kneading with a twin roll kneader at 180 ° C. In this table, 0 is no discoloration, 1 is not yet discolored, 2 is slightly discolored, 3 is clearly discolored, 4 is strongly discolored Indicates.
As is clear from this table, it is recognized that the basic zinc phosphite double salt resin stabilizer according to the present invention has an excellent resin stabilizing effect against heating.

[Table 2]

3. UV stability test For resin compositions using powders 1 to 9,
Sample with kneading time of 15 minutes (hereinafter referred to as "Sample A") and 3
A sample of 0 minutes (hereinafter referred to as “Sample B”) was placed under 20 W of a 15 W ultraviolet germicidal lamp, and the degree of discoloration over time due to ultraviolet rays was examined. Table 3 shows the results. As is clear from this table, the basic zinc phosphite double salt-based resin stabilizer according to the present invention is recognized to have an excellent resin stabilizing effect against ultraviolet rays.

[Table 3]

[0018]

The basic zinc zinc phosphite double salt type resin stabilizer according to the present invention has the above-mentioned constitution and function, and therefore is not only not toxic like heavy metals such as lead but also excellent. It also has a resin-stabilizing effect and is sufficiently used for resins that require transparency and the like.

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Claims (3)

[Claims] 1. A basic zinc phosphite complex containing at least one metal selected from the group consisting of calcium, magnesium, strontium and aluminum in a molar ratio of 0.1 to 3.0 with respect to zinc. Basic Zinc Phosphite Double Salt Resin Stabilizer Based on Salt 2. A basic zinc phosphite complex containing at least one metal selected from the group consisting of calcium, magnesium, strontium and aluminum in a molar ratio of 0.1 to 3.0 with respect to zinc. A base containing, as a main component, one or both of cerium and silver supported in a total weight ratio of 1.0% by weight or more and 20.0% by weight or less with respect to the salt. Zinc Phosphite Double Salt Resin Stabilizer 3. An apparatus having high miscibility with inorganic fine particles such as harmless metal stearate, titanium oxide, hydrotalcite and silica in a weight ratio of 0.3% by weight or more and 10.0% by weight or less. The basic zinc zinc phosphite double salt resin stabilizer according to claim 1 or 2, characterized in that