JPS6035941B2 - Gypsum fiber-polyvinyl chloride resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composition of gypsum fibers and polyvinyl chloride resin, and its purpose is to promote gelation of a mixture of gypsum fibers and polyvinyl chloride resin, and to convert the gypsum fibers into polychlorinated resins. The purpose is to improve the impact strength of composite materials by dispersing them in vinyl resins.

Gypsum fibers and methods for their production are known from various documents.

This gypsum fiber is made of polyvinyl chloride (hereinafter referred to as PVC)
It has become clear that when mixed with a mixture of In order to sufficiently disperse the gypsum fibers in PVC, it is necessary to promote gelatinization and thoroughly knead the fibers, or to forcibly knead the fibers using a processing machine with strong shearing force. In the former case, the amount of lubricant in the PVC is reduced to speed up gelation, but conversely, the lubricity after gelation is insufficient,
Retention occurs in the die, resulting in so-called "scattering" of PVC.In the latter case, the full-flight screw used for normal processing of PVC is insufficient, and it is used for compounding crystalline polymers. A screw with strong shearing force, such as a dalmage screw, is required. Using this screw improves the dispersion of gypsum fibers, but the dalmage part of the screw suffers from "H" and cannot be operated for a long time. Ta. Therefore, the conditions for sufficiently processing a mixture of gypsum fibers and PVC using ordinary processing machines are to maintain, preferably increase, the slipperiness after gelation, and to accelerate the gelation of the mixture. is necessary. However, in general, PVC thickeners with high stickiness are known to delay the gelation of PVC. For example, if the amount of lead stearate is increased to impart lubricity to a lead-based formulation, the gelation will be delayed. conversion is significantly delayed. The only exception is calcium stearate (Ca-St). This Ca-St is also PVCI
If the amount exceeds 1 part, a plate-out phenomenon will occur,
Moreover, it is not preferable because it increases the mixed bran torque. The present inventors have conducted extensive research on methods for improving the above-mentioned contradictory effects, increasing lubricity, and accelerating the gelation of PVC, and as a result, have arrived at the present invention.

That is, the content of the resin composition is a mixture of gypsum fiber and polyvinyl chloride resin, which is characterized by containing a saturated higher fatty acid having 2 or more carbon atoms or a derivative thereof. The gypsum fiber of the present invention is obtained by recrystallizing dihydrate gypsum or dihydrate obtained by rehydrating calcined gypsum in water or in water containing polyhydric alcohol, acid, etc. Hydrogypsum fibers, Q-hemihydrate gypsum fibers obtained by oxidizing calcium sulfite in water, m-type or O-type anhydrous gypsum fibers obtained by treating the above fibers at high temperatures, or a mixture thereof.

Furthermore, these gypsum fibers include those treated with water glass, aluminum sulfate, magnesium sulfate, and those treated with organic surface treatment agents such as silane coupling agents, organic titanates, etc. The filling amount of gypsum fiber is usually 5~
Used at 75% by weight. The vinyl chloride resin used in the present invention includes vinyl chloride homopolymer, vinyl chloride and vinyl acetate, vinylidene chloride, ethylene, propylene,
Copolymers with acrylic acid esters, phthalic anhydride, phthalic acid, maleic anhydride, maleic acid, and others are included.

Generally, PVC contains a stabilizer that provides thermal stability during processing, a glue that provides tenacity, a processing aid, and, if necessary, ABS, MBS, chlorinated polyethylene, pigments, etc. However, these additives may be optionally included. Any type of stabilizer may be used, but lead-based stabilizers, calcium-zinc-based stabilizers, calcium-barium-based stabilizers, etc. are particularly effective. Also, PV
C can be used as hard, semi-hard, or soft depending on the presence or absence of a plasticizer and its amount, and in the present invention, any of these may be used.
Remarkably effective on hard or semi-hard materials. The higher saturated fatty acids having 24 carbon atoms in the present invention are C2, 43CO
CmH2n + ICOOH over O days (e.g. behenic acid)
Higher saturated fatty acids as represented by the general formula (nZ21), more preferably higher fatty acids having 24 carbon atoms, and those having 35 or less carbon atoms are practically used.

These fatty acids can be partially or completely replaced by their derivatives. Derivatives include esters and metal salts of these fatty acids, including higher monoalcohol esters, gesters, and partially hydrolyzed compounds thereof (e.g., Ca salts).
can be used. The alcohol residue in ester has 6 to 6 carbon atoms.
A 3 night star is favorable. The amount of such higher fatty acids or derivatives thereof to be used may be determined as appropriate depending on the intended use of the composition of the present invention, but in general, 0.05 parts by weight or more is preferably 2 parts by weight based on PVCIOO parts by weight. rarely exceeds. Regarding the mixing method, it is optional, but preferably, a stabilizer, a lubricant, a processing aid, and a higher saturated fatty acid having 2 or more carbon atoms or a derivative thereof are added to PVC, mixed with a high-speed mixer, and then gypsum fiber is added. , the length-to-diameter ratio (hereinafter referred to as aspect ratio) of the gypsum fibers is 10.
or pre-mix PVC and gypsum fibers, and separately add a small amount of PVC, stabilizers, lubricants, processing aids, and high-quality materials with a carbon number of 2. A method is used in which a required amount of fatty acids or derivatives thereof is mixed in a high-speed mixer, the two are mixed, and the mixture is further mixed in a mixer so that the gypsum fiber aspect ratio is maintained at 10 or more.

As a processing method for the composition mixed in this way, the usual P
Examples of methods used for processing VC include extrusion molding, calendar molding, injection molding, blow molding, etc., and either powder molding or pellet molding may be used.

The effects of the present invention will be further explained.

When gypsum fibers are added to a lead-based vinyl chloride compound and mixed with a mixer such as a super mixer to improve the dispersion of the gypsum fibers, gelation is significantly delayed, resulting in a compression rate of 3.2. When processed using a full-flight screw, gelation does not occur, and the impact strength of the resulting molded product becomes significantly lower. In addition, even if PVC alone has sufficient lubricity, if gypsum fiber is filled into the compound, the lubricity after gelation will be insufficient, so an additional lubricant will be required. If lead stearate or the like is added to the gel, it will not gel even more. Therefore,
A compound that accelerates gelation and increases lubricity is required. However, most of the lubricants used for PVC, with the exception of calcium stearate, have the effect of delaying the gelation of PVC, and common sense suggests that it is impossible to accelerate gelation and increase lubricity. Ta. In the case of the saturated fatty acids or derivatives having 2 carbon atoms or more according to the present invention, the gelation of polyvinyl chloride alone is delayed, and the effect becomes larger as the carbon number increases. However, in the presence of gypsum fibers,
It shows no phenomenon. Stearic acid with 18 carbon atoms, 2 carbon atoms
With zero arachidic acid, gelation is delayed, but when behenic acid with 22 carbon atoms is added, gelation becomes faster, and the number of carbon atoms increases with cerotic acid, which has 26 carbon atoms, and montanic acid, which has 28 carbon atoms. It was found that gelation was significantly accelerated as the temperature increased. Similar effects can be obtained with these conductors. That is, Hoechstwax E, which is a montanic acid ester, Hexstowax OP, which is a partial calcium salt of a montanic acid ester, and Hoechstwax GL-3, which is a partial calcium salt of a saturated fatty acid ester having 30 carbon atoms, exhibits similar effects. As mentioned above, it is surprising that when the present invention's saturated fatty acids with a carbon number of 2 or more or their derivatives are used in a compound of gypsum fiber and PVC to accelerate gelation, the impact strength is significantly increased. This is a desirable effect.

Next, examples of the present invention will be described.

Examples 1 to 8, Control Examples 1 to 3 Polyvinyl chloride (Kanevinyl S-10 manufactured by Kanebuchi Chemical Industry Co., Ltd.)
01) 100 parts, tribasic lead sulfate 3 parts, dibasic lead stearate 1.5 parts, lead stearate 0.5 parts, calcium stearate 0.5 parts, Kanease P as a processing aid
A-20 (Kanebuchi Chemical) 2. Blend in 110 kobe
Mixer blend (super mixer) with
(referred to as basic compound PVC).

0.7 parts of this basic blend of PVCI and 0.0 parts of the compounds listed in Table 1.
Add 5 parts and further mixer blend at 110℃,
Add 27 parts of gypsum fiber produced by the method below to make 80
Blend with a mixer for 3 minutes at qo (low speed frame of a super mixer). This compound 73 was used in a Brabender Plastograph (chamber capacity 55cc, 195q).
o, 40 revolutions, material preheating time 4 minutes), and the gelation start time was measured. The results are shown in Table 1. Table 1: For the production of gypsum fibers, add 1% by weight of calcined gypsum powder to 20 oz of water and hydrate for 3 minutes while shaking.

The obtained fine dihydrate gypsum slurry is sent to a reaction tank and 1
After heating at 130o○ for about 5 minutes while heating at 2pm,
The hemihydrate gypsum fibers obtained by dehydration were fired at 700° C. for 2 minutes to obtain O-type anhydrous gypsum fibers with a diameter of 0.5 to 1 and a length of 50 to 80 threads. This fiber was used after the coarse powder was classified and removed using Cycloplex (manufactured by Yaskawa Electric). The compound where the plastograph was measured was attached to a 40-piece extruder (HV-40-28 manufactured by Tabata Kikai, full flight screw compression ratio 3.2, G = 12000, C2 = 175
00,C3=18500,C,=18500,D=19
0℃) to extrude a belt of medium 3 length/thickness 3 willow,
Measure the tensile properties based on JISK-7115,
For the same test piece, DuPont impact strength (3/8 inch percussion core, half height at break in terms of 300 ta) was measured.

These results are shown in Table 1. The contents of the compounds used are as follows. stearic acid C,
7 days 35 COO days arachidic acid C, rainbow 3
9COO day behenic acid C2, day 43C
OO day cerotic acid C25 day 5, COO
Montanic acid C27 day 55C00 day Hequistwax E Montanic acid Esthete'Rehequist wax OP'' partial Ca salt Hequistwax GL-3 Synthetic fatty acid ester derivative of C3o Carnauba wax Cerotic acid Esthe're Lx-40-A
-2 (Kyodo Yakuhin) Partial Ca salts of C24-C26 fatty acid esters As shown in Table 1, higher saturated fatty acids with carbon numbers of 22 or more or their derivatives gel quickly, so their DuPont impact strength is extremely high. I can see that it is happening.

Claims (1)

[Claims] 1. A resin composition comprising a saturated higher fatty acid having 22 or more carbon atoms or a derivative thereof in a mixture of gypsum fiber and polyvinyl chloride resin.